Petersburg, VA 23803 Weather

What Has Changed

Temperatures have trended warmer during the day and cooler at night. Added patchy frost to the forecast for portions of the Piedmont early Thursday morning and Friday night into Saturday morning.

Coastal Flood Advisories expanded in area and time. A Coastal Flood Warning was issued for the city of Virginia Beach mainly for the area surrounding the Lynnhaven Inlet tidal gauge.

Key Messages

1) Sunny and dry Fall weather continues.

2) Prolonged onshore flow will lead to multiple elevated tide cycles this week resulting in rounds of coastal flooding.

Discussion

As of 540 AM EDT Wednesday...

KEY MESSAGE 1...Sunny and dry Fall weather continues.

High pressure remains centered north of the local area, centered over interior portions of New England and SE Canada. Meanwhile, a coastal low lingers well offshore. Temps as of 540 AM ranged from the mid to upper 40s for most inland areas and upper 50s to around 60 along the coast. The low has consistently been farther east than models indicated over the past few days. As such, it is difficult to believe that the low will nudge back west at this point into high pressure. Nevertheless, models still try to show the low nudging a bit west today while deepening. Given the uncertainty, have kept the outer cloud shield from the low reaching far eastern portions of the area later this afternoon into this evening before clouds move back over the ocean as the low pulls away tonight. However, even this may be overdone and it is entirely possible that only a portion of the Eastern Shore sees any clouds today with the vast majority of the forecast area likely remaining sunny. Given the trend for sunny conditions today, temps have trended warmer with highs in the mid 60s across the coast as well as the Eastern Shore and upper 60s elsewhere. Temps may even reach 70F in a few locations.

The coastal low moves farther offshore Thu with high pressure gradually building south into the region through the weekend. This will allow for stagnant weather pattern with sunny and dry weather continuing for the foreseeable future. In fact, some model guidance shows completely dry conditions through the end of the month. Temperatures remain seasonable Thu with highs in the upper 60s to around 70F. However, as the cool, strong high builds into the region Fri into the weekend, cooler temperatures arrive with highs in the lower 60s for most Fri and Sat (potentially upper 50s across the Eastern Shore and mid 60s across NE NC). Temperatures moderate back into the mid-upper 60s by Sun and upper 60s to lower 70s Mon and Tue. Meanwhile, lows are expected to range from the upper 30s across the Piedmont and typically cooler locations near I-95 to the lower 40s east of I-95 and around 50F along the coast tonight into Thu morning. As such, some patchy frost is possible across mainly the Piedmont. However, temperatures don't look to be cool enough to support Frost Advisories at this time. The better chance for a more widespread frost is Fri night into Sat morning with the high centered just to the north of the local area. The best chance for frost will once again be across the Piedmont and typically cooler interior portions of the Northern Neck and S/SE VA. Currently have lows that night in the mid-upper 30s across the Piedmont, upper 30s for most inland areas far from the coast, 40s closer to the coast, and lower 50s along the coast. However, given the strength of the high, it is possible that Louisa gets down to around 32-33F. As such will have to monitor trends in case Frost Advisories are warranted. Sat night/Sun morning will also be cool with additional patchy frost possible, however, it will likely not be as cool as Fri night/Sat morning. Otherwise, winds remain breezy mainly along the coast each day through Fri with gusts up to 25-30 mph today and 20-25 mph Thu an Fri. Inland will not be as breezy, however, gusts up to 20-25 mph are possible today with occasional gusts up to around 20 mph possible Thu and Fri.

KEY MESSAGE 2...Prolonged onshore flow will lead to multiple elevated tide cycles this week resulting in rounds of coastal flooding.

The ETSS, PETSS and STOFS continue to suggest the anomalies will continue to increase today with 2-3 ft anomalies expected. This may allow some of the sites more prone to flooding (Lynnhaven, Smithfield, Bayford, etc.) to touch moderate flooding during the high tides later this afternoon/evening and potentially again Thursday AM. The only location with enough confidence for a warning is Lynnhaven, mainly due to the very large swell at the mouth of the Chesapeake Bay likely aiding in the flood potential. Models have trended too high for this entire event so far and the confidence is just not there to issue any additional warnings at this time. Otherwise, extended the Coastal Flood Advisories out another high tide cycle and now have most of them running through locations adjacent to the York and Rappahannock Rivers.

Aviation

As of 115 PM EDT Wednesday...

VFR conditions prevail through the 18z TAF period. Northerly winds, on the western side of low pressure well offshore, will continue through the afternoon, mainly 10-15 kt with gusts 20-25 kt. SKC for all terminals early this afternoon but occasional cirrus or stratus may creep into SBY, ORF, or ECG as lobes of lift/vorticity rotate around the offshore low. Flight restrictions are not anticipated from these clouds. Winds will decrease to 5-10 kt tonight, becoming NW with time into Thursday as the offshore low begins to lift away to the N and NE.

Outlook: VFR conditions and daytime breezy N winds are expected to prevail through the rest of the week. Winds become light each night away from the coast.