Area Forecast Discussion
Issued by NWS Wakefield, VA
Issued by NWS Wakefield, VA
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696 FXUS61 KAKQ 180734 AFDAKQ AREA FORECAST DISCUSSION National Weather Service Wakefield VA 334 AM EDT Wed Sep 18 2024 .SYNOPSIS... Low pressure located over the Carolinas will weaken today. The low will continue to weaken and move offshore tomorrow into Friday. A backdoor cold front potentially drops south across the region Friday night through Saturday. High pressure builds north of the area this weekend into early next week. && .NEAR TERM /THROUGH TONIGHT/... As of 300 AM EDT Wednesday... Key Messages: - Additional showers and thunderstorms develop today, bringing the potential for locally heavy rainfall. This morning, weakening low pressure is located over eastern TN. Meanwhile, ~1022mb high pressure remains centered off the New England coast. A stationary front is draped just south of the forecast area. Still seeing scattered rain showers over the region, with the highest coverage over the MD Eastern Shore and across our northwestern counties. Some of the showers have been heavy at times, prompting a couple of Flood Advisories just north of Richmond over Henrico County. Expect for the best rain chances to continue to focused over the northern half of the area through the morning hours, though with plenty of moisture around, a light rain shower and/or drizzle cannot be ruled out for anywhere in the forecast area. The abundance of moisture will also allow for patchy fog to develop over the next couple of hours, with the best chances for fog across south central Virginia and northeast North Carolina. Visbilities could drop to 1-2SM at times, with locally heavier patches that could potentially drop visbilities to less than 1SM. Low pressure will continue to move gradually to the northwest and a new coastal low begins to form to our northeast. It will be another unsettled day with additional showers and thunderstorms (best thunderstorm chances across the southern half of the area) expected to develop during the late morning and early afternoon hours and continue into the evening. Any showers today may produce locally heavy rainfall, with WPC highlighting much of the area in a Day 1 Marginal ERO. It will also be another day with little in the way of sunshine, with mostly cloudy to overcast skies expected throughout the day. Temperatures today will range from the lower 70s across the NW, to the lower 80s SE. Rain chances decrease overnight, with only a slight chance for an isolated shower. Additional fog or low clouds are also possible tonight. Lows tonight drop back into the lower 60s NW to upper 60s SE. && .SHORT TERM /THURSDAY 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 TUESDAY/... 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 /08Z WEDNESDAY THROUGH SUNDAY/... As of 210 AM EDT Wednesday... Widespread IFR CIGs across the region early this morning. IFR to patchy LIFR CIGs are expected at all sites through this morning, before a gradual improvement to MVFR CIGs by this afternoon. In addition to low CIGs, VSBYs are also expected to fall this morning and generally range from 2-4SM with DZ/BR. VSBYs may drop to less than 2SM at times across portions of south central Virginia where more widespread fog is expected to develop. Occasional showers continue through the night, with the highest chances across the northern half of the area (impacting SBY). Showers and thunderstorms develop late this morning through this afternoon, with the highest coverage still expected to be inland and away from the coast. Winds average 5-10 knots out of the NE through the period. Additional IFR/MVFR CIGs (and potentially VSBYs) are possible tonight into early Thursday morning. Outlook: Unsettled conditions continue Thursday and Friday, but confidence in the timing and extent of any flight restrictions remains low. Gradually improving conditions are expected Saturday into Sunday. && .MARINE... As of 400 PM EDT Tuesday... Key Messages: - Small Craft Advisories remain in effect for the Chesapeake Bay and lower James River area this evening. - Small Craft Advisories linger into tomorrow for the coastal waters due to elevated seas. - Another round of Small Craft Advisory conditions appears increasingly likely this weekend into early next week. Latest sfc analysis shows an area of 1024+ mb high pressure to centered to the north over New England. To the SW, the weakening remnants of PTC 8 continues to meander over the Carolinas. The tight pressure gradient between these features has allowed for elevated winds and waves to continue this afternoon. Latest obs reflect easterly winds of 15-20kt with a few gusts into the 20-25 kt range, mainly in the lower bay and lower James River. Seas are slowly subsiding as well, but are still up around 6-7ft, with waves 3-5ft, highest in the lower bay. The sfc low will continue to meander to our SW through tonight, allowing the pressure gradient to slowly relax and winds to gradually improve from S to N through the night. Winds should decrease further late this evening and overnight, as a weak area of secondary low pressure passes over the coast overnight. Winds diminish to 10-15kt overnight, which will continue through Wednesday. Seas should also improve through Wed, but the onshore wind and E-NE swell (8-10 second) will make this improvement gradual. SCA has been allowed to drop over the sound and upper rivers, and will extend into late this evening over the Bay and lower James River. Seas will linger in the 4-6 ft range over southern waters through tonight then slowly subside from south to north through the day tomorrow. We`ve made only minor adjustments to SCAs there accordingly. The coastal low then exits to the NE as high pressure builds in from the NW. Winds veer around to the N/NW for Thu-Fri at ~10kt, and it appears that we should get a couple of days of sub- SCA conditions in to the end work week. Seas will be 3-4ft, waves 1-2ft. However, conditions become unsettled once again with another protracted round of SCAs appear increasingly likely over the weekend due to the re-tightening of the sfc pressure gradient between high pressure pushing in from the NNE and low pressure retrograding south just offshore. This will result in re-building NNE winds over the weekend, with seas quickly building to 5-8 ft, driven largely by renewed E-NE swell. && .TIDES/COASTAL FLOODING... As of 400 PM EDT Tuesday... Astronomical tides will continue to increase through this evening 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 tonight. Have issued a round of CF Advisories for the upcoming high tide cycle tonight for much of the bay, VA eastern shore, and adjacent tributaries. Tide levels have so far remained below flood thresholds on the eastern shore, but with the upcoming astronomically higher tide cycle and given the slight upward trend, have issued a CF statement over the bay side of the lower MD eastern shore. 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. So far, moderate flooding is not expected through Friday. 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. Coastal Flood Advisory until 2 PM EDT this afternoon for VAZ076-078-085-522. Coastal Flood Advisory until 11 AM EDT this morning for VAZ084- 086-089-090-093-095>100-523>525. MARINE...Small Craft Advisory until 4 AM EDT early this morning for ANZ632-634. Small Craft Advisory until 6 AM EDT Thursday for ANZ650. Small Craft Advisory until 1 AM EDT Thursday for ANZ652-654. Small Craft Advisory until 1 PM EDT this afternoon for ANZ656- 658. && $$ SYNOPSIS...AJB NEAR TERM...AJB SHORT TERM...AJB LONG TERM...AJB/RMM AVIATION...AJB MARINE...AM/MAM TIDES/COASTAL FLOODING...