Select Area Forecast Discussions 8-14 October 2014

FXUS62 KGSP 081836
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
236 PM EDT WED OCT 8 2014

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF 200 PM WEDNESDAY...THERE IS STILL A FAIR AMOUNT OF
DISAGREEMENT AMONG THE VARIOUS MEDIUM RANGE MODELS AND ENSEMBLES
WITH A DEEP TROF THAT IS EXPECTED TO DIG ACRS THE CENTER OF THE
CONUS SUN-MON...THEN TRACK ACRS THE EASTERN STATES TUE-WED. THE
GFS/GEFS AND CMC HAVE A LESS DEEP/MORE PROGRESSIVE SHORTWAVE THAN
THE ECMWF/ECENS/UKMET SOLNS...WITH THE OP ECMWF THE DEEPEST/SLOWEST
OF THE GUIDANCE. THE LATEST WPC PREFERENCE IS FOR A COMPROMISE
BETWEEN THE TWO CAMPS...WITH A LEAN TOWARD THE ECMWF. THIS RESULTS
IN QUITE A DYNAMIC SHORTWAVE CROSSING THE CWFA AS IT BECOMES
NEGATIVELY TILTED ON TUESDAY. THE ASSOCIATED SFC CYCLONE WILL TRACK
FROM THE CENTRAL PLAINS TO THE GREAT LAKES...AND PUSH A COLD FRONT
ACRS THE CWFA. THE EXACT TIMING IS STILL UNCERTAIN...BUT THERE SHUD
BE NO WEDGE IN PLACE AHEAD OF THE FRONT...AND WITH SUCH A DEEP
SYSTEM...GULF MOISTURE AND INSTBY SHUD BE PRESENT. THERE WILL ALSO
BE PLENTY OF SHEAR...WITH 0-6 KM BULK SHEAR 50-60 KM OVERLAPPING
400-1000 J/KG MUCAPE. BLENDING IN THE HPCGUIDE POP...I HAVE HIGH-END
CHC TO LIKELY POPS DURING THE DAY ON TUESDAY...TAPERING OFF TUESDAY
NIGHT. IF THE ECWMF VERIFIES...THERE IS A DECENT CHC OF A LINEAR
CONVECTIVE SYSTEM THAT MAY BE STRONG TO SEVERE. CONFIDENCE IS STILL
TOO LOW TO MENTION IN THE HWO AT THIS TIME.

AS THE UPPER TROF QUICKLY LIFTS NE OUT OF THE AREA
WEDNESDAY...EXPECT DRY CONDITIONS WITH SLIGHTLY BELOW NORMAL TEMPS.
&&

ARK

FXUS62 KGSP 090751
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
351 AM EDT THU OCT 9 2014

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 AM THURSDAY...THE 09/00Z GFS HAS NOW COME MORE IN LINE
WITH THE VERY CONSISTENT ECMWF. THE PATTERN BECOMES GREATLY
AMPLIFIED AS A RIDGE BUILDS NEAR THE ATLANTIC COAST AND A DEEP TROF
DEVELOPS ACROSS THE CENTRAL CONUS. THE GFS REMAINS MORE PROGRESSIVE
WHILE THE ECMWF IS ABOUT 12 HOURS SLOWER. THE ECMWF HAS CHANGED
SLIGHTLY...KEEPING THE TROF POSITIVELY TILTED OR NEUTRAL AS IT CROSSES
THE AREA...THEN GOING NEGATIVELY TILTED AND CLOSING OFF AN UPPER LOW
EAST OF OUR AREA. SHUD BE COOL AND RELATIVELY WET DAY SUNDAY AS COLD
FRONT REMAINS STALLED NEAR OR SOUTH OF THE AREA AND HIGH PRESSURE IS
RIDGED INTO THE AREA IN A CAD CONFIGURATION. THE FRONT WASHES OUT
MONDAY WITH WEAK RIDGING REMAINING IN PLACE AS A COLD FRONT
STRENGTHENS NEAR THE MS VALLEY. ANY LINGERING CAD DISSIPATES TUE AS
SFC HIGH CENTER MOVES WELL OFF SHORE AND THE STRONG COLD FRONT MOVES
TOWARD THE AREA. THE GFS MOVES THE FRONT INTO THE AREA TUE THEN EAST
OF THE AREA TUE NITE...WHILE THE ECMWF BRINGS THE FRONT IN TUE NITE
THEN EAST OF THE AREA WED. THE CANADIAN MODEL IS IN BETWEEN THE TWO
BUT TRENDING A LITTLE ON THE SLOWER SIDE. EITHER WAY...CHANCE OF A
HIGH SHEAR/LOW CAPE SCENARIO IS DEVELOPING GIVEN THE STRONG SLY FLOW
AHEAD OF THE FRONT AND DEEP FORCING WITH THE TROF. INSTABILITY
REMAINS WEAK WHILE STRONG SHEAR AND HELICITY DEVELOP. STILL WILL NOT
PUT A MENTION IN THE HWO GIVEN THE TIMING DIFFERENCES AND CONTINUED
UNCERTAINTY. THERE WILL BE SOME LINGERING SHRA BEHIND THE FRONT...
ESPECIALLY ACROSS THE MTNS IN LINGERING LOW LEVEL MOISTURE AND NW
FLOW WHILE DRYING DEVELOPS FROM SW TO NE OUTSIDE OF THE MTNS WED.
TEMPS RETURN ABOVE NORMAL AHEAD OF THE FRONT THEN FALL BEHIND.
&&

RWH


FXUS62 KGSP 091850
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
250 PM EDT THU OCT 9 2014

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
AS OF 230 PM EDT THURSDAY...THE LATEST GLOBAL MODELS ARE IN GOOD
AGREEMENT WITH REGARD TO THE OVERALL SYNOPTIC PATTERN THROUGHOUT
THE MEDIUM RANGE PERIOD...THOUGH THERE IS STILL SOME DISAGREEMENT
ON THE TIMING OF A STRONG FROPA SOMETIME BETWEEN TUE AND WED. HAVE
LEANED MORE TOWARDS TO THE PROGRESSIVE GFS/CMC SOLUTION THAT ARE
FAVORED BY THE WPC.

NEARLY ZONAL FLOW ALOFT SUN NIGHT WILL GIVE WAY TO SWLY BY MON AS A
DEEP UPPER TROUGH APPROACHES FROM THE CENTRAL CONUS WHILE AN UPPER
RIDGE OF HIGH AMPLIFIES OVER THE WESTERN ATLANTIC. AS THE TROUGH
PROGRESSES EASTWARD...THE FASTER GFS CLOSE OFF AN UPPER LOW IN THE
VICINITY OF THE UPPER MISSISSIPPI VALLEY BY AROUND 12Z TUE...AND
LIFT NORTHEASTWARD INTO THE OHIO VALLEY BY AROUND 00Z WED WITH ITS
ASSOCIATED NEUTRALLY TILED TROUGH AXIS CROSSING THE REGION BETWEEN
00Z AND 12Z WED...OFFSHORE BY THU 00Z. THE OLD 00Z ECMWF IS AROUND
18-24HRS SLOWER...WITH THE CMC COMPROMISING BETWEEN THE GFS AND
ECMWF. AN UPPER RIDGING WILL BUILD IN FROM THE WEST THU INTO FRI.
AT THE SURFACE...A PERSISTENT SURFACE WEDGE OVER THE CWA WILL WEAKEN
AND DISSIPATE SUN NIGHT INTO MON AS THE CENTER OF PARENT HIGH
MIGRATES OFF THE NE COAST AND A STRONG COLD FRONT APPROACHES FROM
THE WEST. THE FASTER GFS BRINGS A S-N ORIENTED FRONT TO THE EXTREME
WESTERN ZONES OF THE CWA BY AROUND 12Z TUE AND PROGRESSES EASTWARD
ACROSS THE REGION THROUGH 00Z WED WHILE THE ECMWF IS AROUND 24HRS
SLOWER SUGGESTING THE FROPA WILL OCCUR BETWEEN 00Z WED AND 12Z WED.
THE CMC HAS TRENDED TOWARD THE FASTER GFS SOLUTION. HAVE LEANED MORE
TOWARDS THE FASTER GFS/CMC SOLUTIONS FEATURING 60/70 POPS ON TUE AND
RAMPING DOWN THOUGH TUE NIGHT INTO EARLY WED. THE NEW 12S GFS
CONTINUES TO SHOW IMPRESSIVE LLVL 0-3KM BULK WIND SHEAR OF 40-50KTS
WITH SBCAPE AROUND 300-500J/KG DURING THE FROPA. ALSO...PW VALUES
WILL REACH CLOSE TO 2 INCHES FOR MOST LOCATIONS. THE ECMWF HAS
LESSER DEGREE OF SBCAPE/WIND SHEAR. IN ANY RATE...THERE IS THE TREAT
OF HIGH END LOW SHEAR SEVERE WEATHER AS WELL AS HEAVY RAIN/FLASH
FLOODING. WILL HIGHLIGHT THESE ON THE HWO GIVEN BETTER MODELS RUN TO
RUN CONSISTENCY. DRY CONDITIONS EXPECTED LATE WED INTO THU WITH HIGH
PRESSURE BUILDING IN BEHIND THE FRONT. TEMPERATURES WILL BE NEAR
NORMAL MON/TUE WITH AROUND 3-5 DEGREES NORMAL WED/THU.

