Marine Weather and Tide Forecast for Washington, DC

KEY MESSAGES
- 1) A strong cold front brings gusty winds, potential for severe weather, and below average temperatures.

- 2) Dry conditions through next week with temperatures returning to mid-October normals.

DISCUSSION

KEY MESSAGE 1...A strong cold front brings gusty winds, potential for severe weather, and below average temperatures.

Model guidance is in relatively good agreement showing a potent positively tilted trough stretching from the great lakes down towards the Great Plains tracking eastward this morning. At the surface, the trough pushes a strong cold front across the forecast area this afternoon and into the evening. This morning, ahead of the front, cloud cover decreases allowing for sunny conditions and warm temperatures. Highs today rise into the 80s for most with higher elevations staying in the 70s. With warm conditions and sunny skies, a line of thunderstorms is expected to develop along the passing cold front. The Storm Prediction Center has the north east portions of the forecast area spreading from the Washington DC metro area to central MD and eastward, in a slight risk for severe weather today. The primary threat will be damaging wind gusts with NE MD in a 30% probability for severe wind.
Additionally, a quick QLCS tornado is possible, mainly in NE MD, where SPC has a 2% tornado risk.

Precipitation lingers behind the cold front as the upper trough pivots overhead. Gusty winds remain possible beginning Friday night and persisting through Saturday. Winds will likely remain elevated, although higher elevations along the Alleghenies may have peak gusts between 30 and 40 mph. Areas are expected to remain below wind advisory criteria although a few isolated gusts along the ridges are possible.

Noticeably cooler temperatures rush in behind the front with high temperatures on Saturday being approximately 25-30 degrees colder compared to Friday. Highs on Saturday will be in the 40s and 50s across the forecast area with overnight lows dropping into the 30s to low 40s. Frost/Freeze headlines are likely for early Sunday morning, mainly west of I-95 where winds will be lower.

KEY MESSAGE 2...Dry conditions through next week with temperatures returning to mid-October normals.

Heading into next week, high pressure remains overhead through the middle of next week. A dry and benign weather pattern is expected during this time frame with near-normal temperatures for mid- October. Although a few global ensemble members depict a coastal low forming off the Mid-Atlantic shore early next week, most members maintain dry and seasonable weather. If this low pressure system were to move closer to the coast, chances for precipitation could change next week however confidence is low.

AVIATION /07Z FRIDAY THROUGH TUESDAY/
MVFR to IFR ceilings continue through early this morning before conditions improve to VFR. Foggy conditions continue at CHO this morning with patchy fog lingering across the other terminals. A strong cold front crosses the terminals this afternoon and into this evening, bringing a chance for thunderstorms, gusty winds and a wind shift. Sub-VFR conditions are possible during storms.
Some storms may be severe with damaging winds are the primary threat. Low clouds are possible again tonight with VFR conditions returning Saturday. For the winds, southwest winds this morning shift to northwest in the wake of the cold front.
Winds remain out of the northwest on Saturday, gusting 20 to 30 knots. Winds diminish on Sunday with VFR conditions expected.

VFR conditions are expected to persist for all terminals at the beginning of next week. Light northeasterly wind on Monday shifts northerly by Tuesday.

MARINE
Small Craft Advisories are in effect beginning at 9AM this morning across all waters with winds gusting 20 knots. A strong cold front crosses the waters this afternoon and into the evening, bringing gusty winds and a chance for thunderstorms.
SMWs are possible as storms cross the waters later today. Winds shift to northwesterly behind the front tonight and increase to gusts around 34 knots. The Gale Watch has been upgraded to a Gale Warning for late tonight through Saturday. Winds shift to northeast on Sunday and are expected to remain below SCA criteria.

Wind gusts remain below SCA criteria on Monday with light northeasterly winds. Northerly winds could approach SCA criteria on Tuesday.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...Small Craft Advisory from 9 AM this morning to 6 AM EDT Saturday for MDZ008.
VA...None.
WV...None.
MARINE...Small Craft Advisory from 9 AM this morning to 6 AM EDT Saturday for ANZ530>543.
Gale Warning from 6 AM Saturday to 6 AM EDT Sunday for ANZ532>534-537-543.