945 FXUS63 KGLD 200900 AFDGLD Area Forecast Discussion National Weather Service Goodland KS 300 AM MDT Wed May 20 2026 .KEY MESSAGES... - Occasional shower chances through the rest of the week. - Marginal severe risk Thursday afternoon and evening, primarily in Colorado, but could see that into northwest Kansas through the evening hours. && .SHORT TERM /THROUGH FRIDAY NIGHT/... Issued at 255 AM MDT Wed May 20 2026 Through Mid-Afternoon: Guidance continues to indicate that low- level moisture return assoc/w modest SE to SSE low-level flow will be a slow/gradual affair that's confined to eastern Colorado, mainly western portions of Kit Carson/Cheyenne counties where 850 mb dewpoints around -1 to -3C (this morning) are progged to increase to 2 to 7C during the late afternoon (21-00Z). Mid-level (700-500 mb) warm advection in advance of an upper level wave.. a modest 250-350 mb trough / shear-axis progressing slowly east across the central Rockies.. may foster the development of light showers over portions of the area later this morning, mainly west and north of Goodland between ~12-18Z (6a-12p) when/where mid-level warm advection -may- be strong enough to capitalize on/utilize a very meager amount of elevated instability (50-100 J/kg MUCAPE). Expect broken/overcast cloud cover over most or all of the area and 10 to 20 mph SE winds with highs in the upper 50's to mid 60's. Late Afternoon-Toninght: A modest (1013-1015 mb) lee cyclone will develop in southeast CO this late this afternoon into tonight as the aforementioned upper wave emerges from the Rockies and progresses east across the High Plains. Guidance suggests that increasing low-level moisture will foster marginal diurnal destabilization (~250 J/kg mlcape) along/west of a line from Akron-Limon-Lamar this afternoon, when/where low-level convergence in vicinity of the developing lee cyclone will aid in the development of scattered showers/storms that progress downstream/east toward the CO-KS border by sunset (00-02Z), at which point low-mid level (850-600 mb) warm advection on the E and NE periphery of the developing lee cyclone and modest DPVA attendant the upper wave may assist in the development of additional showers/storms over northwest KS this evening. While recent (06Z 05/20) runs of the HRRR and NAM NEST broadly agree that convection will develop in CO late this aft and progress east across northwest KS this evening and overnight, they vary considerably w/regard to convective coverage.. the NAM NEST being the least-agressive solution. While gusty winds may accompany any storms, severe weather is not anticipated. Expect lows in the lower-mid 40's. -Vincent Thursday will see a somewhat similar scenario, but shifted northward as the northern Rockies upper low strengthens and a stronger shortwave trough moves across eastern Colorado at the time of peak heating. The instability axis will shift further east and the REFS has a corridor of 1000-1500 j/kg from Limon to Fort Morgan along with 35kts of deep layer shear. While the surface-based instability will rapidly weaken after 00Z, MUCAPE of at least 500 j/kg as well as deep layer shear of 40kts are forecast as the showers and thunderstorms move in from Colorado Thursday night. The parameters suggest a marginally severe storm or two will be possible with some pockets of MUCAPE up to 1000 j/kg forecast by the NAM through about 06z before weakening. NBM has rain amounts of up to 1" in eastern Colorado Thursday evening with the stronger storms, then around 0.25-0.50" in the rest of the area overnight with rain and isolated storms. The upper trough axis and associated surface cold front will be slowly moving through the area Friday morning with showers and isolated thunderstorms continuing. This morning activity should limitthe afternoon instability, though it is possible some clearing could occur on the western and southern edges of the forecast area. Also will need to see where the front ends up in the afternoon as new convection could develop along it. However, both the GFS and ECMWF currently have the front well to the south, entering Oklahoma, while the NAM is slower and has the front in the southern part of the area. Since this is still a few days out and there will be multiple days of convection which may impact the ultimate timing and location of the front, confidence is low in the details and any potential severe hazards on Friday. Temperatures through the period show little variation with highs in the 60s and lows in the 30s and 40s. && .LONG TERM /SATURDAY THROUGH TUESDAY/... Issued at 110 PM MDT Tue May 19 2026 Saturday, our region is forecast to be under a weak southwest flow with a weak trough along the Rocky Mountains. Expect mostly sunny skies and a slight warming trend through the beginning of the work week. High temperatures are forecast in the 70s for Saturday and the 80s for Sunday and Monday. Saturday will have a 25-35% chance for showers and thunderstorms across the county warning area (CWA) from weak shortwave passages. After Sunday, we transition to more of a ridge pattern, so expect primarily sunny skies and gusts up to 30 mph in the afternoons for our Colorado counties Sunday and Monday. Warm temperatures continue Tuesday with highs forecast in the 80s. Wind gusts up to 40 mph are possible Tuesday for the western CWA. With relative humidity (RH) values overall trending down and forecast in the low 20s for Tuesday, fire weather potential will need to be monitored through the week. Models are in disagreement on the track and evolution of a surface low off the coast of Baja California that starts to develop late Sunday. If this surface low ends up tracking toward our region, we have potential for an active pattern and severe weather potential late next week. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 1145 PM MDT Tue May 19 2026 GLD: VFR conditions are anticipated to prevail through the TAF period, with ceilings at or above ~6,000 ft AGL. SE winds at 7-12 knots will increase to 12-15 knots w/gusts to ~20 knots a few hours after sunrise and persist through the afternoon. Winds will back to the ESE-E and decrease to 10-12 knots after sunset, near the end of the 06Z TAF period. MCK: VFR conditions are anticipated to prevail through the TAF period, with ceilings at or above ~5,000 ft AGL. There is low probability (~30%) for MVFR conditions associated with showers after sunrise, mainly between ~12-16Z. SE winds at 5-10 knots will modestly increase to 10-13 knots a few hours after sunrise and persist through the afternoon. Winds will back to the ESE-E after sunset, near the end of the 06Z TAF period. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...None. CO...None. NE...None. && $$ SHORT TERM...Vincent/024 LONG TERM...Rhoades AVIATION...Vincent  183 FXUS65 KBOI 200903 AFDBOI Area Forecast Discussion National Weather Service Boise ID 303 AM MDT Wed May 20 2026 .KEY MESSAGES... - Mostly dry with temperatures warming through Friday. - Well above normal temperatures over Memorial Day Weekend. Gusty winds and a few mountain showers on Memorial Day. - Turning cooler with gusty winds and increasing chance of precipitation starting Tuesday. && .SHORT TERM /Through Friday Night/... The cool upper level trough of the past several days will be briefly reinforced from the north today in MT and eastern ID, close enough to delay warming, and for a slight chance (10-20%) of showers in eastern Valley County and southern Twin Falls County late today and tonight. On Thursday the trough will exit east and steady warming and drying will take place. Hi-res models show light to moderate (10-20 mph) northwest winds this afternoon, then slightly stronger (15-25 mph with gusts 30 mph) Thursday afternoon, strongest in the Snake Basin southeast of Boise. && .LONG TERM /Saturday through Wednesday/... The warming trend will continue through the weekend and peak Monday (Memorial Day) when high temps reach 85 to 93 in the valleys (hottest near Grand View, ID) and 70s to mid 80s in the mountains. By then flow aloft will become southwesterly and increase as a deep cold upper low approaches from the Gulf of Alaska. A strong cold front is now forecast for Tuesday, with the upper low forecast to pass directly over us on Wednesday. There are similarities with Tuesday's cold front to the one that occurred last week with the strong winds and blowing dust, so this event may become our main concern in the coming days. && .AVIATION /06Z Wednesday through Thursday/... Issued 1159 PM MDT TUE MAY 19 2026 VFR. Scattered to broken middle and high clouds. Isolated rain showers in the central Idaho mountains and in southern Twin Falls County after 20Z. Surface winds variable less than 10 kt, becoming WNW 10-20 kt after 20Z. Gusts to 25 kt in the Snake Basin east of KBOI after 20Z. Winds aloft at 10kft NW 15-20 kt. KBOI...VFR. Scattered to broken clouds AOA 15kft. Surface winds SE 5-10 kt, becoming WNW 10-20 kt after 20Z. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise SHORT TERM...LC LONG TERM....LC AVIATION.....LC  899 FXUS65 KTFX 200912 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 312 AM MDT Wed May 20 2026 .KEY MESSAGES... - A cold front brings a round of scattered to numerous showers and embedded thunderstorms today, mostly over central and north- central Montana. - This activity will transition to general areas of rain and mountain snow as it moves into southwest Montana tonight into Thursday morning. - The precipitation decreases in coverage by Thursday afternoon,with much warmer and drier conditions moving in for most if not all of the holiday weekend. - An approaching cold front will bring breezy to windy conditions and increased shower and thunderstorm activity Monday into Tuesday followed by a period of cooler temperatures, mountain snow, and lower elevation rain. && .UPDATE... Early morning update has been published, with the only change being to PoPS which was to increase chances across North Central Montana where radar returns show shower activity increasing. Otherwise the remainder of the forecast remains on track and no other changes were needed. - Moldan && .DISCUSSION... /Issued 1203 AM MDT Wed May 20 2026/ - Meteorological Overview: Scattered showers over the plains have continued well into the evening hours despite the loss of diurnal heating. The biggest concern with these showers have been localized gusty winds, with a top wind gust of 50 mph reported near the Big Sandy area. Northwesterly flow aloft will maintain these isolated showers through around 1 or 2 AM. Otherwise, the focus shifts to a trough and attendant cold front that will dive southeastward and initiate a round of scattered to numerous showers and embedded thunderstorms over north-central and central MT later this morning and afternoon. Cooler surface temperatures with ML CAPE struggling to reach a couple hundred J/kg will reduce the overall impact from this activity, though isolated instances gusty winds over 40 mph, small hail/graupel, and productive downpours will be present with the stronger cores. The forcing from the trough pushes this activity into southwest MT tonight into Thursday morning, with H700 temperatures falling to around -5C and supporting accumulating snow down to 6000 ft. Snow impacts for Thursday morning look to the be greatest over the higher terrain of Madison and Gallatin counties and will mostly be in the form of cold and wet outdoor conditions. Temperatures will run a few degrees below average on Thursday before weak ridging aloft warms things up heading into the weekend. Westerly flow aloft will be strong enough to mix gusty winds to the surface Sunday and Monday while temperatures warm well into the 70s and 80s. The next trough and cold front will usher in a more unstable southwesterly flow aloft early next week for increased shower and thunderstorm activity and more breezy to windy conditions, windiest over southwest MT. Some storms may become strong to severe depending on the troughs's timing, strength and whether it undergoes shearing or splitting. Note that closed lows such as this one often run a little slower than model guidance. This may result in hotter and drier weather on Monday if the cold front runs late and arrives on Tuesday. There will be at least a period of cooler temperatures and more widespread precipitation/mountain snow on the backside of this system heading towards mid-week, particularly if the main