&&

JOH


FXUS62 KGSP 100654
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
254 AM EDT FRI OCT 10 2014

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 240 AM EDT FRI...A FULL LATITUDE UPPER TROUGH WILL CONTINUE TO
SHARPEN UP AS IT MOVES EWD TOWARD THE MS RIVER ON MON...POSSIBLY
DEVELOPING A CLOSED CIRCULATION NEAR OR NORTH OF THE OH RIVER VALLEY
BY MON NIGHT. SRLY FLOW AND UPGLIDE WILL INCREASE AHEAD OF THIS
TROUGH THROUGH MON AS AN 850 MB JET FORMS AND GRADUALLY STRENGTHENS.
IT WILL BE INTERESTING TO SEE HOW MUCH THE EXISTING SFC CAD LAYER
CAN SCOUR ON MON GIVEN THE RETURNING WARM SECTOR AND INCREASING SRLY
FLOW ALONG WITH A RELATIVE LULL IN UPPER FORCING. IT IS LIKELY THAT
SOME DEGREE OF CAD WILL PERSIST...AT LEAST OVER THE NRN HALF...AND
TEMPS HAVE BEEN ADJUSTED DOWN FOR MON.

THE FIRST ROUND OF STRONGER...DISCRETE CELLULAR CONVECTION AHEAD OF
THE APPROACHING TROUGH AND SHARP COLD FRONT WILL LIKELY START
CLOSING IN ON THE FORECAST AREA FROM NRN GA TOWARD DAYBREAK TUE.
STRONG UPPER FOCING AHEAD OF THE HIGHLY AMPLIFIED SYSTEM WILL THEN
MOVE EASTWARD ACROSS THE AREA ON TUE. NEARLY ALL OF THE
MODEL/ENSEMBLE FORECASTS ARE COMING IN LINE WITH A TUE TIMING FOR
THE SYSTEM...AND HIGH LIKELY TO LOW END CATEGORICAL POPS WILL BE
FEATURED FOR THE HEART OF THE FORECAST AREA...WITH A MAINLY AFTN
FOCUS.

THE SRLY LOW LEVEL JET WITH THE SYSTEM WILL LIKELY PRODUCE SFC TO 3
KM BULK SHEAR VALUES APPROACHING 50 KT TUE AFTN. ANY SEMBLANCE OF A
TRIPLE POINT LOW PRES CENTER MOVING ENE ALONG A RETREATING WEDGE
FRONTAL BOUNDARY WOULD FOCUS MUCH OF THAT SHEAR IN THE SFC TO 1 KM
LAYER AND HEIGTHEN THE TORNADO THREAT FOR OUR FORECAST AREA TUE
AFTN. SOME LIMITING FACTORS FOR SEVERE CONVECTION WILL BE RELATIVELY
MODEST MID LEVEL LAPSE RATES AHEAD OF THE DEEP TROUGH AND VERY DEEP
MOISTURE IN THE SOUNDINGS TO LIMIT SFC BASED CAPE. HOWEVER...DEEP
DYNAMICAL FORCING MIGHT WELL OVERCOME ANY DEFICIENCIES IN
INSTABILITY. IN ADDITION TO THE SEVERE THREAT...PRECIPITABLE WATER
VALUES WILL LIKELY SURGE TO NEARLY TWO INCHES IN THE BEST MOISTURE
FLUX TUE. A FOCUS OF TERRAIN FORCED PRECIPITATION COULD WELL LEAD TO
VERY HEAVY RAINFALL RATES/TOTALS IN THE MTNS...WITH PERHAPS MORE
ISOLD/TRAINING TYPE HYDRO ISSUES OUTSIDE OF THE MTNS. THE CURRENT
SEVERE/HYDRO THREAT WORDING IN THE HWO APPEARS WELL PLACED FOR TUE.
EXPECT FROPA THROUGHOUT BY TUE NIGHT...WITH THE UPPER TROUGH AXIS
PASSAGE AND DEEP LAYER DRYING ARRIVING BY WED. WINDY CONDITIONS POST
FROPA WILL LINGER THROUGH WED BEFORE THE PRES GRADIENT RELAXES ON
THU AS RIDGING BECOMES DOMINANT ONCE AGAIN. BELOW NORMAL MAXES WED
WILL START TO MODERATE ON THU. THERE IS AN OUTSIDE CHANCE OF ISOLD
FROST PROBLEMS IN SHELTERED LOCATIONS IN THE MTNS THU MORNING.

&&

HG


FXUS62 KGSP 101932
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
332 PM EDT FRI OCT 10 2014

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 330 PM FRI...MODELS CONTINUE TO INDICATE SIGNIFICANT IMPACTS
ASSOCIATED WITH A STRONG COLD FRONT ON TUESDAY. HOWEVER...THE LLVL
JET ON THE GFS HAS DECREASED BY 20 KTS FROM THE 6Z RUN TO THE 12Z
RUN. FORECAST SOUNDINGS AND PLAIN VIEW OF THE GFS INDICATES THAT
SOUTH WINDS AHEAD OF THE FRONT WILL STRENGTHEN TO 35 KTS BY 6Z
TUES...REACHING NEAR 50 KTS BY 12Z TUESDAY. BETWEEN 18Z AND
0Z...WINDS WILL VEER AND H85 SPEEDS SHOULD DECREASE TO 20-30 KTS. I
WILL FORECAST GENERAL GUSTY SOUTH WINDS AHEAD OF THE FRONT.
HOWEVER...ELEVATIONS ABOVE 3500 FEET COULD EXPERIENCE GUSTS AROUND
50 MPH TUESDAY MORNING.

GFS FORECAST SOUNDINGS INDICATE IMPRESSIVE PRE FRONTAL WIND FIELDS
TUESDAY MORNING...WITH 0-1KM HELICITY BETWEEN 250-350 M2/S2 AT 12Z
ACROSS THE PIEDMONT. HOWEVER...CAPES DURING THE EARLY DAYLIGHT
PERIOD RANGE GENERALLY BELOW 500 J/KG. IT APPEARS THAT THE GREATEST
OVERLAP OF SHEAR AND INSTABILITY WILL OCCUR ACROSS THE I-77 CORRIDOR
BETWEEN 12Z-15Z...WITH 0-3 KM EHI VALUES ABOVE 0.5 M2/S2. GIVEN THIS
ENVIRONMENT...ORGANIZED THUNDERSTORMS COULD DEVELOP ALONG AND AHEAD
OF THE COLD FRONT. ANY WELL DEVELOPED QLCS COULD YIELD DAMAGING WIND
GUSTS AND/OR ISOLATED TORNADOES. IN ADDITION...PW VALUES WILL SURGE
ABOVE 1.75 INCHES WITH K-INDEX SPIKING IN THE UPPER 30S. THE
POTENTIAL EXISTS FOR A QUICK 1.5 TO 2 INCHES OF RAIN COULD FALL
TUESDAY MORNING THROUGH EARLY AFTERNOON...YIELDING POSSIBLE HYDRO
PROBLEMS.

IN THE WAKE OF THE COLD FRONT...A BLEND OF MEDIUM RANGE GUIDANCE
INDICATES THAT A DRY AND COOL AIRMASS WILL SETTLE ACROSS THE REGION
FOR REST OF THE WORK WEEK. THE FORECAST WILL FEATURE BELOW NORMAL
TEMPERATURES...MODERATE HUMIDITY...AND LIGHT WINDS.

