Marine Weather and Tide Forecast for Girdletree, MD

NEAR TERM /UNTIL 6 AM FRIDAY MORNING/
As of 910 PM EDT Thursday...

Key Messages:

- The Severe Thunderstorm Watch has been canceled.

- Mild tonight with lows in the mid to upper 60s.

Thunderstorms have either dissipated or moved out of the area this evening with CIN increasing which should prevent further storm development. As such, the Severe Thunderstorm Watch has been canceled. Mostly dry conditions are expected overnight with patchy fog possible late tonight into early Fri morning. Mild and partly to mostly cloudy skies are expected tonight with lows in the mid- upper 60s to around 70F SE.

SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/
As of 400 PM EDT Thursday...

Key Messages:

- Isolated to scattered showers and storms possible Friday and Saturday afternoons/evenings, some of which could be strong to severe.

- Temperatures trend warmer, with a summer-like feel on Friday.

Upper air ridging will continue to influence the region, while an upper level low strengthens over the northern Midwest. The ridging and sub-sequential SW flow will bring warm temperatures to the area.
Highs are looking to warm up to the upper 80s to lower 90s with dewpoints in the upper 60s to lower 70s. With the high humidity, the day will feel hot and muggy in the lower to mid 90s during peak daytime heating hours.

The big question for Friday will be if storms develop. The forcing mechanisms do not look to be strong, with ridging aloft and fairly constant pressure heights. With the highs in the upper 80s to lower 90s and the trough heights near 5800 mb, the capping may be more easily broken with the weaker trough. Any lifting would have to come from some boundary, potentially as excess energy from the MCS to the northwest. The CAMs model (excluding the NAM) show initiation and a large convective complex Friday evening into overnight. There is uncertainty based on the recent CAMs, which show that storms may develop earlier. Models tend to struggle with events like this, so they are taken with caution. The coverage amount and timing remains in low confidence as model show very little agreement. If these storms can develop, they would enter a volatile environment for strong to severe storms. The moisture and warm temperatures will help the atmosphere become very favorable for high levels of instability. Recent CAMS models show values 2500+ J/kg of SBCAPE.
Efficient shear to support thunderstorm growth is likely with models showing values of effective shear of 40-50 kt. Lapse rates from 7.0- 7.5 C/km and strong DCAPE could be favorable for strong winds and severe hail. With this environment, Friday is an all-hazards type of threat. In fact, SPC has upgraded the entire CWA today for this event, now with most all of VA and MD under a slight risk (level 2/5) and NC under a marginal risk (level 1/5). SPC has the wind threat as the highest risk at 15% for VA and MD as well as a 2% tornado risk and 5% within the slight risk.

As for Saturday, a cold front will move through the region in the afternoon, but after the daytime highs is reached in the upper 80s.
The environment will be similar to today's, favorable with ample instability and shear, but yet again the forcing mechanism will be the limiting factor as the front is forecast to weaken before reaching the area. With the warm temperatures like Friday, instability values of 1500-2000 J/kg SBCAPE are expected. Supportive shear values for storm development are forecast as well.
Additionally, SPC has the majority of the area in a slight risk (level 2/5) except for the far NW counties of the CWA There is still lower confidence in timing and coverage, but isolated to scattered showers and storms are possible, with a few potentially becoming severe.

LONG TERM /SUNDAY THROUGH THURSDAY/
As of 400 PM EDT Thursday...

Key Messages:

- Drying out Sunday into the early half of next week as high pressure returns.

- Unsettled weather could return Wednesday and Thursday.

Behind Saturday's cold front, high pressure will move back into the region from the north. An upper air trough will take over the majority of the CONUS. The next surface low pressure system will begin to develop out in the Central Plains. With the high pressure, dry conditions will be favorable for the first half of next week.
Temperatures will return to seasonable with the trough. An upper level low is favored to develop in the Midwest Wednesday and Thursday, which will lead to an unsettled weather pattern. Afternoon showers and storms chance will increase in the middle of the week.

AVIATION /01Z FRIDAY THROUGH TUESDAY/
As of 745 PM EDT Thursday...

CIGs were mainly VFR across the area this evening. Storms will continue to be possible at ECG over the next few hours before convection tapers off. Farther north, RIC has a conditional chance to see a storm tonight between 2-5z. However, given the current storm motion, it appears storms may remain W of the terminal. For now, have gone with a PROB30 for showers to account for the uncertainty. Any showers/storms taper off overnight with SCT-BKN sky cover. Otherwise, a marine layer may attempt to push inland overnight with MVFR/IFR CIGs possible at SBY. Patchy fog is also possible at SBY, RIC, and PHF. MVFR or IFR VIS will be possible in any fog. MVFR CIGs may linger at SBY until 15-16z Fri. Additionally, an isolated shower/storm is possible at SBY by late Fri morning into early Fri afternoon.

Outlook: Additional storms are possible Friday afternoon into Friday night. While there is a decent amount of uncertainty with respect to timing, some of the storms could be severe with gusts up to 50 kt (or higher). Predominate VFR conditions return over the weekend.

MARINE
As of 300 PM EDT Thursday...

Key Messages:

- Generally sub-SCA conditions into the weekend, but with elevated SW flow ahead of a cold front Saturday, and elevated NW flow behind the front Sunday-Monday.

- Locally strong to severe storms possible into tonight and again late Friday/Friday night.

A weak pressure gradient across the area this aftn has led to light and variable winds, slowly shifting from SW to more of an E-SE direction across the lower Bay, and to the S elsewhere.
Seas are still a bit elevated with SE swell, at 3-4 ft, with waves in the Bay/rivers/sound 1 foot or less, except near 2 ft at the mouth of the bay. Scattered storms, potentially strong to severe, are possible this evening/tonight, especially for the Bay/rivers and will be handled via MWS/SMWs as needed.

Otherwise, winds increase a bit on friday, becoming S-SW ~10-15 kt, with yet another round of scattered showers and storms possible, but mainly holding off until very late in the aftn or early evening into Friday night. There may be brief period of elevated, near sub-SCA SW winds Saturday afternoon and evening, especially across the lower James/lower Bay. Winds veer around to the W/NW Sunday and Sunday night in the wake of a passing cold front. Next chance for SCA level winds comes with a secondary surge of cooler, drier air Sunday night into Monday, though this remains uncertain at this range.

HYDROLOGY
As of 300 PM EDT Thursday...

Flood Warnings continue along the James River, at Richmond- Westham, and Richmond Locks have crested, but will remain in minor flood stage through Friday night. See water.noaa.gov for more site- specific information.

AKQ WATCHES/WARNINGS/ADVISORIES
MD...None.
NC...None.
VA...None.
MARINE...None.