Tidal Potomac from Key Bridge to Indian Head MD Marine Forecast
|Rest Of The Overnight...S Winds 5 Kt. Waves Less Than 1 Ft.|
|Today...Ne Winds Around 5 Kt. Waves 1 Ft. Snow With Rain Likely. Vsby 1 To 3 Nm.|
|Tonight...N Winds 10 To 15 Kt With Gusts To 25 Kt. Waves 1 To 2 Ft. Snow. Vsby 1 To 3 Nm.|
|Sat...Nw Winds 15 To 20 Kt With Gusts To 35 Kt. Waves 2 Ft.|
|Sat Night...Nw Winds 15 To 20 Kt. Gusts Up To 35 Kt...Diminishing To 25 Kt After Midnight. Waves 1 To 2 Ft.|
|Sun...W Winds 5 To 10 Kt. Waves 1 Ft.|
|Sun Night...Se Winds Around 5 Kt. Waves 1 Ft.|
|Mon...Ne Winds Around 5 Kt. Waves 1 Ft Or Less.|
|Tue...Se Winds Around 5 Kt. Waves 1 Ft.|
| Area Forecast Discussion|
National Weather Service Baltimore MD/Washington DC
418am EST Fri Jan 28 2022
A cold front will approach the area today, then a rapidly deepening area of low pressure will pass offshore tonight into Saturday. High pressure is then expected to return Sunday through Tuesday. A low pressure system will approach from the west Wednesday and Thursday.
Near Term - Through Tonight
A positively tilted trough currently situated over the Great Lakes will become more neutrally tilted as it approaches the Appalachians this evening. Eventually the trough will take on a negative tilt as it moves overhead later tonight. As the trough approaches, a zone of weak low-level frontogenesis will develop across the area later this afternoon into this evening. This will lead to a prolonged period of light precipitation across the forecast area this afternoon through this evening. Precipitation will initially start off as a rain/snow mix in many locations (outside of the mountains), before rapidly transitioning over to all snow. Temperatures will make it into the mid to even upper 30s in many spots prior to the snow starting, so it may have trouble accumulating initially over the lower elevations. Temperature will drop below freezing in all locations this evening. All locations should see at least some accumulating snow. A widespread 1-3 inches of snow is expected across most of the area. Some locations in the mountains could see slightly more due to cooler surface temperatures at the start and resultant higher snow to liquid ratios. Snow to liquid ratios may be higher than climatology everywhere once surface temperatures drop below freezing (and surface melting ends), as it will be very cold aloft, with ample ascent through the dendritic snow growth zone. Locations across north central MD and eastern WV along the I-81 corridor may see slightly less than other locations, as the best frontogenesis will reside to their south. For locations west of I-95 the light snow should wind down by around midnight. However, snow may linger through the duration of the night along the bay as a coastal low forms offshore in response to the approaching negatively tilted trough. With the snow continuing through the duration of the night, locations along the bay should see the highest totals, with 3-5 inches expected across St. Mary's, Calvert, and Cecil Counties. Winds will also start to become gusty out of the northwest during the second half of the night as the coastal low strengthens offshore.
Short Term - Saturday Through Sunday Night
By daybreak Saturday, the mid-upper level trough axis will be situated directly overhead and the rapidly deepening coastal low will be located at our latitude well offshore. Throughout the day, the coastal low will continue to rapidly strengthen as it lifts off toward the northeast. Snow will likely continue through the first half of the morning for counties directly adjacent to the bay, but elsewhere snow will have moved out prior to daybreak. Additional minor accumulations may be possible along the bay. Any snow should depart the area by late morning.
Winds will be the main story through the remainder of the day. Strong northwesterly winds will filter into the area as the powerful coastal low lifts off to our northeast. Winds may gust in excess of 40 mph through much of the day. When coupled with temperatures holding in the 20s, it will be very cold. Winds chills will hold in the single digits to lower teens across the lower elevations, and will stay below zero the entire day in the mountains. Wind chill headlines may eventually be needed, especially in the mountains. Winds will remain elevated, but gradually weaken throughout the night Saturday night. Wind chills will bottom out in the single digits to below zero everywhere.
Troughing will continue to reside along the East Coast on Sunday, leading to continued below average temperatures. With weaker winds, wind chills will make it into the 20s. Most of the area should remain dry, but a few snow showers may be possible in the mountains as a shortwave descends down the backside of the trough and approaches the area in northwesterly flow.
Long Term - Monday Through Thursday
A large area of high pressure will extend along the eastern seaboard Monday and Tuesday while the upper level pattern becomes more zonal and eventually anticyclonic. Dry weather and a steady warming trend can be expected.
Moisture will begin to advect toward the area in the southwest flow aloft Wednesday, although the bulk of precipitation chances likely hold off until at least Wednesday night when low pressure will be near or approaching the Ohio Valley. Rain should prevail for most of the area as we will be entrenched in the warm sector with above normal temperatures. Moderate rainfall will be possible at times with seasonably high precipitable water values. Model spread increases by Thursday in regards to the evolution of the system, but the most likely outcome points to continued rain chances with above normal temperatures.
Winds are out of the south early this morning, but will turn northerly this morning. The winds will pick up this evening out of the north to northwest, and Gales are in effect for the second half of tonight through tomorrow and into the first half of Saturday night. SCA (Small Craft Advisory) conditions may linger through Saturday night into at least the morning hours of Sunday.
Light northwest winds on Monday will become southerly on Tuesday as high pressure departs. Winds appear to remain below advisory criteria at this time.
Tides / Coastal Flooding
Anomalies will crash tonight into Saturday as strong low pressure offshore generates a strong north flow. Some locations, especially the northern part of the bay, could reach blowout levels. Tides are forecast to quickly snap back Sunday into Monday, although most guidance is not forecasting any flooding at this time.
NOAA Baltimore MD/Washington DC Office: Watches - Warnings - Advisories
DC...Winter Weather Advisory from 4pm this afternoon to 4am EST Saturday for DCZ001. MD...Winter Weather Advisory from 4pm this afternoon to 10am EST Saturday for MDZ011-013-016-506. Winter Weather Advisory from 4pm this afternoon to 4am EST Saturday for MDZ504. Winter Weather Advisory from 4pm this afternoon to 1pm EST Saturday for MDZ008-014-017-018-508. VA...Winter Weather Advisory from 10am this morning to 4am EST Saturday for VAZ503-504-507-508. Winter Weather Advisory from 4pm this afternoon to 10am EST Saturday for VAZ055>057. Winter Weather Advisory from 4pm this afternoon to 4am EST Saturday for VAZ025-026-029-036>040-050>054-502. WV...Winter Weather Advisory from 10am this morning to 4am EST Saturday for WVZ505-506.
Small Craft Advisory from 6pm this evening to midnight EST tonight for ANZ531>534-537-539>543. Gale Warning from midnight tonight to 4am EST Sunday for ANZ531>534-537-539>543. Small Craft Advisory from 6pm this evening to 6am EST Saturday for ANZ530-535-536-538. Gale Warning from 6am Saturday to 4am EST Sunday for ANZ530- 535-536-538.