&&

NED


FXUS62 KGSP 110741
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
341 AM EDT SAT OCT 11 2014

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 230 AM SATURDAY...THE PATTERN WILL BE IN THE PROCESS OF
AMPLIFYING SUNDAY-MONDAY AS UPPER RIDGE AXIS MOVES FROM THE ERN
SEABOARD OUT ONTO THE ATLANTIC. EARLY SUNDAY THE RIDGE WILL BE IN
JUST THE RIGHT PLACE TO REINFORCE THE SFC HIGH OVER THE MID-ATLANTIC
STATES AND ASSOCIATED COLD AIR DAMMING INTO THE CAROLINAS. THOUGH THE
PATTERN IS PROGRESSIVE ENOUGH TO PUSH THE HIGH OFFSHORE SUNDAY
NIGHT...ABUNDANT MOISTURE RETURN WILL OCCUR OVER MUCH OF THE ERN
CONUS AHEAD OF INTENSIFYING LOW PRESSURE OVER THE MISSISSIPPI VALLEY.
WELL-DEFINED WARM UPGLIDE ATOP THE WEDGE WILL CONTINUE INTO
MONDAY...AND WITH THIS MUCH MOISTURE A DECENT CLOUD LAYER SHOULD
PERSIST AND ALLOW THE WEDGE TO HOLD ON THRU MUCH OF THE DAY EVEN AS
THE UPPER SUPPORT FOR THE CAD DIMINISHES. WILL ADVERTISE MAX TEMPS
7-10 DEG BELOW CLIMO ON SUNDAY AT THE PEAK OF THE WEDGE...WARMING
SOME MONDAY BUT REMAINING AT OR BELOW CLIMO OVER MOST OF THE AREA.
MONDAY NIGHT THE MISSISSIPPI VALLEY SFC LOW WILL CONTINUE TO DEEPEN
AND LIFT NWD TOWARD THE GREAT LAKES...WHILE THE STRONG COLD FRONT
EXTENDING SWD FROM IT WILL BE OVER THE TENN VALLEY. NAM/GFS ARE IN
FAIRLY CLOSE AGREEMENT ON THE FRONTAL TIMING...BOTH BEING
CONSIDERABLY FASTER THAN THE 10/12Z EC WHICH WAS THE ONLY MODEL
SHOWING IT STILL ACROSS OUR CWFA AT 00Z WED. NEW 11/00Z EC IS
ACTUALLY EVEN SLOWER. WPC HAS PREFERRED A SOLUTION CLOSE TO GFS
TIMING OF LATE...BUT THE LATEST WORD IS THAT THE GFS MAY BE A BIT TOO
FAST. NONETHELESS THERE IS GOOD SUPPORT FOR THE FRONT CLEARING OF OUR
AREA BEFORE PEAK AFTERNOON HEATING.

VIRTUALLY ALL OF THE AVAILABLE GUIDANCE POINTS TO A TREMENDOUS 850MB
JET PRECEDING THE FRONT WHICH MAKES SHEAR PARAMETERS VERY IMPRESSIVE.
HODOGRAPHS FEATURE REMARKABLE LOW-LEVEL CURVATURE...IN FACT MOST OF
THE 40-50KT OF 0-3KM SHEAR BEING ADVERTISED IS ACTUALLY WITHIN THE
LOWEST KM. HOWEVER WITH DEEPLY SATURATED PROFILES IN THE VERY MOIST
WARM SECTOR A LIMITING FACTOR IS INSTABILITY...BEING UNDER 500 J/KG
ON THE GFS. EVEN THE SLOWER EC DOES NOT DEVELOP MUCH MORE
CAPE...PERHAPS A REFLECTION OF THE WIDESPREAD PREFRONTAL CLOUD COVER.
ANOTHER SAVING GRACE MIGHT BE THE FACT THAT THE BEST DPVA WILL BE TO
OUR NORTH WITHIN THE TRACK OF THE UPPER WAVE. TAKING ALL OF THIS INTO
ACCOUNT...THE MODELS ARE SHOWING GOOD CONSISTENCY AS FAR AS THE
POTENTIAL SENSIBLE IMPACTS OF THE SYSTEM. FRONTAL TIMING MAY
DETERMINE HOW WIDESPREAD THESE IMPACTS ARE AND EXACTLY WHERE THEY
OCCUR...BUT CONFIDENCE IS HIGH THAT THE CWFA WILL SEE AT LEAST
ISOLATED DAMAGING WIND EVENTS AND/OR TORNADOES. FLASH FLOODING IS
ALSO A CONCERN WITH SEASONALLY HIGH PWAT VALUES AND THE DEEP
UNIDIRECTIONAL FLOW KEEPING CORFIDI VECTORS SHORT. HOWEVER ASSUMING
THE FRONT CONTINUES MOVING AS THE NON-EC SOLUTIONS SHOW...DURATION IS
NOT LIKELY TO CAUSE WIDESPREAD FLOODING.

ASIDE FROM SEVERE CONVECTION ONE MUST NOTE THE STRONG GRADIENT WINDS
ALOFT WHICH COULD PERSIST FOR SEVERAL HOURS IN THE HIGHER TERRAIN.
THESE WILL RELAX TO SOME DEGREE ONCE THE FROPA OCCURS BUT DEEP MIXING
IN COLD ADVECTION COULD BRING DOWN SOME PRETTY STRONG GUSTS INTO TUE
NIGHT.
&&

JCW


FXUS62 KGSP 111853
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
253 PM EDT SAT OCT 11 2014

.SHORT TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 250 PM SATURDAY...MONDAY MORNING...MID LEVEL HEIGHTS ACROSS
THE REGION WILL BEGIN TO FALL...AS A RIDGE REMAINS OVER THE WESTERN
ATLANTIC AND A DEEP TROUGH OR CLOSED LOW AMPLIFIES ACROSS THE
PLAINS. AT THE SFC...RIDGING WILL REMAIN ACROSS THE WESTERN
CAROLINAS...SOURCED FROM A MID ATLANTIC HIGH. ONGOING ISENTROPIC
LIFT AND UPSLOPE FLOW SHOULD SUPPORT NUMEROUS SHRA ACROSS THE EAST
FACING SLOPES...WITH SCT COVERAGE EAST. TEMPERATURES ARE FORECAST TO
GENERALLY RANGE IN THE MID 50S TO NEAR 60.

ON MONDAY...LINGERING AREA OF COLD AIR DAMMING SHOULD ERODE THROUGH
THE DAY...BECOMING MORE LIMITED TO THE FOOTHILL AREAS. UPSLOPE FLOW
AND WEAK ELEVATED INSTABILITY SHOULD CONTINUE TO SUPPORT SHOWERS
ACROSS THE MTNS...WITH TS EAST. OVERALL...COVERAGE OF CONVECTION IS
EXPECTED TO REMAIN IN THE CHC RANGE. HIGH TEMPERATURE PATTERN WILL
REFLECT A LINGERING WEDGE OF HIGH PRESSURE...WITH 60S ACROSS THE
UNIFOUR AND UPPER 70S ACROSS PORTIONS OF THE UPPER SAVANNAH RIVER
VALLEY.

ON TUESDAY...SHORT RANGE GUIDANCE HAS TRENDED SLOWER FROM RUNS
YESTERDAY. HOWEVER...AGREEMENT BETWEEN GUIDANCE IS FAIR WITH THE
TIMING AND PLACEMENT OF MAIN FEATURES...I WILL USE A BLEND OF THE
NAM AND GFS. BY 12Z TUESDAY...THE SFC COLD FRONT IS FORECAST TO RUN
FROM MIDDLE KY/TN SOUTH TO ALONG THE GA/AL LINE. THE NAM WIND FIELDS
INDICATE THAT A LLVL JET WILL BEGIN TO ENCOUNTER THE MTNS AROUND
12Z...WITH H85 WINDS AROUND 50 KTS THROUGH 18Z. I WILL INCREASE
RIDGETOP WINDS...FEATURING MARGINAL WIND ADVISORY GUSTS. DURING THE
DAYLIGHT HOURS...THE GFS INDICATES A CLOSED LOW OVER THE MID WEST
WITH THE TROF AXIS SWEEPING EAST ACROSS THE DEEP SOUTH. Q-VECTOR
CONVERGENCE INCREASES SHARPLY DURING THE LATE MORNING AND REMAINS
INTO THE EVENING. AT THE LLVLS...THE ENVIRONMENT ALONG AND AHEAD OF
THE COLD FRONT WILL FEATURE VERY STRONG SHEAR AND HELICITY
VALUES...WITH PIEDMONT AREAS UNDER 0-1 KM HELICITY VALUES FROM
300-400 M2/S2. INSTABILITY WILL REMAIN THE LIMITING FACTOR... 
HOWEVER...NAM FORECAST SOUNDINGS INDICATE THAT PIEDMONT AREAS 
COULD SEE VALUES RISE ABOVE 500 J/KG BY MID DAY. THIS FORECAST
PACKAGE DOES HAVE THE BENEFIT OF VIEWING THE SIMULATED REFLECTIVITY
FROM THE NAM. THE NAM SHOWS A WELL ORGANIZED QLCS REACHING THE NC
MTNS AROUND 15Z...GSP AREA BETWEEN 18Z-0Z...THEN CLT BETWEEN 0Z-3Z.
SHERB AND EHI VALUES BETWEEN 0-3 KM INDICATE A RIPE HIGH SHEAR LOW
CAPE ENVIRONMENT FOR WIND OR ISO TORNADOES. IN ADDITION...ABOVE
SEASONABLE VALUES OF PW AND MID TO UPPER 30S K-INDEX INDICATE THE
POTENTIAL FOR HEAVY RAIN. FLASH FLOODING WILL BE A CONCERN ACROSS
THE CWA. COVERAGE SHOULD PUSH EAST TUESDAY NIGHT...LEAVING SOME
UPSLOPE SHOWERS ACROSS THE TN/NC LINE THROUGH THE NIGHT.

