... High pressure will weaken today but keep us dry for at least two more days, with moderating temperatures. Remnants of Tropical Storm Beta will bring a threat of rain to the area by the end of the week.
NEAR TERM /THROUGH TONIGHT/... As of 210 AM EDT Tuesday...
Expect frost to on some of the grounds/fields of the Southern Shenandoah Valley/Greenbrier Valley into the Alleghanys when waking up this morning around 6-8am, some frost likely even in the sheltered valleys further south into the New River Valley and NC mountains, though more patchy, hence no advisory.
High pressure starts to drop south and weaken today as Hurricane Teddy slides north in the western Atlantic heading for Nova Scotia. The low level thicknesses slowly rise although upper heights fall somewhat. Still no weather issues and will see highs around 5 degrees below normal, as we trend back to normal. Highs will range from the mid 60s to around 70 in the mountains, to the to lower to mid 70s east.
Tonight, high pressure remains in place at the surface. Meanwhile, upper levels showing a closed low forming over the Ozarks and models are streaming in some high clouds after midnight, so not a completely clear forecast. Surface dewpoints start to moderate, and will not expect frost tonight, with lows in the 40s.
Forecast confidence is high today, and moderate tonight for sky cover.
SHORT TERM /WEDNESDAY THROUGH FRIDAY/... As of 300 AM EDT Tuesday...
Our friendly, dominating bubble of high pressure gradually breaks and shifts eastward out of the Mid-South through Wednesday, and eventually slips offshore Thursday. Replacing the high will be the remnants of Beta pushing across the Mississippi Valley. Eventually, moisture influence provided by Beta combined with a developing omega block pattern for the weekend should cut on the "hose" to pump a more moisture rich airmass into the region late Thursday, into Friday.
Wednesday will be the last fully dry day, as shower activity should initiate in the NC mountains sometime between 18Z Thursday and 6Z Friday, based on most guidance (0Z NAM is looking very dry, even based on model soundings, showing a very dry airmass that's going to be difficult to get saturated with Beta struggling to move northward in the Mid-South). For now, the heaviest of precipitation Friday looks like it will remain confined in the NC Mountains, up to the southern Blue Ridge of VA where upslope flow could enhance local rainfall amounts.
Temperatures through the period stay around average thanks to the increase in moisture to limit diurnal temperature fluxes, as well as the introduction of a warmer airmass from our south. Despite the change to a southerly influenced pattern, the now lower sun angle as well as persistent cloud cover should keep temperatures near average.
Temperature and cloud forecast: High Precipitation forecast: Moderate
LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... As of 155 PM EDT Monday...
The remnants of Beta making for an active start to the weekend ahead. Southeasterly flow will pick up on the back side of the remnant closed low Saturday with lingering moisture expected Sunday and Monday as a cold front approaches from the west. With all that said expect increasing rain chances into the weekend and early next week.
Temperatures look to remain 4-6 degrees above average through the period.
Confidence is low to moderate in the long term based upon where the overall remnants of Beta tracks and how the omega block pattern shakes out.