721 FXUS61 KAKQ 161947 AFDAKQ AREA FORECAST DISCUSSION National Weather Service Wakefield VA 347 PM EDT Sun Oct 16 2022 .SYNOPSIS... A weak boundary gradually shifts south this evening through tonight with showers and isolated storms training along it. A strong cold front pushes through late Monday into Monday night with showers and storms possible ahead of the front Monday afternoon into early Monday night. Behind the cold front, much cooler, drier air moves in, including the potential for a widespread frost/freeze Tues and Wed nights. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... As of 345 PM EDT Sunday... Temps as of 300 PM generally in the mid 70s with upper 70s to near 80F in NE NC. A broad upper-level trough continues to dig southeast over the OH Valley this afternoon. As it begins to move southeast, a shortwave pivoting around the base through the TN Valley and into SW VA will allow for increasing clouds over the area from the SW through the evening. Meanwhile, a ~115kt jet streak over the OH Valley will become curved and shift S overnight, allowing for favorable large scale divergence over the area tonight which will aid in showers increasing in coverage. Showers have begun to develop across W VA and are beginning to push into the far W portions of the FA this afternoon. Expect showers to continue to increase in coverage and move E later this afternoon through tonight. Showers will likely train along a weak boundary which will gradually move S this evening and tonight, potentially causing localized areas of heavy rain overnight given PWATs between the 75-90th percentile at 1.2-1.4". The first round of showers may allow for dew points to rise just enough (upper 50s to near 60F) for 100-300 J/kg of CAPE. This combined with mid level lapse rates of 6-6.5C and sufficient deep layer shear aloft (50-60 kt of 0-6 km shear) may be enough for charge separation and isolated, elevated storms late this afternoon through early tonight. Given the elevated nature of the storms, minimal (if any) wind mixing down and perhaps isolated instances of pea sized hail is possible. Otherwise, total QPF of generally 0.5-1" is expected with localized amounts of 1-1.5+" possible where heavier showers train. There will be a sharp gradient on the S edge of the precip shield with far SE portions of the FA only expected to see a trace (if any). Given cloud cover/precip overnight, lows will be mild in the mid to upper 50s. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/... As of 345 PM EDT Sunday... Showers quickly taper off Mon morning as the shortwave pulls away. A strong upper level low moves into the Great Lakes Mon, pushing a strong cold front through the area late Mon afternoon through Mon night. Ahead of the cold front, showers are expected to form (during the afternoon into the early overnight hours) with enough instability and speed shear aloft for isolated, low-topped thunderstorms. SPC has maintained a marginal risk for severe storms in NE NC and extreme SE VA Mon for a few strong wind gusts. Showers are expected to remain generally confined to SE VA/NE NC E of I-95. Showers and storms move offshore Mon evening/early Mon night with much cooler, drier weather moving in Mon night. Dry weather returns Mon night through the end of the week. Highs Mon in the upper 60s NW to the upper 70s to near 80F SE with lows in the mid to upper 30s NW to the upper 40s SE. Some patchy frost will be possible in the far NW Piedmont late Mon night/Tues morning given lows of 35-37 degrees, but dry air with a ~8-10 degree temp/dew point depression make frost uncertain. Much colder air filters in for Tues and Wed with highs in the mid to upper 50s and lows in the lower 30s inland (mid 30s for urban areas) and upper 30s to lower 40s closer to the coast Tues and Wed nights (Wed and Thurs mornings). As such, a widespread, early season frost/freeze is expected both nights for much of the inland portion of the FA with the colder night expected to be Wed night. A hard freeze is even possible Wed night for far NW portions of the FA with upper 20s possible. This will likely mark the end of the growing season for many of these areas and may be damaging to any outdoor vegetation/crops. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 345 PM EDT Sunday... An upper level low lifts off to the NE Thurs with the trough over the area weakening/breaking down Thurs into Fri. By Fri night, the PNA flips to negative with the NAO rising to near neutral. This will allow for a pattern flip with a ridge developing over the eastern half of the country while a trough develops over the western half. These two features will continue to amplify through the weekend allowing for a warming trend and dry weather. Highs in the upper 50s to lower 60s Thurs, mid to upper 60s Fri, upper 60s to lower 70s Sat, and lower to mid 70s Sun. Lows in the mid to upper 30s Thurs night, upper 30s W to lower to mid 40s E Fri night, lower 40s W to lower 50s E Sat night, and mid 40s W to mid 50s E Sun night. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... As of 145 PM EDT Sunday... Clouds will move in from the west this afternoon through this evening with BKN/OVC conditions expected everywhere by this evening. CIGs will gradually lower but should remain VFR at PHF/ORF/ECG. However, CIGs are expected to lower to MVFR at RIC/SBY tonight around 3-6z. CIGs may briefly drop to IFR at RIC between 10-12z Mon. Otherwise, CIGs gradually rise Mon with RIC holding on to MVFR CIGs the longest (~16z). A shortwave moves through late this afternoon through tonight which will allow for showers to increase in coverage from west to east after 20z (4PM). Showers are likely through tonight before tapering off from west to east Mon morning. In addition, a few embedded storms may occur late this afternoon through early tonight mainly along and south of I-64 and north of the VA/NC border due to storms interacting with a boundary. At this time, the best chance is at RIC and therefore only have a mention of VCTS at RIC. Locally reduced VIS will be possible with any showers/storms with the overall VIS tonight generally 4-6 SM. Winds are generally SW 5 kt this afternoon, becoming light and variable tonight, then becoming SW 7-12 kt Mon with gusts 15-20 kt Mon afternoon. Outlook: A cold front will cross the area late Monday with showers and a few storms redeveloping Mon afternoon into early Mon night generally east of I-95. Flight restrictions will be possible during this time. && .MARINE... As of 230 PM EDT Sunday... A cold front over the lower Great Lakes will approach the waters late tonight, then stall over of just west the waters on Monday. Ahead of the front, south winds of 5-10 kt will increase to 10-15 kt and become southwesterly. Latest high resolution guidance suggests winds of 15-20kt across the northern bay immediately ahead of the front late tonight into Monday morning and have opted to issue a Small Craft Advisory (SCA) for that zone late tonight/Mon AM. With the front stalling over the area Monday, expect winds to diminish through the day. By Monday night, the front will finally push through the area with NW winds developing. Latest guidance has increased winds slightly which makes sense given the strong cold advection and deep mixing. As such, have increased winds to 15kt in the Ches Bay with SCA conditions possible Mon night into Tuesday. High pressure builds south and west of the area by Wednesday, allowing for winds to becoming westerly then southwesterly while staying below SCA. Seas currently around 1 ft in the bay and 2-3 ft over the ocean. With increasing southerly flow tonight, waves in the bay will increase to 1 to 3 ft with 2-4 ft over the ocean (highest north). Waves then build to 2-4 ft in the bay Mon night/Tue with 4-5 ft over the ocean. Waves gradually diminishing for the reminder of the week with offshore flow and weakening winds. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 3 AM to noon EDT Monday for ANZ630. && $$ SYNOPSIS...RMM NEAR TERM...RMM SHORT TERM...RMM LONG TERM...RMM AVIATION...RMM MARINE...MRD