&&

NED


FXUS62 KGSP 120713
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
313 AM EDT SUN OCT 12 2014

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 250 AM SUNDAY...MAJOR AMPLIFICATION OF THE UPPER LEVEL FLOW
PATTERN WILL CONTINUE ON MONDAY...AS A CLOSED CIRCULATION DEEPENS
OVER THE PLAINS WHILE STRONG RIDGING BUILDS OVER THE ERN SEABOARD.
SRLY LOW LEVEL FLOW WILL STEADILY INCREASE ON MON AHEAD OF THE
OCCLUDING CENTRAL CONUS SYSTEM. HOWEVER...MOISTURE MAY REMAIN
RELATIVELY SHALLOW AND MOST SCATTERED SHOWERS/TSTMS WILL LIKELY BE
CONFINED IN AND NEAR MTN UPSLOPE AREAS WHERE THE TERRAIN FORCING
WILL BE GREATEST. THE SFC HIGH CENTER WILL MIGRATE FARTHER OFFSHORE
ON MONDAY...LEAVING THE LINGERING CAD LAYER EXPOSED TO GRADUAL
SCOURING FROM THE SOUTH THROUGH THE DAY. HOWEVER...NRN SECTIONS WILL
LIKELY RETAIN SOME DEGREE OF CAD THROUGH SUNSET. WILL FEATURE COOLER
THAN MOS TEMPS THROUGHOUT...ESPECIALLY IN THE NRN TIER.
THE H5 CLOSED CIRCULATION WILL MEANDER EASTWARD INTO THE CONFLUENCE
OF THE MS AND LOWER OH RIVER VALLEYS MON NIGHT THROUGH TUE. THE
PREFERRED CONSENSUS TIMING OF THE GFS/ECM/ENSEMBLE MEANS FEATURES
THE STRONGEST DEEP LAYER QG FORCING AHEAD OF THE CYCLONE IN THE LATE
TUE AND TUE NIGHT PERIODS. THE BEST 850 MB JET WILL LIKELY CROSS THE
FORECAST AREA TUE EVENING COINCIDENT WITH THIS DEEPER FORCING. THE
LACK OF STRONG INSTABILITY OR STEEP LAPSE RATES CONTINUES TO BE THE
MAIN LIMITING FACTOR FOR WIDESPREAD SEVERE CONVECTION TUE/TUE
NIGHT...WITH MOST MODELS/ENSEMBLES SHOWING LESS THAN 500 J/KG OF
CAPE EVEN IN MOST UNSTABLE SRN SECTIONS. HOWEVER...THE TREMENDOUS
LOW LEVEL WIND SHEAR SHOULD SUPPORT THE DEVELOPMENT OF A STRONG AND
PERSISTENT QLCS GIVEN SFC TO 6 KM BULK SHEAR VALUES OF 40 TO 50
KT...AND 30+ KT POSSIBLY CONCENTRATED IN THE SFC TO 1 KM LAYER AT
TIMES LATE TUE. IN ADDITION...STRONG ENVIRONMENTAL WINDS JUST OFF
THE SFC WILL CREATE A STRAIGHT LINE WIND THREAT WITH JUST ABOUT ANY
MODEST CONVECTION. FURTHER...THE DEEP MOISTURE IN PROFILES SHOULD BE
SUFFICIENT TO GENERATE A 3 TO 3.5 INCH MAXIMUM OF QPF IN THE UPSLOPE
PREFERRED AREAS OF THE SRN MOUNTAINS FOR EVENT TOTALS THROUGH EARLY
WED. HOWEVER...THE BAND OF HEAVIEST RAINFALL MAY BE JUST PROGRESSIVE
ENOUGH TO LIMIT DURATION FLOODING SO NO FLOOD WATCHES ARE NEEDED
YET. WILL RETAIN THE CURRENT HWO SEVERE/FLOODING TAGS.

&&

HG


FXUS62 KGSP 121931
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
331 PM EDT SUN OCT 12 2014

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 330 PM SUNDAY...MONDAY NIGHT...LLVL SE FLOW IS FORECAST TO
GRADUALLY STRENGTHEN AND VEER THROUGH THE NIGHT. SHORT RANGE MODELS
ARE IN GOOD AGREEMENT WITH UPSLOPE SHOWERS. I WILL HIGHLIGHT THE
EAST FACING MTN SLOPES AND ADJACENT FOOTHILLS WITH 40 TO 50
POPS...WITH SCHC EAST. LOW TEMPERATURES ARE FORECAST TO RANGE FROM
NEAR 60 WITHIN THE MTN VALLEY TO MID 60S EAST.
ON TUESDAY...MODEL GUIDANCE CONTINUES A SLOWING TREND INTO THE 12Z
RUNS. SHORT RANGE MODELS INDICATE THAT A CLOSED MID LEVEL AND SFC
LOW ACROSS THE OHIO RIVER VALLEY. IT APPEARS THAT THE COLD FRONT
NEAR THE LOW CENTER WILL OCCLUDE ON TUESDAY. THE RESULT SHOULD BE A
SLOWER COLD FRONT TO SLIDE ACROSS THE SOUTHERN APPALACHIAN REGION
TUESDAY INTO TUESDAY NIGHT. ALONG AND AHEAD OF THE FRONT...0-1 KM
HELICITY VALUES ARE FORECAST TO RANGE FROM 200-400 M2/S2.
HOWEVER...CAPES SHOULD GENERALLY RANGE FROM 200-400 J/KG FROM
TUESDAY AFTERNOON INTO THE OVERNIGHT...PEAKING AROUND 18Z TUESDAY
AROUND 400 J/KG. SIMULATED NAM REF INDICATES THAT A WELL
ORGANIZED BAND OF CONVECTION WILL REACH THE UPPER SAVANNAH RIVER
VALLEY BETWEEN 18Z-21Z...THEN EVOLVES INTO CLUSTER OR BROKEN LINES
INTO THE EVENING/EARLY WED MORNING. IT APPEARS THAT THE OVERLAP OF
WEAK INSTABILITY AND HIGH SHEAR WILL SUPPORT SEVERE THUNDERSTORMS
DURING THE DAYLIGHT HOURS TUESDAY INTO EARLY WEDS MORNING. SPC HAS A
SLGT RISK FOR THE REGION ON DAY 3.

THE RISK FOR EXCESSIVE RAINFALL APPEARS GREATEST TUESDAY
EVENING/EARLY WEDNESDAY MORNING. GFS INDICATES THAT Q-VECTOR
CONVERGENCE WILL INCREASE ACROSS THE REGION AROUND 0Z WED...PIVOTING
OVERHEAD THROUGH TUESDAY NIGHT. BAND OR CLUSTERS OF CONVECTION
APPEARS TO BE NEARLY PARALLEL TO MID LEVEL HEIGHTS...RESULTING IN
SLOWER THAN TYPICAL STORM MOTIONS. THE DURATION OF CONVECTION...PW
VALUES NEAR 1.75 INCHES...AND K INDEX VALUES IN THE MID TO UPPER 30S
SUPPORT A HEAVY RAIN/FLASH FLOOD EVENT. I WILL INCREASE STORM TOTAL
RAINFALL...INDICATING VALUES NEAR 4 INCHES ACROSS PORTIONS OF THE
MTNS...WITH 2-3 INCHES GENERALLY COVERING THE FOOTHILLS AND MTNS. IN
ADDITION...LLVL JET WILL ENCOUNTER THE MTNS TUES INTO TUESDAY
EVENING. I WILL INCREASE WINDS AND WIND GUSTS TO AROUND WIND
ADVISORY LEVELS ABOVE 3500 FEET ELEVATION.

THE MID LEVEL CLOSED LOW IS EXPECTED TO SUPPLY MOIST UPSLOPE FLOW
ACROSS THE TN BORDER COUNTIES. CHC POPS WILL REMAIN ACROSS THE
WESTERN NC MTNS. TEMPERATURES WILL REMAIN BELOW NORMAL.

