Marine Weather and Tide Forecast for Irvington, VA

KEY MESSAGES
1) Dry and becoming seasonably cool this weekend through the middle of next week.

2) The weather pattern potentially becomes more amplified later next week with low-end rain chances returning follow by a brief surge of colder air.

DISCUSSION
As of 320 AM EST Saturday...

KEY MESSAGE 1...Dry and becoming seasonably cool this weekend through the middle of next week.

An upper low is centered over the eastern Great Lakes early this morning. Meanwhile, the shortwave trough and frontal boundary that produced yesterdays heavy rain and tstms is now well offshore. Drier air has been slow to move in from the N and areas of fog and stratus have developed, particularly from central VA southward into interior NE NC as well as the lower MD Eastern Shore. Fog/stratus should gradually lift and scatter from N-S as drier air filters in from the N through sunrise.

Cooler and drier air advects into the area today behind the secondary cold front, with high pressure building to the W. 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, with similar values Wednesday. Low temperatures late tonight/early Sunday morning will be in the mid to upper 30s inland and lower/mid 40s along the coast. Patchy frost is possible, particularly in the Piedmont and counties that have already ended their growing season, but there could be some frost into interior portions of S-central VA and NE NC as well. Will continue to monitor trends for areas where the growing season has not yet ended. 07/00z ensemble guidance is continuing to show dry weather persisting at least into the middle of next week. A NW wind will become breezy today across the Eastern Shore as the upper low tracks from the eastern Great Lakes to southern New England.

KEY MESSAGE 2...The weather pattern potentially becomes more amplified later next week with low-end rain chances returning followed by a brief surge of colder air.

07/00z EPS, GEFS, and CMC GEPS are all depicting an anomalous 500mb trough developing across the Southeast and southern Mid- Atlantic by Thursday-Friday of next week. Low-end rain chances return later Thursday/Thursday night with the potential for developing low pressure ahead of the deepening trough.
Confidence in details is low at this forecast range, but most ensemble guidance has at least a 40- 60% chc of receiving at least 0.1" of rain (best chc N), with negligible probs for exceeding 0.5". A surge of colder air follows with below average temperatures favored by Friday-Saturday of next week.

AVIATION /08Z 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 320 AM EST Saturday...

Key Messages:

- Small Craft Advisories are in effect for most of the local waters through the early afternoon today as N-NW winds increase to 15-25 kt.

- Another period of elevated NW flow is expected tonight into Sunday morning and additional Small Craft Advisories are likely. Winds turn to the SW Sunday and then NW again Monday behind a cold front.

Winds have shifted to the NW early this morning, behind an earlier cold front passage. Winds speeds are currently sub-SCA, but upstream observations and forecast/model data indicate elevated winds are coming over the next 2-3 hours. These winds are expected to increase to 15-25 kt with gusts to 25-30 kt, peaking in the 4 AM-10 AM timeframe. Small Craft Advisories are in effect for all of the Chesapeake Bay, coastal waters, and Currituck Sound. While winds will be a bit lower on the rivers, there is enough confidence in frequent 20-25 kt gusts to add the lower James to the ongoing SCA. Seas increase to 3-5 ft in the 0-20 nm zones and 5-6 ft in the 20-60 nm zones, with 2-4 ft waves in the bay. With winds having a nonzero westerly component, seas will struggle to build much higher than this.
Winds diminish to ~15 kt this afternoon as high pressure nudges into the area from the west. However, the pressure gradient remains more compressed in the northern bay and have extended the SCA N of New Point Comfort through Sunday morning. Have also extended the SCA for the coastal waters through Sunday morning due to a continuation of the 5 ft seas. Additional SCAs are likely to be issued for the lower bay late tonight as another surge in winds drops across the local waters, but will hold off on extending the ongoing headlines due to the relative lull in winds this afternoon and evening.

High pressure situates south of the area Sunday and winds should shift to the W by Sunday afternoon and then SW by the evening hours. Winds speeds also diminish with sub-SCA conditions by the afternoon as well. Additional periods of elevated winds are possible again Sunday night (in SW flow) and then Monday morning-afternoon (in W-NW flow) behind another cold front. SCAs are again possible. Sub- SCA/generally benign conditions return Tuesday through Thursday. A stronger system could affect the waters late next week, but overall confidence is low.

AKQ WATCHES/WARNINGS/ADVISORIES
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory until 10 AM EST Sunday for ANZ630-631-650- 652-654-656-658.
Small Craft Advisory until 1 PM EST this afternoon for ANZ632- 634.
Small Craft Advisory until 1 PM EST this afternoon for ANZ633.
Small Craft Advisory until 10 AM EST this morning for ANZ639.