circulation stays close enough to exert a stronger influence over the Northern Rockies. - RCG - Forecast Confidence & Scenarios: Today's showers and thunderstorms will transition to areas of rain and mountain snow tonight into Thursday morning... Scattered to numerous showers and embedded thunderstorms develop over central and north-centrtal MT by the late morning hours. This activity will bring more productive rainfall than those of the last couple of days. Although severe weather is not expected with the cooler temperatures behind the front, there may be localized instances of gusty winds over 40 mph, small hail or graupel, and heavy downpours over a quarter inch with the stronger cores. This activity will expand in coverage and become more stratiform as it slides southward into southwest MT tonight into Thursday morning. H700 temperatures falling to around -4 to -7C combined with lingering convective processes may drop snow levels as low as 5000 ft at times, though accumulating snow looks to primarily be confined to areas above 6000 to 6500 ft and even higher. Snowfall amounts look to be most significant over the northern portions of the Madison/Gallatin ranges where the probabilities for 3 inches of snow or more are currently running above 70% tonight through Thursday morning. Other mountain areas of the southwest, along the Continental Divide, and over the central island ranges will generally see trace amounts up to around an inch or two on the high end. Overall, cold and wet outdoor recreation will be the primary impact with this system. Total rainfall/liquid equivalent amounts will generally range between a tenth to a quarter inch for most lower elevation locations with a sharp decreasing gradient to just a few hundreths or so along the Hi-Line and the drier southwest valleys along and west of I15. Of course rainfall amounts in excess of a half inch will be more common for areas over and near higher terrain. Precipitation diminishes and becomes more scattered in nature by Thursday afternoon. - RCG && .AVIATION... 20/06z TAF Period An upper level disturbance moving over the Northern Rockies will spread precipitation from north to south across North Central through Southwest Montana, with VFR CIGS falling to MVFR/low-VFR between 15-21z Wednesday and then persisting through the remainder of the 2006/2106 TAF period. While terminals will predominately see light rain or rain showers the KGTF, KLWT, and KHLN terminals have the best opportunity for an isolated thunderstorms; however, even these chances were to low to mention. Mountain obscuration will begin to increase between 09-15z Wednesday. - Moldan && .PRELIMINARY POINT TEMPS/POPS... GTF 56 36 60 37 / 90 60 20 0 CTB 54 33 62 37 / 70 20 10 0 HLN 63 36 61 37 / 60 90 20 0 BZN 61 33 56 31 / 30 90 50 0 WYS 56 28 51 23 / 20 90 40 0 DLN 61 33 58 32 / 20 80 30 0 HVR 61 34 65 35 / 50 10 20 0 LWT 56 33 55 33 / 80 60 40 0 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls  314 FXUS63 KIWX 200925 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 525 AM EDT Wed May 20 2026 .KEY MESSAGES... - Cooler and drier today into Thursday with highs only in the 60s. - Next chance for rain and a few storms arrive Friday. - Gradual warming with highs in the 70s with periods of showers and thunderstorms this weekend into the beginning of next week. && .DISCUSSION... Issued at 336 AM EDT Wed May 20 2026 Cold front has just about pushed completely through the area overnight with a few light sprinkles accompanying the boundary. A trace of precipitation was received here at the weather office with the showers. Today will run about 20 degrees cooler in most areas with drier and cooler airmass with ridging pushing in behind the front today. Dew points will go from the current values in the 50s to the 30s and 40s by this evening. Breezy to gusty conditions will prevail today and will be messaging hazardous beach conditions possible along Lake Michigan shoreline areas through this evening. High temperatures today through Friday will only get into the mid to upper 60s across the area. Perhaps a few locations may see the low 70s by Friday. Lows overnight tonight and again on Friday morning will drop mainly into the 40s. A slow moving shortwave moves northeastward on Friday within the southwesterly flow on the backside of the ridging that will slide eastward. This will increase chances for rain showers and even some embedded afternoon/evening thundershowers. This activity will continue into the weekend with periods of showers and afternoon thundershowers into the beginning of next week with increasing temperatures due to thermal ridging over the region. Highs will gradually increase Saturday through the middle of next week with highs in the 70s Saturday through Monday, a few areas will flirty with the lower 80s Monday before warming further with highs into the 80s for most locations on Tuesday and Wednesday. At this time, the expectation will not be for a complete washout this holiday weekend but with convective showers it will be hard to pin down the exact timing and locations that do receive them. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 524 AM EDT Wed May 20 2026 VFR conditions expected through the remainder of this TAF period. A few light sprinkles possible this morning before shortwave ridging pushes into the region. Northerly winds with gusts up to 20 kts possible after 17z Wed. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...Beach Hazards Statement through late tonight for INZ103. OH...None. MI...Beach Hazards Statement through late tonight for MIZ177-277. MARINE...Small Craft Advisory until 2 AM EDT Thursday for LMZ043-046. && $$ DISCUSSION...Andersen AVIATION...Andersen  400 FXUS63 KEAX 200927 AFDEAX Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 427 AM CDT Wed May 20 2026 .KEY MESSAGES... * Cooler conditions continue through the end of the workweek, with rainfall chances arriving as soon as Thursday morning (10-30%). The greatest chance for rain is overnight Thursday through Friday morning (70-80%). * Low-end chances (20-30%) for rain extend into the weekend with temperatures creeping into the upper 70s and lower 80s. && .DISCUSSION... Issued at 424 AM CDT Wed May 20 2026 A loop of the latest H5 analyses depicts the unwavering nature of the upper-level trough out west. While this system was enjoying its West Coast vacation, lee cyclogenesis has begun in northern British Columbia and Alberta as a 130+ kt jet streak runs over the Northern Rockies. Over the next 24 hours, this process will produce two distinct mid-level cyclones. One is expected to hold north along the U.S./Canada border while the other is pulled south by the upper- level jet. The latter's influence may be felt as early as Thursday as it ejects a series of shortwaves into the region. Guidance suggests the first shortwave could move through as early as midnight on Thursday. However, dry air aloft will limit rain potential for at least several more hours. There are some indications that mid-level moisture could improve as soon as Thursday morning, but this comes many hours after the subtle vort max passes by. Rain is not out of the question during the earlier portions of the day on Thursday, but it will be reliant on the timing of saturation aloft relative to that of the shortwave. Given these conditional circumstances, hourly PoPs have been limited to 10-30% between 06Z and 18Z Thursday. Increasingly southerly mid and low-level flow throughout the afternoon and evening on Thursday will bolster rain chances as a second shortwave is introduced to the region. The coincident timing of the shortwave and moisture increases confidence in precipitation late Thursday afternoon through early Friday morning, with the greatest 6-hourly PoPs (70-80%) occurring overnight and early Friday morning. As the mid-level low dives south along the Rocky Mountain range, lee cyclogenesis looks to be induced yet again with a small lee cyclone appearing just east of the New Mexico border as early as Friday morning. Although rainfall chances should generally decline throughout the day on Friday, the primary cyclone is outlooked to bend northeastward through Nebraska and northwest Iowa late in the day leading to increased low-level south/southwesterly flow, so WAA induced showers remain a possibility. Some weak to modest instability may be able to develop in the southern fringes of the CWA, but shear looks to remain poor. Regardless, a rogue elevated and sub-severe storm cannot be ruled out Friday evening. Increased WAA courtesy of the primary mid-level low will help boost temperatures into the lower 70s and upper 80s heading into the weekend. By Saturday morning, the mid-level lee cyclone is expected to arrive. Ample uncertainty remains on the type of impact this system could have locally as current projections keep the surface cyclone and boundary near the southern and eastern fringes of the CWA. Should the placement be further north, shower and storm chances would increase with more opportunities for ascent at the ready. Modest instability also looks to exist south of the surface boundary, so a further northward progression could open the door for some degree of convective development Saturday afternoon. Like Friday evening, though, shear profiles remain unimpressive. A day to keep an eye on, but nothing to write home about for now. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 1048 PM CDT Tue May19 2026 High pressure continues to settle into the region and has help improved the MVFR ceilings to VFR across most of the area. Area of drizzle has pushed into southern Missouri. Winds will gradually veer from northerly to northeasterly during the overnight hours. VFR ceilings will scatter out by late morning. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...None. KS...None. && $$ DISCUSSION...Macko AVIATION...Krull  991 FXUS63 KBIS 200941 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 441 AM CDT Wed May 20 2026 .KEY MESSAGES... - Near to below freezing temperatures across central and eastern North Dakota early this morning. - Warmer and windy conditions today could lead to near-critical fire weather conditions. - Low to medium chances for showers and isolated thunderstorms across western and north central North Dakota late this afternoon through the evening, then medium to high chances across the western half of the state Thursday through Friday. - Temperatures remain closer to normal through Friday, then warm to well above normal by the end of the holiday weekend. && .DISCUSSION... Issued at 438 AM CDT Wed May 20 2026 Early morning surface analysis shows high pressure from the Red River through Lower Missouri River Valleys, with a low pressure trough along the Alberta-Saskatchewan border into northeast Montana. Flow aloft is turning more zonal as a transient mid level ridge precedes a shortwave digging down the Canadian Rockies. The placement of the surface high has allowed temperatures to fall to near or below freezing across the eastern half of the state. Meanwhile, an increase in southerly return flow is keeping temperatures above freezing in the western half of the state, except in a few low- lying, sheltered spots. The Freeze Warning and Frost Advisory remain in good shape. A weak shortwave that appears to be embedded in the mid level ridge is producing light showers aloft, little of which is reaching the ground on account of a very dry low level layer of air. A slight chance of sprinkles remains in the forecast as this feature crosses northern North Dakota this morning. A southeastward advancement of the upstream surface trough will squeeze the pressure gradient over central North Dakota later this morning and afternoon, increasing winds to near 30 mph and gusting to 40 mph. But temperatures are forecast to be much warmer today, with highs ranging from the mid 60s east to mid 70s west. This could lead to near-critical fire weather conditions in parts of western and central North Dakota this afternoon, but the lowest RH of around 20 percent in the southwest is not forecast to overlap with the strongest winds between Highways 83 and 281. By late afternoon today, mid level DCVA is forecast to spread into western North Dakota ahead of a closed low circulation spinning over southwest Saskatchewan. At the surface, a low pressure with an attendant warm front to the east, dryline to the south, and cold front to the southwest is