625 FXUS61 KOKX 190205 AFDOKX Area Forecast Discussion National Weather Service New York NY 1005 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... Heat advisory for NE NJ and NYC Metro 11AM Tuesday to 8PM Wednesday. Air Quality Alerts for unhealthy for sensitive groups air quality for high ozone for both rest of today into this evening as well as Tuesday into Tuesday evening for portions of the region. Small craft advisory for ocean waters Tuesday afternoon through Tuesday night. && .KEY MESSAGES... 1) Hot airmass moving into the forecast region. Airmass getting relatively more humid also heading into midweek. Heat advisory NE NJ and NYC Tuesday late morning through Wednesday early evening. 2) Possible showers and thunderstorms Tuesday afternoon into early Tuesday evening. Higher chances of showers and thunderstorms Wednesday into Wednesday evening. Marginal severe thunderstorm possibility. 3) Much cooler airmass expected Thursday into the holiday weekend with chances of showers. 4) Cold water safety concerns continue this week with good boating weather, and water temperatures still in the 50s. && .DISCUSSION... .KEY MESSAGE 1... That back door cold front is now east of the area. Ridging aloft has kept the area dry and warm. Mainly dry conditions continue into Tuesday with strong ridging aloft. Offshore high pressure and increasing low level SW warm air advection will make for much warmer temperatures Tuesday and Wednesday as well. The models have shifted a few hours later with the timing of the cold front on Wednesday, thereby allowing for more daytime heating and less clouds. Heat advisory for NE NJ and NYC Metro 11AM Tuesday to 8PM Wednesday. This is the first high heat index event of the year for NE NJ and NYC. Warmest day Tuesday with SW flow and daytime mixing. Temperatures in the 90s for all of NYC, NE NJ, Lower Hudson Valley and much of interior Southern CT as well as much of Nassau County NY. Mid to upper 90s for high temperatures much NE NJ and NYC Metro for temperatures and heat indices. Dewpoints are mostly in the low 60s Tuesday. Slightly cooler high temperatures and heat indices for Brooklyn and Queens but still getting in the mid 90s especially for northern portions of those zones. This same distribution exists for high temperatures on Wednesday as well but a few degrees cooler on average. The dewpoints increase ahead of the cold front Wednesday with values mainly in the low to mid 60s. So for Wednesday, temperatures a little less than the previous day but dewpoints a little higher than the previous day. Highs mostly in the lower 90s Wednesday for much of NE NJ and NYC with corresponding heat indices in the mid 90s. Again, slightly cooler high temperatures and heat indices for Brooklyn and Queens but still getting in the mid 90s especially for northern portions of those zones. .KEY MESSAGE 2... There is some indication within the forecast models showing a pre-frontal trough developing across the interior for Tuesday afternoon into Tuesday evening. There is a slight chance of a shower or thunderstorm for northern parts of the region. Possibility too for a strong to severe thunderstorm, with quick downburst of wind. This is just marginal risk. CAMs indicate this possibility of convection within their reflectivity fields. The cold front looks to move in first for Lower Hudson Valley and Southern CT latter half of Wednesday afternoon and then crosses through the NYC Metro and coastal sections by early evening. Chances for showers and thunderstorms increase Wednesday afternoon through early Wednesday evening. There is potential for severe thunderstorms with damaging winds and large hail. Flooding threat minimal with the westerly flow in the atmosphere and quick steering flow. However, a quick period of heavy rain and possible minor flooding cannot be ruled out with some thunderstorms. .KEY MESSAGE 3... Mid level ridge suppressed for late week into the holiday weekend with quasi-zonal flow. At the surface, high pressure moves in from the Great Lakes Thursday but then moves northward into Northern New England and eventually the Canadian Maritimes Friday into the holiday weekend. In its place, low pressure approaches from the south and west. Model variances on how far north the low reaches. Max temperatures forecast decrease by near 15 to 20 degrees for Thursday compared to the previous day. Max temperatures are in the upper 60s to lower 70s Thursday. Northerly flow presents downslope warming first half of the day, allowing for coastal locations to be relatively warmer than inland. Cooling trend continues Friday with high temperatures forecast mainly in the mid 60s to near 70 and then just low to mid 60s for most locations on Saturday. Overall, the low level flow will become more easterly really limiting the daytime warmth with more maritime influence. Along with that aside from Thursday and Friday which are forecast to be mainly dry, there will be an increasing chance of showers heading into the holiday weekend with high pressure getting farther away and low pressure approaching from the south and west. .KEY MESSAGE 4... Cold water safety concerns this week as water temperatures remain in the 50s. The cold water temperatures can quickly cause hypothermia and physical incapacitation to anyone suddenly immersed in the water. Anyone going out on small boats, canoes or kayaks should plan accordingly and use extreme caution to avoid this threat. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... High pressure remains over the western Atlantic with a frontal system over the mid section of the country slowly approaching the area into Wednesday. VFR through the TAF period. There is a very low chance of the development of low stratus or patchy fog for KISP and KGON tonight. There is also a low chance of a shower or thunderstorm tomorrow afternoon, mainly NW of the NYC metro. Confidence in the occurrence of both of these phenomena were low enough to not include in the TAFs at this time. Winds diminish to under 10 kt from the S/SW or may become light and variable. Winds are expected to increase once again on Tuesday with gusts once again to near 20kt. Gusts may be more occasional at times. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Gusts may be more occasional Tuesday afternoon. Very low chance of a shower or thunderstorm Tuesday afternoon/evening. .OUTLOOK FOR 03Z WEDNESDAY THROUGH SATURDAY... Tuesday night: VFR. Isolated thunderstorm potential afternoon into early eve, mainly north of NYC terminals with brief MVFR or lower possible. Wednesday: VFR, giving way to possible MVFR or lower with Showers and thunderstorms likely in the afternoon and evening. S/SW winds 10-15g20-25kt day into eve. Peak gusts to near 30 kt possible. NW windshift in the evening. Thursday: Mainly VFR. Friday: MVFR or lower possible with a chance of showers. Saturday: MVFR or lower in rain. