Area Forecast Discussion
Issued by NWS Wakefield, VA
Issued by NWS Wakefield, VA
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747 FXUS61 KAKQ 220002 AFDAKQ AREA FORECAST DISCUSSION National Weather Service Wakefield VA 802 PM EDT Sat Sep 21 2024 .SYNOPSIS... High pressure builds south along the Mid-Atlantic coast into early next week. Meanwhile, a series of shortwave troughs will slide across the region in northwest flow aloft bringing on and off rain chances. Seasonal temperatures are expected to start next week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... As of 335 PM EDT Saturday... Key Messages: - Pleasant weather this afternoon with highs in the low 80s inland, 70s immediately near the coast. - Shower/storm chances increase late this afternoon in the west, progress east overnight. A severe storm or two possible in the piedmont. Mostly sunny this afternoon with high pressure centered well N of the region and ridging S along the Mid-Atlantic coast. Temperatures range from the upper 70s to lower 80s. Meanwhile, showers/tstms are developing across the higher terrain to the W ahead of a shortwave trough and approaching cold front.21/12z CAMs remain in good agreement regarding timing and coverage of precip spreading across western portions of the area late this afternoon and evening. Scattered showers/storms then gradually cross the area overnight as secondary shortwave energy slides across the area. SPC has far western portions of the area in a MGNL for today. There will be decent shear in the area, as the 12z HREF shows ~30-35kt of effective shear. However, the window for severe weather will be limited given the narrow timeframe for sufficient CAPE prior to sunset. If severe tstms do form, the threats would be damaging wind gusts and hail. A weak backdoor cold front pushes onshore late tonight. There is a potential for stratus late tonight, and some patchy fog across the Piedmont. Low temperatures will primarily be in the 60s. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... As of 335 PM EDT Saturday... Key Messages: - Isolated shower chances for Sunday with a backdoor cold front - Pleasant start to the week with dry weather and highs in the 70s The backdoor cold front is forecast to cross into the local area early Sunday morning and lingers in the area through the day. Isolated/widely scattered showers will accompany the front, so slight chance PoPs have been maintained in the NE early then progressing SW through the day. High temperatures will depend on the location of the front through the day, but generally expect low-mid 70s in the NE and around 80F in the SW. Mostly cloudy to overcast conditions are expected across most of the area. The ridge axis aloft shifts toward the E coast Monday. Meanwhile, surface low pressure offshore finally makes some progress to the SE and farther offshore. Monday should be pleasant, albeit a bit cloudy. Highs will be in the low-mid 70s across northern counties and upper 70s S of I-64. Lows Mon night will be around 60. Another shortwave trough approaches from the NW Tuesday as high pressure remains centered NE of the region with the surface ridge axis extending SW along the Mid-Atlantic coast. This will bring a chc of showers inland. High temperatures range from the lower 70s NW to the upper 70s SE, after morning lows in the lower to mid 60s. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As of 335 PM EDT Saturday... Key Messages: - Multiple low-end chances for precip next week. Moisture will gradually slide back into the area next week around the edge of a ridge offshore, and ahead of a trough well to the W. Confidence in the forecast for midweek and after is low, but there are daily rain chances with increased moisture. Temperatures will gradually warm a bit as thicknesses rise with the ridge pushing up the coastline. Highs are forecast to be in the mid 70s to around 80 degrees. Lows will mainly be in the 60s. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... As of 800 PM EDT Saturday... A cold front and an upper trough will approach from the NW this early tonight. Then, a backdoor cold front will slide in from the NE late tonight into early Sun morning. The best chc of showers/tstms will be at RIC this evening. Brief heavy rain and reduced vsby along with locally strong wind gusts are possible with any tstms. A chc of showers and perhaps a tstm will shift E later tonight, mainly after 04-05z. There is a potential for MVFR and IFR CIGs late tonight into Sun morning, with the best potential for IFR cigs at RIC. Additionally, MVFR vsby is possible. The backdoor cold front will slide across the region Sun. MVFR CIGs will potentially linger into Sun aftn, esply at all TAF sites except