Mechanicsville, VA Weather

What Has Changed

- SCAs have been cancelled for the lower Bay and lower James river.

- Coastal Flood Statements have been issued for the high tide cycle today for Va Beach/NC OBX, and for locations along the Rappahannock/Potomac and bayside of the MD eastern shore and Accomack VA.

Key Messages

1) Continued dry with seasonable temperatures through midweek, trending to above normal late in the week.

2) Nuisance flooding expected with today's morning to early afternoon high tide cycle.

Discussion

As of 350 AM EDT Sunday...

KEY MESSAGE 1...Continued dry with seasonable temperatures through midweek, trending to above normal late in the week.

The latest WX analysis continues to show a highly amplified upper level pattern, with sfc high pressure centered from southern New England into the Delmarva. SCT-BKN clouds are passing through far southern VA and NE NC, with a mainly clear sky elsewhere. Temperatures are currently mostly in the 40s, with pockets of upper 30s over the far north, and 50s at the immediate coast in the SE. Expect readings to fall a few degrees through sunrise, with patchy frost possible over the far north, but not enough for a Frost Advisory. As the high continues to settle in from the north later today, cloud cover should be less than the past 2 days, but a period of SCT-BKN cumulus are still likely for southern VA and NE NC. High temperatures warm a few degrees with highs in the mid 60s along the coast and upper 60s to near 70F across the inland areas. For tonight/early Monday morning will likely see the greatest potential for a more widespread frost spreading east from the piedmont to interior SE VA as better decoupling is expected with the sfc high nearly overhead. Continued the same thinking as the previous shift to go a few degrees (or several degrees in some areas) colder than NBM, with mid 30s forecast for the piedmont (locally lower 30s possible) and and mid- upper 30s for interior SE VA. Depending on trends later today, a Frost Advisory may be considered for portions of the area, especially in the NW where temperatures are most likely to approach freezing.

After the cold start, turning warmer Monday and Tuesday ahead of the next (dry) front, then slightly cooler Wednesday and staying dry. Temperatures warm above normal late in the week with high temperatures well into the 70s for most, along with no rain chances as moisture is expected to stay offshore off the SE US coast. The 25/00z ECMWF ensemble/GEFS chance for measurable rain (.01"+) of rain through the end of the month is basically zero aside from some low probs showing up in southeastern portions of the area later in the week into the following weekend, but when switching the threshold to 0.1" the chance is less than 10% area-wide. It should be noted that despite the ongoing drought/precipitation deficit across much of the area, none of our long-term climate sites will rank among the 10 driest Octobers on record (as October has several occurrences with monthly rainfall amounts of less than 0.50").

KEY MESSAGE 2...Nuisance flooding expected with today's morning to early afternoon high tide cycle.

Tidal anomalies will remain elevated today although they continue to trend downward. These elevated anomalies in tandem with the higher of the two astronomical tides of the day will push water levels close to minor flooding thresholds this morning into the early afternoon for locations adjacent the middle/upper Chesapeake Bay and Rappahannock River. Coastal Flood Statements have been issued to account for this.

Aviation

As of 630 AM EDT Sunday...

Mainly VFR conditions are expected to prevail for the 25/12z TAF period. Winds are from the NE ~10 kt near the coast, and light/variable inland. Some patchy ground fog is being observed across interior SE VA, but this is not expected to affect any of the main terminals. The wind remains NE to ENE today as the high gradually builds southward. Less cloud cover is expected and should mainly be confined to the southeastern terminals, but will probably see a few hrs worth of SCT cu at RIC as well. Mainly SKC with light winds tonight into early Monday. Could see some patchy fog, but it will likely miss the main terminals so have not included any VSBY restrictions at any of the TAFs.

Outlook: Lighter N to NE winds are expected on Monday. Elevated N to NE winds return Tuesday and Wednesday. It remains dry, with VFR conditions continuing.