Marine Weather and Tide Forecast for Rock Hall, MD

KEY MESSAGES
-1) A retreating front could bring a wintry mix of precipitation Monday night into Tuesday.

-2) Well above normal temperatures today will be followed by a cold front on Sunday with minimal precipitation chances.

-3) A warming trend will develop Wednesday through Friday.

DISCUSSION
KEY MESSAGE 1...A retreating front could bring a wintry mix of precipitation Monday night into Tuesday.

Strong high pressure will build north of the area Monday, eventually wedging southward along the eastern side of the Appalachians. Northerly low level flow will bring cold and dry advection. While some slight chance PoPs remain in the forecast for now, most 00Z guidance keeps the daytime hours of Monday dry. High temperatures will mostly remain in the 30s to perhaps lower 40s.

The front that was shoved into the southeastern states is expected to retreat northward as a warm front Tuesday. While there isn't a well defined low pressure system, notable lift will be provided as warm, moist air overruns the cold high pressure. Most 00Z models have precipitation spreading northward Monday night into Tuesday morning. Cold air will remain at the surface (forecast lows in the 20s), but the southwesterly flow aloft will be advecting warmer air. This wind direction and the retreating front could lead to a mixture of snow, sleet, and freezing rain. However, if precipitation is delayed far enough into Tuesday, more areas may just see plain rain. Regardless, current guidance indicates modest precipitation amounts (generally less than one half inch of liquid), so at this time it appears only light accumulations of any wintry precipitation would be expected. With the surface high quickly retreating off the coast, most areas should just be seeing rain by Tuesday afternoon. As we get deeper into the weekend and more data comes in, we can narrow the possibilities of who gets what type and how much.

KEY MESSAGE 2...Well above normal temperatures today will be followed by a cold front on Sunday with minimal precipitation chances.

High pressure is pushing out into the Atlantic this morning.
Some low clouds persist toward central Virginia but likely won't make too much northward progress before likely dissipating during the midday hours. Fog has been slow to form thus far, and while some patchy fog is possible, am not expecting widespread issues like Friday morning.

The thermal ridge crosses the area today, resulting in well above normal high temperatures in the mid 50s (northeast MD) to upper 60s (central VA). There should be plenty of sunshine through the afternoon hours.

A cold front trailing low pressure well to the north in Canada will settle into the area tonight. No precipitation is expected, but winds may shift northeasterly, with some indication of low clouds and/or fog developing. An approaching shortwave trough will bring some moisture advection toward Sunday morning, and a subtle wave of low pressure may move along the front. Some light precipitation may affect the Allegheny Mountains and could skirt along northern portions of the forecast area. At that point, thermal profiles are likely still warm enough to result in rain, even in the mountains. Precipitation is most likely to end as snow in the Alleghenies. Some CAMs indicate a wintry mix farther east with faster cold advection. However, am skeptical of this outcome as it would require on temperatures continuing to fall after sunrise which seems unlikely. In any event, forecast precipitation amounts are forecast to be very light. The front will be shoved to the south in the afternoon, and strong pressure rises will result in gusty northwest winds. Much colder conditions can be expected Sunday night with widespread lows in the 20s.

KEY MESSAGE 3...A warming trend will develop Wednesday through Friday.

An associated cold front will trail the winter storm as it moves eastward out of the eastern Great Lakes on Wednesday. This front may not make its way through our region, but could stall or get strung along across Pennsylvania or the Mason-Dixon into Wednesday night. Wednesday highs will be milder and slightly above average. The front that will not be too far away could produce some light rain. Throughout the days of Thursday and Friday, this pattern of storm system and front and another storm system and another front will continue to occur but could remain to the north of the region. Thus, much warmer days ahead for Thursday and Friday with highs in the 60s and pushing the 70 degree mark.

AVIATION /15Z SATURDAY THROUGH WEDNESDAY/

VFR conditions with light south winds are expected this afternoon.

A cold front will slowly slide into the area tonight before surging southward Sunday. Winds will become light and variable as the front stalls overhead tonight. Guidance is currently split as to whether any low clouds and/or fog spread into the area late tonight in light northeast flow. Will keep any mentions to MVFR for now. Some light rain showers could also spread across northern areas (MRB/BWI/MTN) Sunday as a wave of low pressure develops. At this point, there may be a greater chance of MVFR ceilings. However, CHO may remain dry and VFR.
By afternoon, ceilings should lift and northwest winds could gust to around 20-25 kt.

Monday has been trending drier thanks to strong high pressure, although some low ceilings can't be ruled out.

MVFR to IFR conditions with potential for a wintry mix late Monday night into Tuesday morning. Any precipitation should be rain by Tuesday afternoon. MVFR conditions could linger at MRB and BWI and MTN if areas of rain occur along a front through Wednesday. Elsewhere, VFR conditions expected Wednesday and Wednesday night. Winds south to southwest 5 to 10 knots Tuesday and Tuesday night. Winds shifting northwest to northeast then southeast 5 knots Wednesday into Wednesday night.

MARINE
High pressure will provide light winds today, generally south or southeast in direction. Some patchy fog is possible this morning over portions of the Chesapeake Bay, mainly north of the Bay Bridge.

A cold front will settle into the area tonight and stall, leading to variable winds. The front will surge southward Sunday afternoon. Northwesterly winds will pick up, with SCAs becoming more likely by Sunday afternoon/evening. Winds will gradually taper off Monday as high pressure builds into the area.

No marine hazards Tuesday. Small craft advisories are possible Tuesday night. No marine hazards Wednesday and Wednesday night.
Winds south to southwest around 10 knots Tuesday and Tuesday night.
Winds becoming variable and 5 to 10 knots Wednesday and Wednesday night.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.