textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Temperatures have increased slightly for the latter half of the week.

KEY MESSAGES

1. Cold air damming will gradually weaken over our area, allowing temperatures to warm back above normal over the next few days. 2. Rain chances return during the latter half of the week as a moist frontal system moves through our area from the west.

DISCUSSION

Key message 1: Cold air damming will gradually weaken over our area, allowing temperatures to warm back above normal over the next few days.

A cold air damming pattern will linger across the western Carolinas tonight and into Monday, but will steadily weaken as its parent surface high, now centered near Long Island, slowly moves off the Mid-Atlantic Coast. An embedded mid/upper level shortwave approaching from the west has been providing some amount of isentropic lift up and over the wedge producing bands of sct light showers over our fcst area today. Generally weak lift along with a dry sub-cloud layer has resulted in minimal amounts of precip reaching the ground so far today with most of the rain falling as virga. Locations that do receive rainfall thru tonight will likely get little more than a few hundredths of an inch.

As the sfc high drifts further east over the next couple of days, the CAD pattern will dissipate. Nonetheless, a weakening ridge axis will maintain some degree of ELY low-level flow across our area into mid-week. Shower chances diminish later tonight and into Monday as upper support and upglide diminishes over our area. This will result in dry weather thru at least Tues evening. Temperatures will steadily warm each day, with high temps expected to be at least 5 degrees above normal by Tues.

Key message 2: Rain chances return during the latter half of the week as a moist frontal system moves through our area from the west.

A complex upper pattern will set up over the CONUS by mid-week with an omega block developing over the western/central CONUS, and a downstream ridge building along the East Coast. At the sfc, a moist occluded front will gradually approach our area from the west early Wednesday, and slowly make its way thru the area over the next 24 to 48 hours. In response, PoPs increase to at least likely across the western half of our fcst area by late Wednesday and peak early Thursday. Most of the current guidance still has some amount of weak instability ahead of the frontal boundary within a modestly sheared environment. However, weakening occluded fronts such as this one typically do not have very favorable dynamics for producing severe weather and/or excessive rainfall. Nonetheless, a minimal threat still appears to exist.

Otherwise, precipitation chances dwindle late in the work week as the frontal boundary moves further east and continues to weaken. Slight chance to chance PoPs do linger thru Friday, but any precip amounts should be minimal after Friday morning. Little temperature change is expected behind the front, with above normal temperatures continuing into the weekend.

AVIATION /00Z MONDAY THROUGH FRIDAY/

At KCLT and elsewhere: VFR continues for the 00Z TAF period. Thick cirrus and altostratus will continue to stream across the area tonight atop a defined surface wedge, generally above 5 kft but with some potential for lower ceilings to develop tonight into Monday morning...especially at the Upstate sites. Flight restrictions look unlikely, if perhaps not completely out of the question. NE winds should continue through the period, except at AVL where they'll be channeled to the SE by the French Broad Valley. BKN to OVC VFR altostratus looks to remain in place across the region on Monday, with some improvement to SCT sky cover possible Monday afternoon and evening...but this will be brief, if it happens at all.

Outlook: Mostly dry, VFR conditions should continue through Tuesday. Rain and associated restrictions are expected to return during the middle of the week. With ample cloud cover expected over the next few days, mountain valley fog should be limited.

GSP WATCHES/WARNINGS/ADVISORIES

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