textproduct: Blacksburg

SYNOPSIS

A chilly airmass will continue to be seen across the Mid- Atlantic through mid-week, thanks to an area of high pressure over eastern Canada. A series of storm systems will move across the region through Thursday, allowing periods of much needed rain to continue to be seen. Drier weather conditions are expected to return to our area by Halloween.

NEAR TERM /NOW THROUGH TONIGHT/

Issued at 335 AM EDT Tue Oct 27 2025

Key Messages:

- Off-and-on rain continues across the forecast area through much of today.

- Temperatures remain below normal heading into mid-week.

Whether you call it "the wedge" or cold-air damming, it's the dominant weather pattern that's in control of our region's weather early this morning. Winds blowing clockwise, around surface high pressure centered over the Northeast, continue to bring a drier airmass into our forecast area. Meanwhile, moisture continues to be drawn northward toward the Mid-Atlantic as an ejecting shortwave trough pushes an area of low pressure northeastward off the coast of the Carolinas. The struggle is real, as the moisture/stratiform rain tries to move northward but can only make it "so far" into the drier air from the Northeast U.S. The result are weather conditions that are clammy or dank, as the precipitation and abundant cloud cover keeps high temperatures below what's expected for late October (the 60s in most places). If there's any good news from this, we are getting some much-needed rainfall.

The rainfall associated with this storm system should diminish today. As the axis of the shortwave trough swings through our region, the surface low (currently) off the South Carolina Coast should move northeast. The northeasterly wind flow should become more dominant as this happens, which should result in a gradual decrease in the coverage (end?) of precipitation over our area. Timing on this will likely be late morning over our western areas, while this may not happen until mid- or late afternoon across some parts of Southside Virginia/North Carolina Piedmont. And while I can't totally discount additional, more drizzly rain into the evening hours (we're talking about "the wedge" after all!), the odds of seeing measurable precipitation drop across our region - albeit briefly - by late afternoon. Our next opportunity to get precipitation should arrive by mid- week...but more on that in a moment.

Thanks to the persistent cloud cover, and rainy/drizzly conditions, temperatures will remain some 10 to 15 degrees below seasonal norms for this time of year.

SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/

As of 130 AM EDT Tuesday...

Key Messages:

1. Widespread rainfall Wednesday, lingering into early Thursday.

2. Below normal temperatures, and breezy conditions through the period.

3. Dry, but windy and cooler for Halloween night.

Widespread rainfall is expected Wednesday, beginning by Wednesday morning, as a strong low pressure system tracks northward from the mid Tennessee Valley into the Ohio Valley and northern Mid Atlantic, supported by a deep 500mb low. The overrunning precipitation and warm air advection will slowly erode the high pressure wedge situated over the area, and so will likely see rain beginning as light, but increasing in intensity by the afternoon as the wedge erodes. Cannot rule out a few rumbles of thunder along the edge of the wedge, especially in the VA southside where model soundings are suggesting some elevated instability. However, given that the center of the low moves over the Appalachians overnight Wednesday, confidence is low in any sort of nocturnal thunder, especially during late October.

Most of the rain that falls will be beneficial, as much of the local forecast area in at least abnormally dry conditions, but moderate to severe drought exists west of the Blue Ridge. There remains a Marginal Risk of excessive rainfall leading to flash flooding for Wednesday for most of the area, as rain rates could be high at times, and thus lead to flooding of low lying and poor drainage areas, especially with leaf litter that may clog drains. 48 hour rainfall amounts through Thursday night range from 1.25" to over 2", and some locations along the Blue Ridge around 2.5" to near 2.75", as the terrain enhances the rainfall totals.

Dry air will get wrapped into the low pressure system, and the upper level low pivots farther north Thursday and into Friday, thus will see rain tapering off for much of the area by Thursday afternoon, save for lingering upslope showers in the west with the surface and 500mb flow turning northwesterly. Cold air filtering into the region Thursday night into Friday morning could result in some snow mixing in with the rain for the highest elevations of southeast WV, but no accumulations are expected.

By Friday morning, the center of the low will move into the northern Mid Atlantic and the northeast US, well away from the area, with dry weather forecast for Halloween. Winds will be gusty through the period, generally between 20 to 30 mph areawide, on the higher end of the range along and west of the Blue Ridge. Winds will lessen slightly Friday night, as the pressure gradient between the departing low and high pressure building across the southern US decreases.

Temperatures will be below normal through the period, between 10 to 17 degrees below normal Wednesday, in the mid 40s to mid 50s, increasing slightly to 5 to 10 degrees below normal by Friday, into the upper 40s to low 60s. Overnight lows will be near normal.

LONG TERM /SATURDAY THROUGH MONDAY/

As of 130 AM EDT Tuesday...

Key Messages:

1. Mostly dry weather over the weekend, though rain chances increase Sunday.

2. Temperatures remain below normal through the period.

The broad 500mb trough loses amplitude over the beginning of the weekend, and high pressure over the southern US will build into the Mid Atlantic, which will keep the weather over the local forecast area mainly dry. A shortwave will rotate through the base of the main trough, and cause it to deepen over the eastern US later in the weekend. By Sunday, long range models start to diverge in the evolution of the 500mb pattern, as some models have the trough becoming a cutoff low over the Midwest and Gulf Coast states, while others have it remaining an open wave, thus leading to increasing forecast uncertainty later in the weekend. That being said, with some upper level energy reaching the area Sunday, will see increasing chances for precipitation, though remaining mostly confined to the western half of the forecast area.

Temperatures will remain below normal through the long term forecast period, in the mid to upper 40s in the higher elevations in the west, and mid to upper 50s elsewhere, though some locations could reach the low 60s in the Piedmont and Southside.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

Issued at 703 AM EDT Tue Oct 27 2025

Expect flight restrictions through 29/1200 UTC as periods of -RA results in fairly widespread MVFR CIGs, with occasional reductions into IFR territory. "Round 1" of the precipitation should diminish in coverage, generally from W to E today. Even though I've made some minor adjustments to the timing of this based on the latest information, RA should gradually end starting late this morning at terminals W of the Blue Ridge, with precip ending farther S/E late in the afternoon.

Of secondary impact to aircraft will be gusty winds through this afternoon. NE to E winds, with speeds of 10-15 kts at most terminals, will be seen. Occasional gusts greater than 20 kts will be possible as well.

As this initial system departs our area, there will will likely be a brief break in the RA. Flight categories are expected to briefly improve during this time, with CIGs AOA 035 in many places this afternoon and evening. Restrictions will return overnight ahead of the next storm system, and additional RA will likely commence just prior to 29/1200 UTC.

OUTLOOK WEDNESDAY THROUGH SATURDAY...

Wednesday-Thursday: Restrictions expected as another storm system brings periods of -RA.

Thursday night: Improving flight categories anticipated as the storm system exits the region.

Friday-Saturday: No restrictions anticipated at this time.

RNK WATCHES/WARNINGS/ADVISORIES

VA...None. NC...None. WV...None.