704
FXUS62 KGSP 181431
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
931 AM EST TUE NOV 18 2025
SYNOPSIS
COOL, DRY HIGH PRESSURE WILL MOVE OFF THE EAST COAST TODAY AS A WARM
FRONT BRINGS ABOVE NORMAL TEMPERATURES FROM WEDNESDAY THROUGH THE
WEEKEND. MOISTURE INCREASES LATE THIS WEEK AS LOW PRESSURE TRIES TO
ORGANIZE TO THE WEST OF THE AREA, WHICH GRADUALLY INCREASE RAIN
CHANCES.
NEAR TERM /THROUGH TONIGHT/
AS OF 915 AM TUESDAY: AN UPDATE TO THE TEMPS AND DEWPTS TO REFLECT
VERY DRY AIR STILL IN PLACE TODAY. BASED ON LAST COUPLE DAYS,
WENT STRAIGHT 10TH PERCENTILE NBM DEWPTS FOR THIS AFTN. THUS,
CRITICAL RH STILL EXPECTED AGAIN THIS AFTN AND WARRANTING A FIRE
DANGER STATEMENT FOR NE GA (SEE FIRE WEATHER SECTION BELOW). THE
REST OF THE FORECAST LOOKS ON TRACK.
OTHERWISE...WEAK LOW LEVEL RETURN FLOW WILL STEADILY BECOME
ESTABLISHED ACROSS THE REGION TODAY...IN RESPONSE TO HEIGHT FALLS
ASSOCIATED WITH A COMPACT UPPER LOW THAT WILL OPEN UP AND WEAKEN
AS IT EXPEDITES FROM THE CENTRAL GREAT PLAINS EARLY THIS MORNING
TO THE MID-ATLANTIC COAST BY THE END OF THE PERIOD. THE S/SW FLOW
AND MORE SHALLOW MIXING INDICATES DEWPOINTS SHOULD NOT CRATER AS
MUCH THIS AFTERNOON AS IN THE PREVIOUS TWO DAYS...BUT THE AIR MASS
WILL REMAIN VERY DRY JUST OFF THE SURFACE, AND IT STANDS TO REASON
THAT SOME OF THAT WILL MIX TO THE SURFACE THIS AFTERNOON...LIKELY
RESULTING IN MARGINALLY CRITICAL RH. SEE THE FIRE WX DISCUSSION
FOR ADDITIONAL DETAILS. MAX TEMPS ARE FORECAST TO BE A COUPLE OF
DEGREES WARMER THAN ON MONDAY IN MOST AREAS...MORE THAN 5 DEGREES
ABOVE CLIMO.
AS HEIGHT FALLS OVERSPREAD THE OHIO VALLEY LATE TODAY THROUGH
TONIGHT...RESPONDING LOW LEVEL FRONTOGENESIS WILL RESULT IN
WIDESPREAD SHOWER DEVELOPMENT TO OUR NW THROUGHOUT TODAY...WITH SOME
OF THIS ACTIVITY MAKING A RUN TOWARD THE NC MOUNTAINS AS WELL AS
THE I-40 CORRIDOR OVERNIGHT. HAVING SAID THAT, PASSAGE OF THE DEEPER
FORCING TO OUR NORTH, A LACK OF APPRECIABLE INSTABILITY TO SUPPORT
SHOWER MAINTENANCE, AND UNDERWHELMING MOISTURE PROFILES SUGGEST
SHOWERS WILL HAVE DIFFICULTY MAKING INROADS INTO THE CWA. 60- 80
POPS (FOR LOW QPF MOSTLY OF .25" OR LESS) ARE ADVERTISED FOR THE
NC COUNTIES BORDERING TN TONIGHT, BUT CHANCES QUICKLY DIMINISH
TO THE SOUTH AND EAST, WITH <20% CHANCES FOR THE I-85 CORRIDOR
AND POINTS SE. IN LIGHT OF WEAK, ELEVATED CAPE, CAN'T RULE OUT
A STRAY THUNDERSTORM IN THE WESTERN ZONES, BUT CHANCES ARE ONLY
10-20%. MIN TEMPS WILL BE AROUND 10 DEGREES ABOVE NORMAL IN THE
RELATIVELY MOIST/RELATIVELY WELL-MIXED WARM SECTOR REGIME.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
AS OF 1207 AM EST TUESDAY: ACTIVE SOUTHERN STREAM JET STREAM WILL BE
DRAPED FROM THE SOUTHERN PLAINS THROUGH THE MIDWEST AND OH VALLEY
DURING THE FORECAST PERIOD. LEADING SHORTWAVE WILL BE IN THE MIDST
OF EXITING THE MID-ATLANTIC COAST AT THE BEGINNING OF THE FORECAST
PERIOD. A WEAK, DIFFUSE FRONTAL BOUNDARY LOOKS TO SAG SOUTH OVER THE
AREA WEDNESDAY, WITH AN OROGRAPHIC COMPONENT CAPABLE OF SPARKING
A FEW SHOWERS ALONG THE NC/TN BORDER, WHILE THE BETTER FORCING
FOR ASCENT AND MOISTURE REMAINS NORTH OF THE CWFA. A CLOSED UPPER
LOW GRADUALLY SHIFTS FROM SOUTHERN CALIFORNIA TO THE FOUR CORNERS
DURING THE SHORT TERM AND HELPS TO SHARPEN THE JET STREAK, WHICH
ALLOWS AN UPPER RIDGE TO BUILD OVER THE AREA BEHIND THE DEPARTING
SHORTWAVE. DEEP LAYER SOUTHWESTERLY FLOW FROM THE SOUTHERN PLAINS
THROUGH THE MIDWEST WILL BRING DEEP MOISTURE ACROSS THIS REGION,
INFLUENCED BY AN EMBEDDED BAROCLINIC ZONE AND FORCING FOR ASCENT. A
FEW SHOWERS MAY SCRAPE BY THE MOUNTAINS BY THURSDAY NIGHT ONCE THIS
SETUP BECOMES FULLY ESTABLISHED, BUT UPPER RIDGING WILL CONTROL
THE OVERALL PATTERN AND SUPPRESS MUCH IN THE WAY OF QPF RESPONSE
ACROSS THE REST OF THE CWFA. RISING HEIGHTS FROM THE BUILDING
UPPER RIDGE OVER THE EASTERN CONUS WILL LEAD TO AFTERNOON HIGHS ON
WEDNESDAY AND THURSDAY TOPPING OUT IN THE LOW TO UPPER 70S, WITH
A FEW LOCATIONS LIKELY REACHING 80. OVERNIGHT LOWS WILL INDUCE A
WARMING TREND AS WELL WITH A WARM AND MOIST AIR MASS SETTLING IN,
KEEPING DEWPOINTS ELEVATED IN THE 50S. IN THIS CASE, OVERNIGHT
LOWS ON WEDNESDAY AND THURSDAY WILL RUN 12-18 DEGREES ABOVE NORMAL.
