National Weather Service (2024)

Area Forecast Discussion
Issued by NWS Sterling, VA

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-- Discussion containing changed information from previous version are highlighted. --712FXUS61 KLWX 241317AFDLWXArea Forecast DiscussionNational Weather Service Baltimore MD/Washington DC917 AM EDT Mon Jun 24 2024.SYNOPSIS...
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High pressure will briefly traverse the area through Tuesday.The next cold front will cross the area late Wednesday intoThursday. High pressure will pass to the north Friday, thenanother frontal system will approach over the weekend.
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See Also
What is a heat dome? Scorching temperatures forecast for Greenville, Upstate SC
As of mid morning, a cold front was dropping southeastward awayfrom the region. Northwesterly winds were increasing, withgusts of 20-30 mph expected today. Remaining clouds will clear,with a few to scattered cumulus. High temperatures will returncloser to normal in the mid 80s to near 90. However, humiditylevels will plummet, with dew points in the lower to middle 50sby mid/late afternoon.That dry airmass will lead to a relatively cool night as highpressure builds in from the west and winds abate. The urbancenters and bayshore may stay close to 70, but interiorlocations will drop to the mid 50s to mid 60s. Some of the highelevation valleys could fall into the 40s.
-- End Changed Discussion --&&.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...The surface high will translate through on Tuesday and move tothe southeast Tuesday night. Comfortable dew points in the midto upper 50s remain through the day, although temperatures willrebound a little to the upper 80s and lower 90s. A lightsoutherly flow and potential clouds will result in warmerconditions Tuesday night. Dry conditions are most likely,although some guidance shows the potential for a few showers andthunderstorms Tuesday night across northwestern parts of the CWAon the leading edge of theta-e advection.With the low level ridge to the southeast Wednesday,southwesterly flow will advect heat and humidity back into thearea. A series of troughs and a cold front will also beapproaching from the northwest. Early day clouds and evenremnant showers are not out of the question, which could inhibittemperatures somewhat. However, the potential is still there forhighs in the mid to upper 90s and heat index values around100-105. With the building instability and approaching forcing,a thunderstorm threat will eventually develop, although detailsare still fuzzy at this range. Current timing favors a laterafternoon to evening peak. Increased flow with the incomingtrough will support a risk for strong to severe thunderstorms.The cold front looks like it will push through late Wednesdaynight, which would diminish rain chances.&&.LONG TERM /THURSDAY THROUGH SUNDAY/...As a cold front exits early Thursday, some shower activity couldlinger into Thursday morning. Temperatures lower behind the coldfront Thursday into the 80s to low 90s, but dewpoints look to remainin the low-mid 60s during the day, dropping into the 50s overnightwith lows temps in the 50s to near 70 along the waters.A quick-moving area of high pressure passes to our north on Friday.Mostly dry conditions are expected, but a few showers can`t be ruledout around the Shenandoah Valley/Virginia Piedmont as the center ofhigh pressure swiftly moves offshore by the evening and minorperturbations pass by aloft. Temperatures look relatively cooler,topping out in the upper 80s. Lows hover in the 60s.Confidence has increased for the potential of warm frontal precip onSaturday, focused in the afternoon and evening. The cold frontassociated with the approaching system looks to arrive Sunday.&&.AVIATION /12Z MONDAY THROUGH FRIDAY/...
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Winds have shifted to the northwest. Gusts of 20-30 kt will belikely through the afternoon before abating this evening.No significant weather expected tonight through Tuesday night ashigh pressure moves across the area. Thunderstorm chancesincrease Wednesday into Wednesday evening, perhaps in multiplerounds, as the next system approaches the area. Southwesterlywinds may also gust to 20 kt Wednesday.Prevailing VFR conditions are expected Thursday and Friday. Mostlydry conditions are expected as high pressure passes to the north,but a few showers/t-storms can`t be ruled out Thursday AM and FridayPM. NW flow Thursday turns SW on Friday.
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A Small Craft Advisory is in effect for all waters today. Gustsof 20-25 kt are likely, with a few gusts to 30 kt not out ofthe question. Winds gradually subside tonight, with advisoriescontinuing along the bay until 2 AM.High pressure builds across the area Tuesday, with light westwinds becoming southerly by Tuesday night. An SCA may be neededfor the bay Tuesday night due to southerly channeling. SCAconditions may expand to all waters Wednesday into Wednesdayevening as southwesterly flow increases. There will also be anincreasing threat of strong thunderstorms Wednesday afternoonand evening as the next frontal system approaches.Sub-SCA conditions are expected Thursday and Friday as high pressurepasses to our north. A frontal system arrives over the weekend.
-- End Changed Discussion --&&.TIDES/COASTAL FLOODING...Tidal anomalies decrease today through Tuesday with NW flow. Afew sensitive sites may approach or exceed Action stage today,but no flooding is expected at this time. A return of southwestwinds Wednesday will bring another increase in water levels,although no flooding is forecast at this time.&&.CLIMATE...
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Very hot temperatures are expected on Wednesday. Severalrecords could be in jeopardy. Below is a list of record hightemperatures for June 26th, the year the record was set, andthe current forecast high temperatures for that day. A plus signafter the date signifies the record was set multiple times,with the most recent year indicated below. RERs are only issuedfor DCA, IAD, BWI, and MRB, but other sites are shown forreference. Wednesday Jun 26thWashington-National (DCA) 101F (1952) 97FWashington-Dulles (IAD) 95F (1998) 96FBaltimore (BWI) 99F (1954+) 97FMartinsburg (MRB) 102F (1943) 94FCharlottesville (CHO) 99F (1998) 96FAnnapolis (NAK) 98F (1952) 92FHagerstown (HGR) 98F (1954+) 93F
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DC...None.MD...None.VA...None.WV...None.MARINE...Small Craft Advisory until 2 AM EDT Tuesday for ANZ530>534- 537>541-543. Small Craft Advisory until 8 PM EDT this evening for ANZ535- 536-542.
-- End Changed Discussion --&&$$SYNOPSIS...ADS/DHOFNEAR TERM...ADS/DHOFSHORT TERM...ADSLONG TERM...CASAVIATION...ADS/DHOF/CASMARINE...ADS/DHOF/CASTIDES/COASTAL FLOODING...LWXCLIMATE...LWX