textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Temperatures have trended a tad warmer for Saturday night and Sunday.

Rainfall amounts have trended slightly lower across most of our forecast area for Monday.

The aviation discussion was updated to reflect the recent 18Z TAF issuance.

KEY MESSAGES

1. Quiet conditions continue the rest of the weekend. 2. Shower and thunderstorm chances increase on Monday as a cold front moves thru the area. Expect dry conditions in the wake of the front on Tuesday. Another weak cold front may bring a few more showers and thunderstorms Wednesday into Thursday.

DISCUSSION

Key message 1: Quiet conditions continue the rest of the weekend.

Generally quiet conditions across the area. A weakly-baroclinic zone extending across the Deep South continues to drive widespread high- and mid-level cloud cover across the western Carolinas, with lower clouds from this morning only slowly scattering out. Other than the possibility for some brief, very isolated showers to develop over the I-40 corridor later this afternoon (as depicted in recent runs of the HRRR, RRFS, and NAMnest) the next day and a half should be dry and quiet. Some low-end wind gusts are likely across the low terrain this afternoon, but with no major impacts expected.

Cloud cover will begin to retreat on Sunday morning as a shortwave digs across the Gulf coast and at a drier air mass noses down the Eastern Seaboard. Temperatures on Sunday have trended warmer owing primarily to anticipated clear, sunny conditions, with highs now expected to climb into the mid-80s outside the mountains.

Key message 2: Shower and thunderstorm chances increase on Monday as a cold front moves thru the area. Expect dry conditions in the wake of the front on Tuesday. Another weak cold front may bring a few more showers and thunderstorms Wednesday into Thursday.

Broad upper trofing will gradually move over the NE CONUS on Monday and Tuesday with the backside of the trof getting reinforced on Wed- nesday and Thursday of next week. At the sfc, an elongated cold front slowly drops toward the area on Sunday and moves thru our fcst area on Monday. At the same time, a series of weak low pressure systems develop along a broad baroclinic zone just to our east and south. Overall, the latest model guidance appears to be trending slower with regards to the frontal passage on Monday and subsequent low development. Most of the guidance still produces minimum QPF over our CWA, with the heavier showers remaining to our south. Expected amounts are currently up to 0.1 inches roughly north of I-85 and up to about 0.25 inches south of I-85. In addition, most of the precip is now expected to fall Monday afternoon with some showers lingering into the evening. There is some thunder potential over our southern and southeastern zones on Monday, but the higher CAPE values appear to remain to our south. In addition, SPC's current Day 3 Severe Out- look has a Marginal Risk just to our south. In the wake of the front, broad sfc high pressure will spread over our region from the north on Tuesday. Another weak cold front will move thru our area Wednesday into Thursday and could produce some sct showers and/or a few thunderstorms, mostly over our northern zones. Any precip amounts will likely be minimal. Dry high pressure returns for Thurs and Fri. Near-normal temperatures are expected for most of the period, with Tues being the main exception. In the wake of the cold front, lows over the higher elevations of the NC mtns may bottom-out in the mid to upper 30s Tues morning.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

At KCLT and elsewhere: Lingering MVFR ceilings are still in place across much of the South Carolina Upstate, intermittently affecting GSP, GMU, and AND. Guidance remains in good agreement that these restrictions will become more and more sporadic over the next 2 hours or so, and a return to VFR by mid- to late-afternoon is expected. Thereafter a bank of cirrus will remain in place to our south overnight, meaning SCT to BKN high cloud cover is expected through most of the night. Before dawn, cirrus will finally begin to pull south...resulting in FEW/SKC conditions by mid-morning Sunday. Some of the hi-res guidance depicts very isolated showers developing over the I-40 corridor through early this evening, but confidence was much too low for a mention in the TAFs. Otherwise, expect a steady SW wind with low-end gusts up to 20mph this afternoon, and light/variable winds overnight.

Outlook: A cold front will cross the area Sunday night into early Monday, bringing another round of rain and associated flight restrictions. Dry and VFR conditions will return by Tuesday.

GSP WATCHES/WARNINGS/ADVISORIES

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