Marine Weather and Tide Forecast for Rustburg, VA

KEY MESSAGES
1) Showers end this evening, some stratus and fog overnight, but warmer and clearing for Monday and Tuesday. Enjoy it before cool and wet weather arrives mid week.

2) Precipitation likely by middle of the week, details still murky.

3) Windy and colder conditions with the frontal passage.

DISCUSSION
KEY MESSAGE 1: Showers end this evening, stratus and fog in some areas overnight, but warmer and clearing for Monday and Tuesday. Enjoy it before cool and wet weather arrives mid week.

A cold front was slowly moving through the forecast area today, helping to provide plenty of cloud cover along with scattered showers. Showers and thunderstorm chances peak during the heat of the day this afternoon, with thunder being confined to the Piedmont out ahead of the front. Could see a few storms with gusty winds, but severe weather is not anticipated due to lack of instability and shear. As the front slides into eastern VA and central NC tonight, rain will come to an end. The front will then stall there through Tuesday morning.

Forecast soundings indicate stratus is likely to linger over the far Piedmont overnight into tomorrow morning, with additional stratus trailing in from the west for the western mountains. Light and variable winds and dew points still in the 40s and 50s overnight will also support patchy fog.

Monday and Tuesday will be mostly dry with sunny skies and WSW winds. Temperatures remain above normal, and are likely to increase slightly each day this work week in a broad WAA regime ahead of the next, stronger cold front coming Thursday. This will yield daily highs in the 60s and 70s tomorrow, and in the low 70s to low 80s Tuesday.

Key Message 2: Precipitation likely by middle of the week, details still murky.

Conditions are looking favorable for another round of precipitation towards the middle of the week. A mid-level cutoff low in southwestern CONUS will move east and be absorbed by a northern zonal flow. This flow will bend southward thanks to the cutoff low and form a trough as it continues towards the east coast. The cutoff low will be assimilated into the trough but a part of it looks to extend just ahead of it in the process. During the same time period, a surface low forms and grows from the Great Lakes and stretches a long cold front to the south. (A secondary low may also form with the remains of the cutoff low in the Deep South and extend the cold front further south). The front is likely to pass through by Wednesday night and provide some rain for the region. The question becomes how much of this rain is through thunderstorms and whether these storms will be severe. Similar to yesterday's forecast, a lot will depend on timing. Instability and shear look to be favorable for scattered severe weather but only if the storms arrive by Wednesday afternoon. On this day, temperatures will be in the 70s to lower 80s with dew points in the 50s and lower 60s which will assist in instability. Bulk shear of 40-60 kts instead of 100 kts look to be more likely around the same time period. With some parameters favorable for severe weather, some machine learning products have also picked up on the signal. The Storm Prediction Center, however, still expresses uncertainty as recent model guidance showed the storms arriving Wednesday night into Thursday night. The instability at this time would be lost and storm development would be quite underwhelming. This event is still a few days away so there could be changes in the forecast by then.

Key Message 3: Windy and colder conditions with frontal passage.

When the cold front passes, it will significantly shift wind direction and wind speed and break the warming trend. Wind will gust

from the southwest initially as a low level jet passes through overnight Wednesday night and then transition from the northwest by Thursday morning. Winds currently look to gust between 25-40 mph west of the Blue Ridge and between 40-50 mph at ridge tops and higher elevations. The new air mass that arrives will bring in drier and colder temperatures. Dew points will belly flop into the 20s and 30s and high air temperatures will sink towards the 40s and 50s. The air, especially in the far western counties, may be cold enough to briefly support some upslope snow Thursday morning. By Friday, winds start to decline and temperatures recover and warm a little as winds at the surface and aloft become more southwesterly/westerly.

AVIATION /00Z MONDAY THROUGH FRIDAY/
Mainly VFR this evening outside any showers at LYH/DAN which may bring a period of MVFR vsby/cigs. A few models have some lower cig start to develop over BLF this evening after 02z, so have 2kft cig there but appears could be a case where its in and out or BKN V SCT.

With the rain today, especially southeast of ROA/BCB, am leaning toward poor flying conditions developing at DAN by 07-09z, with IFR or lower cigs/vsbys with fog. Some MVFR also possible into mid morning Monday at LWB.

Should see improvement to VFR all sites after 14-15z Monday with west to southwest winds under 10kts.

EXTENDED AVIATION OUTLOOK...

Mainly VFR through Tuesday, some potential for late night fog in the river valleys, but low confidence. Increasing chances for showers arrive by late Wednesday into Thursday where sub-VFR is more likely. Southwest winds pick up ahead of the front Wednesday, then shift to the northwest Thursday with potential gusts over 30kts. By Thu afternoon should be improving to VFR east of the mountains and Thursday night into the mountains which should persist into Friday.

RNK WATCHES/WARNINGS/ADVISORIES
VA...None.
NC...None.
WV...None.