... High pressure slowly moves east tonight. A warm front approaches and stalls early next week yielding a few days of rain for some. Much warmer for the second half of the week.
NEAR TERM /THROUGH TONIGHT/... As of 310 AM Saturday...
After a mostly clear morning, clouds are expected to develop during the afternoon as several waves of mid-level energy pass over the area. Dry weather is expected to continue throughout the day due to low level dry air and surface high pressure in place across the area. Temperatures will be quite pleasant with afternoon highs in the low 70s in the lowlands, and mid 50s to upper 60s in the higher elevations.
Tonight, moisture and cloud cover will increase over the area as a warm front develops and slowly approaches to the south. Precipitation chances will gradually increase south to north late in the night with better chances to occur beyond the near term period. Low temperatures are expected to be in the 40s to 50s...several degrees warmer than the previous night, but still a bit cooler than normal.
SHORT TERM /SUNDAY THROUGH TUESDAY/... As of 235 AM Saturday...
A warm front over southern KY Sunday morning will slowly drift north into SW VA and S WV through the day. A stream of Gulf moisture ends it's circuitous path north through the southern and central plains then eastward paralleling this slow moving boundary. This should yield a fairly narrow swath of light rainfall roughly oriented W-E somewhere over the southern half of the forecast area while areas outside of this remain largely dry through the day. Monday more or less maintains the status quo with the warm front remaining parked over the region. Slightly better moisture transport coupled with additional synoptic ascent with the right rear exit quadrant of a departing jet max should yield a little better rainfall rates with light to moderate rainfall expected in again, a relatively narrow swath. Still some uncertainty regarding how far the effective warm front makes it during the day Monday and have drawn up a bit broader area of precipitation than will likely occur to cover any wiggle. Similarly, did not stray too far from national blended model guidance on afternoon highs for Monday, although locations that end up south of the effective warm front will likely be just a little too cool while locations under the steadier precipitation will likely be just a little too warm. Tuesday will be largely similar to Sunday as the warm front lingers in the region but additional synoptic forcing fades. Instability on all 3 days will be marginal at best with the elevated mixed layer remaining pinned to the southern and central plains amid persistent southerly mid-level flow out of S Texas and Northern Mexico source regions - thunder mentions have largely been capped at isolated and confined to the afternoon hours each day.
LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... As of 235 AM Saturday...
Model consistency in the long term period remains mixed with the EPS generally much better clustered than the GEFS solutions. Have largely deferred to the EPS/EC guidance which ends up fairly close to central guidance values with minimal tweaks.
An amplifying ridge over the eastern half of the country yields +2 sigma H500 heights overhead with surface high pressure wobbling around between the Mid-Atlantic plain and the upper TN valley. Low levels will be adequately moist to generate at least some afternoon conditional instability despite poor mid-level lapse rates through at least Thursday and have coded up mainly chance SHRA and isolated to scattered TS PoPs for each afternoon. As the upper ridge is slightly suppressed equatorward heading into the weekend, may see some better mid-level lapse rates beginning to work into the northern half of the forecast area amid increasingly westerly flow yielding slightly better TS chances for the afternoon hours Friday and Saturday. Based on aforementioned minimal conditional instability and generally light flow in the vicinity of the upper ridge, severe weather is not currently expected.
With the previously mentioned higher heights aloft and surface high pressure in place, afternoon highs will run between 5 and 10 degrees above normal each day.