textproduct: Greenville-Spartanburg

SYNOPSIS

Dry high pressure builds in today, then a dry cold front cross the area from the north on Sunday. A warm front may bring small chances of mountain precipitation in the middle of next week, otherwise, dry weather can be expected with a warming temperature trend through the end of the week.

NEAR TERM /THROUGH TONIGHT/

As of 1230 am Saturday: A fast, quas-zonal upper flow pattern will prevail across the Conus through the near term, with a low-amplitude trough expected to become established across the East late in the period, as a speed max brushes the northeast quadrant of the country. The leading edge of an associated frontal zone is expected to be on the CWA's doorstep at the end of the period, but with broad surface ridging over the Southeast and Gulf cutting off any substantive pre-frontal moisture return, the front will be dry. Speaking of dry, low afternoon RH will be the headline for the near term, as some of the very dry air aloft should mix down to the surface this afternoon, with RH likely dipping into the 22-27% range across much of the area. Temps this afternoon through tonight are forecast to be slightly above normal.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

As of 1200 AM EST Friday:

Key Message #1: Warm and dry Sunday. A dry cold front will bring a brief cooldown and low RH for Monday.

A flat upper trough will cross the Ohio Valley to the Mid-Atlantic Coast Sunday, with an associated dry cold front slipping in from the northwest during the day. No mentionable PoPs will be carried with this fropa, due to lack of moisture. Breezy conditions expected thru Sunday aftn and evening, mainly in the mountains. Temps will be near normal in the mountains, but 5 to 10 deg above normal east of the mountains, thanks to downslope warming negating the low-level CAA.

A 1036 mb sfc high will slide from the Ohio Valley to eastern NC on Monday. This should result in less wind than Sunday, with a return to slightly below normal temps under sunny skies. The air mass will be very dry, and aftn RH values may drop below 25% across most of the Piedmont and lower mountain valleys. This may cause increased fire danger if fuels have dried out enough since recent rainfall.

Key Message #2: Small precip chances may return to the mountains before daybreak Tuesday.

The center of the cool, dry high pres will slide off the Carolina Coast Monday night, allowing increased SWLY return flow to set up atop the forecast area. A plume of Gulf moisture will extend from the Lower MS Valley into KY and TN around the western periphery of the high. Forecast soundings near the TN/NC show deep enough moisture to support at least a slgt chc of precip before 12z Tuesday. Temps will likely fall below freezing Monday evening across most of the mountains before clouds and WAA increase overnight. Pockets of sub-freezing temps may overlap PoPs just enough for a non-zero threat of patchy freezing rain. But temps will quickly warm above freezing early Tuesday morning and QPF will be spotty and very light. So no little to no ice accretions are expected. Dry conditions with increasing clouds elsewhere with lows near normal.

LONG TERM /TUESDAY THROUGH FRIDAY/

As of 1230 AM EST Friday:

Key Message: Significant warming trend through the week, with well-above normal temperatures for Christmas Day and the day after Christmas.

An upper ridge will steadily build over the central CONUS with the axis remaining nearly stationary through at least Thursday. A warm and generally dry westerly to northwesterly flow regime will persist across the region. There will be some moisture banking up against the NC mountains near the TN border at times, mainly Tuesday thru Tuesday night. Temps look too warm for any wintry p-type concerns, with just some spotty light rain possible. Downslope flow will limit PoPs elsewhere thru the end of the week. The bigger story will be the temps. Tuesday looks to be a few deg above normal, then warm to 10-15 deg above normal Wednesday and 15-20 deg above normal for Christmas Day. Friday (day after Christmas) may be the warmest day of the week, with the latest National Blend of Models showing temps in the low to mid 70s east of the mountains (about 20+ deg above normal). Unfortunately, this pattern means no white Christmas for any part of the forecast area this year.

AVIATION /06Z SATURDAY THROUGH WEDNESDAY/

At KCLT and elsewhere: A dry air mass will support continued VFR conditions through this forecast period. In fact, other than FEW/SCT thin high clouds, SKC is expected to prevail. Winds will become light/variable at most sites by daybreak, then become light S/SW by early afternoon.

Outlook: Generally VFR conditions continue through Monday. Low end gusty winds possible with a dry cold front Sunday. A weak front may bring small chances for rain and restrictions Tuesday into Wednesday.

GSP WATCHES/WARNINGS/ADVISORIES

GA...None. NC...None. SC...None.