Area Forecast Discussion
Issued by NWS Wakefield, VA

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628 FXUS61 KAKQ 052351 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 651 PM EST Mon Dec 5 2016 .SYNOPSIS... High pressure moves into New England tonight. A complex area of low pressure crosses the region Tuesday, then moves offshore Tuesday night. A strong cold front crosses the area Thursday. Cold high pressure builds into the area late in the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Latest MSAS has this mornings low well offshore with high pressure over srn Ohio. Meanwhile, low pressure and associated fronts remain over the deep south. Models quickly move this high over PA this evening then into New England late. This retreating high will allow moisture from the south to quickly overspread the fa after midnight. Will first see clouds increase this evening with overrunning pcpn breaking out after 06Z first across the SW to near the Ches Bay by 12Z. Eastern shore will likely stay dry. This timing is generally a model blend given how the models generally underestimate just how fast pcpn can break out. Pops will quickly ramp up late tonight (likely/cat) across the SW...chc pops further east. Like yesterday, although there may be a few sleet pellets mixed in at the start across the NW, this will be insignificant and will not be mentioned in the grids. Lows in the mid-upr 30s north to lwr 40s sern zones. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday appears to be a washout with widespread rainfall across the fa. The initial low tracks NE to a position over the KY/Ohio valley Tuesday afternoon while a secondary low develops along the stalled coastal front. This coastal low progged to become the dominant low as it tracks NE across eastern NC then the northern Outer Banks Tuesday afternoon to a position east of VA Beach by 00Z Wed. Abundant GOM / Atlantic moisture becomes entrained allowing for a widespread mdt rainfall across the region. Given the progged forcing, some of the rainfall could be heavy at times. Kept pcpn type stratiformed for now but some convective elements are possible after 18Z across the extreme SE. Any thunder progged to remain offshore ivof Gulf stream. Added areas of fog to the grids as well. Temps always a challenge given an insitu-wedge across the piedmont and coastal front approaching from the SE. Little if any temp rise expected across NWRN most zones where highs will be hard pressed to reach 40. Temps stay in the 40s along and west of the I95 corridor, 50-55 coastal areas ranging to the upr50s-lwr 60s across the nrn Outer Banks ivof the low. Rainfall continues into Tuesday evening across the fa with the pcpn quickly tapering off then ending SW-NE after midnight as the low and best lift pull away from the region. Skies remain cldy with lows from the mid 30s NW to upr 40s SE. Total QPF expected between 1 to 1.25 inches. High pressure builds into the area from the west Wed and Wed night. Dry with near seasonal conditions. Highs in the mid-upr 50s under pt cldy skies. Lows in the mid 30s-lwr 40s. Much advertised cold crosses the region Thursday. Initial band of moisture progged to weaken as it crosses the mts given a downsloping wind flow. However, enough moisture seen to carry low chc pops with the fropa (30 pop north, 20 pop south). CAA not expected to kick in until the moisture passes to the east so expect any pcpn to remain in liquid form. Highs in the upr 40s-mid 50s but falling dp temps in the afternoon. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... Long term period starts off Thu night/Fri with dry weather behind an offshore moving cold front. Main story in the extended will be cold temps, with lows in the mid/upr 20s Thu night dropping to the low/mid 20s Fri night and Sat night under continued dry weather with sfc high pressure in the vicinity. High temps Fri and Sat avg in the low 40s both days. Next chance of pcpn arrives Sun night/Mon with an approaching cold front, but have capped pops for now at 20-30% with this several days out. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... VFR conditions are expected at all terminals through the first half of the night. Moisture from an approaching low pressure system will begin to stream into the area after 00Z, leading to gradual lowering of ceilings through the night. Winds should remain light through the night out of the the NNE. Rain is expected to overspread the region from south to northeast by Tuesday morning. Guidance continues to show IFR conditions with areas of fog, low ceilings, and the potential for some moderate precip during the day on Tuesday. Have IFR conditions building in at all TAF sites from west to east tomorrow late morning and into the afternoon. Expecting the IFR to persist through the end of the forecast period. Occasional periods of LIFR due to low ceilings and visibility cannot also be ruled out at all TAF sites, generally after 15Z Tuesday. Outlook: IFR conditions continue into Tuesday night as the storm slowly pulls away to the NE. Improving conditions to VFR behind the system on Wednesday. A strong cold front will impact the area on Thursday and bring a chance of scattered showers. && .MARINE... Latest sfc analysis shows high pressure in the vicinity with low pressure developing near the GOM coast. The low advances northeastward tonight, with another area of low pressure developing over the eastern Carolinas Tue. Winds/waves/seas increase ahead of the low, with SCA conditions expected over all waters by Tue aftn. Latest guidance continues to increase winds north and west of the sfc low as it strengthens offshore Tue eveng/night, enough that there is 50% confidence for a few hours of gale winds over the ocean, so have hoisted a gale watch there. Highest likelihood will be over northern coastal wtrs. The low pushes farther offshore Wed as weak high pressure builds into the area with winds/waves/seas decreasing. Sca conditions may linger into Wed with 5 ft seas continuing. A strong cold front then pushes across the waters Thu, with strong SCA conditions to low-end gale conditions possible Thu night through Fri night. SCA conditions expected over the weekend. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 1 PM Tuesday to 1 AM EST Wednesday for ANZ635>638. Small Craft Advisory from 10 AM Tuesday to 7 AM EST Wednesday for ANZ630>634. Gale Watch from Tuesday afternoon through Wednesday morning for ANZ650-652-654-656-658. Small Craft Advisory from 10 AM to 4 PM EST Tuesday for ANZ650- 652-654. Small Craft Advisory from 4 AM to 4 PM EST Tuesday for ANZ656- 658. && $$ SYNOPSIS...MPR NEAR TERM...MPR SHORT TERM...MPR LONG TERM...MAS AVIATION...AJB/MPR MARINE...MAS is the U.S. government's official web portal to all federal, state and local government web resources and services.