Marine Weather and Tide Forecast for Vienna, MD

KEY MESSAGES
1) Drying out and becoming seasonably cool this weekend into early next week.

DISCUSSION
As of 810 PM EST Friday...

KEY MESSAGE 1...Drying out and becoming seasonably cool this weekend into early next week.

Latest analysis reveals low pressure over coastal New England early this evening, with the associated surface cold front now pushing offshore of the mid-Atlantic coast. Aloft, a potent closed low continues to slide east across the Eastern Great Lakes into the interior northeast. This feature will push the secondary/reinforcing cold frontal passage late tonight, which will initiate some better mixing and more breezy conditions for late tonight and Saturday. After some ground fog late this evening, cool, dry advection should scatter out any lingering fog and low clouds by sunrise Sat morning.

Much cooler and drier air is forecasted to advect into the area tomorrow, as chilly high pressure builds to the west through tomorrow. High temperatures settle back to near seasonal averages. High temperatures this weekend will be in the low to mid 60s, rising to the mid to upper 60s early next week, with potential for ~70F on Tuesday for a large portion of the area.
Tonight's lows will be moderate compared to the next coming days with lows in the 40s W and N to mid 50s SE. Then, Sunday morning's lows will be in the mid to upper 30s inland and low 40s along the coast. Patchy frost is possible, particularly in the piedmont and counties that have already ended their growing season. Will continue to monitor trends for areas where the growing season has not yet ended. The recent ensemble guidance is continuing to show dry weather persisting at least into the middle of next week.

AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
As of 1255 AM EST Saturday...

An initial cold front has pushed offshore as of 06z. Meanwhile, a secondary cold front with drier air is approaching from the NW. Ahead of this boundary there is some patchy fog and stratus producing localized IFR/LIFR conditions. A NNW wind should increase to 5-10kt after 08-09z in the wake of the secondary front. This should bring an end to any patch IFR/LIFR conditions, with VFR conditions prevailing thereafter for the remainder of the day into tonight. A NW wind should generally be 8-12kt today and locally 10-15kt with gusts to ~20kt at SBY.
The wind will then become very light out of the NW tonight as high pressure builds in from the W.

Outlook: VFR conditions are expected to continue Sunday into the middle of next week. Some additional weak/dry cool air advection will bring gusty NW breezes on Sunday, especially across the Eastern Shore. Some additional periods of breezy NNW winds with weak cold frontal passages are expected early Monday and again on Tuesday.

MARINE
As of 250 PM EST Friday...

Key Messages:

- Small Craft Advisories have been issued tonight into Saturday as northerly winds increase behind a cold front passage.
Another period of SCA conditions is possible Saturday night into Sunday morning.

A cold front is making its way south across local waters this afternoon. Latest obs show that winds have turned to the N over most of the marine zones excluding the southern coastal waters. It is a bit breezy behind the front at 10-15kt and a few gusts to 20kt. The stronger push of cooler, drier air will not be until later tonight, so the post-frontal surge will be delayed from the passage of the front itself. NW should pick up to 15-20kt over the bay and coastal waters after midnight tonight and remain gusty through Saturday morning. A brief period of 20-25kt is possible around sunrise Saturday. Small Craft Advisories have already been issued for the bay, southern coastal waters, and Currituck Sound for late tonight through much of tomorrow. The northern coastal waters were added with this forecast package to cover the potential for 5ft seas during the day tomorrow. The offshore wind direction will keep seas from building much higher than that, though. High pressure will be slow to build in overhead, so gusty NW winds will likely continue into Sunday morning. Did not extend the SCAs, however, because guidance suggests a period of sub-advisory level winds during the afternoon and evening Saturday. High pressure over the mid-south builds E/NE towards the Mid-Atlantic on Sunday allowing winds to shift to the W and diminish to 10-15kt. Seas will then fall back to 3-4ft. May need additional SCAs on Monday across northern waters on where the pressure gradient is tighter on the north side of high pressure. Sub-advisory conditions are then expected Tues-Thurs.

AKQ WATCHES/WARNINGS/ADVISORIES
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory until 1 PM EST this afternoon for ANZ630- 631.
Small Craft Advisory until 1 PM EST this afternoon for ANZ632- 634.
Small Craft Advisory from 6 AM this morning to 1 PM EST this afternoon for ANZ633.
Small Craft Advisory from 6 AM this morning to 4 PM EST this afternoon for ANZ650-652.
Small Craft Advisory until 4 PM EST this afternoon for ANZ654- 656-658.