textproduct: Wakefield

WHAT HAS CHANGED

Small Craft Advisory in effect for the Chesapeake Bay tonight.

KEY MESSAGES

1) Drier weather returns to end the week and continues this weekend and likely into early next week.

DISCUSSION

As of 315 AM EDT Thursday...

KEY MESSAGE 1...Drier weather returns to end the week and continues this weekend and likely into early next week.

GOES water vapor channels depict an upper trough digging across the Great Lakes and Northeast early this morning. At the surface, a cold front is nearing the Mason-Dixon line. Scattered showers precede the front across the Eastern Shore. Farther to the S, a cluster of stronger showers/tstms is now well off the Outer Banks, but there are a few lingering light showers across NE NC. Some patchy fog/stratus is possible through sunrise prior to the arrival of the cold front. Otherwise, partly to mostly cloudy with temperatures in the mid 60s to around 70F early this morning.

The front gradually pushes south of the area this morning as the aforementioned trough continues to dig into the Northeast CONUS. Much drier air will overspread the area today with dewpoints dropping into the lower to mid 50s across the I-64 corridor and points northward, and upper 50s to lower 60s to the S. Due to a well mixed boundary layer, forecast high temperatures remain in the low- mid 80s today. PoPs have continued to trend lower today with only a very minimal chc of a few showers across the SW Piedmont (< 15% chc) this afternoon. Dry and pleasant tonight with lows mainly in the 50s (60s immediate coast). Friday will be mild and dry as high pressure settles from the Great Lakes to the Mid-Atlantic, with highs in the upper 70s to around 80 F inland, and in the mid 70s for coastal areas.

By this weekend, another trough digs out of Canada and pushes another cold front south across the Mid-Atlantic. However, a strong northern stream will suppress moisture well to the S and a dry frontal passage is expected. 28/00z EPS/GEFS each depict PW values remaining below normal through the weekend, and even into early next week. NBM PoPs are now less than 15% Saturday and Sunday, which is reasonable given PW anomalies of 50-70% of normal. Another potent northern stream trough and cold front dive out of Eastern Canada Monday, with the trough digging across the Northeast CONUS Tuesday/Wednesday as an omega block is in place over Central Canada. NBM PoPs nudge up to 30-40% Monday, and then back down to ~20% Tuesday/Wednesday, which are near climo. 30-40% PoPs seem generous Monday given a lack of moisture recovery (PW anomalies to 70-90% of normal), so dry conditions are favored Monday, and even through Tuesday/Wednesday as well as PW anomalies in the 00z EPS/GEFS are around 60-70% of normal.

Temperatures will be slightly below normal overall from Saturday through Wednesday, with highs in the mid 70s to around 80F inland, and lower to mid 70s toward the coast, with lows mainly in the 50s, with some upper 40s possible over the Piedmont Sunday morning. Overall, quite pleasant for the end of May into the beginning of June.

AVIATION /12Z THURSDAY THROUGH MONDAY/

As of 640 AM EDT Thursday...

A cold front is arriving from the N prior to 12z. RIC and SBY are likely to have a wind shift to NNW by 12z, with the frontal passage reaching PHF, ORF, and ECG by 13-15z. Any light rain at SBY should dissipate by 12z. Partly to mostly sunny and VFR today with increasing N winds (NNE at ORF/ECG) later this morning, with gusts to ~20 kt (20-25 kt at SBY). VFR and clear tonight with a light N/NE wind.

Outlook: VFR and dry Friday. Another cold front arrives by Saturday, but this is expected to be a dry frontal passage with increased northerly winds and VFR conditions. High pressure and VFR conditions prevail by Sunday. Another cold front potentially slides across the region by Monday with a very limited chc of showers.

MARINE

As of 230 AM EDT Thursday...

Key Messages:

- Small Craft Advisory is in effect for tonight as as a cold front will push south across the area today with a brief northerly surge tonight.

- Elevated onshore flow and higher seas are expected this weekend as another front moves through the local waters.

All storm activity had pushed well offshore early this morning and winds were generally west at 5 to 15 kt. Winds will gradually become NW this morning then N as a front pushes south. Winds may surge briefing this morning / early afternoon to around 15 kt, but decrease this afternoon. A stronger northerly surge is expected tonight. Guidance suggest a brief period of marginal SCA conditions on the Bay tonight. SCA is in effect from 10 pm tonight to 8 am Friday. North winds will increase to 15 to 20 kt with the brief surge, then decrease Friday.

High pressure builds in Friday with light winds becoming southerly Friday evening and increasing overnight ahead of the next cold front. The Saturday system will be stronger bringing a period of N/NE winds this weekend, with building seas and potential SCAs. There is good model agreement that a strong surface low will develop over Quebec and drop down across the Northeast US and move offshore sometime on Friday night into Saturday. Models are in some good agreement that the tightest pressure gradient over the mid-Atlantic should occur Saturday though some timing differences remain.

Seas remain in the 2-3 ft range today through at least Friday night with 4 ft well offshore. Similarly, waves in the Chesapeake Bay will only be in the 1-2 ft range today. Waves on the Bay increase to 2 to 3 tonight with the northerly surge of 15 to 20 kt. Seas could build briefing off the coast as well adding a foot to the existing seas. Building seas are more likely later Saturday into Sunday; this is again ultimately dependent on the magnitude of onshore flow and strength of the lows offshore. Seas of 4 to 6 ft are forecast over the coastal waters and offshore this weekend.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 10 PM this evening to 8 AM EDT Friday for ANZ630>632-634.