LONG TERM /FRIDAY THROUGH MONDAY/
AS OF 1242 AM EST TUESDAY: AN AMPLIFIED SYNOPTIC PATTERN WILL
BE UNDERWAY DURING THE EXTENDED FORECAST PERIOD AS THE CLOSED
UPPER LOW FROM THE SHORT-TERM OVER THE FOUR CORNERS REGION EJECTS
WITHIN THE AFOREMENTIONED SOUTHERN STREAM JET AND OPENS UP OVER THE
CENTRAL CONUS ON FRIDAY. FLOW BECOMES STEADILY MORE COMPLEX AND
SPLIT AS A SECOND CLOSED UPPER LOW DIGS OVER THE DESERT SOUTHWEST
AND A CLOSED UPPER LOW SHIFTS INTO EASTERN CANADA WITH THE NORTHERN
STREAM JET. AS A RESULT, THE SOUTHERN STREAM JET LOOSELY SHIFTS SOUTH
AS ACTIVE SHORTWAVES MOVE WITHIN THE MEAN FLOW OF THE JET. MODEL
GUIDANCE STILL HAVE A HARD TIME COMING TO A REAL CONSENSUS ON
THE SENSIBLE WEATHER FOR THE CWFA DUE TO THE COMPLEXITY OF THE
PATTERN. THE MAIN SHORTWAVE THAT TRAVERSES TOWARDS AND OVER THE
AREA SEEMS TO OCCUR SOMETIME OVER THE WEEKEND. POPS HAVE ESCALATED
AS THE NBM PICKS UP ON BETTER AGREEMENT FOR PRECIP, BUT OVERALL
TIMING AND AMOUNTS VARY A GOOD BIT. THE LATTER HALF OF THE EXTENDED
WILL FALL ON WHAT HAPPENS TO THE SECOND CLOSED UPPER LOW OVER THE
SOUTHWESTERN CONUS AND HOW FAR SOUTH OR NORTH IT TRAVELS ONCE IT
DEPARTS FROM THIS REGION AND ENCROACHES THE EASTERN CONUS BY THE
VERY END OF THE FORECAST PERIOD. ANOMALOUSLY HIGH HEIGHTS REMAIN IN
PLACE THROUGH MUCH OF THE EXTENDED PERIOD, RESULTING IN TEMPERATURES
10-15 DEGREES ABOVE NORMAL THROUGH THE EARLY PART OF NEXT WEEK.
AVIATION /14Z TUESDAY THROUGH SATURDAY/
AT KCLT AND ELSEWHERE: A VERY DRY AIR MASS WILL SUPPORT CONTINUED
VFR/MOSTLY SKC CONDITIONS ACROSS THE TERMINAL FORECAST AREA
THROUGH THIS FORECAST PERIOD. AN AREA OF DIMINISHING RAIN SHOWERS
ASSOCIATED WITH A WEAKENING COLD FRONT WILL APPROACH THE AREA
OVERNIGHT, AND PROB30S FOR -SHRA ARE ADVERTISED ONLY AT KAVL AND
KHKY. RELATED TO THIS, A BRIEF PERIOD OF VFR CIGS IN THE 040-60
RANGE IS POSSIBLE AT THE NC TERMINALS BETWEEN 06-12Z. CALM OR
LIGHT/VARIABLE WINDS EARLY THIS MORNING WILL BECOME S/SW AT 5-10
KTS BY EARLY AFTERNOON...DECREASING SLIGHTLY DURING THE EVENING,
WITH DIRECTIONS STEADILY BECOMING MORE W/SW THROUGH THE OVERNIGHT.
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.
SYNOPSIS...CAC
NEAR TERM...ARK/JDL
SHORT TERM...CAC
LONG TERM...CAC
AVIATION...JDL
FIRE WEATHER...JDL/ARK
CLIMATE...
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