Area Forecast Discussion
Issued by NWS Greer, SC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KGSP 271043
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
643 AM EDT MON OCT 27 2014

.SYNOPSIS...
HIGH PRESSURE WILL GIVE WAY TO A PROGRESSIVELY WARMER SOUTHWEST
FLOW BEFORE A COLD FRONT CROSSES THE REGION ON WEDNESDAY. A LARGE
AREA OF HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST LATE IN THE
WEEK HEADING INTO THIS WEEKEND...RESULTING IN MUCH COOLER
TEMPERATURES.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM...CLEAR AND CALM CONDITONS CONTINUED ACROSS THE REGION.
THE COMBINATION OF FULL SUNLIGHT...LIGHT RETURN FLOW...AND MILD LLVL
TEMPS SHOULD PUSH HIGHS WITHIN 5 DEGREES OF RECORDS ACROSS THE
SC PIEDMONT.

RECORDS...
GSP  86      1891
CLT  86      1939 / 1919
AVL  85      1939

AS OF 330 AM...NEAR TERM GUIDANCE AGREES THAT THE AXIS OF THE H5
RIDGE WILL RIPPLE OVER THE FORECAST AREA THIS AFTERNOON. AT THE
SFC...THE CENTER OF HIGH PRESSURE IS FORECAST TO PUSH OFF THE
CAROLINA COAST AS A COLD FRONT SWEEPS ACROSS THE CENTRAL CONUS. THIS
PATTER WILL PROVIDE LIGHT SOUTH WINDS THROUGH THE DAYLIGHT HOURS. I
WILL BASE THE HIGH TEMPERATURE FORECAST GENERALLY ON PERSISTENCE
FROM SUNDAY. AFTERNOON RH VALUES MAY FALL INTO THE LOW TO MID 20S
ACROSS THE NC PIEDMONT. TONIGHT...THE CWA WILL REMAIN UNDER MID
LEVEL RIDGING WITH HIGH PRESSURE CENTERED OVER THE WESTERN ATLANTIC.
WINDS SHOULD REMAIN LIGHT FROM THE SOUTH AS A COLD FRONT REACHES THE
OHIO RIVER VALLEY. SKY SHOULD REMAIN CLEAR TONIGHT. MIN TEMPS ARE
FORECAST TO RANGE FROM THE MID 40S ACROSS THE MTNS TO LOW 50S EAST.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM MONDAY...THE LARGE HIGH PRES SYSTEM WILL SHIFT EAST
OFF THE EAST COAST ON TUESDAY...AS BROAD LONGWAVE TROF ENTERS THE
MIDWEST. INCREASING SWLY LLVL FLOW AND ANOTHER SUNNY DAY SHUD
RESULT IN ONE LAST VERY WARM AFTN ACRS THE CWFA.

MODELS IN GOOD AGREEMENT ON THE TIMING/DEPICTION OF A COLD FROPA ON
WEDNESDAY. THE BULK OF UPPER ENERGY AND THE PARENT SFC LOW WILL LIFT
INTO ONTARIO...WHILE THE SRN EXTENT OF THE FRONT LOSES STEAM. A
NARROW BAND OF RH WILL ACCOMPANY THE FRONT AS IT SAGS SOUTHEASTWARD
THRU THE AREA DURING THE DAY ON WEDNESDAY. BOTH THE NAM AND GFS
INDICATE SCATTERED SHWRS WITH SBCAPE OF 500-800 J/KG ACRS THE
UPSTATE AND SRN NC PIEDMONT BY MID AFTN. I WILL CONTINUE TO INDICATE
A CHC POP WITH MENTION OF THUNDER ACRS THE SRN HALF OF THE CWFA.
TEMPS WILL CONTINUE TO BE ABOVE NORMAL...BUT NOT AS WARM AS
TUESDAY...ESP ACRS THE MTNS WHERE CLOUDS SHUD MOVE IN BEFORE PEAK
HEATING OF THE DAY. THE FRONT AND ASSOCIATED SHWRS SHUD EXIT TO THE
SE WEDNESDAY EVENING. TEMPS WILL RETURN TO AROUND NORMAL FOR
OVERNIGHT LOWS.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...A FAIRLY SHARP UPPER TROF WILL DIG ACRS THE
CAROLINAS TO FL ON THURSDAY...THEN A STRONG REINFORCING SHORTWAVE
TROF WILL FOLLOW ON FRIDAY. THIS WILL ALLOW A COLD CONTINENTAL AIR
MASS TO DROP SOUTH OUT OF CANADA AND BUILD ALL THE WAY INTO THE
GULF OF MEXICO BY SATURDAY. THIS WILL USHER IN THE COLDEST TEMPS
OF THE FALL SO FAR...WITH A SOLID FREEZE LIKELY IN THE MTNS AND
FROST AND POSSIBLE FREEZE IN THE PIEDMONT SATURDAY NIGHT. FROST
AND FREEZE CONCERNS WILL ALSO BE LIKELY IN THE MTNS FRIDAY
NIGHT...AS STRONG COLD ADVECTION DROPS 850MB TEMPS BELOW 0C ALONG
THE TN BORDER. LITTLE IF ANY MOISTURE WILL BE AVAILABLE FOR PRECIP
WITH EITHER SURGE OF COLD AIR. SO I AM GOING WITH A DRY FCST THRU
THE MEDIUM RANGE WITH A SHARP COOLING TREND. TEMPS THURSDAY AND
FRIDAY WILL BE ABOUT 5 DEG BELOW NORMAL...THEN 10-15 DEG BELOW
NORMAL FOR SATURDAY AND SUNDAY. WINDS MAY ALSO BE A CONCERN IN THE
MTNS WITH THE BIG SURGE OF COLD AIR FRIDAY NIGHT AND SATURDAY.
ACCORDING TO THE 00Z GUIDANCE...IT LOOKS LIKE THEY SHUD REMAIN
UNDER WIND ADVISORY CRITERIA.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS EXPECTED EAST OF THE
MTNS THROUGH THE PERIOD. THE CENTER OF SFC HIGH PRESSURE WILL PASS
TO THE NORTH OF THE REGION THIS MORNING. AS THE CENTER
PASSES...LIGHT WINDS SHOULD REMAIN FROM THE NNE OR BECOME CALM.
THROUGH THE REST OF TAF PERIOD...HIGH PRESSURE SHOULD REMAIN OVER
THE WESTERN ATLANTIC AS A COLD FRONT APPROACHES FROM THE NORTHWEST.
SFC WINDS SHOULD BECOME SOUTH BY MID MORNING AND REMAIN THROUGH THE
EVENING. NAM12 AND FORECAST SOUNDINGS INDICATE THAT WEAK DEWPOINT
RECOVER WILL OCCUR TONIGHT...SUPPORTING ONLY A 2 TO 3 DEWPOINT
DEPRESSION WITHIN THE MTN VALLEYS LATE TONIGHT. I WILL HIGHLIGHT THE
FOG POTENTIAL WITH A TEMPO FROM 10Z TO 12Z TONIGHT AT KAVL.

OUTLOOK...DEEP LAYER RIDGING WILL DOMINATE THE PATTERN THROUGH THE
FIRST PART OF THE WORK WEEK LEADING TO QUIET WEATHER AND A LOW
PROBABILITY OF FLIGHT RESTRICTIONS. A COLD FRONT IS EXPECTED TO
CROSS THE REGION ON WEDNESDAY WHICH COULD BRING SOME BRIEF
RESTRICTIONS WITH SHOWERS.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...ARK
NEAR TERM...NED
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...NED



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.