... A cold front extended from low pressure over the Great Lakes into the Southern Plains. This front will move east today through Saturday and will trail from eastern Virginia into the Gulf of Mexico by Saturday evening. High pressure wedges down the east slopes of the central Appalachians behind the front with cooler and wet weather through Monday.
NEAR TERM /THROUGH TONIGHT/... As of 225 AM EDT Friday...
Batch of mid and high clouds over the Carolinas and Virginia will drift slowly north today. low clouds and fog will fill in the river valleys and will form in patches over the piedmont early this morning. After sunrise the stratus and fog will dissipate leaving a mix of sun and clouds for the rest of the day.
Winds will start from the south to southwest today then become west ahead of the approaching cold front tonight. Synoptic scale models were in good agreement with the timing and placement of the front by Saturday morning. Cloud cover will increase from west to east tonight and deeper moisture arrives ahead of a cold front. Will slightly slow down the arrival time of the precipitation closer to Saturday morning.
Another day with above normal temperatures. Highs will be 10 to 15 degrees above normal. Increasing clouds will limit drop in temperatures tonight. Will stay close to NBM/MAV guidance for highs today. Even bias corrected MET guidance looked too cool.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... As of 200 AM EDT Friday...
The upper ridge axis will continue to move east into the Atlantic ocean. A cold front will travel east across the region Saturday into Saturday night. In general rainfall amounts will be the greatest around an quarter of an inch from the southern Blue Ridge to Martinsville area, while everyone else will struggle for a tenth. High temperatures on Saturday will vary greatly from the upper 50s in the northwest mountains to around 80 degrees in the piedmont.
An isolated evening thunderstorm may be possible in the east otherwise mostly cloudy with a few showers. Added the mention of fog Saturday night into Sunday morning. Low temperatures Saturday will vary mid 40s in the west to the mid 50s in the south.
Continued the trend of lowering high temperatures for Sunday with high pressure wedging into the area after the front. Isolated showers and drizzle are possible with the wedge, with slightly better pops along the southern Blue Ridge into the North Carolina mountains where the fetch could enhance rain along the southern edge of the wedge boundary. High Sunday will range from the mid 40s in the north to the lower and mid 60s outside the wedge in the west and south. The Wedge conditions of cloudy, cool, with pockets of fog and drizzle will continue into Sunday night. Low temperatures Sunday night will generally be from the lower 40s in the north to near 50 degrees in the south.
Medium confidence in Short Term Forecast.
LONG TERM /MONDAY THROUGH THURSDAY/... As of 200 PM EDT Thursday...
High pressure builds back in from the east as ridging takes over the region Monday, allowing for temperatures to gradually warm that afternoon, as well as Tuesday, with highs looking to reach back into the upper 70s by Tuesday afternoon.
Forecast confidence beyond Tuesday drops, as guidance remains divided on how an upper level trough and potential closed off low interact with the area: models are in agreement of a closed off low forming out of a high amplitude trough over the desert SW, being left behind by the northern stream and having to rely on the southern stream to push it east. The main difference in guidance is over how fast this low progresses eastward to the Mid-Atlantic. GFS is extremely fast with this, meaning rainfall could quickly return following a front that will move through the area Tuesday. ECMWF on the other hand is substantially slower, not bringing it here until late in work week. Before its arrival, we could see some drier weather following the front Tuesday. Because of these differences, forecast population was done with NBM, with minor tweaks.