&&

NED


FXUS62 KGSP 130704
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
304 AM EDT MON OCT 13 2014

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AT 210 AM EDT MONDAY...ON TUESDAY MORNING A CLOSED UPPER LOW WILL BE
LOCATED OVER THE ID MS RIVER VALLEY...WHILE AND UPPER RIDGE WILL
DOWNSTREAM OVER THE WESTERN ATLANTIC. THE DEEPENING LOW MOVES ONLY
VERY SLOWLY TOWARD THE LOWER OH RIVER VALLEY BY WEDNESDAY. AFTER
THAT...MODEL SOLUTIONS DIVERGE...WITH THE GFS MOVING THE LOW UP THE
OH VALLEY...ANOTHER ECMWF PARKING IT ABOUT IN PLACE.
A SLOW MOVING COLD FRONT WILL EXTEND FROM THE MID OH AND TN VALLEYS
TO THE CENTRAL GULF COAST TUESDAY MORNING. ROBUST GULF INFLOW AHEAD
OF THE FRONT WILL HAVE JUST REACHED THE SOUTHERN APPALACHIANS. THIS
INFLOW SPREADS SLOWLY EAST ACROSS THE FOOTHILLS AND PIEDMONT DURING
THE DAY. THE COMBINATION OF STRING SOUTHERLY ISENTROPIC UPGLIDE AND
UPSLOPE FLOW WILL SUPPORT HEAVY RAINFALL...ESPECIALLY NEAR THE SOUTH
FACING BLUE RIDGE ESCARPMENT...RAISING FLOODING CONCERNS. RAINFALL
OF OVER THREE INCHES MAY BE POSSIBLE IN THE UPPER MOST SAVANNAH
RIVER VALLEY. ALTHOUGH INSTABILITY WILL BE SOMEWHAT LIMITED...SHEAR
VALUES WILL BE SUBSTANTIAL...AND SEVERE WEATHER IS A POSSIBILITY.
WINDS MAY REACH ADVISORY CRITERIA ON THE VERY HIGHEST PEAKS OF THE
SW NC MOUNTAINS ON TUESDAY.
THE COLD FRONT SLOWLY CROSSES THE AREA TUESDAY NIGHT. MOISTURE LAGS
BEHIND THE BOUNDARY...BUT BY WEDNESDAY MORNING...A DRY SLOT MOVES
OVER OUR AREA FROM THE SOUTH. HEIGHTS FALLS ASSOCIATED WITH THE
UPPER SPREAD EAST ACROSS THE AREA ON WEDNESDAY...AND ON WEDNESDAY
NIGHT MOISTURE ASSOCIATED WITH THE LOW SPREAD EAST AS WELL. THE
RESULTING COOL POOL INSTABILITY...THOUGH APPEARING LIMITED AT THIS
TIME...WILL SUPPORT ANOTHER ROUND OF SHOWERS OVER THE MOUNTAINS...
AND PERHAPS THE FOOTHILLS AND PIEDMONT.
MAXIMUM TEMPERATURES WILL RUN NEAR NORMAL ON TUESDAY...AS WARN
ADVECTION IS OFFSET BY CLOUDS AND PRECIPITATION. MINIMUM
TEMPERATURES TUESDAY NGHT WILL RUN AROUND 5 DEGREES ABOVE NORMAL
UNDER CLOUDS WITH THE WIND STAYING UP. MAXIMUM TEMPERATURES ON
WEDNESDAY WILL BE NEAR 6 DEGREE BELOW NORMAL AS HEIGHTS FALL
ALOFT...FOLLOWED BY MINIMUM TEMPERATURES SLIGHTLY BELOW NORMAL
WEDNESDAY NIGHT UNDER INCREASING CLOUD COVER.
&&

JAT


FXUS62 KGSP 132107
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
507 PM EDT MON OCT 13 2014

.NEAR TERM /THROUGH TUESDAY/...
AS OF 300 PM EDT MONDAY...HIGH AMPLITUDE LONGWAVE UPPER TROF AND
ASSOCIATED CLOSED LOW CONTINUE TO SLIDE EAST THROUGH THE MID
MISSISSIPPI RIVER VALLEY INTO THE MIDSOUTH.  CAD WEDGE CONTINUES TO
RETREAT AS PARENT SURFACE HIGH ACROSS THE NORTHEAST MIGRATES OUT TO
SEE AS SURFACE TROF MOVES INTO THE THE OHIO/TENNESSEE VALLEYS.
CLOSER TO HOME...LIGHT SHRA/DRIZZLE CONTINUES ACROSS THE HIGH
TERRAIN TIED TO WEAK UPGLIDE AND INCREASING SOUTHERLY FLOW AHEAD OF
ABOVE MENTIONED COMPLEX.  VEERING LOW LEVEL FLOW WILL ALLOW FOR
CONTINUED EROSION OF THE CAD ALL THE WHILE ADVECTING ATLANTIC
MOISTURE INTO THE REGION.  THUS...POPS WILL RAMP UP FROM SLIGHT
CHANCE...TO CHANCE LEVELS ALONG THE BLUE RIDGE THIS EVENING WITH
ONLY SLIGHT CHANCE POPS FAVORED FURTHER EAST.  BEYOND THAT...AS
MOISTURE CONTINUES TO ADVECT IN AHEAD OF THE APPROACHING
UPPER/SURFACE TROFS...POPS WILL INCREASE FURTHER WITH CHANCE POPS
FEATURED OVER THE PIEDMONT BY MORNING WITH CATEGORICAL LEVEL POPS
ACROSS THE WESTERN MOST HIGH ELEVATION ZONES.  STRONG LOW LEVEL JET
AHEAD OF THE VERY DYNAMIC SYSTEM WILL YIELD RATHER IMPRESSIVE
SOUTHERLY FLOW LEADING TO ENHANCED UPSLOPE POTENTIAL AND GUSTY
WINDS.  WILL FORGO FLASH FLOOD WATCH AT THIS TIME DUE TO SOME MODEL
INCONSISTENCIES HOWEVER CONDITIONS CONTINUE TO TREND WETTER.  AS FOR
WINDS...WILL GO AHEAD AND ISSUE A WINDS ADVISORY FOR TUESDAY ACROSS
THE HIGH TERRAIN AS SOME GUSTS OF UP TO 50 MPH ARE POSSIBLE AT THE
HIGHER PEAKS AND RIDGETOPS.  POPS WILL CONTINUE TO INCREASE ACROSS
THE REGION THROUGH THE DAY ON TUESDAY AS LINE OF STRONG CONVECTION
SLIDES INTO WESTERN NC...NORTHEAST GA...AND THE WESTERN UPSTATE BY
PERIODS END.  INSTABILITY CONTINUES TO BE A PRIMARY LIMITING
FACTOR...HOWEVER MORE RECENT GUIDANCE RUNS INDICATE IMPROVING
MOISTURE FIELDS AMONGST LONG/RIGHT TURNING HODOGRAPHS POTENTIALLY
SETTING UP A HIGH SHEAR LOW CAPE SCENARIO INTO LATE DAY TUESDAY.
THUS...SOME THUNDERSTORMS ON TUESDAY AFTERNOON COULD BE
STRONG/SEVERE WITH DAMAGING WINDS BEING OF PRIMARY CONCERN.
&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 310 PM MONDAY...A SIGNIFICANT WX EVENT MAY BE ONGOING OR
POISED TO ENTER THE CWFA AT THE START OF THIS PERIOD...AS A STRONG
UPPER LOW AND COLD FRONT AFFECT THE AREA.
THE AFOREMENTIONED UPPER LOW WILL MOVE FROM THE MS VALLEY INTO
THE OH VALLEY AND ON TO THE GREAT LAKES THRU THE PERIOD. A SERIES
OF SHORT WAVES WILL ROTATE AROUND THE LOW AND ACROSS THE AREA THRU
WED NITE. THE UPPER TROF AXIS SOUTH OF THE UPPER LOW WILL MOVE
EAST OF THE AREA THU AS THE LAST OF THE SHORT WAVES ROTATE AROUND
THE LOW AND EAST OF THE AREA AS WELL.
AT THE SFC...THE COLD FRONT WILL BE MOVING INTO THE WRN CWFA AT THE
START OF THE PERIOD. STRONG SLY WINDS AND CONVECTION WILL BE ONGOING
AHEAD OF THE FRONT. AS THE FRONT MOVES EAST...THE STRONG WINDS AND
CONVECTION WILL MOVE EAST AS WELL. RIGHT NOW...IT STILL LOOKS LIKE A
GOOD CASE FOR A HIGH SHEAR/LOW CAPE EVENT. THERE APPEARS TO BE
ACTUAL INSTABILITY...EVEN WITH THE LOW LAPSE RATES...AS LFC LEVELS
WILL BE LOW AND DEW POINTS WILL BE HIGH. THERE WILL ALSO BE STRONG
FORCING FROM THE SHORT WAVES AND UPPER JET MAXES. STRONG WIND SHEAR
AND HIGH HELICITY VALUES DEVELOP AS A LOW LEVEL JET MOVES IN AHEAD
OF THE FRONT. THERE COULD EVEN BE A LINGERING LOW LEVEL BOUNDARY IF
THE CAD DOES NOT FULLY DISSIPATE. THEREFORE...WILL HAVE TO WATCH THE
EXPECTED SQUALL LINE AS IT MOVES ACROSS THE AREA FOR STORMS
PRODUCING DAMAGING WINDS AND ISOLATED TORNADOES TUE NITE.
THE FRONT MOVES EAST OF THE AREA TUE. HOWEVER...THE SQUALL LINE
COULD STILL BE ONGOING ACROSS THE I-77 CORRIDOR AT THE BEGINNING OF
THIS PERIOD. THEREFORE...DEPENDING ON THE SPEED AND MOVEMENT OF THE
LINE...SVR STORMS MAY STILL BE POSSIBLE TUE MORNING. CLEARING
DEVELOPS BEHIND THE LINE...BUT CLOUDS RETURN AS LOW LEVEL MOISTURE
MOVES BACK IN IN THE SWLY FLOW BEHIND THE FRONT. IN ADDITION...SCT
SHRA WILL LINGER ACROSS THE MTNS WITH ISOLATED ELSEWHERE.
THE LOW LEVEL MOISTURE AND SWLY FLOW LINGER THRU THU WITH COLD MID
LEVEL TEMPS AROUND THE UPPER TROF. THEREFORE...EXPECT CLOUDS TO
REDEVELOP WITH HEATING AND SCT SHRA MTNS AND ISOLATED NC FOOTHILL
AND PIEDMONT.
TEMPS START OUT NEAR NORMAL MTNS THEN FALL BELOW NORMAL...WHILE
ELSEWHERE TEMPS START OUT ABOVE NORMAL THEN FALL TO NEAR NORMAL.
&&

CDG
RWH


FXUS62 KGSP 140716
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
316 AM EDT TUE OCT 14 2014

.SYNOPSIS...