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Sub-SCA conditions through Tuesday morning. SCA on the ocean Tuesday afternoon through Tuesday night, marginal SCA for non- ocean waters but mostly below SCA criteria. Potential widespread SCA conditions Wednesday into Wednesday night. Mainly below SCA thereafter until holiday weekend when SCA conditions potentially return. Cold water safety concerns this week as water temperatures remain in the 50s. The cold water temperatures can quickly cause hypothermia and physical incapacitation to anyone suddenly immersed in the water. Anyone going out on small boats, canoes or kayaks should plan accordingly and use extreme caution to avoid this threat. && .CLIMATE... Record High Temperatures: May 19: KEWR: 98/1962 KBDR: 89/2017 KNYC: 99/1962 KLGA: 96/2017 KJFK: 92/2017 KISP: 89/2017 Record High Minimum Temperatures: May 17: KEWR: 68/2015 KBDR: 60/2025 KNYC: 70/1906 KLGA: 68/1965 KJFK: 63/1965 KISP: 62/2015 May 18: KEWR: 74/2017 KBDR: 66/2017 KNYC: 75/2017 KLGA: 80/2017 KJFK: 65/2017 KISP: 63/1977 May 19: KEWR: 67/1986 KBDR: 66/2017 KNYC: 68/1986 KLGA: 68/2017 KJFK: 67/2017 KISP: 65/2017 May 20: KEWR: 72/1996 KBDR: 61/2019 KNYC: 74/1996 KLGA: 77/1996 KJFK: 63/1996 KISP: 62/1996 && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Air Quality Alert until 11 PM EDT this evening for CTZ005>007- 009>011. Air Quality Alert from 11 AM to 11 PM EDT Tuesday for CTZ005>012. NY...Air Quality Alert until 11 PM EDT this evening for NYZ067>075- 176-178. Air Quality Alert from 11 AM to 11 PM EDT Tuesday for NYZ069>075-078>081-176>179. Heat Advisory from 11 AM Tuesday to 8 PM EDT Wednesday for NYZ072>075-176-178. NJ...Air Quality Alert until 11 PM EDT this evening for NJZ002-004- 006-103>108. Air Quality Alert from 11 AM to 11 PM EDT Tuesday for NJZ004- 006-103>108. Heat Advisory from 11 AM Tuesday to 8 PM EDT Wednesday for NJZ002-004-006-103>108. MARINE...Small Craft Advisory from noon Tuesday to 6 AM EDT Wednesday for ANZ350-353-355. && $$ DISCUSSION...JM AVIATION...MW MARINE...JM  748 FXUS63 KIND 190207 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 1007 PM EDT Mon May 18 2026 .KEY MESSAGES... - Severe storms possible Tuesday afternoon and evening with damaging winds the primary threat - Heavy rain and some flooding are possible into the evening and again Tuesday - Highs in the 80s Tuesday - Storms will end Wednesday as the front shifts south, but unsettled weather likely returns late this week into the holiday weekend && .FORECAST UPDATE... Issued at 1005 PM EDT Mon May 18 2026 Expect mostly quiet weather overnight as the disturbance which brought active weather to central IN earlier today continues to shift east. Current KIND radar imagery shows lingering light precipitation mainly across far south-central IN which should move out over the next few hours. A few additional showers or an isolated thunderstorm may develop late tonight, mainly across northern counties near a weak boundary. Southerly winds remaining elevated will help limit the potential for fog despite recent heavy rainfall. Areal Flood Warnings and Flood Advisories remain in effect for portions of central Indiana as water continues to slowly recede. Do not drive through flooded roadways. && .DISCUSSION (This evening through Monday)... Issued at 246 PM EDT Mon May 18 2026 Rest of This Afternoon and Tonight... Please see the latest Mesoscale Discussion section for details on the current convective situation. Thunderstorms will continue to move east this afternoon, with faster movement across the northern forecast area. To the south, the cold pool is having a harder time moving south, and showers and storms continue to develop as the low level jet impinges upon it. Later this afternoon into early evening, some additional upper energy will produce additional showers and thunderstorms. Will continue high PoPs this afternoon into early evening, especially southwest where the regeneration of storms will continue along the cold pool boundary. This regeneration of showers and storms in the southwest may lead to flooding, so will continue the Flood Watch. May have to adjust the location of the watch if the area of regeneration shifts. The main threat for severe will be out ahead of the initial line of storms into the afternoon. Damaging winds will be the primary threat. Coverage of rain will diminish this evening into the overnight as most forcing exits. However, some weak upper energy may keep the threat for a few showers around northwest. Went cooler than guidance for lows given the rain cooled air. Tuesday... Uncertainty remains on how convection will develop on Tuesday with the surface cold front moving in. There may be cloud cover in the morning from upstream convection which would help limit instability. Some CAMs limit coverage to the southeast forecast area, while larger scale models bring rain to all areas Tuesday into Tuesday night. Given the strength of the front and the plentiful moisture, went likely PoPs all areas at some point Tuesday afternoon and evening. The severe threat will depend on how well the instability is able to build. Damaging winds will be the primary severe threat. Given today's rainfall and the plentiful moisture Tuesday, heavy rain and flooding will remain a threat for Tuesday as well. Highs on Tuesday could reach the middle and upper 80s if morning clouds are thin enough and rain holds off long enough. Wednesday and Thursday... Some rain may linger Wednesday morning in the south, so kept some low PoPs there. There remains some uncertainty on how far south the front will then settle and thus how fast it returns north. GFS seems aggressive with returning rain on Thursday, so will keep most of the area dry through the daytime Thursday. Rain chances begin to spread north Thursday night. Much cooler air will return for this period with highs in the upper 60s to around 70 and lows in the middle 40s to lower 50s. Friday through Memorial Day... A northern stream upper trough will move into the central USA while a southern stream smaller upper wave moves into the area. These will help bring the surface front northward back into the area into Saturday. Decent moisture will move back north with it, so will have likely or higher PoPs Friday into Friday night. Upper