Marine Weather and Tide Forecast for Gloucester Courthouse, VA

NEAR TERM /THROUGH SUNDAY/
As of 400 PM EDT Saturday...

Key Messages:

- A Flood Watch remain in effect for most of our VA counties through late tonight.

- A Marginal Severe Risk is in effect for VA-MD zones.

The latest WX analysis indicates ~1025 mb sfc high pressure off the New England coast, with ~1012 mb sfc low pressure centered across southern IL/IN, with a sfc trough and associated stationary front extending east through the OH Valley into the northern mid- Atlantic region. Aloft, a rather deep trough is nearly co- located with the sfc low, with broad upper level ridging from the eastern Gulf to the Bahamas. The result is a moist W-SW flow aloft locally, which allowed the front to move just to the N of the MD eastern shore last night. The frontal boundary has dropped south into the MD eastern shore this aftn, with winds now out of the NE. Latest satellite imagery and radar shows that some scattered showers/storms are pushing into central and southern VA, just south of the front. Temperatures have risen to the upper 80s/lower 90s south of the front, but have fallen into the 70s at the coast of the eastern shore.
Dew pts generally in the low- mid 70s area-wide. Current mesoanalysis indicates sfc-based CAPE values >3000 J/Kg W of Ches Bay, which much lower values to the NE (Along with some CIN into the ern shore). High PW values of >2.0" are in place from about RIC and pts SE. Expect showers and tstms to become widespread over the next few hrs over most of the area (with somewhat lower PoPs over the ern shore and in NE NC). Heavy rain/flash flooding will be the primary concern into tonight. A Slight ERO is in place for nearly the entire CWA, but the greatest threat will probably align somewhere along the I-64 corridor, especially from about 21Z through midnight where training cells will become possible along and S of the front.

A Marginal SVR risk is also in place, mainly for our VA counties. Weak mid level lapse rates (5 to 5.5C/Km) and a very saturated warm/moist airmass suggest hail would require some excessively tall storms today, so overall, wind is the most likely threat with the strongest storms. Shear is on average ~25kt in NC (where only Gen Thunder is in place) to around 30kt elsewhere (locally higher N). The 12Z HRRR 3"/3 hr neighborhood probabilities continue to show the greatest potential roughly along the I-64 corridor through midnight. PoPs gradually diminish overnight with lows in the mid 60s NE and in the upper 60s to lower 70s elsewhere.

The front is expected to stall in the vicinity of south central VA and NE NC Sunday (but exactly where is uncertain). Nevertheless, expect more unsettled weather and additional heavy rain. The moist airmass will continue with PW values above 2"+ across much of the area. Total QPF values are 2-3" for much of the area through Sunday evening. With the scattered nature of the storms, locally higher amounts are possible. The likely timing of the rainfall will be in the afternoon to evening again. An additional Flood Watch may be needed for southern VA and possibly portions of NE NC. This will also be dependent on how rainfall totals evolve through tonight. A Marginal SVR Risk is in effect for the majority of the area on Sunday, given slightly stronger flow aloft, though the northern extent is somewhat uncertain as a result of cooler more stable easterly flow. The best chances for heavy rain and some severe WX Sunday will be along and S/SW of I-64. High Sunday will show a fairly large gradient, ranging from the lower 70s MD eastern shore, to the mid-upper 80s for portions of south central VA and NE NC.

SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/
As of 345 AM EDT Saturday...

Key Messages:

- Additional rounds of heavy rain could lead to additional flash flooding.

- A Marginal Risk for severe weather is in effect for the majority of the area Sunday with the primary threat of damaging winds.

Temperatures Sunday will be quite the gradient, again based on the front with the Eastern Shore only seeing highs in the mid 70s and NE NC seeing highs in the upper 80s. Overnight lows will be in the upper 60s to lower 70s. Monday's temperatures will be similar to Sunday's.

Unsettled weather will continue Monday as the front continues to stall to the south. Rainfall amounts are expected to be less than today and Sunday.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/
As of 345 AM EDT Saturday...

Key Message:

- Shower/storm chances drop off to near climo, with temperatures trending back above normal by mid to late week.

Upper level ridging over the SE US coast will expand into the region, bringing near-climo precip. This ridging will bring warming temperatures, with a rather hot stretch (and high humidity) likely Wed-Thu with highs peaking into the low- mid 90s. Thursday could see heat indices above 100F, possibly close to headlines in the SE (though this is several days out so confidence is not high). PoPs drop off to only 20-40% chc Tue-Thu (highest inland).

AVIATION /20Z SATURDAY THROUGH THURSDAY/
As of 200 PM EDT Saturday...

Mainly VFR conditions at the terminals to start the TAFs, but showers/tstms become more widespread after 20Z, as a front slowly drops south into the area. Have TEMPO and PROB30 groups to cover tstms which are primarily between 21Z-03Z, followed by deteriorating CIGs overnight even as the rain starts to diminish. IFR conditions are likely to develop for all sites but ECG between 06-12Z/Sunday. Slowly improving conditions later Sunday morning, but additional showers are expected Sunday afternoon/evening. Tstms will again be possible, except at SBY where cooler onshore flow will be more conducive to SHRA.

Outlook: Scattered to numerous, mainly aftn/evening showers/tstms are again expected Monday, bringing localized flight restrictions in heavy rain and gusty winds. Rain chances remain a bit elevated Tue, then diminish Wed.

MARINE
As of 340 PM EDT Saturday...

Key Message:

- Relatively benign across the marine area into next week outside of convection.

A cold front has been nearly stationary just N of the area and will gradually shift south tonight and Sunday. Sub- SCA conditions prevail with benign marine conditions. Seas are between 2 to 3 ft, with 1 ft waves in the Bay. SW winds are 5-10kt over much of the area, with 10-15kt off the coast of the MD Eastern Shore N of the front. As the front drops south tonight, E-NE winds develop, gradually shifting south with time by later Sunday. Seas are expected to build to ~3 ft (building to 3-4 ft over the waters N of Parramore Island in building SE swell). Showers and thunderstorms are likely across the waters today, with SMWs possible to handle any strong winds. The front gradually washes out next week, with a more S/SW flow again by Tuesday, with sub- SCA conditions continuing.

Rip currents are expected to remain low today, then moderate N and low S for Sunday.

AKQ WATCHES/WARNINGS/ADVISORIES
MD...None.
NC...None.
VA...Flood Watch until 2 AM EDT Sunday for VAZ048-060>062-064- 067>069-075>078-080>086-088>090-092-093-095>100-509>525.
MARINE...None.