Marine Weather and Tide Forecast for Palmyra, VA

NEAR TERM /UNTIL 6 AM SUNDAY MORNING/
As of 1200 PM EDT Saturday...

Key Messages:

- A Flood Watch is in effect for central and eastern VA through late tonight, with an additional Flood Watch for SE VA that goes into effect later in the afternoon through late tonight.

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

The latest WX analysis indicates ~1025mb sfc high pressure to the north of the Great Lakes, with ~1013mb 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 boundary is currently across DE, and some scattered showers/storms are now developing across the eastern shore near this feature with aided lift. Temperatures have risen into the lower 80s over the CWA, with dew pts generally in the low-mid 70s. Current mesoanalysis indicates sfc-based CAPE values already into the 1500-2500 J/Kg range (highest W of the Bay). These values are expected to increase to >3000 J/Kg by later aftn W of the Bay (they may decrease on the eastern shore if outflow boundaries push the front back south). High PW values of >2.0" will remain in place across the area, which will once again help with the development of widespread showers and thunderstorms later today, with heavy rain/flash flooding as the primary concern later this aftn 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. PoPs increase through the aftn, becoming highest after 21Z and persisting through the evening for most of the area, with training cells probable along and S of the front.

A Marginal SVR risk has been introduced fro our MD-VA zones.
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 ~20kt in NC (where only Gen Thunder is in place) to around 30kt across northern zones. Highs today will mostly be into the upper 80s, though the eastern shore will likely see temperatures steady or falling into the 70s. PoPs gradually diminish overnight with lows in the mid 60s NE and in the upper 60s to lower 70s elsewhere.

SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/
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.

The front will continue to linger in the southern part of the area on Sunday, which will bring more unsettled weather. The moist airmass will continue with PW values above 2"+ across the area.
Additional 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 extended for portions currently in the Flood Watch. This will also be dependent on rainfall totals evolve today. A Marginal SVR Risk is in effect for the majority of the area on Sunday, as there is a slightly stronger flow aloft, but there is still uncertainty in place regarding the eventual orientation of the frontal boundary.

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 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 become lower Tue-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.