energy may interact with the lingering front to produce some rain on Saturday, so will keep PoPs around. A couple of upper troughs will bring more rain chances Sunday into Memorial Day. There remains some decent uncertainty on timing and strength, so will broadbrush PoPs and keep them under the likely category until uncertainty improves. With the surface front having lifted north, warmer air will return, with perhaps 80s again by the latter half of the holiday weekend. However, confidence isn't high in these given the uncertainty in rain coverage Sunday into Memorial Day. && .AVIATION (00Z TAF Issuance)... Issued at 757 PM EDT Mon May 18 2026 Impacts: - Showers at times into tonight - Peak wind gusts Tuesday afternoon at 25 to 30kts - Showers and storms possible Tuesday afternoon and evening Discussion: Rain and thunderstorms have decreased in intensity across central Indiana. However, lingering showers are expected to be present to some extent through about 06z. Brief reductions in visibility are possible with shower activity. Showers and thunderstorms are possible again Tuesday afternoon, but uncertainty is a bit higher than usual since this activity is due to storms currently far to our west over Kansas. How they evolve will determine timing and likelihood of rain tomorrow over central Indiana. Southwesterly flow continues with marginal LLWS possible (30-35kt). Shear decreases after sunrise Tuesday with surface winds out of the SW picking up to between 10-20kt gusting 25-30kt at times. && .IND WATCHES/WARNINGS/ADVISORIES... Flood Watch until 11 PM EDT this evening for INZ043>047-051>055- 060>063-067. && $$ UPDATE...Melo AVIATION...Eckhoff DISCUSSION...50  795 FXUS65 KBYZ 190208 AFDBYZ Area Forecast Discussion...Updated National Weather Service Billings MT 808 PM MDT Mon May 18 2026 .KEY MESSAGES... - Frost/freeze tonight into Tuesday morning. Make sure to protect sensitive vegetation. - Weather system brings the chance (40-90%) of precipitation Wednesday into Thursday. Snow levels around 6,500 ft. - Moderate chance of seeing at least 0.50 inches of liquid precipitation over south-central Montana and north-central Wyoming Wednesday into Thursday. - Warmer but still unsettled weather continues into the weekend. && .UPDATE... The showers impacting the mountains and foothills of south- central Montana and the plains of far eastern Montana this evening will gradually taper off over the next few hours before coming to an end by tonight. Temperatures tonight will be cold in the mid 20s to low 30s. With this, make sure to protect sensitive vegetation. Patchy fog is also possible by Tuesday morning over the plains, especially where precipitation recently occurred (up to a 20 percent chance). Tuesday will then be a mostly dry day as temperatures warm into the 50s and 60s. With that said, during the afternoon and evening, a few light showers are possible (~15 percent chance) with some mid- level moisture and instability. However, dry air near the surface may favor virga over precipitation making it the surface. This may also produce some brief erratic winds with gusts up to 30 mph. Another weather system will then move into and through the area Wednesday and Thursday, bringing elevated chances of precipitation to many locations. See the discussion below for more information. Arends && .DISCUSSION... Today through Monday... A widespread freeze is expected Tuesday morning with temperatures in the mid to high 20s F for most locations. Act now to protect sensitive plants. Temperatures increase into the 60s Tuesday afternoon. Wednesday will see a 500 mb wave impact the region. Models continue to indicate this wave diving further south with increasing precipitation values. A cold front will move through the region late Wednesday bringing 40-90% precipitation chances late Wednesday through Thursday with chances decreasing from west to east. Weak low pressure over Northeast Wyoming/Western Dakotas is expected to turn 700 mb winds northeasterly bringing good upslope for foothills locations. Ensembles show that the farther the trough digs south and the farther west the trough sets up, the more precipitation the region can expect to receive. The NBM is giving locations west of Rosebud County a 40-90% chance of getting greater than 0.25 inches of precipitation with the highest chances in the mountains and foothills. Locations from Rosebud County and east have a 20-40% chance for greater than 0.25 inches. Precipitation type will be snow in the mountains and rain for the lower elevations with snow levels around 6,500 ft. Given the favorable setup for the Beartooth foothills there is a 50% chance for getting greater than 0.75 inches of precipitation. This could cause concern for the East Side burn scar. Storms are not expected and the precipitation is expected to be long duration acting to limit any burn scar risks. Snow levels will also be important, if snow levels set up lower there will be no risk to the burn scar. Temperatures are expected to be in 70s F Wednesday before cooling into the 60s F Thursday and Friday. Saturday and Sunday will see temperatures increase into the 70s and 80s F with dry conditions. Torgerson .AVIATION... Isolated rain and snow showers will continue to decrease this afternoon and evening. MVFR to local IFR conditions are possible with the showers. Expect occasional mountain obscuration due to mountain snow through the evening. As skies clear and winds decrease overnight, some patchy fog is possible (20% chance) for central and eastern valleys, including near KSHR and KMLS. Archer && .PRELIMINARY POINT TEMP/POPS... Tue Wed Thu Fri Sat Sun Mon ----------------------------------------------------------- BIL 030/067 042/071 043/061 040/068 043/079 049/085 052/088 01/U 11/B 87/T 21/B 00/U 01/U 01/U LVM 026/062 036/065 036/057 034/066 038/075 045/081 047/083 12/W 23/T 98/T 21/B 10/U 11/U 11/N HDN 026/067 036/073 041/061 037/069 040/078 046/085 049/088 01/U 10/B 57/T 31/B 10/U 01/U 01/U MLS 030/065 040/073 044/065 040/069 042/077 047/083 051/087 00/U 10/B 44/W 21/B 10/U 01/U 10/U 4BQ 029/062 039/072 042/064 040/066 042/076 047/083 051/087 00/U 00/U 16/T 42/W 10/U 01/U 00/U BHK 028/060 036/073 039/066 037/066 040/075 046/083 049/086 20/U 00/B 25/T 32/W 20/U 01/U 00/U SHR 024/060 031/067 036/055 033/064 035/074 040/082 043/086 00/U 01/B 39/T 43/W 11/U 01/U 01/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings  258 FXUS61 KCAR 190213 AFDCAR Area Forecast Discussion National Weather Service Caribou ME 1013 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... - 10:13PM UPDATE...Adjusted POPs across Northern Maine with isolated to scattered showers developing. Monitoring a line of Thunderstorms crossing the St. Lawrence River in Quebec that will track ESE into Western New Brunswick and just north of the St. John Valley potentially skimming past the valley. Canadian Doppler Radar (CASVD) has a good look at this activity and there is a tail developing which may bring showers and perhaps a strike or two of lightning so made adjustments for the Thunderstorm activity in the grids. Potential arrival time for the Fort Kent to Madawaska region is between 11PM and Midnight. No other major changes. && .KEY MESSAGES... 