A STRONG COLD FRONT WILL SLOWLY APPROACH THE WESTERN CAROLINAS AND
NORTHEAST GEORGIA TODAY...CROSSING THE AREA BY EARLY WEDNESDAY
MORNING. DRIER WEATHER WILL RETURN LATE IN THE WEEK AND PERSIST
THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM EDT...DEEP 500 MB LOW PRES IS CENTERED OVER THE MIDWEST
EARLY THIS MORNING WITH A SHARPENING TROUGH EXTENDING SWD TO THE
MOUTH OF THE MS RIVER. A STRONG FETCH OF MOISTURE IS INVADING THE
DEEP SOUTH AHEAD OF THIS FEATURE...WITH ONGOING BUT WEAKENING
CONVECTION LINED UP FROM NW GA TO ERN TN AND SLOWLY PROGRESSING EWD.
THE SFC COLD AIR DAMMING LAYER CONTINUES TO ERODE ACROSS THE WRN
CAROLINAS AND NE GA. SFC WINDS HAVE TURNED SE AND OCCASIONALLY GUSTY
JUST ABOUT EVERYWHERE BUT THE NRN NC FOOTHILLS...AND FURTHER CAD
EROSION WILL LIKELY OCCUR THERE THROUGH THE MORNING HOURS. THE
WEAKENING SQUALL LINE TO THE W SHOULD REACH THE NE GA MTNS TO THE NC
SMOKIES BY DAYBREAK...WITH ADDITIONAL SHOWERS AND EMBEDDED TSTMS
FILLING IN OVER THE MTNS AND FOOTHILLS IN WARM ADVECTION AND UPSLOPE
FLOW...AND POSSIBLY ALSO OUT OVER THE INTERSTATE 77 CORRIDOR IN THE
IMPROVING ATLANTIC FETCH. POPS WILL THUS RAMP UP STEADILY EVERYWHERE
THROUGH THE MORNING HOURS.

A FEW HIGHER TERRAIN LOCATIONS ARE ALREADY SEEING OCCASIONAL GUSTS
TO 40 MPH EARLY THIS MORNING AND THESE GUSTS SHOULD INCREASE THROUGH
THE DAY ALONG WITH THE PRES GRADIENT. THE CURRENT WIND ADVISORY
LOOKS WELL PLACED AS THE BEST 50 TO 55 KT 850 MB JET CROSSES THE
MTNS TODAY BEFORE MOVING EAST THIS EVENING. STILL CANNOT RULE OUT
SOME DOWNED TREES WITH ANY SHOWERS...BUT WIDESPREAD DAMAGING WINDS
ARE NOT EXPECTED WITH THE WARM ADVECTION GRADIENT FLOW ON THE NC
SIDE OF THE SPINE.

AS THE MIDWEST SYSTEM CONTINUES TO OCCLUDE TODAY...THE TRAILING SFC
COLD FRONT WILL GRADUALLY MOVE EASTWARD AND FOCUS A SHARPER LINE OF
CONVECTION OVER OUR AREA LATER TODAY INTO TONIGHT. DEEP QG FORCING
AHEAD OF THE CYCLONE WILL PROVIDE PLENTY OF LIFT FOR WIDESPREAD POPS
THROUGH THE AFTN AND EVENING HOURS...AND HIGH PRECIPITABLE WATER
VALUES SHOULD GENERATE HEAVY RAINFALL RATES. THE FFA WILL BE
EXPANDED NWD ALONG THE NC MTN CHAIN...OVER THE NRN NC
FOOTHILLS...AND ALSO IN THE NE GA AND EXTREME WRN SC MTNS. THESE
LOCATIONS HAVE RECEIVED THE MOST RAINFALL THUS FAR THIS MORNING AND
ARE PRIMED TO TAKE ADVANTAGE OF TRAINING SRLY UPSLOPE GENERATED
CONVECTION THROUGH THE NEAR TERM. THE PRE/FRONTAL CONVECTIVE LINE
SHOULD BEGIN TO REGENERATE NEAR THE SRN APPALACHIANS BY 18Z
TODAY...PERHAPS STRENGTHENING AS IT TRANSITS THE UPSTATE AND
FOOTHILLS THROUGH THE EVENING HOURS IN THE RICH EQUIVALENT POTENTIAL
TEMP AIRMASS...AND THEN MOVE EAST OF INTERSTATE 77 DURING THE EARLY
MORNING HOURS WED. 0 TO 6 KM BULK SHEAR VALUES APPROACHING 50 KT AT
TIMES SHOULD BE ABLE TO TAP ENOUGH INSTABILITY FOR SEVERE CONVECTION
TO BE POSSIBLE ANYWHERE IN THE CWFA...WITH BRIEF TORNADOES POSSIBLE
NEAR ANY LINGERING BOUNDARIES AND IN SRN TIER SECTIONS WHERE
INSTABILITY WILL BE HIGHEST AND SFC WINDS SLIGHTLY BACKED. ENHANCED
HWO WORDING WILL BE USED THIS MORNING AND SEVERE CONVECTIVE WATCHES
ARE LIKELY LATER ON.

&&

HG


FXUS62 KGSP 141123
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
723 AM EDT TUE OCT 14 2014
.SYNOPSIS...

A STRONG COLD FRONT WILL SLOWLY APPROACH THE WESTERN CAROLINAS AND
NORTHEAST GEORGIA TODAY...CROSSING THE AREA BY EARLY WEDNESDAY
MORNING. DRIER WEATHER WILL RETURN LATE IN THE WEEK AND PERSIST
THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM EDT...THE FORECAST HAS BEEN UPDATED FOR THE TORNADO
WATCH. THIS MAY BE THE FIRST ROUND OF SEVERE CONVECTION...WITH
MESOSCALE MODELS INDICATING A LATER ROUND WITH THE IMMEDIATE FRONT.
OTHERWISE...DEEP 500 MB LOW PRES IS CENTERED OVER THE MIDWEST THIS
MORNING WITH A SHARPENING TROUGH EXTENDING SWD TO THE MOUTH OF THE
MS RIVER. A STRONG FETCH OF MOISTURE IS INVADING THE DEEP SOUTH
AHEAD OF THIS FEATURE...WITH ONGOING CONVECTION LINED UP FROM
W/CNTRL GA TO SE TN AND SLOWLY PROGRESSING EWD. THE SFC COLD AIR
DAMMING LAYER IS ALL BUT GONE AT THIS HOUR WITH DEWPOINTS NOW IN THE
UPPER 60S ACROSS THE NRN NC FOOTHILLS. SHOWERS HAVE FILLED OUT ALONG
THE UPSLOPE AREAS OF THE SRN APPALACHIANS...NEAR THE INTERSTATE 77
CORRIDOR IN THE BETTER SELY ATLANTIC FETCH...AND THEN JUST UPSTREAM
INTO GA. POPS WILL RAMP UP STEADILY EVERYWHERE THROUGH THE MORNING
HOURS.

HIGHER TERRAIN LOCATIONS ARE ALREADY SEEING OCCASIONAL GUSTS TO 40
MPH THIS MORNING AND THESE GUSTS SHOULD INCREASE THROUGH THE DAY
ALONG WITH THE PRES GRADIENT. THE CURRENT WIND ADVISORY LOOKS WELL
PLACED AS THE BEST 50 TO 55 KT 850 MB JET CROSSES THE MTNS TODAY
BEFORE MOVING EAST THIS EVENING. STILL CANNOT RULE OUT SOME DOWNED
TREES WITH ANY SHOWERS...BUT WIDESPREAD DAMAGING WINDS ARE NOT
EXPECTED WITH THE WARM ADVECTION GRADIENT FLOW ON THE NC SIDE OF THE
SPINE.

