Mechanicsville, VA 23116 Weather

What Has Changed

- Josephine has weakened and is no longer a Subtropical cyclone.

- Coastal Flood Advisories have been extended through tonight's high tide cycle for most of the area.

Key Messages

1) Continued dry with seasonable temperatures through the middle of next week.

2) Elevated tidal anomalies persist through tonight with minor tidal flooding forecast.

Discussion

As of 345 AM EDT Friday...

KEY MESSAGE 1...Continued dry with seasonable temperatures through the middle of next week.

As Josephine interacted with a cold front last evening, the circulation has weakened considerably while pushing E to Atlantic Canada and is now no longer a subtropical storm. The upper level flow depicts an amplified pattern, with anomalous ridging over the central CONUS, and the downstream low spinning off the coast of Maine and into Atlantic Canada. The sfc cold front is diving south into the local area early this morning, and is expected to weaken into a trough as it crosses the region later today. Ahead of the boundary, the sky is clear and with light winds, decoupling has allowed temperatures to drop mostly into the 40-45F range, but ranging from as as low as the mid 30s over much of interior southern VA and NE NC to the lower 50s at the immediate coast. Patchy frost is likely in the most sheltered areas of southern VA through ~8 AM, but coverage is not enough to warrant any Advisories.

Otherwise, ~1030mb sfc high pressure centered over Ontario and Quebec, will build SE into eastern NY/interior New England by tonight. This setup will lead to increasing N to NE winds later this morning, and an increase in low level moisture later today, especially for areas closer to the coast. Model soundings show enough moisture underneath the subsidence inversion to support SCT-BKN stratocumulus by late morning/aftn for most of the CWA (highest cloud cover for SE VA and NE NC). In addition, it will become a bit breezy with gusts to 15-20 mph inland and 20-30 mph near the coast in SE VA and NE NC. Highs will be a little cooler compared to Thursday, ranging from the low-mid 60s north to near 70F over NE NC. The high continues to build south and into the local area later tonight through the weekend, with a developing sfc trough of low pressure off the SE US coast. The compressed pressure gradient will tend to keep the airmass mixed with milder temperatures for at least the SE 1/2 of the CWA tonight but northern and NW sections should see lows back into the 30s, potentially leading to patchy frost by sunrise Saturday.

High pressure will dominate the local weather pattern this weekend and likely well into next week. Not much change in the forecast with seasonal temperatures and near zero indications for much needed rainfall returning to the region. At this time, both Saturday night/Sunday AM and Sunday night/Monday AM have the potential for at least patchy frost over much of the interior, with the greatest potential in the piedmont. Have continued to undercut NBM values by several degrees except at the immediate coast.

KEY MESSAGE 2...Elevated tidal anomalies continue through Friday with minor tidal flooding forecast.

Aviation

As of 700 AM EDT Friday...

Clear skies and VFR conditions with N winds starting to increase to start the 12z TAF period. Winds continue to increase, and become elevated from the NE later this morning in the wake of a cold frontal passage. This should allow for an increase in low level moisture, with some lower clouds moving onshore by the late morning and persisting through the afternoon, mainly at ORF/PHF/ECG. While there is some chance for MVFR CIGs across SE VA/NE NC, will keep any CIGs at VFR (CIGs >3000 ft). Winds by late morning/aftn are expected to gust to 15-20 kt inland, but to 20-25 kt at ORF. Winds remain elevated at ORF/ECG tonight, but diminish to ~5 kt or less inland.

Outlook: SCT/BKN lower cloud cover may return Saturday, but CIGs should primarily be VFR. VFR then prevails Sunday-early next week. Forecast winds are out of the E-NE through this period, with a typical diurnal max/min expected.