Area Forecast Discussion
Issued by NWS Sterling, VA

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257 FXUS61 KLWX 260801 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 401 AM EDT Sun May 26 2024 .SYNOPSIS...
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A warm and humid air mass will persist through Memorial Day. A strong cold front will push through the area Monday night. A secondary cold front moves in by mid-week before high pressure builds in late next week.
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&& .NEAR TERM /THROUGH TONIGHT/...
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Low-mid level height rises are expected through the day today which should help suppress convective cvrg and keep any activity disorganized and short-lived. Despite the ridging, a weak pressure trof remains over the area, remnant outflows from yesterday`s evening convection, and any bay breeze may be just enough to spark isold random convection about anywhere. Best chance would be over the ridges and along the bay breeze. A large convective complex is likely to evolve across the OH Valley tonight and likely cross the Appalachian region after midnight. While this complex is likely to weaken with time, some guidance show the complex remaining strong overnight as it moves across central VA and the I-64 corridor.
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&& .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
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Memorial Day...Large scale ascent and strengthening sfc convergence along a pre-frontal trough is expected to generate widespread showers and thunderstorms from Noon through about 8PM. Environment will be favorable initially for HP supercells capable of producing isold tornadoes with additional t-storm activity congealing quickly into an organized complex as shown by simulated satellite imagery from various global models. Damaging winds will be the primary hazard, but a couple of tornadoes can`t be ruled out. The model signal for heavy rain has decreased somewhat since the past couple of days. Eastern areas, particularly central and northeast MD, would be at greatest risk of any flooding once thunderstorm complex evolves. Fast storm motions of 30-35 kt should keep this threat isold at best. Front pushes quickly east of the area after 00Z Tue with thunderstorm threat ending. Additional shortwave energy moving around the base of the upper trough will keep low-topped showers in the forecast through Tuesday.
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&& .LONG TERM /WEDNESDAY THROUGH SATURDAY/...
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Mid-level cyclonic flow will allow for NW flow through much of the long term - resulting in lower heights and a period of below normal temperatures with low relative humidity. The last of a series of shortwaves will be departing on Wednesday, with a few showers or even a thunderstorm possible. This feature will also have an accompanying weak sfc cold front. Tds will fall into the mid-upper 40s for Thursday and Friday - making it feel more like fall wx than that of late May in the Mid-Atlantic. A favorable pattern for radiational cooling will develop Wednesday night through Friday night. Overall, lows will be in the 40s to low 50s for most. The typical high elevation cold pockets could definitely make a run at 32F. H5 heights start to rise by next weekend with moisture returning to the area. Lots of spread, but have chance POPs again for next Saturday into Sunday.
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&& .AVIATION /08Z SUNDAY THROUGH THURSDAY/...
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Chance of thunderstorms too low today, but may increase tonight. Severe thunderstorms are likely Monday afternoon with the primary hazard being damaging wind gusts. Prevailing VFR conditions are likely Wednesday, though a passing shower is possible. VFR Thursday. Winds will become northwesterly at about 10-15 kts Wednesday before decreasing Thursday.
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&& .MARINE...
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Southerly winds are expected to increase tonight into Memorial Day as pressures fall in advance of a strong cold front. SMWs will be required on Memorial Day due to likelihood of severe thunderstorms. A passing shower is possible over the waters Wednesday. Winds will be prevailing out of the NW about 10 kts, with gusts up to 15-20 kts during the afternoon hours behind the secondary cold front.
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&& .TIDES/COASTAL FLOODING...
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Minor coastal flooding is possible this morning and again on Memorial Day.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory from 6 AM to 6 PM EDT Monday for ANZ530- 535-536-538-542. Small Craft Advisory from 8 PM this evening to 6 PM EDT Monday for ANZ531>534-537-539>541-543.
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&& $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...LFR LONG TERM...CPB AVIATION...LFR/CPB MARINE...LFR/CPB TIDES/COASTAL FLOODING...LFR