Marine Weather and Tide Forecast for Harborton, VA

KEY MESSAGES
1.) Dry conditions and near to below average temperatures prevail tonight through Saturday.

2.) Low pressure tracks near the region Sunday into Sunday night bringing the potential for widespread rainfall.

DISCUSSION
As of 300 PM EST Wednesday...

KEY MESSAGE 1...Dry conditions and near to below average temperatures prevail tonight through Saturday.

A cold front moved through the area earlier today, with a brief lag in the CAA. Current temperatures are very mild for this time of year, with highs of 60-65F inland, and 50-55F along the coast. The stronger CAA arrives tonight, bringing temperatures back down below average through the end of the week. Temperatures will trend back to around normal on Saturday as winds become SW and increase ahead of an approaching low pressure system. With high pressure remaining largely dominant through the week, dry and mostly clear conditions will prevail through the remainder of the week and through the start of the weekend.

KEY MESSAGE 2...Low pressure tracks near the region Sunday into Sunday night bringing the potential for widespread rainfall.

While confidence has increased that a southern stream low pressure system will impact the area late this weekend into early next week, the exact evolution and track of the low are still somewhat uncertain. There remains notable differences in the evolution and location of the low between ensembles, with a wide spread of possible scenarios. The deterministic GFS continues to splits the upper trough, with one piece sliding across the Mid-Atlantic and Carolinas with the other becomes a closed low dropping SE across FL heading toward the Bahamas. Meanwhile, the CMC and ECMWF remain consistent in showing one primary 500mb trough that becomes considerably more organized than the lows depicted by the GFS. Any outliers hinting at the possibility of snow across mainly our NW piedmont have backed off and kept any wintry precipitation to our north with the 12z guidance. Current NBM probabilities of seeing any snow (>0.1") remain at or below 20% for areas west of I-95, with 0% for the remainder of the forecast area. Overall, rain is much more heavily favored for this event. Despite the difference in model differences, the remains good agreement that PW values will exceed 200% of the normal values for this time of year, ranging between roughly 1-1.5" across the region during this event. Being this far out from the event, exact QPF totals are not yet forecast, but ensembles are favoring the southern portion of the forecast area at this time, with probabilities of seeing 1+" ranging from 30-50%.
Regardless of the exact amount, this rainfall will be beneficial for the entire area, especially as fire season commences on February 15th. Dry conditions are then expected by Tuesday into the middle of next week as high pressure builds in behind the late weekend system.

The NBM shows high temperature ranging from the mid 40s NW to lower 50s SE Sunday. Likely, high temperatures will struggle to get out of the upper 30s to lower 40s along and NW of the low track, with 50s concentrated to the SE of the low track. There is little to no CAA behind this system and temperatures are expected to moderate above average by the middle of next week.

AVIATION /06Z THURSDAY THROUGH MONDAY/
As of 1230 AM EST Thursday...

High pressure is building in from the NW as of 06z. VFR under a clear sky at most sites, with SCT-BKN SC at SBY ~5kft, and a N/NW wind less than 10kt at most sites, but locally ~10kt with gusts to 15-20kt at SBY. VFR conditions are expected to prevail today into tonight as high pressure continues to build into the region. A NNW wind increases to 8-12kt with gusts ~20kt by 13-14z for most sites, potentially by 10-12z at ORF, and locally NW 10-15kt with gusts to 20-25kt at SBY. SCT-BKN CU develops (or persists) from RIC-SBY late morning into the aftn with bases ~5kft. Mostly clear by tonight with a calm to light N wind.

Outlook: Primarily VFR conditions are expected Friday through Saturday night with high pressure prevailing. Widespread rain is likely by Sunday into early Monday with flight restrictions probable.

MARINE
As of 300 PM EST Wednesday...

Key Messages:

- SCA remain in effect for late tonight into Thursday afternoon for all local waters as NW winds and seas increase due to strong cold air advection.

- Another round of SCA is possible for the bay as a second surge of drier air moves into the area early Friday morning.

- Sub-SCA conditions prevail Friday and through the majority of the weekend as high pressure remains dominant. The next system approaches the area Sunday and could bring additional headlines.

Afternoon weather analysis shows the cold front from the low to the north just south of the area. Winds have shifted out of the north, but remain around 5 to 10 kt as the pressure gradient over the area remains weak and the colder and drier air remains further north. Seas remain low with around 1 ft in the bay and 2-3 ft across the ocean. Tonight, winds will increase as the pressure gradient tightens and the colder and drier air enters the area. Winds increase out of the north between 15 to 20 kt with gusts upwards of 25 kt. There is also likely the chance for some gusts upwards of 30 kt across the coastal waters. Seas will also begin to increase tonight with waves peaking around early Thursday morning. Waves are expected to be between 3 to 4 ft across the bay and 3 to 5 ft across the coastal waters. There could be the possibility of waves nearing 6 ft across the the southern two ocean zones. Due to conditions deteriorating, Small Craft Advisories remain in effect from tonight into Thursday afternoon. By Thursday afternoon, conditions will improve. However, there may be a secondary surge of colder and drier air that could bring gusts upwards of 20 kt across the bay. However, confidence at this time is low to extend the SCA for the bay is low at this time. Friday through Sunday, benign marine conditions are expected across the coastal waters as high pressure remains in place. For Sunday into Tuesday there could be a potential systems that brings elevated marine conditions across the local waters. However, due the spread in models there continues to remain some uncertainty.

AKQ WATCHES/WARNINGS/ADVISORIES
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory until 1 PM EST this afternoon for ANZ630- 631-650-652.
Small Craft Advisory until 1 PM EST this afternoon for ANZ632- 634-654.
Small Craft Advisory from 4 AM early this morning to 1 PM EST this afternoon for ANZ633.
Small Craft Advisory from 4 AM to 10 AM EST this morning for ANZ635>638.
Small Craft Advisory until 4 PM EST this afternoon for ANZ656- 658.