forecast to enter northwest North Dakota at a similar time. CAMs are in agreement on widespread shower and thunderstorm activity initiating closer to the cold front in eastern Montana this afternoon, but also indicate a lower degree of coverage developing into western and north central North Dakota by early evening. There is potential for up to 500 J/kg of CAPE to build just ahead of the dryline, but models are fairly consistent in keeping the buoyancy displaced downstream of stronger shear, and HRRR/RAP soundings show a skinny CAPE profile with equilibrium levels only approaching 25,000 ft. Stronger convection is therefore highly unlikely late this afternoon and evening, but the inverted-v thermodynamic profiles could support gusty winds. Showers and storms are forecast to gradually dissipate late this evening into tonight, which will have milder low temperatures in the upper 30s to mid 40s. On Thursday, the mid/upper level trough axis is forecast to reorient itself and deepen from southern Saskatchewan to northern Utah, inducing lee cyclogenesis with an inverted surface trough extending northward through the western Dakotas. The inverted surface trough will be the focal axis for high chances of showers Thursday afternoon through Thursday night. There is still some uncertainty on the placement of the inverted trough and associated maximum QPF, but the range has narrowed in scope to as far west as the Montana border and as far east as a line roughly from the Turtle Mountains to the Standing Rock Reservation. The NBM places its averaged maximum QPF axis from around Hettinger to Stanley, with high chances of exceeding 0.25" and low to medium chances of exceeding 0.5". But embedded thunderstorms along a ribbon of up to 1000 J/kg CAPE could produce locally higher amounts, as indicated by the HREF localized probability-matched mean QPF showing pockets of 1-2". Training convection, high deep-layer RH, and precipitable water approaching 75th-90th climatological percentile values near 1 inch could also contribute to enhanced rainfall rates on a localized basis. The mid/upper trough is forecast to pivot into the High Plains on Friday with two distinct vort maxima over southeast Saskatchewan and northeast Colorado, respectively. Numerous showers are likely to persist along the inverted surface trough on Friday, which may only shift slightly to the east. But there is a much lower risk for thunderstorms on Friday as guidance is showing little to no CAPE. There are several potential outcomes for multi-day rain totals depending on how much or little the inverted surface trough shifts around. If it remains nearly stationary all the way through Friday, there could be a narrow corridor of +1 inch amounts surrounded by widespread amounts under a quarter of an inch. If the inverted trough does shift eastward, there could be a broader area or perhaps two separate areas of around half an inch. The latest NBM shows a narrow axis of medium chances (50 to 60 percent) for exceeding half an inch of rain Thursday through Friday night from Hettinger to just west of Minot, with low chances (10 to 20 percent) for exceeding 1 inch. Temperatures will remain closer to normal Thursday and Friday, although showers and associated cloud cover could cause some deviations. Friday in particular looks like a day where a large portion of the area could see cooler daytime temperatures under persistent clouds and shower activity. Overnight temperatures are forecast to remain well above freezing, with only parts of southwest North Dakota having a low chance of falling into the mid 30s Friday night. A significant warm up continues to be strongly favored by ensemble guidance through the holiday weekend as there is now increasing ensemble agreement on mean ridging over the central CONUS. The NBM shows moderate to low spread given the forecast time range with highs in the mid 70s to mid 80s on Sunday and around 80 to 90 degrees on Memorial Day. Chances for rain under this pattern are low, but there could be some shortwaves traversing the top of the ridge over the Northern Plains before the ridge becomes more amplified. Above normal temperatures of highs in the mid 70s to upper 80s are favored to continue through the middle of next week, with increasing uncertainty in the eastward progression of the central CONUS ridge as a stronger wave digs down from the Gulf of Alaska. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 438 AM CDT Wed May 20 2026 VFR conditions are mostly expected through the forecast period. A few sprinkles are possible across northwest and north central North Dakota this morning, with no impacts to aviation. From mid afternoon through this evening, scattered showers and isolated thunderstorms are forecast to develop over western and north central North Dakota. Heavier showers and storms could produce brief downpours with IFR visibility and gusty winds. Outside of showers and storms, southerly winds will increase over central North Dakota this morning and afternoon, with sustained speeds reaching 20-30 kts and gusts as high as 35 kts. In western North Dakota, expect southerly winds around 15 kts with low level wind shear through the early morning, then becoming more southwesterly around 10-15 kts through the afternoon. && .BIS WATCHES/WARNINGS/ADVISORIES... Frost Advisory until 9 AM CDT /8 AM MDT/ this morning for NDZ003-004-012-019-020-022-035-041-042-044-055>062. Freeze Warning until 9 AM CDT this morning for NDZ005-013-023- 025-036-037-046>048-050-051. && $$ DISCUSSION...Hollan AVIATION...Hollan  066 FXUS62 KCHS 200943 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 543 AM EDT Wed May 20 2026 .WHAT HAS CHANGED... The Aviation section was updated for the 20/12z TAFs. && .KEY MESSAGES... - 1) Areas of fog, locally dense, are possible across the South Carolina Lowcountry and Southeast Georgia this morning. - 2) Rain chances likely to increase late in the week, though no hazardous weather is anticipated at this time. && .DISCUSSION... KEY MESSAGE 1: Areas of fog, locally dense, are possible across the South Carolina Lowcountry and Southeast Georgia this morning. Low-level moisture appears to be a tad deeper compared to the past few mornings with