SBY. The wind will mainly be ENE 8-12kt behind the backdoor front. There is a potential for lower CIGs late Sun night/early Mon morning. Otherwise, mainly dry and VFR Mon. Minimal chcs of showers are forecast Tue through Thu. && .MARINE... As of 405 PM EDT Saturday... Key Messages: - Small Craft Advisories remain in effect for all coastal waters through Monday (primarily for seas). - Winds increase Sunday, but remain mainly sub-SCA. Waves may build to 4 ft late Sunday/Sunday night at the mouth of the Bay. - Persistent long period swells keep seas elevated into the middle of next week. Sfc low pressure (~1007mb) lingers well off the southern New England and NJ coast, with high pressure centered well to the N, across NewFoundland/Labrador. SE winds ~10 kt (10-15 kt across the bay) continue into this evening, diminishing to 5-10 kt overnight. Winds become E 10-15 kt with perhaps a few gusts to around 20 kt Sun behind a weak area of low pressure which moves SE across VA and into E NC. Winds become NE 15-20 kt across the coastal waters and lower bay (15 kt with a few gusts to around 20 kt for the rest of the bay) Sun evening into early Sun night before diminishing to 10-15 kt. Cannot rule out a few gusts up to 25 kt across the northern coastal waters. Waves and seas were 1-2 ft (2-3 ft at the mouth of the bay) and 4-5 ft respectively this afternoon. Expect seas to build to 5-7 ft Sun night into Mon, potentially remaining elevated through mid week. As such, have maintained SCAs for the coastal waters until Mon evening. Will note that these SCAs will need to be extended in future updates. Confidence is still too low for any headlines (outside of 3-4 ft waves at the mouth of the Ches Bay). && .TIDES/COASTAL FLOODING... As of 400 PM Saturday... - Key Message: Long duration coastal flood event continues across the region, with flooding likely to persist through mid week. Various headlines remain in effect (see latest CFWAKQ for details). Tidal departures have risen slightly over the past 12 hrs, with some areas now >+1.5 ft above astro tide levels. This afternoon`s high tide cycle is the higher of the daily cycle (astronomically), which will lead to water levels into moderate flood thresholds for most sites in the mid/upper Bay, as well as the VA eastern shore. Va Beach and Currituck, NC peaked at right around moderate flood stage. The high tides Sunday and Monday afternoon look to be slightly higher than this afternoon`s high tide. As such, expect additional rounds of moderate coastal flooding through Monday evening. Portions of the upper bay may see moderate coastal flooding continue into Tuesday. For now, have issued Coastal Flood Warnings for most of the Chesapeake Bay, Virginia Beach, Currituck, and Eastern Shore (apart from around Ocean City, MD) through Monday evening. Confidence was too low at Yorktown to extend the Coastal Flood Warning beyond Sunday, but this may need to be extended in future updates. Have opted to leave Norfolk and Chesapeake in a Coastal Flood Advisory (as opposed to a Coastal Flood Warning) given that the Elizabeth River and Swell`s Point look to remain below moderate flood stage. However, if tides trend up, they may need to be added to the warning. A Coastal Flood Advisory remains across the Atlantic side of the Maryland Eastern Shore with Ocean City looking to remain in minor flood stage through Monday afternoon. Additional coastal flooding looks to continue into mid week. In addition, a High rip current risk is in effect through Sunday and will likely be extended into Monday as well. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...Coastal Flood Warning until midnight EDT Monday night for MDZ021>023. Coastal Flood Advisory until 4 PM EDT Monday for MDZ024-025. NC...Coastal Flood Warning until 4 PM EDT Sunday for NCZ102. VA...Coastal Flood Warning until midnight EDT Monday night for VAZ075-077. Coastal Flood Warning until 4 PM EDT Sunday for VAZ098. Coastal Flood Warning until 10 PM EDT Monday for VAZ076-078- 085-521-522. Coastal Flood Advisory until 8 PM EDT Monday for VAZ083-518- 520. Coastal Flood Advisory until 4 AM EDT Sunday for VAZ084-086- 523. Coastal Flood Warning from 11 AM to 6 PM EDT Sunday for VAZ084- 086-523>525. Coastal Flood Advisory until 6 AM EDT Sunday for VAZ089-090- 093-096-524-525. Coastal Flood Warning from 11 AM Sunday to 10 PM EDT Monday for VAZ089-090-093-096. Coastal Flood Advisory until 6 PM EDT Monday for VAZ095-097. Coastal Flood Warning until 8 PM EDT Monday for VAZ099-100. MARINE...Small Craft Advisory until 6 PM EDT Monday for ANZ650-652-654- 656-658. && $$ SYNOPSIS...AJZ NEAR TERM...AJZ/AM SHORT TERM...AJZ/AM LONG TERM...AJZ/AM AVIATION...AJZ/TMG MARINE...LKB/MAM/RMM TIDES/COASTAL FLOODING...AKQ