textproduct: Wakefield

WHAT HAS CHANGED

- Rain chances and rainfall amounts tonight have continued to trend down, especially for SE VA/NE NC.

KEY MESSAGES

1) A cold front brings a chance for showers and possibly a rumble of thunder late today through tonight.

3) Cool Thursday, then warming up to above average temps for the weekend into the middle of next week.

DISCUSSION

As of 330 AM EDT Wednesday...

KEY MESSAGE 1...A cold front brings a chance for showers and possibly a rumble of thunder late today through tonight.

Early morning WX analysis indicates zonal flow aloft with a trough N of the Great Lakes. Sfc low pressure is located near Lake Huron, and is starting to occlude, with sfc high pressure well off the mid-Atlantic and Carolina coast. There is also an area of low pressure across Florida. Southerly low level flow has kept temperatures mostly in the 50s early this morning (much warmer than 24 hrs ago when they were in the 30s and 40s). For today, the upper trough is forecast to dive SE, with a cold front approaching the local area from the west late in the day, and crossing the region overnight into early Thursday. The models continue to trend drier with the pattern over the next 24 hrs, perhaps being robbed of moisture from the sfc low ejecting NE from Florida. Overall, expect a dry and breezy day today under a mostly sunny sky through mid aftn, with increasing clouds across the NW 1/2 of the area late. S winds are expected to gust to 25-30 mph this aftn, highest across the eastern shore. Instability is basically zero this aftn with dew pts expected to be in the 40s to lower 50s. Highs today will mostly be in the mid to upper 70s, with a few spots potentially reaching 80F. The latest HRRR and most of the other models show very limited potential for any tstms locally, but will maintain a slight chc mention this evening for the NW portions of the area to about the north 1/2 of metro RIC. This is likely to just be a rumble of thunder if if does occur, and no severe or even strong storms are expected. PoPs have been dropped to chc (50% or lower) for roughly the Se 1/2 of the area, with 60-80% PoPs this evening, lingering into early Thu AM focused across the north. Even in these areas, only ~0.10" is expected, with perhaps up to 0.25" if any briefly heavier showers. Of note, a few of the models show a brief uptick in precip chances around daybreak Thursday across the SE (associated with the shortwave pushing through), but confidence in this precise scenario is low so PoPs will only be 20-30% Thursday morning in the SE. LOws overnight into Thursday will range from the upper 40s/around 50F NW to the upper 50s SE.

KEY MESSAGE 2...Cool Thursday, then warming up to above average temps for the weekend into the middle of next week.

Temperatures remain cool Thursday, as the upper low becomes centered over the NE and mid- Atlantic region. Highs Thursday will be about 5- 10 degrees below normal, generally in the upper 60s to lower 70s. Expect variable cloudiness, with some uptick in aftn cloud cover likely due to daytime heating from the strong May sun angle. Would not be surprised to see a few sprinkles or isolated showers redevelop in the aftn. For now, the models seem to focus this across the far SE where sfc dew pts are a little higher, but this still could occur farther NW as well.

Significant changes are on the way by the end of the week, after a dry Friday with near normal temperatures for mid May. Decent model agreement remains that a flat upper ridge over the southern US starts to amplify and become anchored from the Gulf coast to off the SE coast. Surface high pressure parked offshore will allow southerly flow to prevail, leading to above normal temperatures returning by the weekend, with highs in the mid- upper 80s Sat, and then likely into the upper 80s to lower 90s for much of the area Sunday (locally cooler on the eastern shore and immediate coast). Some of the deterministic models do show some chance for precip along a warm front Sunday, and the latest NBM/blended guidance does have some slight chc PoPs for this. Current ensemble guidance shows a high probability for highs into the 90s Mon-Tue, with dry conditions, and the deterministic forecast has high 90-95F for most of the region. This is reasonable given the pattern and the antecedent drought conditions should make this rather easy to occur.

AVIATION /07Z WEDNESDAY THROUGH SUNDAY/

As of 200 AM EDT Wednesday...

VFR conditions prevail through most of the 06Z TAF period. Mostly clear skies prevail through most of today, with southerly winds 5-10 kt, increasing after 12-15Z to 10-15 kt with gusts 20-25 kt, slightly higher at SBY where the gradient will be tightest. Forecast soundings show at least some moisture at the top of the mixed layer so FEW/SCT CU are expected as heating gets underway, though this will be high based at 6-8k ft. Any showers or isolated storms are forecast to remain north and west of the terminals through 00z. Have included prevailing showers late at RIC/SBY, a PROB30 group at PHF, while keeping ORF/ECG dry for now. Only brief flight restrictions are expected at RIC/SBy, probably with MVFR VSBYs in rain.

Outlook: Winds shift to the NW Thursday, with VFR conditions. Dry and VFR conditions continue Fri-Sat.

MARINE

As of 315 AM EDT Wednesday...

Key Messages:

- Small Craft Advisories remain in effect for the bay and Tidal rivers. The bay is in effect now and last through tonight, while the rivers go into effect this afternoon and last through this evening.

- Sub-Small Craft Advisory conditions are expected for most of the day Thursday, with another chance of advisories overnight Thursday in the bay.

- Benign marine conditions are expected this weekend and into early next week with primarily southerly winds.

Early morning weather analysis shows high pressure off the coast of the Outer Banks. The pressure gradient from the high pressure and approaching cold front remains weak over the area at this moment and is only leading to winds out of the S around 10 to 15kt with some gusts approaching 20kt. Seas at this time are between 1-2ft across the bay and 2-3ft across the ocean. Small Craft Advisories are in effect now for the bay due to the marginal gusts up to 20kt. However, expect conditions to worsen later today.

Through the day the pressure gradient is expected to tighten as the cold front approaches the area. This will lead to stronger SSE early this afternoon. Winds across the bay are expected to increase to 20- 25kt with gusts nearing 30kt. Across the tidal rivers winds increase to 10-15kt with gusts nearing 20kt. Small Craft Advisories go into effect for the tidal rivers early this afternoon. While across the ocean winds will increase to 15-20kt with gusts nearing 25kt north of Cape Charles. While south of the Capes winds are expected to be between 10-15kt with gusts nearing 20kt. With the winds increasing this afternoon waves will also increase to 3-4ft across the bay and 4 to potentially 5ft across the ocean. Will note the best chance for 5ft seas is north of Cape Charles. For this forecast update no SCA have been issued for the ocean waters north of Cape Charles. This is due to the the 25kt gusts and 5ft seas being marginal and for a short period of time. By early tonight winds will decrease as the cold front is pushing through the area and winds will shift to the NW. Mainly Sub-SCA conditions are expected tonight into Thursday. However, there could be a brief period of SCA conditions across the bay mid Thursday morning. Will note that these conditions will be brief and the Sub-SCA conditions will last through much of Thursday. The next best chance for solid SCA come Thursday night into Friday AM across the bay as a second push of drier air moves into the area. Winds could gusts between 20-25kt during this time period. After Friday AM, mainly benign marine conditions are forecasted for with winds primarily out of the S to SW.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 1 AM EDT Thursday for ANZ630>632- 634. Small Craft Advisory from 1 PM this afternoon to 10 PM EDT this evening for ANZ635>637-639.