Marine Weather and Tide Forecast for Portsmouth, VA

KEY MESSAGES
1) Remaining mainly dry through the middle of next week.
Temperatures today-Sunday will be mostly above average but still seasonable. Very warm to borderline "hot", potentially challenging record highs Tuesday through the end of next week.

DISCUSSION
As of 215 AM EDT Friday...

KEY MESSAGE 1...Remaining mainly dry through the middle of next week. Temperatures today-Sunday will be mostly above average but still seasonable. Very warm to borderline "hot", potentially challenging record highs Tuesday through the end of next week.

High pressure off the NE coast continues to extend across the Mid- Atlantic today, but will gradually become centered over the Southeast through tonight as it is suppressed southward by a low pressure system that is forecast to swing through the Northeast U.S.
today. This low will drag a front through the area on Saturday, though no rainfall and only a brief increase in cloud cover is expected. Though northerly flow will bring in a slightly cooler airmass to the area behind the front, temperatures are still expected to be near to even slightly above normal on Saturday, with highs reaching the upper 60s NE to upper 70s SW. Similar temperatures are expected across the area Sunday, though inland areas could see highs increase a degree or two while onshore flow will keep coastal communities in the upper 60s to lower 70s.

For next week, winds become southwesterly as upper ridging builds over the eastern U.S. and surface high pressure builds off the Southeast coast. Very warm to hot area advects into the area, with highs climbing into the 80s on Monday and then upper 80s to lower 90s (potentially mid 90s in spots) Tuesday through Friday. Looking at daily record highs, they are mostly in the 90s, but will still potentially be challenged. This setup will exacerbate the already dry conditions, that are very likely worsen in the medium range.
Little to no chance for any rainfall over the next 7 days, with the NBM showing a 5% or less chance for a wetting rain (>0.10") over the entire forecast area. The latest 6-10 day precipitation outlook from the Climate Prediction Center also the entire forecast area highlighted in below normal chances for precipitation.

AVIATION /12Z FRIDAY THROUGH TUESDAY/
As of 625 AM EDT Friday...

Patchy dense fog has developed at SBY, PHF, and ECG this morning, though it is been more intermittent at the southern terminals. Have decided to keep mention of FG/BR at all terminals except for RIC through 13Z, though this may be overdone time-wise as the fog has already been bouncing back and fourth with VIS. Once the fog burns off, VFR conditions will rapidly return to all terminals and continue through tonight. Winds will generally be light and variable through the afternoon, then will start to shift to the south/southwest tonight as a front approaches the area.

Outlook: Dry with VFR conditions expected to persist through early next week. A weakening cold front drops across the region Saturday that will bring some clouds and a wind shift, but rain chances remain very limited through early next week.

MARINE
As of 215 AM EDT Friday...

Key Messages:

- Small Craft Advisory conditions on the ocean due to elevated seas could persist through part of the weekend, though winds will generally remain sub-SCA. A brief period of SCAs is possible on the bay Saturday morning/midday with northerly winds behind a cold front.

- Sub-SCA on Sunday, with low-end SCAs possible with SW winds Sunday night and Monday.

Light onshore flow prevails early this morning with high pressure centered to the NE of the waters. However, long period easterly swell is keeping seas around 5 ft (with 3-4 ft waves at the mouth of the bay). SCAs continue for all ocean zones and the mouth of the bay to account for this. The SCAs remain in effect through this evening for now, but may need to be extended through Saturday in future updates (especially across the southern coastal waters).
Light winds become SE at 10-15 kt with gusts to 20 kt by late aftn/early evening as the gradient increases on the back side of the departing high (ahead of an approaching dry cold front). Winds become SW and remain 10-15 kt tonight. That front crosses the waters Saturday morning, and there is the potential for a brief surge to 15- 20 kt as winds become northerly behind the front. Peak winds likely occur between 9 AM-2 PM Saturday. May need a brief SCA for the bay to account for the post frontal winds. Local wind probs show a 30- 60% chc of sustained 18 kt winds on the bay for a ~3 hour period late Sat AM/midday.

Winds veer to the east and diminish to ~10 kt Saturday evening, with E-SE winds of 10-15 kt expected on Sunday as another area of high pressure slides past overhead and settles offshore. A period of low- end SCAs is possible Sun night/Mon as winds become SW at 15-20 kt as the high becomes suppressed to our SE and weak low pressure tracks well to our north. The best chc of SCAs is on the bay Sunday night with SCAs possible on the bay and perhaps the rivers during the day on Monday due to mixing over adjacent land area.

AKQ WATCHES/WARNINGS/ADVISORIES
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory until 7 PM EDT this evening for ANZ634.
Small Craft Advisory until 1 AM EDT Saturday for ANZ650-652- 654-656-658.