Area Forecast Discussion
Issued by NWS Wakefield, VA
Issued by NWS Wakefield, VA
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150 FXUS61 KAKQ 181958 AFDAKQ AREA FORECAST DISCUSSION National Weather Service Wakefield VA 358 PM EDT Wed Sep 18 2024 .SYNOPSIS... Low pressure located over the Carolinas will weaken today, and will move offshore tomorrow into Friday. A backdoor cold front potentially drops back south across the region Friday night through Saturday. High pressure builds north of the area this weekend into early next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 1030 AM EDT Wednesday... Key Messages: - Additional showers today, with a few storms possible over southern sections. Any showers bringing the potential for locally heavy rainfall. Latest analysis reveals the remnant low of PTC8 weakening over the west-central portion of SC. To the east, weak secondary low pressure continues to develop offshore. Meanwhile, ~1022mb high pressure remains centered off the New England coast. Only minor changes to the going forecast for the afternoon. Low pressure will continue to weaken as it moves gradually to the northwest and the coastal low takes shape offshore. Remaining unsettled day, with scattered showers, and potentially a few thunderstorms across the southern half of the area where some clearing will ensue through mid-afternoon. Given the low to the south, deep layer moisture and some weak forcing for ascent along the occluded front lifting north, a few showers could produce locally heavy rainfall. WPC continues to highlight much of the central and eastern VA area in a Day 1 Marginal ERO. Mostly cloudy to overcast skies throughout the day, though thinning clouds could provide for some opaque sunshine across southern VA and NE NC (mainly US-58 southward). Temperatures today will range from the lower 70s across the NW, to the lower 80s SE. Rain chances quickly decrease with loss of heating and taper down further overnight, with only a slight chance for an isolated shower. Low-level moisture along the front likely portends another night of fog and/or low clouds late tonight and overnight. Lows tonight drop back into the lower 60s NW to upper 60s SE. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... As of 330 AM EDT Wednesday... Key Messages: - Decreasing rain chances Thursday and Friday As the coastal low lifts further to the NE on Thursday, expect a drier day compared to today with even some partial clearing (especially west) late in the day. Still, isolated to scattered afternoon showers or storms will be possible, with the best chances across far southern Virginia into northeast North Carolina (30-40% PoPs). High temperatures on Thursday will generally be in the upper 70s area-wide and low temperatures will range from the upper 50s to lower 60s. Sunshine returns Friday with temperatures warming into the upper 70s to around 80. A backdoor cold front pushes south into the area later Friday into Friday night, bringing a slight chance for an afternoon shower (mainly across the MD Eastern Shore). Low temperatures Friday night range from the upper 50s to the lower 60s. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 330 AM EDT Wednesday... Key Messages: - Drier and cooler weather arrives this weekend into early next week. Aloft, a tall upper level ridge builds well into Canada and Greenland with an upper level trough along the East Coast this weekend into early next week. At the surface, low pressure lingers off the Mid Atlantic coastline through the weekend, gradually shifting south Sunday into early next week. Meanwhile, high pressure remains centered in Quebec through Saturday before dropping south into New England by Monday. Cooler weather is expected by Sunday and especially Monday, with highs only in the low to mid 70s. Overnight lows will generally be in the 50s away from the coast. Given the low off the coast, coastal areas can expect breezy conditions with gusts to 25-30 mph this weekend into Monday along with greater cloud cover and humidity. Additionally, cannot rule out a few isolated showers along the coast (15-25% PoPs). && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... As of 645 AM EDT Wednesday... Widespread IFR to LIFR CIGs continue across the region this morning. IFR CIGs likely try to hang on during much of the daytime hours, with ECG having the best potential to see a brief window of MVFR CIGs this afternoon. Additional showers develop this morning through this afternoon, leading to the potential for MVFR to IFR VSBY restrictions under any heavier showers. Winds average 5-10 knots out of the NE through the period. IFR to LIFR CIGs redevelop tonight and are expected for the remainder of the forecast period. Outlook: Sub-VFR CIGs likely stick around into early Thursday afternoon, before a potential improvement late. Gradually improving conditions are then expected on Friday and Saturday. && .MARINE... As of 355 PM EDT Wednesday... Key Messages: - Small Craft Advisories continue for coastal waters off the Delmarva into Thursday. - Another round of Small Craft Advisory conditions appears increasingly likely this weekend into early next week. An elongated area of low pressure has developed from Northeast North Carolina to off the Virginia Capes this afternoon as the upper level trough over South Carolina slowly begins to lift northeastward. Gradually, this area of low pressure will become more defined well off the Delmarva and NJ coast on Thursday. In the interim, expect conditions to remain rather unchanged with N to NE flow in the 10 to 15 kt range on the Ches Bay and Northern Coastal waters and 5 to 10 kt across the adjacent NC waters. Seas remain elevated from the long time of NE flow earlier in the week, but are coming down with seas from the Mouth of the Bay southward in the coastal waters are in the 3 - 4 ft range. Farther north they are slower to drop and are still in the 4 -7 ft range. So have maintained the SCA for this area and actually extended the SCA through mid day for the northern 2 coast zones. By Thursday afternoon, the area of low pressure should be coming more organized, but will also be relatively stationary a couple hundred miles off the NJ coast. This will allow for NNW winds to persist for several days through Saturday. Generally winds should remain mostly 10 - 15 kt through the period with maybe a slight increase across the northern coastal waters for Friday night. But overall, think most areas will stay below SCA levels through Saturday. By Saturday night, the coastal low finally begins to move and actually drops SE heading toward Bermuda. But is it leaves, it will begin to strength and the winds across the waters will increase out of the NE with building seas once again. SCA conditions look likely across the area waters from Sunday through early next week as the seas jump up into the 5 - 8 ft range into Tuesday before conditions relax with high pressure building over the area waters. && .TIDES/COASTAL FLOODING... As of 350 AM EDT Wednesday... Astronomical tides will continue to increase with the approach of the next full moon. Higher astro tides along with prolonged onshore flow will lead to nuisance to low- end minor tidal flooding across much of the area along the bay and tidal rivers through the end of the week. Have extended CF Advisories through the morning high tide cycle tonight for much of the bay, and adjacent tributaries. Have also extended the coastal flood statement for the Eastern Shore given levels hitting minor flood thresholds at Bishop`s Head, but remaining under flood thresholds other nearby sites. Additional advisories/extension of Advisories will likely be needed through the end of the week and into the weekend due to extended periods of onshore flow and high astro tides. Low end moderate flooding is possible at particularly vulnerable spots (Bishop`s Head, Oyster), but otherwise staying within minor flood thresholds so far. However, a building flood tide Saturday into Saturday night does bring the potential for tide levels reaching moderate Coastal Flood Thresholds (best chances northern coastal zones and lower bay) for tide cycles over the upcoming weekend. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...Coastal Flood Advisory until 5 PM EDT this afternoon for VAZ075-077. MARINE...Small Craft Advisory until 6 AM EDT Thursday for ANZ650. Small Craft Advisory until 1 AM EDT Thursday for ANZ652-654. && $$ SYNOPSIS...AJB NEAR TERM...MAM SHORT TERM...MAM LONG TERM...AJB/MAM AVIATION...AJB/MAM MARINE...ESS TIDES/COASTAL FLOODING...