AS THE MIDWEST SYSTEM CONTINUES TO OCCLUDE TODAY...THE TRAILING SFC
COLD FRONT WILL GRADUALLY MOVE EASTWARD AND FOCUS A SHARPER LINE OF
CONVECTION OVER OUR AREA LATER TODAY INTO TONIGHT. DEEP QG FORCING
AHEAD OF THE CYCLONE WILL PROVIDE PLENTY OF LIFT FOR WIDESPREAD POPS
THROUGH THE AFTN AND EVENING HOURS...AND HIGH PRECIPITABLE WATER
VALUES SHOULD GENERATE HEAVY RAINFALL RATES. THE FFA HAS BEEN
EXPANDED NWD ALONG THE NC MTN CHAIN...OVER THE NRN NC
FOOTHILLS...AND ALSO IN THE NE GA AND EXTREME WRN SC MTNS. THESE
LOCATIONS HAVE RECEIVED THE MOST RAINFALL THUS FAR THIS MORNING AND
ARE PRIMED TO TAKE ADVANTAGE OF TRAINING SRLY UPSLOPE GENERATED
CONVECTION THROUGH THE NEAR TERM. THE PRE/FRONTAL CONVECTIVE LINE
SHOULD BEGIN TO REGENERATE NEAR THE SRN APPALACHIANS THROUGH 18Z
TODAY...PERHAPS STRENGTHENING AS IT TRANSITS THE UPSTATE AND
FOOTHILLS THROUGH THE EVENING HOURS IN THE RICH EQUIVALENT POTENTIAL
TEMP AIRMASS...AND THEN MOVE EAST OF INTERSTATE 77 DURING THE EARLY
MORNING HOURS WED. 0 TO 6 KM BULK SHEAR VALUES APPROACHING 50 KT AT
TIMES SHOULD BE ABLE TO TAP ENOUGH INSTABILITY FOR SEVERE CONVECTION
TO BE POSSIBLE ANYWHERE IN THE CWFA...WITH BRIEF TORNADOES POSSIBLE
NEAR ANY LINGERING BOUNDARIES AND IN SRN TIER SECTIONS WHERE
INSTABILITY WILL BE HIGHEST AND SFC WINDS SLIGHTLY BACKED. ENHANCED
HWO WORDING WILL BE USED THIS MORNING AND SEVERE CONVECTIVE WATCHES
ARE LIKELY LATER ON.

&&

HG


FXUS62 KGSP 141244
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
844 AM EDT TUE OCT 14 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL SLOWLY APPROACH THE WESTERN CAROLINAS AND
NORTHEAST GEORGIA TODAY...CROSSING THE AREA BY EARLY WEDNESDAY
MORNING. DRIER WEATHER WILL RETURN LATE IN THE WEEK AND PERSIST
THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 840 AM EDT TUESDAY...LEADING EDGE OF CONVECTIVE LINE CONTINUES
TO SLIDE EAST ACROSS PORTIONS OF THE SC UPSTATE AND SOUTHWEST NC.
TORNADO WATCH REMAINS IN EFFECT THROUGH 2PM.  AS THE LINE PUSHED
THROUGH NORTHEAST GA...ENHANCED BULK SHEAR MAXIMA LED TO MULTIPLE
VELOCITY COUPLETS BEING OBSERVED ON RADAR.  HAVE NOT RECEIVED ANY
CONFIRMED REPORTS OF TORNADOES...HOWEVER MULTIPLE REPORTS OF WIND
DAMAGE ACROSS STEPHENS COUNTY GA ARE STARTING TO FILTER INTO THE
OFFICE.  TWEAKED POPS/WX GRIDS TO ACCOUNT FOR THE LINES PROGRESSION
AND ALSO TO CONTINUE WORDING OF DAMAGING WINDS POSSIBLE AHEAD OF AND
ALONG THE LINE.  SPEAKING OF WINDS...EXPANDED THE WIND ADVISORY
ACROSS WESTERN NC TO INCLUDE THE LOWER ELEVATIONS AS REPORTS OF
TREES DOWN IN WEAVERVILLE...AND ACROSS BUNCOMBE COUNTY CAME INTO THE
OFFICE.  OTHERWISE...TWEAKED TEMPERATURES AND DEWPOINTS TO REFLECT
LATEST OBSERVATIONS.

PREVIOUS DISCUSSION...
OTHERWISE...DEEP 500 MB LOW PRES IS CENTERED OVER THE MIDWEST THIS
MORNING WITH A SHARPENING TROUGH EXTENDING SWD TO THE MOUTH OF THE
MS RIVER. A STRONG FETCH OF MOISTURE IS INVADING THE DEEP SOUTH
AHEAD OF THIS FEATURE...WITH ONGOING CONVECTION LINED UP FROM
W/CNTRL GA TO SE TN AND SLOWLY PROGRESSING EWD. THE SFC COLD AIR
DAMMING LAYER IS ALL BUT GONE AT THIS HOUR WITH DEWPOINTS NOW IN THE
UPPER 60S ACROSS THE NRN NC FOOTHILLS. SHOWERS HAVE FILLED OUT ALONG
THE UPSLOPE AREAS OF THE SRN APPALACHIANS...NEAR THE INTERSTATE 77
CORRIDOR IN THE BETTER SELY ATLANTIC FETCH...AND THEN JUST UPSTREAM
INTO GA. POPS WILL RAMP UP STEADILY EVERYWHERE THROUGH THE MORNING
HOURS.

HIGHER TERRAIN LOCATIONS ARE ALREADY SEEING OCCASIONAL GUSTS TO 40
MPH THIS MORNING AND THESE GUSTS SHOULD INCREASE THROUGH THE DAY
ALONG WITH THE PRES GRADIENT. THE CURRENT WIND ADVISORY LOOKS WELL
PLACED AS THE BEST 50 TO 55 KT 850 MB JET CROSSES THE MTNS TODAY
BEFORE MOVING EAST THIS EVENING. STILL CANNOT RULE OUT SOME DOWNED
TREES WITH ANY SHOWERS...BUT WIDESPREAD DAMAGING WINDS ARE NOT
EXPECTED WITH THE WARM ADVECTION GRADIENT FLOW ON THE NC SIDE OF THE
SPINE.

AS THE MIDWEST SYSTEM CONTINUES TO OCCLUDE TODAY...THE TRAILING SFC
COLD FRONT WILL GRADUALLY MOVE EASTWARD AND FOCUS A SHARPER LINE OF
CONVECTION OVER OUR AREA LATER TODAY INTO TONIGHT. DEEP QG FORCING
AHEAD OF THE CYCLONE WILL PROVIDE PLENTY OF LIFT FOR WIDESPREAD POPS
THROUGH THE AFTN AND EVENING HOURS...AND HIGH PRECIPITABLE WATER
VALUES SHOULD GENERATE HEAVY RAINFALL RATES. THE FFA HAS BEEN
EXPANDED NWD ALONG THE NC MTN CHAIN...OVER THE NRN NC
FOOTHILLS...AND ALSO IN THE NE GA AND EXTREME WRN SC MTNS. THESE
LOCATIONS HAVE RECEIVED THE MOST RAINFALL THUS FAR THIS MORNING AND
ARE PRIMED TO TAKE ADVANTAGE OF TRAINING SRLY UPSLOPE GENERATED
CONVECTION THROUGH THE NEAR TERM. THE PRE/FRONTAL CONVECTIVE LINE
SHOULD BEGIN TO REGENERATE NEAR THE SRN APPALACHIANS THROUGH 18Z
TODAY...PERHAPS STRENGTHENING AS IT TRANSITS THE UPSTATE AND
FOOTHILLS THROUGH THE EVENING HOURS IN THE RICH EQUIVALENT POTENTIAL
TEMP AIRMASS...AND THEN MOVE EAST OF INTERSTATE 77 DURING THE EARLY
MORNING HOURS WED. 0 TO 6 KM BULK SHEAR VALUES APPROACHING 50 KT AT
TIMES SHOULD BE ABLE TO TAP ENOUGH INSTABILITY FOR SEVERE CONVECTION
TO BE POSSIBLE ANYWHERE IN THE CWFA...WITH BRIEF TORNADOES POSSIBLE
NEAR ANY LINGERING BOUNDARIES AND IN SRN TIER SECTIONS WHERE
INSTABILITY WILL BE HIGHEST AND SFC WINDS SLIGHTLY BACKED. ENHANCED
HWO WORDING WILL BE USED THIS MORNING AND SEVERE CONVECTIVE WATCHES
ARE LIKELY LATER ON.

&&

HG


FXUS62 KGSP 141530
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1130 AM EDT TUE OCT 14 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL SLOWLY APPROACH THE WESTERN CAROLINAS AND
NORTHEAST GEORGIA TODAY...CROSSING THE AREA BY EARLY WEDNESDAY
MORNING. DRIER WEATHER WILL RETURN LATE IN THE WEEK AND PERSIST
THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1115 AM EDT TUESDAY...CANCELLED TORNADO WATCH FOR EASTERN
PORTIONS OF THE SC UPSTATE IN ADDITION TO LOCATIONS ALONG AND EAST
OF THE I77 CORRIDOR ACROSS THE NC PIEDMONT.  RECENT RADAR TRENDS
HAVE INDICATED SLOWER/WEAKER BANDS OF CONVECTION EMBEDDED WITHIN
BROAD PRECIP SHIELD ACROSS THE CENTRAL UPSTATE WITH RATHER
UNIMPRESSIVE UPDRAFTS ON THE WHOLE.  STILL CANNOT RULE OUT AN
ISOLATED TORNADO ACROSS THE HIGH TERRAIN AND THE FOOTHILLS WHERE
BEST UPDRAFTS CURRENTLY RESIDE IN ASSOCIATION WITH SHEAR
MAXIMA...THUS THE CONTINUED WW.  LATEST MODEL GUIDANCE TO INCLUDE
CONVECTIVE ALLOWING MODELS CONTINUES TO INDICATE A SECONDARY BAND OF
CONVECTION JUST AHEAD OF THE FRONT SLIDING INTO THE REGION THIS
AFTERNOON.  INCREASING INSTABILITY DUE TO SOUTHEASTERLY ATLANTIC
MOISTURE ADVECTION ALONG WITH HEATING WILL LEAD TO THE RETURN OF
FAVORABLE SEVERE WEATHER CONDITIONS AHEAD OF THIS SECONDARY BAND OF
CONVECTION.

