Chesapeake Bay from North Beach to Drum Point MD Marine Forecast
|Tonight...Ne Winds 5 To 10 Kt...Becoming Se Late. Waves 1 To 2 Ft.|
|Sat...S Winds 10 To 15 Kt With Gusts To 25 Kt. Waves 1 Ft... Building To 3 Ft In The Afternoon. Rain, A Chance Of Snow And Sleet. Vsby 1 To 3 Nm.|
|Sat Night...Sw Winds 10 To 15 Kt With Gusts To 20 Kt. Waves 2 To 3 Ft. Rain Likely.|
|Sun...Nw Winds 10 To 15 Kt With Gusts To 25 Kt. Waves 2 To 3 Ft.|
|Sun Night...Nw Winds 15 To 20 Kt With Gusts To 25 Kt. Waves 3 Ft.|
|Mon...Nw Winds 10 To 15 Kt With Gusts To 25 Kt. Waves 2 To 3 Ft.|
|Mon Night...Nw Winds 10 Kt With Gusts To 20 Kt. Waves 2 Ft.|
|Tue...N Winds 5 To 10 Kt. Waves 2 To 3 Ft.|
|Wed...Nw Winds Around 5 Kt. Waves 1 To 2 Ft.|
Area Forecast Discussion|
National Weather Service Baltimore MD/Washington DC
919pm EST Fri Jan 17 2020
Arctic high pressure will slide out to sea tonight as low pressure in the western High Plains heads east to the Great Lakes on Saturday. This low will cross New England into Atlantic Canada by Sunday as another large arctic high pressure builds southward across the eastern and central United States early next week.
.NEAR TERM /UNTIL 7am SATURDAY MORNING/... Core of high pressure centered along the Quebec/Ontario border this evening, with a ridge axis situated south into the Mid Atlantic. Dewpoints still at +4F at BWI, although most of the area in the 10-15F range. Regardless, its a super-dry air mass. The leading edge of snow evident on the regional radar mosaic in southern OH/WV. Suspect it will have trouble crossing the Appalachians ridge line as a portion will be dedicated to moistening...and evaporative cooling too.
Temperatures not dropping quite as fast as forecast, likely due to a veil of cirrus overhead. Made only minor temperature forecast changes (a degree here or there) as believe that wetbulb effects will make up the difference.
Warm advection will arrive before dawn. Will maintain at least a chance of light snow developing before sunrise I-81 west, with the greatest chance in the Allegany Front.
.SHORT TERM /7am SATURDAY MORNING THROUGH SUNDAY NIGHT/... Two precipitation periods are expected to cross the region on Saturday. The first, starting early in the morning, will be focused more to the north, with locations south of I-66/US 50 seeing little if any precipitation with it. The atmosphere will remain cold enough with this first shot for it to fall entirely as snow, and with cold ground, accumulations will likely be quick.
After the initial band of snow, a lull is likely before the second, more intense band of precipitation moves in. This will have a more significant low level jet with it, pushing warm air into the region quickly aloft, and resulting in a fast transition to sleet and freezing rain. Thus, most locations which do not see snow with the first precipitation in the morning likely will not see any later in the day, though some locations such as north-central Maryland could still see some snow on the front end of the second push of precipitation before the transition to ice occurs. This is why that location is most likely to see more than an inch of snow. Elsewhere, cold air lingering at low levels will likely be tough to scour out, so have gone near the cold end of guidance for temps and held onto ice much of the day before allowing a brief change to rain near the end of the day before precipitation ends. Fortunately, precipitation amounts look fairly light, less than a half inch in most places, so it would be hard to get warning level ice.
The warm front likely never really gets through our region before the cold front crosses the area Saturday night. Any lingering showers should end in most areas, but upslope snow showers may bring a spotty inch or two along the Allegany Front. Breezy and chilly conditions will follow through the remainder of the weekend as high pressure builds in, with highs in the 30s/low 40s and lows in the teens/low 20s Sunday/Sunday night.
Long Term - Monday Through Friday
With exception to a couple of possible upslope snow showers in the west Monday, most locations will be dry thanks to strong high pressure building in from the west and settling overhead Monday night through Wednesday night.
By Thursday and Thursday night, high pressure will move to the East Coast but continue to influence dry conditions. Temperatures will remain chilly.
A southeast flow will develop Friday as high pressure offshore the East Coast interacts with strong low pressure over the Midwest and Lower Great Lakes. There is a slight chance for rain and snow showers in the west but it wouldnt be until late Friday.
Light winds will prevail tonight into early Saturday. Southerly flow ahead of the next low pressure passing to the north Saturday night may result in SCA (Small Craft Advisory) conditions in the afternoon, but uncertainty is high with this given potential for the warm front to get stuck to the south. SCA (Small Craft Advisory) more likely later Saturday night and Sunday behind the cold front.
Small craft advisories will be possible Monday through Tuesday. Northwest winds will average 15 knots gusts 20 to 25 knots, diminishing Tuesday night.
Tides / Coastal Flooding
NW flow has resulted in negative anomalies today. Winds go light tonight then southerly Saturday, with near minor flooding possible by Saturday night. NW flow resumes and allows anomalies to drop thereafter.
NOAA Baltimore MD/Washington DC Office: Watches - Warnings - Advisories
DC...None. MD...Winter Weather Advisory from 7am to 7pm EST Saturday for MDZ003>006-011-503>508. Winter Weather Advisory from 4am to 7pm EST Saturday for MDZ501-502. VA...Winter Weather Advisory from 10am to 7pm EST Saturday for VAZ025-026-029-036>040-050-051-507-508. Winter Weather Advisory from 7am to 7pm EST Saturday for VAZ028-030-031-052-053-501>506. Winter Weather Advisory from 4am to 7pm EST Saturday for VAZ027. WV...Winter Weather Advisory from 7am to 7pm EST Saturday for WVZ052-053-505-506. Winter Weather Advisory from 4am to 7pm EST Saturday for WVZ050-051-055-501>504. MARINE...None.