higher 1000 hPa condensation pressure deficits noted. The risk for shallow fog will increase over the next few hours as the boundary layer decouples and radiational cooling maximizes. With slightly favorable fog parameters in place, shallow fog layers could thicken a bit more than what has been experienced over the past few mornings resulting in a bit more in the way of meaningful fog and lower visibilities. The fog that does form could be locally dense at times with visibilities dropping to 1/4 NM or less at times, especially near bodies of water and other low-lying areas such as marshes, swamps and large ditches. The area from Reidsville to Townsend north to Hampton, Beaufort and Walterboro, including parts of the Savannah Metro Area, looks to be the corridor of most concern for more meaningful fog development through daybreak. The need for a Special Weather Statement or even a Dense Fog Advisory will be reassessed as the early morning progresses. KEY MESSAGE 2: Rain chances likely to increase late in the week, though no hazardous weather is anticipated at this time. The area will remain along the western flanks of Atlantic high pressure centered well offshore. Early morning water vapor imagery shows a well defined Tropical Upper Tropospheric Trough (TUTT) low positioned near 29N/75W at 20/06z. Broad subsidence aloft along the western flanks of the TUTT will continue to reside over the area through tonight with subtropical ridging progged to hold aloft across much of the Southeast States. The TUTT is forecast to slowly weaken and remain well offshore as the it propagates west/northwest along the backside of the Subtropical Anticyclone meandering near Bermuda. The net result will be a continuation of warm, rain-free conditions with some high clouds spreading in at times. Low-level thicknesses are progged to max out about 10-30 meters higher than Tuesday as subsidence aloft builds. Highs are poised to warm into the lower-mid 90s inland with upper 70s/near 80 at the beaches. Temperatures across the coastal counties will remain what somewhat tempered as another robust, pure sea breeze circulation propagates steadily inland through the afternoon. Similar to the past few nights, it will take until the early morning hours Thursday before the boundary fully decouples and influences from the afternoon sea breeze wane. Lows will range from the mid 60s inland to the lower 70s at the beaches. Low- level moisture profiles and 1000 hPa condensation pressure deficits do not look as favorable for fog development compared to this morning, but some shallow ground fog appears likely, especially away from the immediate coast. Upper level ridging lingers across the southeastern CONUS Thursday, as a sfc cold front stalls out along the Tennessee River Valley. As such, should see largely dry conditions prevail across our area, with highs forecast to rise into the lower 90s under mostly sunny skies. Will see the aforementioned cold front sag southward over the Carolinas by Friday, causing the upper level ridge to shift over the Atlantic. While the exact position of the front and how far south it progresses will be the key factor in determining rainfall coverage and amounts, current trends continue to favor a strong Atlantic ridge. This would keep the front displaced just to our west and north, and thus limit our chances for seeing meaningful rainfall. Ensemble guidance continues to follow this trend as well, with probabilities for seeing rainfall greater than an inch through Saturday remaining less than 25%. So, while trends currently favor a drier, less impactful event, still encourage folks to monitor the latest forecast as subtle shifts in track may still occur. Otherwise, expect the severe potential with any shower/storm to remain low, given the lack of forcing and moisture in place. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... 20/12z TAF Discussion: KCHS/KJZI/KSAV: Fog will quickly mix out after daybreak with VFR conditions. Shallow ground of will be possible at all three terminals again early Thursday morning. Extended Aviation Outlook: There are no high confidence concerns. && .MARINE... Through Tonight: Quiet conditions will persist with the region positioned along the western flanks of Atlantic high pressure centered well offshore. East/southeast winds will prevail with speeds less than 15 kt, although some local enhancement along the land/sea interface and Charleston Harbor will likely occur with the sea breeze. Seas will average 2-4 ft. Thursday through Sunday: No marine concerns are expected. High pressure to the east will drive onshore east-southeasterly flow each day, with wind speeds mostly topping out in the 10-15 knot range. Each afternoon and evening there could be some local enhancement along the land/sea interface with the diurnal sea breeze. Seas will average 2-4 feet through the period. Rip Currents: A lingering 9 sec, 2-3 ft swell will keep a moderate rip current risk in place for all beaches through this evening. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$  396 FXUS66 KLOX 200951 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 251 AM PDT Wed May 20 2026 .SYNOPSIS...20/1210 AM. Light offshore flow will continue this morning and will bring one more sunny and warm day. Beginning Thursday there will be a return to cooler May Grey conditions which will last through the weekend. && .SHORT TERM (TDY-FRI)...20/229 AM. Not much in the way of weather for the short term (or the long term for that matter). At the upper levels the base of a weak pos tilt trof will be over Srn CA with hgts around 576 dam. At the sfc there will be weak offshore flow this morning but then there will be increasing onshore flow through Friday both to the east and north. By Friday the onshore push will be moderate to strong. Skies will be clear today. Some low clouds will develop tonight but will likely only affect the Central Coast and the LA county coast. By Friday most of the csts and some of the lower vlys will wake up to low clouds. The SBA south coast will have a local offshore push and this should keep that area stratus free. Aside from the stratus and some high clouds Thursday night skies will be mostly clear. Today will