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 270221
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1021 PM EDT SUN OCT 26 2014

.SYNOPSIS...
HIGH PRESSURE WILL GIVE WAY TO A PROGRESSIVELY WARMER SOUTHWEST FLOW
OF AIR BEFORE A COLD FRONT CROSSES THE REGION ON WEDNESDAY. STEADILY
COOLER TEMPERATURES WILL BE THEN SEEN INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH MONDAY/...
AS OF MID EVENING...THE FCST STILL LOOKS LIKE IT IS ON TRACK. NO
CHANGES.

REMAINDER OF PREVIOUS DISCUSSION...

SURFACE HIGH PRESSURE SLIDES OVERHEAD THROUGH THE OVERNIGHT HOURS
LEADING TO A RELAXING PRESSURE GRADIENT UNDER CLEAR SKIES.  SURFACE
MOISTURE FIELDS ARE NOT ALL THAT IMPRESSIVE AS IT PERTAINS TO FOG
OVERNIGHT DUE TO CONTINUED CAA PATTERN THROUGH TODAY AND TONIGHT.
THAT SAID...WITH WINDS CALMING UNDER ABOVE MENTIONED CLEAR SKIES
WOULD NOT BE SURPRISED TO SEE SOME RADIATION FOG IN THE MOUNTAIN
VALLEYS ESPECIALLY THE LITTLE TN RIVER VALLEY WHERE DENSE FOG COULD
FORM.

STRONG UPPER RIDGE WILL MAINTAIN CONTROL ACROSS THE SOUTHEAST CONUS
ON MONDAY WHILE THE ABOVE MENTIONED SURFACE HIGH SLIDES EAST.  THIS
WILL ALLOW FOR THE RETURN OF SOUTHERLY FLOW AND INCREASED LOW LEVEL
MOISTURE BY PERIODS END.  THAT SAID...MOISTURE FLUX IS EXPECTED TO
BE MINIMAL THROUGH THE MAJORITY OF THE DAY ALLOWING FOR SKIES TO
REMAIN MOSTLY SUNNY REGIONWIDE.  TEMPERATURES ON MONDAY WILL ONCE
AGAIN BE NEARLY AN ORDER OF MAGNITUDE ABOVE NORMAL.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 245 PM...SURFACE TO H5 RIDGE AXIS ROUGHLY ACROSS THE SOUTHEAST
PART OF THE COUNTRY WILL SHIFT EAST MONDAY NIGHT AND TUESDAY. WHILE
THIS IS HAPPENING AN UPPER LEVEL LOW WILL BE AMPLIFYING ACROSS THE
UPPER MIDWEST. THE UPPER LEVEL LOW WILL HAVE A BROAD TROF EXTENDING
INTO THE MISSOURI VALLEY. SENSIBLE SHORT TERM WEATHER WILL BE FOR
FAIR SKIES MONDAY NIGHT/TUESDAY ACROSS OUR FORECAST AREA (FA). WE
HAVE NOT STRAYED FAR FROM THE LOW TEMPERATURE SUITE OF GUIDANCE
MONDAY NIGHT BUT HAVE GONE ABOVE GUIDE TUESDAY...WITH AMPLE
SUNSHINE...BRISK AND GUSTY SOUTHWEST WINDS...AND DRY ANTECEDENT
CONDITIONS. THE RETURN SOUTHWESTERLY FLOW SHOULD ADVECT LOW LEVEL
MOISTURE INTO OUR REGION BUT WILL HAVE TO KEEP AN EYE ON ANY FIRE
DANGER ISSUES.

BASED ON THE GFS/EUROPEAN GUIDE WE HAVE SLOWED PRECIPITION INTO OUR
REGION UNTIL AFTER MIDNIGHT/WEE HOURS WEDNESDAY MORNING...AND HAVE
REMOVED ELSEWHERE. CLOUDS HOWEVER SHOULD BE ON THE UPTICK TUESDAY
NIGHT ACROSS THE FA...WHICH WILL HELP KEEP TEMPERATURES FROM FALLING
MUCH.