PREVIOUS DISCUSSION...
OTHERWISE...DEEP 500 MB LOW PRES IS CENTERED OVER THE MIDWEST THIS
MORNING WITH A SHARPENING TROUGH EXTENDING SWD TO THE MOUTH OF THE
MS RIVER. A STRONG FETCH OF MOISTURE IS INVADING THE DEEP SOUTH
AHEAD OF THIS FEATURE...WITH ONGOING CONVECTION LINED UP FROM
W/CENTRAL GA TO SE TN AND SLOWLY PROGRESSING EWD. THE SFC COLD AIR
DAMMING LAYER IS ALL BUT GONE AT THIS HOUR WITH DEWPOINTS NOW IN THE
UPPER 60S ACROSS THE NRN NC FOOTHILLS. SHOWERS HAVE FILLED OUT ALONG
THE UPSLOPE AREAS OF THE SRN APPALACHIANS...NEAR THE INTERSTATE 77
CORRIDOR IN THE BETTER SELY ATLANTIC FETCH...AND THEN JUST UPSTREAM
INTO GA. POPS WILL RAMP UP STEADILY EVERYWHERE THROUGH THE MORNING
HOURS.

HIGHER TERRAIN LOCATIONS ARE ALREADY SEEING OCCASIONAL GUSTS TO 40
MPH THIS MORNING AND THESE GUSTS SHOULD INCREASE THROUGH THE DAY
ALONG WITH THE PRES GRADIENT. THE CURRENT WIND ADVISORY LOOKS WELL
PLACED AS THE BEST 50 TO 55 KT 850 MB JET CROSSES THE MTNS TODAY
BEFORE MOVING EAST THIS EVENING. STILL CANNOT RULE OUT SOME DOWNED
TREES WITH ANY SHOWERS...BUT WIDESPREAD DAMAGING WINDS ARE NOT
EXPECTED WITH THE WARM ADVECTION GRADIENT FLOW ON THE NC SIDE OF THE
SPINE.
AS THE MIDWEST SYSTEM CONTINUES TO OCCLUDE TODAY...THE TRAILING SFC
COLD FRONT WILL GRADUALLY MOVE EASTWARD AND FOCUS A SHARPER LINE OF
CONVECTION OVER OUR AREA LATER TODAY INTO TONIGHT. DEEP QG FORCING
AHEAD OF THE CYCLONE WILL PROVIDE PLENTY OF LIFT FOR WIDESPREAD POPS
THROUGH THE AFTN AND EVENING HOURS...AND HIGH PRECIPITABLE WATER
VALUES SHOULD GENERATE HEAVY RAINFALL RATES. THE FFA HAS BEEN
EXPANDED NWD ALONG THE NC MTN CHAIN...OVER THE NRN NC
FOOTHILLS...AND ALSO IN THE NE GA AND EXTREME WRN SC MTNS. THESE
LOCATIONS HAVE RECEIVED THE MOST RAINFALL THUS FAR THIS MORNING AND
ARE PRIMED TO TAKE ADVANTAGE OF TRAINING SRLY UPSLOPE GENERATED
CONVECTION THROUGH THE NEAR TERM. THE PRE/FRONTAL CONVECTIVE LINE
SHOULD BEGIN TO REGENERATE NEAR THE SRN APPALACHIANS THROUGH 18Z
TODAY...PERHAPS STRENGTHENING AS IT TRANSITS THE UPSTATE AND
FOOTHILLS THROUGH THE EVENING HOURS IN THE RICH EQUIVALENT POTENTIAL
TEMP AIRMASS...AND THEN MOVE EAST OF INTERSTATE 77 DURING THE EARLY
MORNING HOURS WED. 0 TO 6 KM BULK SHEAR VALUES APPROACHING 50 KT AT
TIMES SHOULD BE ABLE TO TAP ENOUGH INSTABILITY FOR SEVERE CONVECTION
TO BE POSSIBLE ANYWHERE IN THE CWFA...WITH BRIEF TORNADOES POSSIBLE
NEAR ANY LINGERING BOUNDARIES AND IN SRN TIER SECTIONS WHERE
INSTABILITY WILL BE HIGHEST AND SFC WINDS SLIGHTLY BACKED. ENHANCED
HWO WORDING WILL BE USED THIS MORNING AND SEVERE CONVECTIVE WATCHES
ARE LIKELY LATER ON.

&&

CDG/HG


FXUS62 KGSP 141853
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
253 PM EDT TUE OCT 14 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE EAST OF THE AREA LATER TONIGHT AND
THEN OFFSHORE BY TOMORROW NIGHT. AS HIGH PRESSURE GRADUALLY MOVES
BACK INTO THE REGION FROM THE WEST ON THURSDAY AND FRIDAY...DRIER
WEATHER WILL RETURN AND PERSIST THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 250 PM EDT TUESDAY...RATHER POTENT UPPER TROF AND ASSOCIATED
COLD FRONT CONTINUES TO HIGHLIGHT THE NEAR TERM PORTION OF THE
FORECAST.  LATEST DAY ONE CONVECTIVE OUTLOOK FROM SPC CONSUMES THE
ENTIRE FORECAST AREA WITHIN THE SLIGHT RISK REGION...WITH AN
ADDITIONAL 5 PERCENT AREA FAVORABLE FOR TORNADOES.  THIS COINCIDES
WITH VERY IMPRESSIVE SHEAR PROFILES ASSOCIATED WITH APPROACHING
LONGWAVE TROF...UPPER JET...AND BACKED FLOW AT THE SURFACE.  MOST
RECENT SURFACE ANALYSIS INDICATES INCREASING INSTABILITY AMONGST
CONTINUED SOUTHERLY FLOW WITH ALMOST THE ENTIRE FORECAST AREA
REACHING INTO THE 500-1000J/KG RANGE.  CONVECTIVE ALLOWING GUIDANCE
SOURCES CONTINUE TO INDICATE STRENGTHENING OF A SECONDARY LINE OF
SHOWERS AND THUNDERSTORMS WHICH ARE NOW PUSHING THROUGH
NORTH/CENTRAL GA.  IMPROVED UPPER SUPPORT BACKED BY AN APPROACHING
SHORT WAVE IMPULSE AND ASSOCIATED UPPER JET MAX WILL PROVIDE AMPLE
DIVERGENCE/LIFT IN THE MID/UPPER LEVELS TO AID THE ABOVE MENTIONED
CONVECTION THIS EVENING...AND THROUGH THE OVERNIGHT DESPITE HEATING
LOSS.  LONG RIGHT TURNING HODOGRAPHS IN THE WARM SECTOR AHEAD OF THE
COLD FRONT ARE INDICATIVE OF IMPRESSIVE SHEAR THROUGH THE PROFILE.
BACKED FLOW AT THE SURFACE COULD SUPPORT TORNADOGENESIS WITHIN THE
STRONGEST UPDRAFTS THIS EVENING/OVERNIGHT.  THUS THE PRIMARY SEVERE
WEATHER CONCERNS CONTINUE TO BE ISOLATED AND SHORT LIVED TORNADOES
ALONG WITH DAMAGING WIND GUSTS.

IN ADDITION...CONTINUED HEAVY RAINFALL THROUGH THE DAY TODAY WILL
PROVIDE SUPPORTIVE ANTECEDENT CONDITIONS FOR POSSIBLE FLASH FLOODING
WITHIN AND ADJACENT TO ANY OF THE STRONGER CELLS THROUGH THE FIRST
12 HOURS OF THE FORECAST PERIOD.  THUS THE FLASH FLOOD WATCH WILL
REMAIN IN EFFECT.  WIND ADVISORY ACROSS THE HIGH TERRAIN WILL LIKELY
BE ALLOWED TO EXPIRE ON SCHEDULE AS THE PRESSURE GRADIENT RELAXES
BEHIND THE FROPA OVERNIGHT.  CONDITIONS WILL IMPROVE AFTER DAYBREAK
AS THE FRONT SLIDES INTO CENTRAL NC AND THE MIDLANDS OF SC.
TEMPERATURES WILL REMAIN RATHER STATIONARY THROUGH THE PERIOD WITH
BELOW NORMAL LEVELS FEATURED IN THE FORECAST.

&&

CDG