Marine Weather and Tide Forecast for Smith Island, MD

NEAR TERM /THROUGH SUNDAY/
As of 908 PM EDT Saturday...

Key Messages:

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

- Additional rounds of heavy rain and a Marginal SVR Risk continue Sunday, mainly along/S of I-64.

As expected, numerous showers and thunderstorms developed this afternoon and evening and brought a barrage of rainfall and lightning to mainly the southern portion of our forecast area.
Multiple flash flood warnings have been issued as these storms were slow moving and produced between 1-3"+ in the hardest hit areas. The Wallops sounding sampled a PW of just under 2", which is well above normal, and strong wind gusts have had trouble mixing to the surface due to the very saturated atmosphere. The main trigger of this convection is a surface front slowly sagging south across our area this evening. The storms that have developed have been able to feed off of the abundant outflow boundaries and juiced atmosphere.
Earlier, MLCAPE values were approaching 3000 J/kg thanks to the help of good surface heating today. With the help of all the instability, an uninhibited environment, high PW values, and some shear, storms maintained themselves well and are a few strong storms are still moving through the Northern Neck and NE NC despite the loss of daytime heating. While the severe threat is waning, there still may be a few isolated instance of flooding through around midnight.
Thereafter, rain chances will diminish as the storms push offshore.
Temperatures will drop into the mid 60s NE and in the upper 60s to lower 70s elsewhere overnight.

From previous discussion:

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 430 PM EDT Saturday...

Key Messages:

- Remaining unsettled Monday-Tuesday.

Unsettled weather will continue Monday, and even into Tuesday, PoPs still mainly 50-60% across the region (well above climo).
Areas along and S/SW of I-64 are in a MArginal ERO Monday, given the frontal boundary still quasi stationary over the region with additional shortwaves moving through the westerly flow aloft.
Highs Monday will be below avg, generally in the 70s for northern and central zones, with low-mid 80s across the south. With an upper trough still off to our W on Tuesday, additional showers/tstms are again expected, with high chc to likely PoPs once again. It will tend to turn warmer Tuesday with highs in the 80s.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/
As of 430 PM 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 north into the local area, bringing near-climo precip, and hot temperatures Wed and Thursday. Model 850 mb temperatures rise to 18-19C Thursday, which would support highs into the low- mid 90s Along with continued moderate to high humidity). Thursday will likely see heat indices above 100F, possibly close to headlines in the SE (though this is several days out so confidence is not high).
The next upper level trough should push a cold front into the area late Thursday, bringing scattered showers/tstms. Fri-Sat currently looks drier (low PoPs and lower humidity), but still very warm with highs in the upper 80s to low 90s.

AVIATION /01Z SUNDAY THROUGH THURSDAY/
As of 732 PM EDT Saturday...

Convection has been ongoing at ORF and PHF this evening, with intermittent thunderstorms nearing RIC. SBY and ECG have steered clear of any storms thus far, so have only included -shra at these terminals this evening. Another storm is tracking towards ORF, so have included a TEMPO for TSRA from 00-02Z there. Otherwise, expecting some of the storms to turn into stratiform rain over the next few hours so most terminals will likely see at least -shra through midnight. CIGS are expected to drop to IFR at all terminals, with at least RIC and SBY potentially dropping to LIFR. CIGS will lift to generally IFR to MVFR tomorrow morning and will remain there through the evening. Convection is expected to wane early tomorrow morning before picking back up again tomorrow afternoon. Once again, there is uncertainty in the evolution of tomorrows storms, so have decided to include a PROB30 for -TSRA at all terminals expect for SBY to account for the the possibility of numerous showers and scattered thunderstorms expected tomorrow. The challenge will be exactly where storms develop and when, so details of become a little more clear and confidence increases, we will likely include TEMPOs to capture the convection.

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.