FXUS61 KLWX 200641 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 241 AM EDT Wed May 20 2026 .WHAT HAS CHANGED... Some subtle changes in regards to the timing of scattered to numerous thunderstorms this afternoon along with placement of greatest coverage. A sharp cooldown with on and off rain chances expected Thursday through the upcoming holiday weekend. && .KEY MESSAGES... 1) Widespread strong to severe thunderstorms expected this afternoon and evening as a strong cold front crosses ending the record heat. 2) Turning showery and sharply cooler Thursday into early next week with several days of much needed rainfall. && .DISCUSSION... KEY MESSAGE 1... Record heat continues through Wednesday. A strong cold front brings widespread strong to severe thunderstorm chances Wednesday afternoon and evening. Relief is on the way today as a strong cold front approaches the region. The front will break the record heat while bringing renewed strong to severe thunderstorm chances to the region. Temperatures will quickly climb from the mid 60s and low 70s this morning back into the mid to upper 90s east of the mountains. Dewpoints will also hover close to 70 degrees making for more of that true summertime feel in the DMV. The added heat and humidity combined with the strong cold front will be the catalyst for thunderstorm development today. The entire region remains in a Marginal Risk (Level 1 out 5) for severe weather per SPC. This aligns with CSU Learning Machine probabilities along with NCARS AI NWP Convective Forecast and NSSL Probs for the afternoon and evening period. The coverage storms looks to be scattered to numerous although the severe threat will be isolated given west to southwest flow aloft. MLCAPE values will peak in the 1000-2000 j/kg range this afternoon with 0-6km shear values less than 30 kts. This would support multicellular clusters capable of producing damaging winds (downbursts) and large hail. Current 00z CAM guidance shows a variety of solutions when it comes to timing. General consensus is for convection to fire along a lee side trough east of the Alleghenies/toward I-81 early to mid afternoon between 1- 4 pm before sliding east into the metros between 3-9pm. The greatest coverage of storms (i.e best organization) appears to be north of I- 66/US-50 given the progression of the front as it drops in from the northwest. Locations further south may see more of a smattering of storms (in multiple rounds) pushing through. Still believe there will be enough coverage of severe thunderstorms for a Severe Thunderstorm Watch to be issued at some point this afternoon for portions of the area. Not expecting flash flooding given current 6 hr QPF values around 1-2" and 3 hr FFG values just above those marks. Could see some increased runoff in typical urban /poor drainage areas and areawide with recent drought concerns. Convection should start to wane between 9-11pm tonight, but showers could linger well into the overnight as the cold front crosses. Lows tonight will fall back into the mid 50s and low 60s. KEY MESSAGE 2...Turning showery and sharply cooler Thursday into early next week with several days of much needed rainfall. Synoptically, looking at a transient/wedge pattern Thursday into the upcoming holiday week. Weak troughing will reside over the Ohio River Valley with high pressure locked across New England/Great Lakes region. The combination of these two features along a stalled front to the south will lead to persistent onshore flow into the region. As a result, expect several days of on and off shower/thunderstorm activity through the remainder of week into the Memorial Day holiday. Sunshine will be limited with plenty of cloud cover expected and cooler than normal temperatures as a result of the east to northeast flow. Highs Thursday will take a 25 to 30 degree dive behind the front with many locations struggling to push 70 degrees. Temperatures will continue to run below normal on Friday, struggling to make it into the 60s. Ensemble guidance shows much larger spread in temperatures Saturday through Monday, with some solutions keeping us locked into low cloud cover and temperatures in the 50s/60s, while some other solutions try to break us out of the low clouds, causing temperatures to climb into the 70s. The most notable thing in the extended, outside of the sharp cooldown will be the much needed rainfall as a result of this active pattern. Periods of on and off showers with overrunning along the boundary will yield rain totals of 1 to 3 inches through early next week. Some localized amounts of 4"+ are possible back across the Alleghenies and up into central/northeast MD. With that said, this should ease some of the severe and extreme drought across the region. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... VFR conditions are expected to continue across the terminals through 18z/2pm ahead of a strong cold front. Sub-VFR restrictions return at times this afternoon and evening due to widespread showers and strong/severe thunderstorms. Expect convection to initiate in the vicinity of KMRB/KHGR/KSHD between 18-21/2-5pm advancing east toward the I-95 corridor terminals between 20-24z/4-8pm. Did opt for TEMPOs toward BWI/MTN/MRB with PROB30s further south toward IAD/CHO/DCA given hi-res model output suggesting a greater focus of convection north of I-66/US-50. Winds will remain out of the west/southwest ahead of the front before shifting back to the north and northwest Thursday at 5 to 15 kts with gusts 20 to 25 kts at times. Some low CIGS may hang on through Thursday morning as the front slowly sags south of the region. Periodic rain showers moving through the region on Thursday afternoon and evening bring additional sub-VFR periods at terminals Wind gusts could reach 15 to 20 knots on Thursday before gradually decreasing. Sub-VFR conditions possible Friday through Sunday with multiple rounds of showers and embedded thunderstorms. Winds generally northeast to east 5 to 10 knots, more gusty in heavy showers. && .MARINE... Winds may near low-end SCA levels in south to southwesterly channeling this afternoon and evening (mainly open/wider waters), and then again in northerly channeling on Thursday. SMWs appear possible this afternoon and evening as thunderstorms move over the waters. East to northeast SCA level winds are expected over much of the bay and surrounding inlets Friday and Saturday given increased onshore flow. No marine hazards are expected Sunday and Monday with winds switching back to the south and southeast. && .CLIMATE... Here are some daily temperature records during the May 19-20, 2026 timeframe: A '+' sign indicates multiple years currently hold that record. A '!' sign indicates the record is forecast to be tied or broken. ***WEDNESDAY, MAY 20TH, 2026*** LOCATION RECORD HIGH (YEAR) RECORD WARM LOW (YEAR) Washington-National (DCA) 96F (1996) 73F (2019) Washington-Dulles (IAD) 93F (1996) 69F (2019) Baltimore (BWI) 95F (1962) 71F (2019)+ Baltimore Inner Harbor (DMH) 97F (1962) 74F (1998)+ Martinsburg (MRB) 97F (1911) 70F (1998) Charlottesville (CHO) 96F (1996) 73F (1996) Annapolis (NAK) 98F (1997) 76F (1898) Hagerstown (HGR) 97F (1996) 66F (1998) && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None.WV...None. MARINE...Small Craft Advisory from 3 PM this afternoon to 8 PM EDT this evening for ANZ533-534-537-542-543. Small Craft Advisory until 3 AM EDT early this morning for ANZ534-543. && $$ DISCUSSION...KLW/DHOF/EST AVIATION...KLW/DHOF/EST MARINE...KLW/DHOF/EST