textproduct: Wakefield

WHAT HAS CHANGED

Subtropical Storm Josephine has formed well offshore.

The Coastal Flood Warning for Virginia Beach was cancelled. Timing was adjusted slightly for some of the existing Coastal Flood Advisories. The High Surf Advisory for the northern beaches was cancelled.

KEY MESSAGES

1) Mostly sunny and dry Fall weather continues.

2) Elevated tidal anomalies through Friday with minor to locally moderate tidal flooding forecast.

DISCUSSION

As of 330 AM EDT Thursday...

KEY MESSAGE 1...Mostly sunny and dry Fall weather continues.

Latest surface analysis depicted high pressure centered over the Great Lakes and Subtropical Storm Josephine well offshore. Skies were mostly clear with light/calm winds across the FA with the exception of the coastline and Eastern Shore where a few high clouds were noted. Given clear skies and light/calm winds, temps have dropped into the upper 30s to lower 40s for most inland locations with low-mid 50s along the coast. Therefore, have lowered temps a bit and now have morning lows in the mid- upper 30s across the typically cooler locations of the Piedmont and south-central to southern VA. As such, patchy frost is possible early this morning across those areas. Along the coast, morning lows around 50F are expected.

Josephine will continue to move NE away from the local area today, allowing for clouds to move offshore by around sunrise. This will allow for another pleasant Fall day with sunny skies and highs in the upper 60s to lower 70s. Lows aren't expected to be as cool tonight with low-mid 40s for most inland areas and low-mid 50s along the coast largely due to a weak backdoor front which allows winds to become light (as opposed to calm) and will likely keep most locations from decoupling. High pressure continues to build into the region this weekend which will allow for continued dry and mostly sunny weather with highs in the mid-upper 60s to lower 70s each day. The only day that looks to have a noticeable amount of clouds in the sky is Fri where partly sunny to occasionally mostly cloudy skies are likely across SE VA/NE NC. However, even these clouds clear out after sunset. The light/calm winds at night with high pressure overhead will allow for favorable radiational cooling at night Fri, Sat, and Sun nights. Each of these nights will have the potential for locally mid 30s inland. However, most areas will likely remain in the upper 30s to lower 40s inland. The coolest night still looks to be Fri night/Sat morning where more widespread mid 30s are possible across northern portions of the area. A few locations may even drop into the lower 30s across the northern tier of counties closer to the high. As such, patchy frost will be possible for several nights. More widespread frost is also possible, however, confidence is too low to reflect in the forecast at this time. Will need to monitor forecast trends in case Frost Advisories are need for a portion of the area.

Otherwise, dry weather continues through at least early next week with most model guidance showing no rain through the rest of the month. If this period of dry weather persists long enough for a dry cold front to pass through the region, fire weather concerns could arise. Fortunately, high pressure is expected to keep winds light into early next week.

KEY MESSAGE 2...Elevated tidal anomalies through Friday with minor to locally moderate tidal flooding forecast.

Low pressure (Josephine) lingering offshore with elevated winds and large swells are resulting in tidal anomalies around 2 ft, expected to increase a bit further over the next ~24 hours. Coastal Flood Warnings remain in effect for bay-side portions of the MD Eastern Shore as well as along the tidal Potomac. Elsewhere, nuisance to minor tidal flooding is forecast over the next few high tide cycles. Coastal Flood Advisories continue through today for most areas and have been into Friday, primarily for the western shore of the Chesapeake Bay and adjacent tidal rivers.

AVIATION /12Z THURSDAY THROUGH MONDAY/

As of 640 AM EDT Thursday...

VFR conditions prevail through the 12z TAF period. Generally clear skies are expected through the period. Light N winds around 5 kt early this morning are expected to increase to around 10 kt during the day. Gusts up to 15-18 kt are possible. Winds become light (<5 kt) again tonight.

Outlook: Primarily VFR conditions are expected to prevail through the weekend. Winds become light each night away from the coast.

MARINE

As of 330 AM EDT Thursday...

Key Messages:

- All Gale Warnings have been discontinued.

- Elevated N to NE winds continue into the weekend. Small Craft Advisories continue over the nearshore waters through Saturday night, through tomorrow night across the lower Chesapeake Bay, and this afternoon across the Middle Chesapeake Bay. However, additional SCA headlines are then likely from tonight into Saturday morning.

- High Surf Advisories remain in effect for the southern beaches into this evening due to persistent large breaking waves of 7 to 9 feet. High Surf Advisories for the northern beaches were cancelled.

Early this morning, high pressure (~1028 mb) remains situated north/northwest of the local waters. Meanwhile, Subtropical Storm Josephine (988 mb) lingers well off the Mid-Atlantic coast. Josephine will pick up speed and track well off to the NNE later today into Friday. Winds are currently out of the N-NE, averaging ~15 to 20 knots with gust to 20 to 25 knots over the Chesapeake Bay and ~15 to 25 knots over the coastal waters with gusts of 25 to 30 knots. Winds over the rivers (including the lower James) are below SCA criteria at this time, generally ~10 knots. Seas are averaging 6 to 10 feet across the nearshore coastal waters and 10 to 14+ feet offshore. Waves in the Chesapeake Bay are generally 2 to 4 feet, with 5+ feet at the mouth of the Bay.

Winds will continue to diminish today as Josephine tracks NNE toward Atlantic Canada. All Gale headlines have been discontinued, but nearshore coastal water SCAs likely continue through the weekend and beyond. Across the Bay, expect that winds drop below criteria later this morning (especially the middle Bay). However, this lull will be short-lived. Strong, chilly high pressure builds in from the northwest tonight and Friday, serving to re-tighten the pressure gradient. As the surface high centers north of the local waters Friday into Saturday, winds veer around to the E-NE. Channeling likely drives winds back up into SCA thresholds, and in-house wind probs have trended up to 60-90% probability of 18-22kt sustained winds across the lower Bay, lower James River, and Currituck Sound during this time period.

Regarding waves and seas, N-NE swell/wind wave subsides slowly through the weekend. However, persistent onshore NE flow will keep coastal seas at 5-8 ft, with waves in the lower Bay at 3-5 ft. Therefore, expect SCA headlines for seas will likely remain necessary along coastal zones and the mouth of the Bay through the weekend and into early next week, even as wind speeds diminish.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...Coastal Flood Warning until 2 PM EDT this afternoon for MDZ021>023. Coastal Flood Advisory until 8 PM EDT this evening for MDZ024- 025. NC...Coastal Flood Advisory until 9 AM EDT this morning for NCZ102. High Surf Advisory until 7 PM EDT this evening for NCZ102. VA...Coastal Flood Warning until 2 PM EDT this afternoon for VAZ075- 077. Coastal Flood Advisory until 8 PM EDT this evening for VAZ099- 100. High Surf Advisory until 7 PM EDT this evening for VAZ098. Coastal Flood Advisory until 8 PM EDT Friday for VAZ076-078- 082>086-089-090-518-520>524-528. Coastal Flood Advisory until 9 PM EDT this evening for VAZ097- 098-525-529>531. MARINE...Small Craft Advisory until 1 PM EDT this afternoon for ANZ630- 631. Small Craft Advisory until 7 AM EDT Saturday for ANZ632-634. Low Water Advisory until 1 PM EDT this afternoon for ANZ633. Small Craft Advisory until 7 AM EDT Sunday for ANZ650-652-654- 656-658.