textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

An Increased Fire Danger Statement was issued for northeast Georgia for this afternoon.

Minor changes were made to the forecast Wednesday and beyond, but the general trend toward wetter conditions through the end of the week remains the same.

Cold Weather Advisory remains in effect for portions of the North Carolina mountains through 7 AM this morning.

KEY MESSAGES

1. Cold wind chills continue early this morning with a cold weather advisory across portions of the mountains. Temperatures quickly moderate through the early week. 2. Low relative humidity and dry fuel moistures have prompted an Increased Fire Danger Statement for northeast Georgia, valid from noon to 7 PM today. Outdoor burning will be more dangerous than usual. Refer to local burn permitting authorities on whether you can burn today. If you do burn, use extreme caution. 3. Precipitation chances return Wednesday and stick around through the weekend. Warm and above normal highs linger through Thursday before cooler and below normal highs return Friday into the weekend.

DISCUSSION

Key message 1: Cold wind chills continue early this morning with a cold weather advisory across portions of the mountains. Temperatures quickly moderate through the early week.

Deep layer northwest flow persists across much of the Appalachians as an upper trough slides across New England and offshore. Winds have relaxed since sunset, but gusts should remain high enough across the mountains to result in cold wind chills as low as 5 below with lows in the teens to single digits. As such, the cold weather advisory will continue through the early Sunday morning hours. Elsewhere, low temperatures will be in the upper teens to mid 20s with light to calm winds outside of the mountains. A warming trend begins today and continues into midweek as northwest flow gives way to flat upper ridging building across the Gulf States into the Southern Appalachians. Warmer, but still below average highs continue today but rapidly warm into the mid to upper 60s by Tuesday with a few readings around 70 not out of the question. A few flurries cannot be ruled out during the daytime hours today across portions of the northern NC foothills and Piedmont as a fast moving clipper dives towards the area, but large dewpoint depressions should generally preclude much more than a stray flurry or two at best. Otherwise, the forecast remains dry.

Key message 2: Low relative humidity and dry fuel moistures have prompted an Increased Fire Danger Statement for northeast Georgia, valid from noon to 7 PM today. Outdoor burning will be more dangerous than usual. Refer to local burn permitting authorities on whether you can burn today. If you do burn, use extreme caution.

Fuel moisture readings from RAWS stations in Northeast Georgia dropped below 8 percent in the very dry and windy conditions on Saturday afternoon. Winds will be much lighter today, though relative humidity will be almost as low as it was Saturday, dropping below 25 percent for most of the afternoon. The dry fuels and low humidity together suggest outdoor fires could easily get out of control, and meet the Georgia state criteria for Increased Fire Danger (IFD). A Special Weather Statement (SPSGSP) is being issued to highlight the risk. RH should drop below 25 percent by noon and remain that low through 7 PM. See the SPS for more details.

In NC and SC, despite RH below 30 percent in most areas, state agencies consider wind to be an additional factor in wildfire danger, and winds will be too light to meet the combined criteria. Furthermore, as of Friday, fuels were still considered to be wet following the recent ice and snow.

Key message 3: Precipitation chances return Wednesday and stick around through the weekend. Warm and above normal highs linger through Thursday before cooler and below normal highs return Friday into the weekend.

A cold front will track across the western Carolinas on Wednesday before stalling across the Deep South Thursday into Friday. This front will bring precipitation chances back starting early Wednesday. Surface high pressure attempts to build in from the north across the central and eastern CONUS behind the front Wednesday night into Thursday which would act to shunt any lingering moisture along the stalled frontal boundary south of the forecast area. This may allow dry conditions to return anytime from Wednesday evening into Friday but confidence is very low as model guidance sources are not in agreement regarding how far south the surface high will build. Global models then depict a surface low pressure system developing near the Ark-La-Tex region late Friday into early Saturday before tracking across the forecast area sometime this weekend, bringing precipitation chances back. However, confidence on timing of precipitation over the weekend is very low as guidance differs regarding the exact track and evolution of both the low pressure system and the surface high.

Depending on how much cold air can build into the region behind the cold front and ahead of the low pressure system, wintry p-types of snow and/or freezing rain may return at times Wednesday night into the weekend (mainly across portions of western North Carolina for now). This potential will also be highly dependent on the timing of precipitation and whether it overlaps with the cold air. Thus, confidence on p-types remains very low at this time.

Warm and above normal temperatures linger through Thursday before cooler and below normal temperatures return Friday into the weekend. Highs on Wednesday will remain ~7-12 degrees above normal with temps east of the mountains climbing into the 60s. Highs drop back into the 40s and 50s for most locations Friday into the weekend leading to highs ~3-6 degrees below normal. Lows each night should remain a few to several degrees above normal.

AVIATION /06Z SUNDAY THROUGH THURSDAY/

At KCLT and elsewhere: VFR. Gap wind appears to be responsible for the gusty winds still being reported at KGSP and KAVL as of issuance time; other sites are mostly NW to NNE but light and 6 kt or less. As winds veer thru the predawn hours winds should diminish at KGSP/KAVL. Midlevel clouds at FL080-110 will begin to filter in close to daybreak, forming cigs at KCLT and KHKY after 12 UTC which linger thru the rest of the day. A stray flurry of snow is not out of the question at those sites though of no impact. Cigs scatter/lift during the afternoon though clouds at similar level may be seen at all sites thru the rest of the period. Winds mainly NE in first few hours of the day (except NW at KAVL) then flip to a S to SW direction late morning to early afternoon for the most part. Went VRB at KAVL in the afternoon due to very light winds and usual behavior in SW'ly flow. KCLT looks to flip back to ENE after sunset; elsewhere went VRB or calm at that time.

Outlook: Dry, VFR conditions are expected through Monday. Moisture will return during the middle part of the week, which could result in some ceiling restrictions.

GSP WATCHES/WARNINGS/ADVISORIES

GA...INCREASED FIRE DANGER from noon EST today through this evening for GAZ010-017-018-026-028-029. NC...Cold Weather Advisory until 7 AM EST this morning for NCZ033- 048>052-059. SC...None.