Area Forecast Discussion
Issued by NWS Wakefield, VA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000 FXUS61 KAKQ 040839 AFDAKQ AREA FORECAST DISCUSSION National Weather Service Wakefield VA 439 AM EDT Sat Apr 4 2020 .SYNOPSIS... Strong low pressure well offshore of the local area continues to move away from the coast today as high pressure builds over the area. High pressure moves offshore on Sunday. A weak cold front approaches the area late Sunday before crossing part of the area on Monday. && .NEAR TERM /THROUGH TONIGHT/... As of 345 AM EDT Saturday... Low pressure well offshore of the VA/NC coast continues to track SE and away from the area early this morning. However, there is one last shortwave near the MD/PA border that is moving south toward the area. N-NNE winds have diminished and are light/calm well inland, but are still gusting to ~15 mph near the coast. Skies are mainly clear over most of the area, with mostly cloudy-overcast skies over the Lower Ern Shore. Temperatures have fallen into the 40s-low 50s in most areas, with a few upper 30s across interior srn/SE VA. Expect temperatures to fall no lower than 40F across most of the area by sunrise, with mid-upper 30s over portions of interior S/SE VA. The weak shortwave in northerly flow aloft will drop southward toward the area today. Not expecting any pcpn from this feature (outside of perhaps a few sprinkles over the Ern Shore) but clouds will be on the increase across most of the region today. Expect skies to become mostly cloudy over much of the area by aftn. There will be a bit more sunshine across the Piedmont and very little (if any) sun over the Lower MD Ern Shore. As such, temperatures will be warmest across the VA Piedmont where mid to upper 60s are forecast. Expect low to mid 60s for the I-95 corridor with mid 50s-low 60s for coastal zones. Weak high pressure currently centered over the Great Lakes/OH Valley builds overhead tonight. Lows range from around 40F E/SE (closest to the center of the high) to the low 40s W. Some of the CAMs are hinting at the possibility of patchy fog across the Lower Ern Shore as well as portions of SE VA/NE NC. Will leave this out of the grids for now, but will re-assess later this morning. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... As of 345 AM EDT Saturday... Weak return southerly flow commences on Sunday as high pressure moves offshore. Continued dry with highs in the low 70s inland, with mainly mid-upper 60s near the bay/coastal SE zones, and low-mid 60s over the Lower Ern Shore. Shortwave energy in WNW flow aloft will approach the area late Sunday-Sunday night. At the same time, a weak cold front slowly moves south toward the area (but remains to our NW through Sun night). A few showers will likely develop to our W late Sun before potentially moving across the area Sun night. Will keep it dry through 21z Sun. Will have PoPs of 15-30% over the area Sun night to account for isolated to perhaps scattered showers. Lows Sun night will be in the upper 40s and low 50s. A 15-30% chc (highest SE) for a few showers will continue Mon AM as the aforementioned front crosses the region from N to S. Some re-development of showers is expected along/ahead of the front Mon aftn (mainly over far srn VA/NE NC) as temperatures warm into the low-mid 70s and dew points rise into the mid 50s. Forecast soundings do show some weak instability across NE NC Mon aftn, so cannot rule out a rumble of thunder or two (although upper forcing will be meager at best). Elsewhere (on the north side of the front), pcpn chances end by mid-late aftn. Warmer on Monday with highs ranging from the upper 60s near the coast to the low-mid 70s elsewhere. The weak boundary moves back N as a warm front Mon night as low pressure tracks ewd across the nrn Plains. Will keep slight chc PoPs across NE NC through 06z Tue, with a slight chc of a shower late over the Lower MD Ern Shore. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 400 PM EDT Friday... A series of weak, low amplitude waves will move through the region early next week, providing slight chances of showers Monday night through Wednesday. A weak warm front lifts N Monday night into Tuesday before stalling to the N and lingering through Wednesday. A backdoor cold front moves through the region Wednesday night/Thursday but should be mostly dry. A cold front moves through Thursday night/Friday morning from the W and provides another isolated chance of showers. Greatest PoPs will be Tuesday morning (30-45% chance)and Wednesday morning (25-40% chance). Highs are expected to be in the mid-70s on Mon and Thurs, upper 70s to near 80F on Tues and Wed, and low-mid 60s on Fri. Lows expected to range from the low 50s N to the upper 50s S on Mon, Tues, and Wed nights. Lows are expected to then cool to the low 40s N to the upper 40s S Thurs and Fri nights behind the stronger cold front. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... As of 135 AM EDT Saturday... Skies are mainly clear across VA/NC early this morning, with BKN CIGs around 5000 ft at SBY as strong low pressure well off the VA/NC coast continues to drift SE away from the area. Skies become BKN inland/BKN-OVC near the coast today as a secondary upper shortwave drops toward the area from the N. However, CIGs at RIC are likely to remain VFR (4000-5000 ft). CIGS will likely drop to MVFR at the other terminals by late morning-midday. There is still a very slight (10-15%) chance of a light rain shower at SBY through this morning, but any light pcpn that does fall will not have any operational impact. CIGS scatter out from this evening through the first part of tonight as high pressure settles into the area. There is a slight chc of patchy fog at the coastal terminals after 06z Sun, but confidence in this is low attm. N-NE winds will average 8-12 kt through the TAF period, with a few gusts to 20 kt likely at ORF/ECG. Outlook...VFR conditions are expected for much of Sunday although a weak front will approach from the west late in the day. Unsettled weather sets up for early next week with chances of rain Monday through Wednesday, with occasional degraded flight conditions possible. && .MARINE... As of 400 AM EDT Saturday... Sfc low pressure now located well off the VA coast, with winds now slowly diminishing across the region. Allowed SCAs to expire for all rivers except the lower James. SCAs remain in effect through 7 or 10am for the lower James, most of the Bay, and Currituck Sound but will stay in effect much longer/into Sun for the mouth of the Bay for swell that will bring waves of 4 ft+ despite the diminishing wind. For the coastal waters, SCAs remain in effect through Sun night, initially today we will continue with gusts to 25kt, but the main hazard will be from seas that will increase to 7-9 ft later today/tonight before gradually subsiding to 5-6 ft Sun aftn/Sun night. This will be from 12-13 sec long period swell from the low pressure well offshore. High pressure will settle across the local area Sun, before drifting SE to the NC coast Sun night. Winds will be light and mainly onshore Sunday, then become SE ~10 kt Sunday night. Seas may stay above SCA criteria (5 ft) into Monday though current forecast has them subsiding to ~4ft by then. A weak cold front is expected to shift the winds to the N on Mon for much of the marine area but there is no real cold air surge and the front is expected to wash out or lift back N Mon night. && .TIDES/COASTAL FLOODING... As of 400 AM EDT Saturday... N to NE winds 15-20 kt this morning will gradually diminish and the main concern for tidal/coastal flooding will be a result of long period (12-13 sec) swell from strong low pressure well off the mid-Atlantic coast. Seas have been underperforming thus far but are now building to 6-7 ft across the northern coastal waters and to 4-6 ft over the S. Have scaled back by about a foot for the maximum seas that are expected later today into tonight (building to 8-9 ft offshore and 7-8 ft nearshore). Have held off on a High Surf Advisory as the chance for nearshore waves to 8 ft looks less likely now (though will continue to monitor this closely). However, the currents data at the mouth of the Chesapeake Bay is showing that the last tide did not ebb (at all) with another flood tide increasing as of this writing. Seeing the response into the lower and middle Bay now so have extended the Coastal flood Advisories to cover both the upcoming high tide later this morning as well as the following high tide this evening. Also did this for the advisories along the Atlantic coast. Some locations may struggle to hit minor flood thresholds with the high tide this morning (but all will be at least within a few tenths). With the increasing swell coupled w/ winds slowly diminishing and shifting more to the NE, expect to see the increasing anomalies translate northward and bring the potential for moderate flooding into the mid/upper Bay by this evening and into Sunday. Thus have raised a Coastal Flood Watch from portions of the northern Neck and over the bayside of the MD eastern shore for Somerset, Wicomico, and Dorchester. As we see how the water levels respond later today, the Watch can be converted either to an Advisory or a Warning as appropriate. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...Coastal Flood Advisory until 9 PM EDT this evening for MDZ024- 025. Coastal Flood Watch from this evening through Sunday afternoon for MDZ021>023. NC...Coastal Flood Advisory until 9 PM EDT this evening for NCZ102. VA...Coastal Flood Advisory until midnight EDT tonight for VAZ078- 084>086-089-090-093-095>097-523>525. Coastal Flood Advisory until 9 PM EDT this evening for VAZ098>100. Coastal Flood Watch from this evening through Sunday afternoon for VAZ075-077. MARINE...Small Craft Advisory until 6 AM EDT Monday for ANZ650-652-654- 656-658. Small Craft Advisory until 7 AM EDT this morning for ANZ630- 631-638. Small Craft Advisory until 6 PM EDT Sunday for ANZ634. Small Craft Advisory until 10 AM EDT this morning for ANZ632- 633. && $$ SYNOPSIS...ERI NEAR TERM...ERI SHORT TERM...ERI/RHR LONG TERM...RMM AVIATION...ERI MARINE...CP/LKB TIDES/COASTAL FLOODING... is the U.S. government's official web portal to all federal, state and local government web resources and services.