1) Warm to very warm with a chance for thunderstorms Tuesday and Wednesday afternoon. A few stronger storms are possible. 2) Below average temperatures are expected Thursday and Thursday Night. Near freezing temperatures are possible early Friday morning across the north, which may require actions to protect vulnerable plants. && .DISCUSSION... KEY MESSAGE 1... Warm to very warm with a chance for thunderstorms Tuesday and Wednesday afternoon. A few stronger storms are possible. KEY MESSAGE 1 DESCRIPTION... A little shortwave ahead of a larger trough will drape a warm front over the area that moves north through the day Tuesday. This warm front will bring warm temperatures and instability. Some cloud cover could prevent increased daytime heating which could limit convection. Thunderstorm chances are highest in central and south Maine. Storms may contain gusty winds and potentially small hail and lightning. The risk of a tornado cannot be ruled out. The models have significantly slowed down the progression of the cold front through the region, with it now progged to move through mainly on Wednesday night. This is due to the front being almost parallel to the winds aloft as well as subsidence under the ridging exiting to the east on Wednesday. As a result, Wednesday likely will be the warmest day of the week across most of eastern and south central Maine. Because of this, models are now keying on convection firing mainly along/just north of the sea breeze front over Downeast Maine and into the Bangor region. With around 1000 J/kg of CAPE, 40-50kt of Bulk Shear, could see strong to locally severe storms across this region, with the main threat being strong gusty winds and hail. The tornado threat remains non- zero, with Energy Helicity Index of 0.5 to 1, 0-3km SRH 100-175 m2/s2 and 0-1km SRH 50-100 m2/s2. However the threat is much lower than on Tuesday. Also of note on Wednesday is that the winds should be rather gusty with gusts of 30-35 mph, with some peak gusts to around 40 mph across the Saint John Valley. Highs on Wednesday should run 15-20 degrees above normal. With Dewpoints peaking out around 60, and falling off in the afternoon, this should limit apparent temperatures to the upper 70s to lower 80s across most of eastern and central Maine, with low-mid 70s across the North Woods. KEY MESSAGE 2... Below average temperatures are expected Thursday and Thursday Night. Near freezing temperatures are possible early Friday morning across the north, which may require actions to protect vulnerable plants. KEY MESSAGE 2 DESCRIPTION... NW flow in the low levels advects in a much cooler air mass into the region Thursday into Thursday night, as Canadian High pressure builds in from the northwest and west. This high then builds over the area through Friday night. The result will be lows running 5-10 degrees below normal both nights. This should result in frost mainly across Northern Maine. Zones 2, 5, 6, 10, 11, 31 and 32 get addedto the frost freeze program on May 21, so a frost advisory could be needed for at least part of that area on both nights if current forecast trends hold. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... 00z TAF UPDATE... Tonight, conditions are starting off predominantly VFR across all terms this eve. The primary concern tonight will be widespread LLWS developing at all TAF sites between 03z to 05z and persisting through roughly 10z-12z before easing. Overnight... KBGR/KBHB: KBHB will see a rapid deterioration to IFR/LIFR due to FG and low stratus after 06z, with visibilities dropping to 1/4SM in FG. KBGR is also expected to see a brief window of IFR conditions in patchy fog and low stratus between 08z and 11z. KFVE/KCAR/KPQI/KHUL: MVFR cigs will begin working into KFVE by 03z and VCSH, low confidence isolated TStorm threat (PROB30 03z-07z). KCAR, KPQI, and KHUL should hold onto VFR cigs. Tuesday AM, marine fog Downeast will lift between 11z-13z, returning KBGR and KBHB to VFR. Conversely, northern terminals will see cigs steadily lower to MVFR, with KFVE deteriorating further to IFR cigs through the late morning and afternoon. By Tuesday afternoon (after 18z), an approaching boundary will trigger scattered to numerous showers and thunderstorms across the region. PROB30 groups have been included for -TSRA at KFVE, KCAR, KPQI, KHUL, and KBGR. Brief IFR vsby (2SM) and erratic, gusty winds can be expected in and near any heavier convective elements. KBHB is expected to remain south of the main convective threat, carrying only VCSH. Surface winds will generally remain light (under 10 kts) out of the S/SW overnight and into Tuesday AM. Winds will become somewhat variable by Tuesday afternoon, eventually shifting to the W/NW late in the TAF period (around 23z). Previous Discussion... Tuesday night...MVFR possible at northern terminals, IFR possible at KFVE. VFR elsewhere. Some rain showers at northern terminals possible. WSW winds 5 to 10 kt, ramping up through the night, with gusts to 20 kt. Wednesday: Low chance of MVFR early at northern terminals, otherwise VFR. Tempo MVFR/IFR is possible at southern terminals in any strong convection. W-WNW winds G25-30KT likely with a chance of gusts to 35KT at far northern terminals. Wednesday night-Saturday: VFR. NW winds G20-30KT possible during the day Thursday and Friday. && .MARINE... Winds stay below SCA criteria Monday night, with some gusts of 25 kt on outer waters Tuesday out of the southwest. Some fog is possible Monday night. Rain showers and some thunderstorms are possible on Tuesday. Marginal Small Craft Advisory seas around 4 to 6 feet are possible over the coastal ocean waters Tuesday night. Wave heights to around 5 to 7 feet along with gusts up to 25 kt are possible across the outer waters. Small Craft conditions are likely across the coastal waters Wednesday through Thursday, with gusts of 25-30kt and seas of 4-6 ft over the outer waters during this time frame as well. From Thursday night through Saturday, sub-SCA conditions are predicted for the coastal waters and winds less than 25 kt and seas of 5 ft or less are forecast for the outer waters. There is a small chance for some strong thunderstorms over the coastal waters Wednesday afternoon and early Wednesday evening. Sea surface temperatures remain very cold, but are beginning to moderate into the mid 40s. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...Air Quality Alert from 10 AM to 10 PM EDT Tuesday for MEZ029- 030. MARINE...None. && $$ DISCUSSION...TF/PM/JS AVIATION...TF/PM/JS  197 FXUS62 KKEY 190211 AFDKEY Area Forecast Discussion National Weather Service Key West FL 1011 PM EDT Mon May 18 2026 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... - Very warm and humid conditions over the next few days will lead to a generally moderate risk of heat illness with periods of high risk conditions. - Rain and thunder chances will remain on a plateau through tomorrow night, and gradually decline thereafter. - A period of on and off breezy conditions over the next few days will help to mitigate some of the discomfort from warm overnight temperatures. && .DISCUSSION... Issued at 1015 PM EDT Mon May 18 2026 A high pressure system north of Bermuda continues to support moderate to fresh breezes. In terms of radar, KBYX scans highlighted pulses of showers, and an occasional thunderstorm, across the Florida Keys waters. The evening 00Z KKEY sounding sampled a PWAT near, but just below, the 90th percentile value. Instability exists across the Keys, one only need go outside to notice how muggy the environment feels. Dew points are still in the mid 70s across the island chain. Everything hints at another humid, warm night across the Keys. The absence of organized showers may be attributed to the lack of a lifting mechanism. The 00Z sounding sampled nearly unidirectional easterly winds below 700 mb. Closer to the surface, breezes along the reef have remained moderate to fresh for the past 24 hours. Current trends suggest persistence is the correct choice for the forecast over the Keys tonight, thus no changes were made to the forecast package. && .MARINE... Issued at 1015 PM EDT Mon May 18 2026 Small Craft Should Exercise Caution for all Florida Keys nearshore and offshore waters. From synopsis, surface high pressure centered north of Bermuda will continue to promote moderate to fresh east to southeast breezes through the next couple of days. Highest breezes will prevail through Tuesday evening. Breezes then undergo a very slow slackening process before the weekend with peaks expected during the evenings and lulls during the day. Rain and thunder chances will remain above normal through much of the week. && .AVIATION... (00Z TAFS) Issued at 1015 PM EDT Mon May 18 2026 VFR conditions will prevail at both EYW and MTH for the upcoming period. Winds are on track to remain in the lower teens with occasional to frequent gusts. The chance of showers is high enough that VCSH is included through the overnight hours. Showers that do form will be fast moving and short-lived. Brief periods of MVFR CIGs cannot be ruled out, but are unlikely enough to not include. && .PRELIMINARY POINT TEMPS/POPS... Key West 80 91 80 90 / 40 40 30 20 Marathon 79 86 80 86 / 40 40 30 20 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...AJP Aviation/Nowcasts....AJP Data Acquisition.....DR Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest  236 FXUS63 KFSD 190212 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 912 PM CDT Mon May 18 2026 .KEY MESSAGES... - Pockets of light to moderate rain will continue through this evening mainly along and north of I-90. Any additional accumulations should be at a 0.10" of an inch or less. - Areas of frost or freeze will be possible by Wednesday morning, with the better chances north of I-90. Make sure to cover/bring in any sensitive vegetation. - Cooler conditions will prevail this week. Dry weather expected mid week. Another round of storms will be possible from Thursday through Friday. && .UPDATE... Issued at 910 PM CDT Mon May 18 2026 While the main severe risk has now pushed east of our area this evening, scattered light to moderate showers will likely persist into the late evening as a mid-level wave lifts through eastern SD and central MN tonight. Given the waning mid-level saturation and lower cloud heights according to sounding, can't rule out a few pockets of drizzle through Tuesday morning as well. While this could lead to persistent dreary conditions overnight, any accumulations will likely be on the lower side with another 0.10" of an inch or less expected for most areas. Otherwise, should see cloud cover begin to gradually clear from west to east starting by Tuesday morning. With lingering cold air advection (CAA) aloft and breezy northwesterly winds at the surface, expected another cool day with highs mainly in the low to upper 50s. With this in mind, make sure to take a jacket when heading out on Tuesday as the cooler and breezier conditions could make things feel a bit chilly at times especially during the first half of the day. && .DISCUSSION... Issued at 1258 PM CDT Mon May 18 2026 Early this afternoon the surface to 925 mb front was across southern NE into southern IA. Given the marginal strength of the incoming wave, this boundary should not lift far enough north and west by late afternoon to get into the area. This should limit any wind and tornado threats and keep them off to the southeast. However, some elevated hailers will remain possible across mainly northwest IA as elevated CAPE values ramp up to about 1000-1500 J/KG and deep layer shear is a fairly strong, unidirectional 40-50 knots. This would be lifting a parcel from above the stratus layer, which would likely be in about the 800-750mb layer. The better chances will be from about 5 pm to 9 pm. After this wave pushes the remaining instability out of the area this evening, dry and cool conditions are expected for Tuesday and Wednesday. The only concerns on these two days will be the potential for frost and freeze conditions, mostly north of I-90, as surface high pressure is in place. Another weaker wave moves through the area on Wednesday but for now this appears to bring mainly mid level cloud cover. The next better chance for showers and thunderstorms will come Thursday night into Friday night. At this time severe weather looks to remain isolated as model instability fields are hinting at 1000 J/kg CAPE or less for the most part. Once this wave passes a warming trend should move in as flat ridging aloft develops ahead of a deepening low pressure in the Northern Rockies. Saturday should be mild, likely in the 70s, while Sunday sees the better chance to warm into the 80s. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 636 PM CDT Mon May 18 2026 Mainly IFR to LIFR ceiling and vsbys continue this TAF period. Taking a look at satellite imagery, we're continuing to see scattered showers and thunderstorms develop east of I-29. While these conditions will likely persist into the evening, should see things transition to mainly MVFR to IFR cigs as the lower ceilings continues to produce pockets of drizzle. Otherwise, breezy northwesterly winds will continue into the overnight to end the TAF period. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ UPDATE...05 DISCUSSION...08 AVIATION...05  200 FXUS63 KLMK 190211 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 1011 PM EDT Mon May 18 2026 .KEY MESSAGES... * Today through Tuesday, temperatures are expected to warm into the mid 80s to low 90s. Some daily max temperature records could be challenged. * This afternoon/evening, showers and/or thunderstorms arrive, especially for our northwestern counties. This is mainly a wind and hail threat. * A line of strong to severe storms is expected to move through ahead of a cold front on Tuesday, possibly bringing strong winds and hail. The line will weaken as it moves east over the region. * More active weather arrive later this week as multiple rounds of showers and scattered thunderstorms are possible going into Memorial Day weekend. && .MESOSCALE... Issued at 1011 PM EDT Mon May 18 2026 Convection continues to slowly move eastward across southern Indiana this evening. We're watching a SW-NE oriented band of very heavy rainfall with some embedded thunderstorms that will train across portions of Meade, Harrison, Clark, and Floyd counties in southern Indiana over the next few hours. Overall, atmosphere is marginally unstable with about 500-700 J/kg of MLCAPE and about 30-35kt of bulk shear. The ongoing convection resides within an enhanced PWAT plume with values 1.6-1.9 inches. With deep layer shear largely parallel to the synoptic scale ascent pattern, expect this convection to slowly move eastward with time while weakening. Latest CAM guidance suggests that this activity will diminish with time, likely in the 12-2 AM EDT time frame. Within this band, a solid 1.5-2.5 inches of rainfall is expected. Areas east of the band across far north-central KY have remained rain-free today, so this rainfall will be welcomed and with rates diminishing with time, good ground absorption will be possible, except in the urban areas. Cold outflow from this convection has pushed southward and down toward the WK/BG Parkway corridor. Current expectations are fore this convection to mainly stay on the Indiana side of the Ohio River, though the southwest edge of the rainfall may make it into the Louisville metro region over the next 1-3 hours. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 241 PM EDT Mon May 18 2026 Current mesoanalysis shows 2000-2500 J/kg of uninhibited SBCAPE, about 20kts of deep layer shear, and steep lapse rates. Not seeing much agitated Cu over our CWA just yet, but just to the west, we have seen some initiation. Shear will slightly increase as the MCS approaches the CWA, which will help storms to become slightly more organized. Over the next few hours do expect some scattered strong to severe storms, with a wind and hail threat. The threat area will be small, over southern Indiana and just along the Ohio River. Most of the region will be spared of any storms. Additionally, PWATs near 1.8-2.0 inches and a slowly moving line of storms will allow for heavy rainfall. This line is also moving aprallel to the LLJ, which will allow for training. Due to this, there is also a risk for heavy rainfall to lead to some minor flooding issues over our far northwestern areas in southern Indiana. As the sun sets, we will quickly lose instability. Showers and storms are expected to quickly dissipate. With broken sky cover and light southerly winds, not expecting a great radiational cooling night. Low temperatures will likely remain warm in the upper 60s and low 70s. This will be close to warm minimum records for May 18. Ahead of an approaching cold front, WAA will continue to keep temperatures in the upper 80s and brushing 90. This will help SBCAPE to increase near 3000J/kg. Dew points will also creep into the upper 60s and low 70s. Though shear will remain low around20kts. Pulse summertime thunderstorms will be possible in the afternoon prior to the cold front and association line of storms. When the cold front approaches, we are expecting a decaying line of storms to outrun the best forcing along the cold front. Wind and hail will be the main threat on Tuesday over the northwestern 2/3rd of the CWA. The cold front will begin to slow its progression southward Tuesday night, making it through most of the CWA by Wednesday morning. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Issued at 241 PM EDT Mon May 18 2026 As the cold front slowly sags the the south on Wednesday, widespread showers and scattered thunderstorms are expected, especially for the southern half of our area. Rich moisture along the front will help fuel these showers and storms, with LREF PW values ranging from 1.4- 1.7" (>95th percentile climatologically). Instability to the south of the front will also help fuel these showers, with LREF mean SBCAPE around 750-1000 J/kg. The wind shear profile is very meager, so we don't currently expect severe weather at this stage. With the front moving through, temperatures will much closer to normal for this time of year, with highs in the mid-to-upper 70s north of the front in southern Indiana and northern Kentucky, and highs in the low 80s south of the front in south central Kentucky. The front stalls out just south of our area by Thursday, but with some moisture still in place over our far southern counties chances for showers will be possible (35-50%). With northerly flow at the surface, temperatures across the region will be slightly cooler than Wednesday, with highs in the low-to-mid 70s. Though an area of surface high pressure tries to build in over the Great Lakes and Ohio Valley regions Thursday, a broad upper level trough over the western CONUS pushes eastward and drives the high out of the area. Ahead of the trough axis, a series of shortwaves surges northeastward, lifting the frontal boundary northward Thursday night. Considerable southerly flow at the surface and aloft