Marine Weather Net

Tidal Potomac from Indian Head to Cobb Island MD Marine Forecast








5 - 10

The Marine Weather Forecast In Detail:
ANZ536 Forecast Issued: 641 PM EST Mon Nov 18 2019

Tonight...Sw Winds Around 5 Kt. Waves 1 Ft. Showers Likely. Patchy Fog. Vsby 1 To 3 Nm.
Tue...S Winds Around 5 Kt. Waves 1 Ft.
Tue Night...Nw Winds Around 5 Kt. Waves 1 Ft.
Wed...Nw Winds 5 To 10 Kt. Waves 1 Ft.
Wed Night...Nw Winds 5 Kt. Waves Less Than 1 Ft.
Thu...W Winds 5 Kt. Waves Less Than 1 Ft.
Thu Night...Sw Winds 5 To 10 Kt. Waves 1 Ft.
Fri...Nw Winds 5 To 10 Kt. Waves 1 Ft. A Chance Of Showers.
Sat...Sw Winds 5 Kt. Waves Less Than 1 Ft. A Chance Of Showers.
SHARE THIS PAGE:           
Area Forecast Discussion
...UPDATED National Weather Service Baltimore MD/Washington DC
940pm EST Monday Nov 18 2019

A pressure trough will cross the area tonight. High pressure will gradually build in from the west during the middle of the week. A cold front will cross the region by week's end.

Near Term - Until 6am Tuesday Morning
...Re-issued to remove mention of coastal flood warning in St Marys County. Other text remains the same... A negatively tilted trough is progressing through the area currently, and has sparked an area of rain across most of Northern Virginia and Maryland. This area of rain is expected to persist over the next few hours, then move out of the area by around 06z. The main concern overnight will be whether or not fog forms behind the area of rain. The rain that has fallen has acted to saturate the lower troposphere. Winds will be calm behind the area of rain, suggesting that the potential is there for fog or low clouds to form. Current thinking is that low clouds will form as opposed to fog (which has happened already at CHO). We will continue to monitor trends overnight with respect to the potential for fog formation.

There's a low chance of some flurries or light freezing drizzle in the upslope areas late tonight, but don't think there will be notable accumulation at this time. Lows will be in the mid to upper 30s, east of the Blue Ridge, and closer to freezing to the west.

Short Term - 6am Tuesday Morning Through Wednesday Night
Any fog/low clouds should mix out by mid morning. However, Upper level troughing will remain overhead on Tuesday and there will be enough moisture associated with it to likely result in mostly cloudy skies. The daylight hours should be dry though, with slightly warmer temperatures in the upper 40s to mid 50s. A vort max and weak surface trough will rotate across the area during the evening. Low level moisture will be lacking, but there could be enough lift to produce a few light showers or sprinkles, especially toward central Virginia and out in the mountains. Light upslope precipitation will continue into Wednesday morning, with any wintry accumulations being very minimal.

Upper troughing finally pushes to the east Wednesday with ridging at the surface and aloft building in from the west. There may be enough moisture in the northwest flow to keep some clouds around, but should be more sunshine overall than Tuesday. Temperatures will be fairly seasonal with a more Pacific airmass, though radiational cooling could allow some below freezing temperatures Wednesday night.

Long Term - Thursday Through Monday
Surface high pressure and ridging aloft will reside over the Eastern Seaboard Thursday before shifting off the coast Thursday night. At the same time, low pressure will track northeastward from the Central U.S. into the Great Lakes, lifting a warm front through the Mid Atlantic Region. A few showers will be possible Thursday night as a result, with temperatures running on the mild side for this time of year. The cold front associated with the aforementioned low will push into our area on Friday, continuing the chance for showers as temperatures rise into the 50s & 60s.

Model guidance is at a bit of a disagreement thereafter in terms of the placement of the frontal boundary as another area of low pressure tracks northeastward along it. As a result, will maintain POPs in the forecast for the first half of the weekend as the area of low pressure tracks through the region. Depending on how much cold air is able to filter in behind the front Friday night, could see a mix of rain/snow showers, with our mountains areas favored for any wintry precipitation. Rain showers will be advertised Saturday/Saturday night with drier conditions expected the second half of the weekend in the wake of the low/front. Slightly below normal temperatures can be expected through the weekend.

All Small Craft Advisories have been cancelled as winds have weakened as low pressure pulls offshore. A weak trough will pass tonight with some light rain showers, but winds should remain below advisory levels into Tuesday night. After a second trough passes Tuesday night and strong high pressure builds in from the west, westerly winds will increase on Wednesday, and Small Craft Advisories may be needed.

SCA (Small Craft Advisory) conditions will be possible Thursday night and early Friday, while looking likely Friday afternoon and Friday night thanks to an increasing gradient as a frontal boundary nears and crosses the waters.

Tides / Coastal Flooding
With northerly flow over our area and becoming lighter, the high anomalies of around and over 2 feet have spread north up into the Maryland section of the bay. A Coastal Flood Warning remains in effect for Anne Arundel (Annapolis) County for tonight where anomalies are expected to reach Moderate Flooding. Coastal Flood Advisories are in effect elsewhere. Anomalies should gradually diminish later Tuesday, but minor flooding is still possible around times of high tide.

NOAA Baltimore MD/Washington DC Office: Watches - Warnings - Advisories
DC...Coastal Flood Advisory until 5am EST Tuesday for DCZ001. MD...Coastal Flood Advisory until 11am EST Tuesday for MDZ018. Coastal Flood Advisory until 5am EST Tuesday for MDZ508. Coastal Flood Advisory until 4am EST Tuesday for MDZ011. Coastal Flood Warning until 4am EST Tuesday for MDZ014. Coastal Flood Advisory until 10am EST Tuesday for MDZ017. VA...Coastal Flood Advisory until 5am EST Tuesday for VAZ054. WV...None. MARINE...None.