be the warmest day with most areas gaining 1 or 2 degrees on ydy's very warm readings. Most csts will be in the upper 70s to mid 80s with the furthest inland coastal areas seeing upper 80s. The vlys will sizzle with reading a couple degrees either side of 90. These max temps are about 10 degrees over normal. The switch to onshore flow will bring 4 to 8 degrees of cooling to the area both Thursday and Friday. This cooling will bring below normal temps to the near shore areas and near normal temps over the rest of the csts and vlys. There will be weak offshore winds this morning but the rest of the period will have standard afternoon sea breezes. One exception to this may be southwest Santa Barbara County where a 2-4mb offshore gradient during the overnight hours will likely create nightly Sundowners with winds gusting between 25 and 40 mph at times, particularly tonight and Thursday night. .LONG TERM (SAT-TUE)...20/229 AM. Very May like weather will be the norm for the 4 day xtnd period. Saggy-baggy troffing will cover most of the state through the period. At the sfc there will be moderate to strong onshore flow to the east and weak to moderate onshore flow to the north. There will be a good dose of night through morning low clouds across most of the coast and many vly areas every day. Due to the strength of the onshore flow some beaches may not clear at all. The strong onshore flow in the afternoon will generate stronger than normal sea breezes as well as gusty west winds in the Antelope Vly. Additionally the western portion of the SBA south coast will see varying degrees of north winds each evening. Most areas will cool 1 or 2 degrees each day except perhaps 2 to 4 degrees on Tuesday. Most csts will see max temps in the mid 60s to mid 70s each day with upper 70s to lower 80s in the vlys. Max temps will mostly end up a few degrees below normal across the csts/vlys and the mtns and far interior will end up a few degrees over normal. && .AVIATION...20/0544Z. At 0522Z at KLAX, there was no marine layer. There was a sfc based inversion with a top of 900 ft with a temperature of 26 C. High confidence in CAVU TAFs. There is a 20% chance of 5SM FU at KVNY. KLAX...High confidence in CAVU TAF. Good confidence that any east wind component will be AOB 5kt. KBUR...High confidence in CAVU TAF. No wind issues expected. && .MARINE...20/219 AM. High confidence in current forecast. Through this weekend, winds and seas are expected to remain below Small Craft Advisory (SCA) levels, with a few exceptions of local SCA level gusts during the afternoons and evenings. Across the outer waters south of Port San Luis, local gusts to SCA levels will be possible each afternoon/evening through Friday, and again on Sunday. For the inner waters along the Central Coast south of Port San Luis, off the coast of Point Dume, across the San Pedro Channel, and in the Santa Barbara Channel, local gusts to SCA levels will be possible this afternoon through early evening. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC...Rorke AVIATION...Rorke MARINE...Lund SYNOPSIS...MW weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox  469 FXUS61 KRLX 200954 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 554 AM EDT Wed May 20 2026 .WHAT HAS CHANGED... Aviation Forecast Discussion update. 332 AM update... The Marginal Risk for severe storms today has expanded northwestward to encompass parts of southeast Ohio and continues to highlight a wind and hail threat. A soaking holiday is still on tap for Memorial Day in response to a wafting frontal boundary. && .KEY MESSAGES... 1) Showers and thunderstorms blanket the forecast area today amid an advancing cold front. Activity today could serve up damaging wind gusts from stronger storms and localized high water issues within heavier downpours and/or training cells. 2) The end of the work week into Memorial Day weekend will feature episodic rounds of showers and storms with the frontal boundary hung up over the region. Cooler temperatures on Thursday will gradually rebound towards unseasonably warm readings by the end of the weekend and into the start of next week. && .DISCUSSION... KEY MESSAGE 1... Upper level troughing in the Great Lakes region will drive a cold front into the forecast area today, beginning a stretch of active weather through the holiday weekend. Radar trends at the time of writing depicts scattered showers and embedded thunderstorms streaming through Ohio and grazing our far northwestern zones. As the front slips into the forecast area today, moisture drawing up ahead of the boundary will help serve up additional rounds of showers and afternoon/evening thunderstorms. Messaging has remained unchanged for convective activity progged for this afternoon, with an axis of destabilization taking place in locations that remain south of the frontal boundary. Only minor modifications were made to the Day One convective outlook, which now expands the Marginal Risk back into our southeast Ohio counties. This suggests a slightly slower progression of the front and more opportunity for instability to make an appearance during peak heating hours. Adequate CAPE and shear levels support isolated damaging winds with storms today in addition to a lesser threat for hail. Storms will be ongoing late tonight along the higher terrain as the frontal boundary sluggishly passes overhead, but becoming mainly stratiform rain in the wake of FROPA. Forecast rainfall amounts ranging from half an inch to an inch from today into Thursday morning will help to put a dent in our prevailing drought conditions. Early morning CAMs do suggest a ribbon of higher amounts streaming in late this evening into the overnight hours from southwestern West Virginia up into the northeast mountains associated with a burst of heavier rain. This could impose localized water issues as heavy, and potentially repetitive, showers and storms press up through this corridor. With climatologically high PWATs invading the area today, floated around the idea of flash flooding concerns, but opted to hold off with this issuance as 3 hour flash flood guidance for the CWA remains above two inches, coupled with antecedent dry soils so far this spring. KEY MESSAGE 