Marine Weather Net

Tidal Potomac from Key Bridge to Indian Head MD Marine Forecast


REST OF TODAY

NW
WINDS
5 - 10
KNOTS

TONIGHT

N
WINDS
10 - 15
KNOTS

SAT

NE
WINDS
10 - 15
KNOTS

SAT NIGHT

N
WINDS
10 - 15
KNOTS

The Marine Weather Forecast In Detail:
ANZ535 Forecast Issued: 938 AM EST Fri Nov 15 2019

SMALL CRAFT ADVISORY IN EFFECT FROM 6 PM EST THIS EVENING THROUGH SATURDAY AFTERNOON
Rest Of Today...Nw Winds 5 To 10 Kt. Waves 1 Ft.
Tonight...N Winds 10 To 15 Kt. Gusts Up To 20 Kt. Waves 1 Ft.
Sat...Ne Winds 10 To 15 Kt With Gusts To 30 Kt. Waves 1 To 2 Ft.
Sat Night...N Winds 10 To 15 Kt With Gusts To 20 Kt. Waves 1 Ft.
Sun...N Winds 10 To 15 Kt With Gusts To 20 Kt. Waves 1 Ft.
Sun Night...N Winds 5 To 10 Kt. Waves 1 Ft.
Mon...W Winds Around 5 Kt. Waves 1 Ft Or Less. A Chance Of Rain.
Tue...Nw Winds Around 5 Kt. Waves 1 Ft.
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Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1007am EST Fri Nov 15 2019

Synopsis
Low pressure will meander off the Carolina coast through the weekend. Meanwhile, a reinforcing cold front will move southward out of Pennsylvania today into tonight as high pressure builds over northern New England. The high will move slowly eastward into the Canadian Maritimes this weekend while low pressure drifts northeastward offshore. A second area of low pressure may develop near the Carolinas and move northeastward during the first half of next week.

.NEAR TERM Through Tonight
The cirrus shield associated with developing low pressure off the Carolina coast has begun to thin out across much of the area. Will likely continue to see bands of high, thin cirrus throughout the day, as the low meanders off the Carolina coast, very slow to begin moving to the northeast throughout the day. As a result, and dense cirrus likely remains over southern Maryland. A few light showers are possible on the periphery of the approaching low across southern Maryland and the far southern waters. Other than that, things will stay dry today. Most guidance has high temperatures eclipsing 50 degrees this afternoon, and am inclined to believe that given the lack of clouds over over much of the region at this time. Low to mid 50s can be expected by the afternoon.

PREVIOUS Thicker clouds and perhaps the very edge of some light rain may continue to oscillate into southern Maryland tonight. Much of the rest of the area will likely see continued scattered to broken high clouds as a secondary reinforcing cold front drops south. A sprinkle or flurry can't be ruled out over the mountains as the front drops south, with the NAM BUFKIT soundings suggesting perhaps a brief period of freezing drizzle on the ridge tops this evening (but very low confidence). Otherwise, mainly dry and cold with increasing northerly winds after midnight.

Short Term - Saturday Through Sunday Night
Low pressure will continue to spiral offshore, only slowly trekking northeastward with high pressure over the Canadian maritimes blocking a hastier exit. Periods of clouds and brisk northeasterly winds will linger much of the weekend with below normal temperatures, especially on Saturday, in the pressure gradient between the two systems. Some guidance tries to pull precipitation westward into the marginally cold air Sunday, but this is a low probability outcome at the present time.

Long Term - Monday Through Thursday
Reasonable consensus exists regarding the larger features through the long term, with the devil being in the details. At the start of the period, low pressure will be east of Ocean City, Maryland, heading slowly northeastward parallel to but fairly far from the coast. However, an approaching sharp shortwave will be moving in from the west. This likely attempts to induce new precipitation development on the back side of the low on Monday even though the low center itself will likely be up near Cape Cod by day's end. Temperatures will remain cool with the clouds and risk of rain, not to mention the gusty northerly winds.

By Tuesday, the low and shortwave are both passing well northeast of the region, so the risk of rain should be ending. However, a reinforcing chilly air mass will be over the region, and with the longwave trough still overhead, can't completely rule out a stray convective shower or perhaps some upslope rain/snow showers in the mountains. That all said, the greater sunshine expected should result in a slightly milder day.

Another shortwave with perhaps a weak surface reflection will cross the region Wednesday, resulting in another risk of a few showers. Temperatures won't change much.

The pattern finally changes by Thursday on most guidance as the trough starts moving out and high pressure builds to the south with a ridge moving in overhead. This should cut the risk of rain down to near nothing, allow greater sunshine, and help to moderate temperatures a bit more, with readings approaching normal.

Marine
Winds turn N to NE tonight into the weekend behind a reinforcing cold front. Tight gradient between low pressure offshore and high pressure will bring Small Craft Advisory conditions to all waters by this evening, as a result a Small Craft Advisory begins this evening. Winds become stronger in the central Bay and lower tidal Potomac, likely reaching Gale conditions, so a Gale warning begins at midnight, continuing through Saturday morning. Small Craft Advisory conditions likely continue through Sunday.

Gusty winds to at least SCA (Small Craft Advisory) levels may even persist Monday, but likely wane by Tuesday as coastal low pressure finally departs to the northeast.

NOAA Baltimore MD/Washington DC Office: Watches - Warnings - Advisories
DC...None. MD...None. VA...None. WV...None.
MARINE...
Small Craft Advisory from 6pm this evening to 6pm EST Saturday for ANZ530>532-535-536-538>542. Small Craft Advisory from 6pm this evening to midnight EST tonight for ANZ533-534-537-543. Gale Warning from midnight tonight to 6pm EST Saturday for ANZ534-537-543. Small Craft Advisory from 10am to 6pm EST Saturday for ANZ533. Gale Warning from midnight tonight to 10am EST Saturday for ANZ533.