will allow deep moisture to surge back northward, helping set up a few decent periods of showers and some thunderstorms into Memorial Day weekend. The southerly flow will also allow temperatures to rise back up into the 80s by the weekend, but with dew points again in the mid 60s, it will also feel rather muggy outside. The more active pattern for rounds of showers is currently expected to last through the end of the forecast period, so a little bit of drought relief may finally be on the way. && .AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 739 PM EDT Mon May 18 2026 A round of showers and thunderstorms are currently moving NE through southern IN causing gusty/strong winds. Rain chances to be out of HNB and SDF by 05z. A marginal signal for LLWS at HNB/SDF overnight (05-07z) as a LLJ scraps across southern IN. Winds will also take a shift to the SW by tomorrow. A mid level cloud deck will move in tomorrow bringing BKN/OVC100 to all sites. Ahead of a cold front, a line of showers and storms will move in tomorrow afternoon/evening. Wind gusts are expected to increase during this time with the potential for lower vis during periods of heavier rain. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ MESOSCALE....MJ SHORT TERM...SRW LONG TERM....BEN AVIATION.....CAL  511 FXUS61 KCTP 190218 AFDCTP Area Forecast Discussion National Weather Service State College PA 1018 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... * Day 2 SPC Outlook upgraded to a Slight Risk (Level 2 out of 5) for damaging winds in northwest PA. && .KEY MESSAGES... 1) More heat & humidity will produce scattered showers and thunderstorms on Tuesday afternoon and evening, some of which could be strong to severe, especially across northern PA. 2) A strong cold front to bring showers and thunderstorms with the potential for severe weather on Wednesday followed by colder temperatures. && .DISCUSSION... KEY MESSAGE 1: More heat & humidity will produce scattered showers and thunderstorms on Tuesday afternoon and evening, some of which could be strong to severe, especially across northern PA. By Tuesday, we'll still be under the influence of the anomalously strong ridge of high pressure, with broad southwesterly flow continuing to pump warmer temperatures and humid conditions into Pennsylvania. Highs on Tuesday should be fairly comparable to today, though afternoon showers/storms in the west could limit how warm it gets there. At the surface, a deepening surface low will lift across the Great Lakes with gradually sinking heights aloft impinging northwest PA. Underneath this sprawling ridge, Pennsylvania will be in a moist and unstable airmass with MUCAPE values expected to reach 1000-1500J/kg. With marginal but sufficient shear, this amount of instability could support a few stronger storms will strong to damaging wind gusts. The SPC upgraded NW PA to a Slight Risk (Level 2 out of 5) of severe weather Tuesday afternoon. The Marginal Risk extends down to about halfway between I-80 and I-76. Low level hodographs do exhibit some spin and an isolated tornado cannot be ruled out in northwest PA closer to the parent surface low pressure system. CAMs disagree on the extent to which convection initiation will occur Tuesday afternoon, but the heat and humidity will provide as much fuel for storm development as we've seen yet this year. Rainfall amounts are not expected to be all that impressive with this system, largely owing to unimpressive/relatively dry moisture profiles with dewpoints in the upper 50s to low 60s. The good news is that these lower dewpoints will keep our heat index values below 100F and mitigate the need for Heat Advisories across the area. Rainfall amounts will be highest west of I-99 and locations farther east may not see much rain at all before Wednesday. -------------------------------------------------------------- KEY MESSAGE 2: A strong cold front to bring showers and thunderstorms with the potential for severe weather on Wednesday followed by colder temperatures. A cold front (accompanied by more widespread and frequent showers/t-storms) brings relief to the relatively short bout of heat and moderate humidity Wednesday into Thursday. High temperatures on Wednesday in northwest PA (behind the front) will be nearly 20 degrees cooler than Monday/Tuesday. The Lower Susquehanna Valley will squeak out another warm day with highs in the upper to 80s to near 90F. Ahead of and along the front, there will be a risk for severe weather again on Wednesday. The magnitude & location of the severe threat will be highly dependent on cold front passage timing and amount of cloud cover in advance of the frontal boundary. A Marginal Risk area covers locations south and east of the I-80/I-99 corridor and highlights locations along and downstream of the cold front between 12PM and 8PM on Wednesday. A few of the hi-res models depict a slower cold front passage. Such a solution would allow for more destabilization ahead of the front and a higher threat for damaging straight line winds. If the front ends up being faster than progged, clouds/rain in the morning could limit instability and lead to an unimpressive gusty shower event. Regardless, this system will feature beneficial rainfall with rainfall amounts generally 0.10-0.25" and locally higher totals possible in thunderstorms. In the wake of the cold front, high pressure will build in for a short time. Temperatures are forecast to cool down back to historical/climo averages for late May for the end of next week. Early indications show the aforementioned cold front stalling out south of the Mason-Dixon line late in the week and lifting back north across PA as a warm front into Memorial Day weekend. The current outlook favors a cooler/wetter stretch through the holiday weekend thanks to that warm front, but there is still a lot of time for the forecast to trend in a more favorable and optimistic direction for the holiday weekend that marks the unofficial start of summer. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... Evening convection that impacted UNV and IPT dissipating as of 02z. With a shortwave trough tracking across the Great Lakes later tonight into the predawn hours Tue, additional showers and storms may develop across western and central PA, but confidence is low (20 pct at most airfields, closer to 30 pct at BFD and JST). Marginal LLWS is also anticipated as sfc winds diminish but winds at 1500-2000 ft AGL increase to near 35 kts from the SW to W. After 12-15z Tue, sfc winds will pick up again with gusts up to 25kts possible. Much of the day will be VFR. Scattered SHRA/TSRA are possible in the late afternoon and into Tue night, primarily in NW PA (including BFD). Outlook... Wed...Restrictions probable through Wednesday night with widespread showers/storms along CFROPA. Thu...Lingering showers across S PA, restrictions possible. Fri...Restrictions likely with rain moving in from south to north, lasting into Fri night. Sat...Restrictions likely with rain. && .CLIMATE... The following climate sites across central Pennsylvania set new daily high temperature records for May 18th: * A record high temperature of 92 degrees was set in Altoona, breaking the previous record of 91 degrees initially set back in 1962. This record was tied two times previously, back in 1996 and 2017. * A record high temperature of 86 degrees was set in Bradford, breaking the previous record of 85 degrees set back in 1962. ** Note: The high temperature for State College will be reported around 7AM on 5/19. This is due to the State College CO-OP observations running 7AM-7AM. Thus, today's (5/18) high temperature will be reported in tomorrow's (5/19) observation. This record, for reference, is 92 degrees set in 1962. --------------------------------------------- Abnormally warm temperatures will continue on May 19th, thus multiple sites could challenge daily record high temperatures. Daily Maximum High Temperatures for May 19th: * Harrisburg: 95F set in 1962 * Williamsport: 96F in in 1996 * Altoona: 92F set in 1996 * Bradford: 85F set in 1962 * State College: 92F set in 1934, tied in 1996. && .CTP WATCHES/WARNINGS/ADVISORIES... Air Quality Alert until midnight EDT tonight for PAZ057-059- 063-065-066. && $$ WHAT HAS CHANGED...Colbert KEY MESSAGES...Lambert/Banghoff DISCUSSION...Lambert/Banghoff AVIATION...Colbert/Bowen CLIMATE...Beaty  702 FXUS66 KSEW 190247 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 747 PM PDT Mon May 18 2026 .SYNOPSIS... The weather pattern remains fairly steady with high pressure situated offshore through the week with morning clouds and afternoon sun. Temperatures will rise a bit each day through the end of the week before beginning to cool off this weekend into early next week. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... North/northwesterly flow prevails across western Washington through the next several days, and with surface high pressure dominating offshore, the pattern remains pretty steady. Plenty of sunshine for most this afternoon with some mountain cumulus and a dissipating front approaching the coast. High temperatures this afternoon on track to reach the mid to upper 60s. This front will, however, be enough to bring a stronger onshore push tonight which will bring more widespread low stratus and some drizzly conditions across the area for Tuesday morning. Lows in the low to mid 40s. Clouds should slowly lift through the day but expect most of the day to be cloudy. Highs a little cooler, in the low to mid 60s. The upper level ridge offshore will begin to amplify and tilt onshore towards WA and BC, which will allow for a warming and sunnier trend to begin. With clouds expected to clear out early Wednesday morning, expect temperatures to be warmer, with highs reaching the upper 60s to low 70s. && .LONG TERM /THURSDAY THROUGH MONDAY/... The warming trend will continue through the end of the week, with the warmest temperatures across the region expected Thursday and Friday as the ridge traverses the area and more robust onshore flow begins to move in Friday into the weekend. Temperatures will top out Thursday and Friday into the low to mid 70s, with upper 70s to near 80 possible in the southwest interior and Cascade valleys. The ridge deamplifies as it moves eastward and shortwaves begin to move through it. This should help to not just start to cool temperatures, but also bring in clouds and chances for showers. Currently the best chances for showers will be Sunday night into Monday, but there is still considerable uncertainty given the trough's evolution/placement, or if the ridge will win out and push the trough elsewhere. 62 && .AVIATION... North to northwesterly flow aloft as upper level ridging remains over the region with onshore flow in the low levels continuing. Puget Sound terminals /PWT, SEA, BFI/ generally seeing light and variable winds while remaining terminals seeing speeds ranging 8-12 kts this evening. These terminals should see speeds decrease late this evening to the 4-8 kts range. Widespread VFR conditions over the majority of W WA this evening although starting to see marine stratus take root over the coastline where MVFR conditions have set up. The combination of the aforementioned onshore flow with an embedded shortwave aloft will allow for the low clouds along the coast to push inland. This will give rise to widespread MVFR conditions over the area Tuesday morning. Upper level ridging aloft will allow for cigs to improve back into VFR conditions with skies clearing by late Tuesday afternoon/early Tuesday evening. KSEA...VFR conditions this evening with variable winds generally at or less than 5 kts. Speeds will increase slightly tonight, generally remaining around to 5 to 10 knots and turning S/SW after 06Z tonight. Cigs to lower overnight,reaching MVFR (50 to 60% chance) by 18Z late Tuesday morning. Conditions will rebound to VFR later Tuesday afternoon. 18/Mazurkiewicz && .MARINE... Surface high pressure will remain over the northeastern Pacific throughout much of the week, bringing north to northwesterly winds over the coastal waters. A splitting weaksystem will cross over the waters tonight into Tuesday, bringing an increased period of onshore flow throughout the Strait of Juan De Fuca. A small craft advisory is in effect through Tuesday morning for increased westerlies. High pressure will rebuild midweek and continue throughout the rest of the week, which will provide continuous periods of onshore flow. Can expect in daily pushes down the Strait of Juan De Fuca through the rest of the week, which would likely generate small craft advisory winds. A weak system looks to enter the area waters Thursday into Friday. Coastal seas generally increasing to 6 to 8 feet through the first half of this week, with seas increasing more to 8 to 10 feet late Thursday and into Friday. Mazurkiewicz && .HYDROLOGY... The daily hydrology discussion has ended until the start of the next rainy season; it will only be updated during this time as needed. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory until 5 AM PDT Tuesday for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca. && $$