2... The frontal boundary will complete its passage through the Central Appalachians Thursday morning, but will become hung up over the Carolinas and the Mississippi Valley as it contends with a strong area of high pressure parked offshore. The close proximity of the boundary will result in ongoing showers and storms for our mountainous areas and as far west as the Charleston metro area during the day Thursday, while locations to the north and west relish in drier weather courtesy of high pressure centered over the Great Lakes. The front will continue to promote unsettled weather over the area through the end of the week as the boundary remains draped just to our south, eventually lifting back north as a warm front heading into the holiday weekend. Widespread chances for rain and afternoon thunderstorms prevail as moisture continues usher in from the southwest as we remain in this holding pattern due to the nettlesome front. Impacts from this multi-day soaking rain could eventually be observed as local creeks and streams gradually become overwhelmed by excessive runoff. Cooler temperatures infiltrate the area on Thursday in the wake of the cold front, bringing an end to the early season heatwave. Should see temperatures gradually rebound each day as the aforementioned boundary lifts as a warm front, returning daytime highs to unseasonably warm readings for Sunday and Memorial Day. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... Showers and thunderstorms upstream of our airspace will gradually shift south and eastward this morning and become widespread throughout the day as a cold front advances. VFR conditions to start will be followed by a period of SHRA/VCTS late this morning into the afternoon, then concluding the valid TAF period with crashing ceilings. By late tonight, all terminals are progged to drop to low MVFR and eventually to LIFR/IFR amid ongoing moderate to heavy rain. This boundary is expected to stir up active weather for the end of the week and into the holiday weekend, likely resulting in restricted flight conditions as a result. Should see a wind shift from southwest to northwest throughout the day amid the encroaching cold front. Outside of strong winds produced by thunderstorms, occasional gusts around 15kts could be observed this afternoon. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY... FORECAST CONFIDENCE: High tonight, medium on Wednesday. ALTERNATE SCENARIOS: Restrictions associated with showers and storms on Wednesday may vary from the forecast. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE WED 05/20/26 UTC 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18 EDT 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H M M H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 12Z THURSDAY... IFR conditions are possible on Thursday with showers and/or low stratus, especially in/near the mountains. Brief IFR is also possible at times Friday through the weekend with showers and/or thunderstorms. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ DISCUSSION...05 AVIATION...05  613 FXUS63 KTOP 200958 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 458 AM CDT Wed May 20 2026 .KEY MESSAGES... - Cool temperatures through the workweek give way to a warming and a mainly dry Memorial Day weekend - highs returning to the upper 70s to near 80. - Showers with embedded thunderstorm chances Thursday into Saturday morning likely across two separate periods. More areawide for Thursday into early Friday. Friday night into early Saturday mainly south of I-70. - Another Pacific trough digs into the western CONUS mid to late next week. Could bring another storm system to the Plains by the middle part of next week. && .DISCUSSION... Issued at 454 AM CDT Wed May 20 2026 Surface high pressure holds firm across the central Plains through Wednesday as a modified Canadian air mass maintains cool and dry conditions. With quality return flow yet to develop, highs will struggle to reach the upper 60s as the stable air mass keeps temperatures well below normal for late May. The first precipitation chance comes into Thursday as isentropic ascent develops along the 295-300K surface ahead of a shortwave trough emerging from the Intermountain West. Southerly flow returning through the H850 level supports a deepening moisture profile with precipitable water values near the 75th climatological percentile for this time of year. With a fairly deeply saturated column, generally weaker instability favors efficient stratiform rainfall over organized convection. Peak rainfall rates and best storm chances are expected late Thursday into Friday morning. A secondary window for rain and storm chances sets up Friday night into Saturday morning as the main trough axis lifts out of the Rockies with more focused ascent just northwest of the area. At least NAM soundings currently indicate that modest elevated instability and marginal shear could overlap mainly across east-central areas. Seems worth monitoring though severe weather potential appears limited at this time. Heights rise across the central CONUS through the weekend. Expect mainly dry conditions for much of the weekend through Memorial Day with temperatures climbing back above normal. Memorial Day highs reach into the middle 80s across the area. The next potential storm system arrives mid to late next week as another Pacific trough digs into the western CONUS. Increasing Gulf moisture return and a more dynamic forcing mechanism warrant close attention as the period draws closer, though spread among the ENS, GEFS and GEPS remains wide at this range. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 1241 AM CDT Wed May 20 2026 VFR for the period with mid clouds increasing into the end of the period ahead of the next weather system. ENE winds increase to around or just above 10kts later this morning into the afternoon as the surface ridge shifts gradually east. Should remain dry this period with any precipitation likely holding until sometime the next period. There could be an hour or so of shallow ground fog mainly at KTOP but this appears to be too low probability to mention. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Drake AVIATION...Drake