Area Forecast Discussion
Issued by NWS Wakefield, VA

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375 FXUS61 KAKQ 191758 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 1258 PM EST Mon Feb 19 2018 .SYNOPSIS... High pressure slides offshore today, allowing for a return of moisture. A warm front lifts through the area tonight. High pressure becomes anchored off the southeast coast Tuesday and Wednesday bringing a return to well above normal temperatures. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Main batch of stdy rain now moving into the srn half of the fa with light rain/drizzle across the rest of the piedmont. Exception is the lower MD eastern shore where little if any rain has fallen. High res data continues to show the pcpn tapering off to light rain/drizzle this aftrn but remaining cloudy/overcast as the lower levels become or remain saturated. Thus, adjusted grids a bit to fit this scenario. Temps slow to rise but do expect readings to reach 50-55 late this aftrn with the lwr 60s across the se. Attention then turns to fog development tonight which will be addressed in the aftrn update. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... Increasing SW flow tonight as upper ridge axis begins to amplify/build off the SE coast. Models indicate some continued light QPF amounts overnight, but there is little forcing for precipitation so will genly keep PoPs capped at less than 20%. Milder with little drop in temperatures due to the SW flow, lows ranging from the upper 40s well inland to the lower-mid 50s SE. The local area will be firmly in the warm sector on Tue, with strong upper ridge centered over the Gulf Stream off the SE coast. However, GFS/NAM continue to depict a lot of low level moisture across the area and fairly shallow mixing per Bufkit soundings through the entire day. This is probably overdone and suspect the SW low level flow and 850mb temperatures rising to +10 to +12 C will be sufficient to scour out the low level clouds by late morning and allow for a partly sunny aftn. Highs expected into the 70s except for locally cooler conditions at the immediate coast. Very warm Tue night into Wed with continued SW flow. Approaching sfc cold front to remain west of the Appalachians through the day which will limit chances for rain. The GFS/ECMWF/NAM do show an area of enhanced moisture pushing into the Piedmont during the late morning/aftn but this will likely just translate into a little more cloud cover. Partly sunny overall with highs mainly ranging from the mid to upper 70s except for locally cooler conditions at the immediate coast. If it turns out mostly sunny with deeper mixing than anticipated, some locales could rise into the lower 80s. See record highs below. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... Region will overall be dominated by mid/upper level ridging during the extended period. Shortwave trof will temporarily break down the ridge Wednesday night/Thursday, allowing a cold front to drop through the region from the N/NW on Thursday. High pressure will build to the north of the region behind the front cold front, with temps dropping back closer to normal for Friday. Front potentially moves back north of the region by Saturday, allowing for another surge of warmer air to move into the region for Saturday/Saturday night. GFS/ECMWF are in some disagreement with how far the warm front gets, as well as how quickly the next cold front moves into/through the region. ECMWF less bullish in moving warm front north, which causes the Saturday/Sunday period to be more unsettled, and potentially cooler than GFS would suggest. At this point, have used the blended model solution, which sides toward a warmer day 6/7 period. Outside of the model inconsistency in the day 6/7 period, the chances for rain appear most likely on Thursday with cold frontal passage, and possible Friday into friday night, as front tries to lift back northward. Temperature-wise, another warm day on Thursday ahead of the cold front, with high temps in the 60s/low 70s. Cooler Friday with highs in the 50s to around 60, then potentially warmer on Saturday, with most areas in the 60s. If ECMWF is correct, warmer temps will be restricted to the southern half or so of the CWA. Sunday also remains uncertain with regard to temperatures, but they should still be above normal. Overnight lows in the 40s to around 50 Thursday and Friday night, then in the 50s Saturday night. && .AVIATION /18Z MONDAY THROUGH SATURDAY/...
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Steady batch of rain has moved east but TSCTNS loaded with moisture at most levels to keep IFR conditions due to drizzle and fog through 12Z. Models showing vsbys as low as 1/2sm in fog tonight. A warm front will lift north of the region Tues morning slowly drying out the upr levels while the lwr levels are slow to scour out. Thus, CIGS will be slow to rise into MVFR range by or shortly after 15Z Tue with VFR conditions not expected until the end of the forecast period. Some SW wind sheer noted ivof the warm front near SBY Tue morning as well. Outlook... A back door cold front approaches from the NW Wed night then drops south across the area Thurs. Expect a return to IFR/MVFR conditions in rain/fog Thurs behind this feature.
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&& .MARINE... Latest Obs/Buoy reports reflect E-SE flow ~10kt this morning. Sfc high pressure in place over the waters is allowing for light winds early this morning, with winds to veer around to the SSE from late morning through this afternoon, then SSW tonight as high moves offshore and Sfc warm front lifts north of the region (accompanied by sct/numerous showers today. Sub-SCA SSW flow persists tonight through midweek, with waves generally 1-2 feet on the Bay, and 2-3 feet on the ocean. With winds remaining below SCA criteria, will need to monitor for marine fog, especially Tuesday night and Wednesday, as dew points increase into the 50s. Back door cold front drops across the region on Thursday, turning winds to the N/NE over at least northern waters during the day on Thursday. Deterministic guidance is still split over how far south the boundary slips before washing out or weakening/lifting back north on Friday. In either event, weak CAA behind the front likely will keep winds below SCA criteria through much, if not all of this period. NWPS indicating potential for some increasing wind wave by Wed night/early Thursday, which could make for some choppy seas during this period in NE Flow before winds gradually veer back to the S by later Friday as boundary lifts back north. && .CLIMATE... Another round of record highs will possibly be challenged Tue 2/20 and Wed 2/21: * Record highs: * Date: Tue 2/20 Wed 2/21 * RIC: 77 (1930) 75 (1930) * ORF: 77 (1991) 79 (2014) * SBY: 75 (1930) 75 (1943) * ECG: 78 (1991) 77 (2014) && .EQUIPMENT...
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KAKQ radar will be down UFN. See FTMAKQ for details.
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&& .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...None. && $$ SYNOPSIS...JDM NEAR TERM...JDM/MPR SHORT TERM...JDM/LKB LONG TERM...WRS AVIATION...MPR MARINE...MAM is the U.S. government's official web portal to all federal, state and local government web resources and services.