Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 221832 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 232 PM EDT Sat Oct 22 2016 .SYNOPSIS... Breezy conditions will subside across the area saturday evening as high pressure over the Ohio Valley moves toward the middle Atlantic into Sunday. This high will shift southeast of the area by Sunday night, allowing another cold front to move across the area Monday. && .NEAR TERM /THROUGH TONIGHT/... Other than the breezy conditions early due to the deep mixed should be a very quiet and seasonablly cool night. The numerical guidance is in good agreement in showing the center of the surface high to stay south of the area tonight. This should allow for enough of a pressure gradient across the area between the low over Quebec and the high over the SE to keep the BL from totally decoupling. As not expect the lows to totally drop to the current dew point (which are currently in the low-mid 30s...especially across the interior). Will therefore keep the lows around 37 across the interior to lower 40s in the coastal plain to the mid 40s near the coast. Cannot totally rule out a little frost on rooftops tonight across the piedmont where the temp touches 36 or 37...but unless the boundary layer decouples more than forecast do not expect any widespread frost. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... No major issues through Tuesday. The high pressure over the Appalachians will shift to the south on Sunday allowing for warm advection to develop across the area on Sunday into Sunday night(with 850mb temps rising to +13c) ahead of another dry cold front. This should allow temperatures to rebound to close to normal or just slightly below normal on Sunday. Despite the cold fropa on Monday, downslope warming will allow for the best CAA later Monday Night which may allow temps to be even slightly warmer on Monday compared to Sunday. More likely to decouple Monday night...but the overall atmosphere will not be as cold as tonight. As is once again possible that there may be a few spots with patchy frost across the interior...but most likely not anything widespread with temps dropping into the upper 30s across the piedmont. Temps will drop back into the mid 60s on Tuesday (as 850mb temps drop back to +6c). This cold front looks quite dry and other than a gradual wind shift from WSW to NW on Monday and perhaps a few more significant weather is expected. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... Strong/1030mb Canadian high pressure builds south across the area Tues then slowly shifts east to a position off the New England coast Wed. Continued dry but cool. Lows Tue nite in the upper 30s/low 40s to upper 40s SE. Highs Wed in the low to mid 60s. Lows Wed nite in the mid 40s to lwr 50s. Low pressure tracks from the nations mid section Wed into the Gt Lakes region Thurs. An assctd warm front progged to lift NNE across the mts and into PA Thu. Best support for pcpn with this feature remains north of the fa but ECMWF does show some weak lift as far south as VA late Thurs / Thurs nite. GFS a bit slower spreading the moisture east of mts. Kept low chc pops across northern half of fa during this time frame. Highs Thurs 65-70. Lows Thurs nite in the 50s. Warm Fri with highs in the upr 60s to mid 70s. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... As of 12Z...the sfc cold front has shifted well offshore, but strong upper low centered over central PA/NY state continues to bring enough instability aloft across NE sections of the CWA this morning for scattered showers through 15Z that may affect KSBY, with variably cloudy skies/VFR cigs of 4-10 K ft elsewhere. Skies become mostly sunny by 14 to 15Z or so (remaining mostly cloudy through 18Z at KSBY). Gusty northwest winds can be expected through the aftn all sites as the low pressure system over the Northeast States intensifies. Gusts of 25 to 30 knots can be expected toward the coast and at RIC through about 21Z today. Diminishing winds/mainly clear skies overnight all areas (some gusts to 20 KT at KSBY still expected through midnight). OUTLOOK...High pressure builds across the Southeast Sunday. A dry cold front sweeps across the area Monday, with high pressure returning Tuesday and Wednesday. VFR conditions dominate. && .MARINE... The well advertised cold front will move farther offshore this morning with high pressure returning late today into tonight. NW winds behind the front have already reached SCA levels early this morning and still expecting winds to increase to gale force thru the morning hours. Strongest gusts up to 40 kt still look to be across the northern coastal waters and middle Ches Bay with gusts to 35 kt across the south. Winds expected to drop below gale on the Ches Bay and coastal waters south of Parramore this afternoon and will be replaced by SCAs at that time. Still anticipating a secondary surge/increase in mixing this evening, so have maintained Gale/SCA headlines into tonight. The offshore NW flow will keep seas from building to much higher than 5-7 ft most areas (highest out 20 NM offshore). Bay waves build to 4-5 ft. Winds remain elevated on Sunday but should diminish to some extent and avg 15-20 KT by afternoon. The next front crosses the area Mon. Appears another surge (albeit much weaker) will likely require SCA headlines late Sunday into Monday. && .EQUIPMENT... NOAA Wx-Radio Transmitter at Driver/Norfolk is back online. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 7 AM EDT Sunday for ANZ633-635>638. Small Craft Advisory until 1 PM EDT Sunday for ANZ631-632-634- 654-656-658. Gale Warning until 10 PM EDT this evening for ANZ630. Gale Warning until 7 AM EDT Sunday for ANZ650-652. && $$ SYNOPSIS...MRD NEAR TERM...MRD SHORT TERM...MRD LONG TERM...MPR AVIATION...LKB MARINE...JDM is the U.S. government's official web portal to all federal, state and local government web resources and services.