textproduct: Greenville-Spartanburg

SYNOPSIS

A warm front crosses our area tonight bringing above normal temperatures from Wednesday through the weekend. Moisture increases late this week as low pressure tries to organize to the west of our area, with gradually increasing rain chances.

NEAR TERM /THROUGH WEDNESDAY/

As of 1240 PM Tuesday: A compact upper trough will track across the Central Appalachians tonight, as it rides an upper ridge that will only briefly flatten across the Southeast. At the sfc, an associated low pres system will track across the Ohio Valley and reach the Mid-Atlantic by 12z Wednesday. This system will bring a warm front thru the forecast area tonight. The actual front will only bring some increase in mid and high clouds across the area and keep the BL a little mixed. However, an area of disorganized showers and a few embedded thunderstorms will develop within the warm sector over the TN Valley and track into the NC mountains overnight. No sfc-based CAPE is expected, but a couple hundred J/kg of MUCAPE may be enough for a slight chc of thunder in the Smokies. Otherwise, spotty light to moderate showers will work into the mountains and generally fizzle out before reaching the Piedmont. The latest NBM PoPs seem to be handling this well. Lows will be 10-15 deg above normal.

Wednesday, the upper ridge will begin to reassert itself over the Southeast, while the sfc low pushes off the Mid-Atlantic coast. A trailing cold front will backdoor into the NC Piedmont in the aftn. But westerly 850 mb flow combined with warm thicknesses will allow temps to top out in the mid to upper 70s east of the mountains under partly to mostly sunny skies. The latest NBM highs are within a couple degrees of records at KGSP and KCLT (see climate section below). Fortunately, dewpts will be much higher behind the warm front and RH values should not be as low as last few days for fire wx concerns.

SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/

As of 1205 PM EST Tuesday: An upper ridge axis moves east of the area through the period as some weak short wave energy moves near the area in the developing westerly flow. At the surface, a weak frontal boundary over the area Thursday lifts back northward as a warm front as a low pressure center moves along it over the OH River valley. Moisture begins increasing across the area in the developing low level southwesterly flow, bringing a chance of rain mainly to the mountains Thu nite into Fri. Lows Wed nite 10 to 15 degrees above normal rise to 15 to 20 degrees above normal Thu nite, easily keeping all precip liquid. Highs around 10 degrees above normal Thu rise to around 15 degrees above normal for Friday.

LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/

As of 1245 PM EST Tuesday: An amplified synoptic pattern develops during the extended forecast period. A weakening upper low crosses the area Saturday with a general northwesterly flow over the area through Monday. On Tuesday, a deep upper low that starts the period over the 4 Corners region, moves into the Mid-South while a short wave ridge ahead of the low moves over our area. At the surface, a weak low associated with the first upper low crosses the area Saturday keeping a chance of showers over the region. Cooler, dry high pressure builds in Sunday and Monday, then moves east Tuesday as a stronger low pressure system moves into the lower MS Valley. This may bring a chance of showers by late in the day. Highs around 15 degrees above normal Saturday, fall to 5 to 10 degrees above normal Sunday and Monday, then around 5 degrees above normal on Tuesday. Lows start out around 20 degrees above normal falling to around 10 degrees above normal by the end of the period.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

At KCLT and elsewhere: VFR conditions expected thru the period. Main concern will be 30-40 kt of SW to WSW wind only 1000-2000 ft AGL tonight for mainly the NC TAF sites. A cold front will approach from the NW and bring some increase in mainly mid and high clouds tonight along with scattered showers. The showers will push into the NC mountains around midnight, but struggle to hold together as they track east. So will continue to only advertise PROB30 for SHRA at KAVL and KHKY in the 06-10z time frame. Confidence still too low to mention at KCLT or the Upstate sites, but a brief, stray shower cannot be ruled out before 12z Wed. The sfc front will push in from the north Wednesday aftn. This should toggle winds from SW to NW at KCLT after 18z. Winds will shift earlier at KAVL with LLWS diminishing.

Outlook: Mostly VFR through the work week, albeit with increasing potential for early morning fog/low stratus...mainly across the mountain valleys. The next front could bring showers and restrictions early in the weekend.

FIRE WEATHER

After collaboration with the FFC office, we have issued a Fire Danger Statement for our NE GA counties for this afternoon thru 6 PM this evening. RH values expected to dip to just below 25% for up to 4 hours this aftn. Winds will be out of the south around 5-10 mph. The FDS in our NC counties looks good.

Humidity and temperatures steadily increase tonight through mid- week, but one more afternoon of near critical RH is likely today, with minimums of around 25% expected for much of the area. Winds will be well below critical levels, but the occasional gust of 15-20 mph is possible this afternoon. Per collaboration with land management agencies and the NC Weather Forecast Offices, a Fire Danger Statement has been issued to encompass much of our NC zones for this afternoon for low RH and the very dry antecedent conditions. Although RH should remain above critical levels for the remainder of the week, very warm temperatures will return. This could create a low-end wildfire risk given low 10-hour fuel moisture values.

CLIMATE

RECORDS FOR 11-19

MAX TEMPERATURE MIN TEMPERATURE STATION HIGH LOW HIGH LOW ------- ---------- ---------- ---------- ---------- KAVL 75 1894 29 1951 65 1906 13 1903 KCLT 78 1942 38 1903 68 1906 14 2014 KGSP 78 1890 40 2000 63 1931 18 2014 1903

RECORDS FOR 11-20

MAX TEMPERATURE MIN TEMPERATURE STATION HIGH LOW HIGH LOW ------- ---------- ---------- ---------- ---------- KAVL 76 1942 20 1914 61 1985 9 1914 KCLT 79 1942 37 1914 61 1906 18 1951 KGSP 78 1942 38 1901 59 1985 19 1903 1896 1931

RECORDS FOR 11-21

MAX TEMPERATURE MIN TEMPERATURE STATION HIGH LOW HIGH LOW ------- ---------- ---------- ---------- ---------- KAVL 76 1994 24 1937 60 1931 11 1914 KCLT 78 1942 38 1937 64 1991 19 1914 1879 KGSP 78 1942 38 1914 64 1991 17 1914

RECORDS FOR 11-22

MAX TEMPERATURE MIN TEMPERATURE STATION HIGH LOW HIGH LOW ------- ---------- ---------- ---------- ---------- KAVL 74 1940 32 1937 57 1934 15 2008 1937 KCLT 76 2011 38 1929 65 1883 13 2008 KGSP 77 2011 38 1937 58 1953 18 1914

GSP WATCHES/WARNINGS/ADVISORIES

GA...Increased Fire Danger until 6 PM EST this evening for GAZ010- 017-018-026-028-029. NC...Increased Fire Danger until 6 PM EST this evening for NCZ035>037-048>050-053-056-057-065-068>072-082-501>510. SC...None.