Marine Weather and Tide Forecast for Galesville, MD

NEAR TERM /THROUGH TONIGHT/
Expansive surface high pressure remains in place over the entire eastern U.S. Arctic air continues to dominate supporting well below average temperatures for mid/late January. Although no daily records are being broken locally, temperatures are running around 15 to 25 degrees below average. Given the nearly cloud- free skies, GOES-16 visible satellite imagery shows a snowpack quite well west of I-95. Otherwise, thickening high cirrus continue to spread from the Alleghenies toward the I-81 corridor. These clouds should not have too much influence on any further daytime heating. Overall high temperatures are likely to be capped around the upper teens to low 20s, locally nearing 25 degrees in the mild spots. Across the mountains, upper single digits to lower teens are expected.

Despite some high clouds passing by overhead, high pressure combining with calm winds and very dry air (dew points are currently around -5 to 0F) will make for quite a frigid night ahead. Given the above environment, have opted to go toward the colder side of the model envelope. This places a bulk of the region between 3 and 10 degrees, locally into the lower teens in the city centers and in far southern Maryland. For the Alleghenies, lows will be near 0 degrees with some added wind.
This supports wind chill temperatures dropping to around -10F.
Consequently, Cold Weather Advisories are in place from this evening through the night along the Allegheny Front and into the central Shenandoah Valley.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/
Coming off another frigid night, temperatures are likely to rebound a bit more given a shift to light south-southwesterly winds. This overall rebound in temperatures will at least bring high temperatures to the upper 20s to mid 30s on Thursday, locally in the 20s across the higher terrain. This comes with a mix of clouds and sun as the next upper trough approaches from the west. A brief period of snow showers is expected along the Alleghenies with around an inch or two possible through early Friday morning, particularly closer to the ridgeline.

Wind fields should stay light enough to allow for decent radiational cooling effects on Thursday night. This yields low temperatures that are forecast to range from 10 to 20 degrees, with mid/upper single digits west of the Shenandoah Valley. It could be slightly cooler in some of these locations owing to the current snowpack.

Heading into Friday, trailing northwesterly flow will ensure a cold finish to the work week. Forecast highs will average in the upper 20s to mid 30s, with teens to mid 20s across mountain locales. The forecast does remain dry after the bout of snow showers along the Allegheny Front. Another frigid night is on tap over the area on Friday night with lows only in the mid single digits to mid teens.

LONG TERM /SATURDAY THROUGH WEDNESDAY/
High pressure will remain overhead on Saturday before sliding to the south and east Sunday. Below normal temperatures will remain for Saturday but will rise closer to normal Sunday. A weak frontal system may pass through Sunday into Monday. There could be some upslope snow in the Alleghenies but otherwise moisture looks limited (outside of increased cloud cover). 12Z guidance continues to trend drier, with potential for precipitation with a trailing low pressure system likely remaining south of the area.

Model spread increases toward the middle of next week. Tuesday will most likely remain dry with near normal temperatures as high pressure remains to the southwest. Amplifying troughing along the east coast could support precipitation chances Wednesday or beyond but uncertainty is high. The NBM temperature spread also becomes quite large at this point, although near to above normal is most likely.

AVIATION /19Z WEDNESDAY THROUGH MONDAY/
VFR conditions are expected at all terminals through the remainder of the work week. Wind fields should remain on the light side given high pressure in place. Winds remain light out of the south/southwest on Thursday before shifting to northwesterly into Friday behind a cold front. Afternoon gusts up to 10 to 15 knots are possible then.

No significant weather is expected Saturday and Sunday as high pressure gradually retreats.

MARINE
The presence of high pressure over the region will keep marine winds on the lighter side the next couple of days. Initial northwesterly winds give way to southwesterly flow by Thursday.
The next frontal system leads to a shift to northwesterlies again into Friday with some gusts possibly approaching Small Craft Advisory levels.

High pressure will retreat over the weekend. A period of increased southerly channeling could lead to marginal advisory conditions along the bay Saturday night.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...Cold Weather Advisory from 7 PM this evening to 10 AM EST Thursday for MDZ001.
VA...Cold Weather Advisory from 7 PM this evening to 10 AM EST Thursday for VAZ503-504.
Cold Weather Advisory from 9 PM this evening to 10 AM EST Thursday for VAZ025-026.
WV...Cold Weather Advisory from 7 PM this evening to 10 AM EST Thursday for WVZ501-502-505-506.
MARINE...None.