THE UPPER LEVEL LOW WILL BE SHIFTING TO THE EASTERN GREAT LAKES ON
WEDNESDAY...WHILE THE TROF EXTENDING SOUTH DEAMPLIFIES. MEANWHILE...
AN ASSOCIATED COLD FRONT WILL EASE ACROSS THE REGION WEDNESDAY.
POOLING OF MOISTURE AND CONVERGENCE ALONG SAID FRONT...COUPLED WITH
SUBTLE HEIGHT FALLS...SHOULD BE ENOUGH TO BRING CHANCE PRECIPITATION
ACROSS OUR REGION. LOOKING AT INSTABILITY PARAMETERS...THE GFS AND
SREF BOTH SHOW ENOUGH INDICATORS FOR CHANCE OF AFTERNOON
THUNDERSTORMS IN PARTS OF NE GA...UPSTATE SC...THEN EXTENDING ALONG
AND NORTH OF THE I85 CORRIDOR. TEMPERATURES SHOULD BE HELD DOWN
WEDNESDAY WITH CLOUDS AND POTENTIAL PCPN.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 215 PM SUN...THE WED COLD FRONT MOVES EAST OF THE AREA WED
NITE TAKING DEEP MOISTURE AND FORCING WITH IT. PRECIP WILL END FROM
WEST TO EAST WED NITE...WITH A DRY AND COOLER THU AS HIGH PRESSURE
BUILDS IN.

GUIDANCE CONTINUES TO VARY FROM RUN TO RUN REGARDING THE LATE WEEK
SYSTEM MOVING ACROSS THE ERN US. ENSEMBLES AND WPC PREFERS A MORE
OPEN AND FASTER MOVING SYSTEM...WHICH IS CLOSER TO THE GFS SCENARIO.
BROAD ERN TROF DEEPENS THU NITE AS A WEAK CLIPPER TYPE SHORT WAVE
DIGS INTO THE TROF. THE TROF AXIS THEN MOVES EAST FRI AND SAT AS A
SECONDARY CLIPPER SHORT WAVE MOVES NORTH OF THE AREA KEEPING NWLY
FLOW IN PLACE. A RIDGE AXIS MOVE TOWARD THE AREA SUN. THE ECMWF IS
MUCH STRONGER AND DEEPER WITH THE SECONDARY CLIPPER...WHILE THE GFS
KEEPS MOST OF THE ENERGY NORTH OF THE CWFA AND DOES NOT CLOSE OFF AN
UPPER LOW UNTIL THE SYSTEM IS OVER NEW ENGLAND SAT. WITH THE
PREFERRED GFS SCENARIO...THERE WILL BE SOME NW FLOW PRECIP POTENTIAL
ACROSS THE TN BORDER COUNTIES...HOWEVER POP KEPT AT SLIGHT CHC FOR
NOW. SYSTEM IS COLD ENUF THAT PRECIP COULD CHANGE TO SNOW ACROSS THE
HIGHEST ELEVATIONS BEFORE ENDING...BUT LIMITED MOISTURE AND DURATION
SUGGESTS NO ACCUM POTENTIAL. DRY FORECAST EXPECTED ELSEWHERE AND FOR
THE REST OF THE PERIOD. LOWS FALL TO 5 TO 10 DEGREES BELOW NORMAL BY
THE END OF THE PERIOD...SUGGESTING FROST/FREEZE POTENTIAL ACROSS
MUCH OF THE AREA. HIGHS FALL TO 10 TO 15 DEGREES BELOW NORMAL BY THE
END OF THE PERIOD.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS ARE EXPECTED THRU MONDAY AT
ALL TAF SITES...COURTESY OF HIGH PRESSURE MOVING OVERHEAD TONIGHT
AND THEN OFF THE NC COAST MONDAY AFTERNOON. WIND WILL BE LIGHT FROM
THE NW OR VARIABLE THIS EVENING...AND WILL PROBABLY GO CALM AT MOST
LOCATIONS DURING THE EARLY MORNING HOURS. WHEN THE LIGHT WIND
RETURNS LATE MONDAY MORNING...IT SHOULD BE FROM THE SE OR S AS THE
CENTER OF THE HIGH MOVES TO OUR EAST. SOME FOG IS POSSIBLE MAINLY IN
THE LITTLE TN RIVER VALLEY. THERE IS A SMALL CHANCE THAT SOME FOG
COULD MOVE OFF THE RIVER NEAR KAVL AND THE LAKE NEAR KAND AROUND
DAYBREAK...BUT THE CHANCE IS TOO SMALL TO INCLUDE IN THE TAF AT THIS
TIME. SKY SHOULD REMAIN CLEAR THROUGH MONDAY.

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...RWH
NEAR TERM...CDG/PM
SHORT TERM...TS
LONG TERM...RWH
AVIATION...PM



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