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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KCAE 211145
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
745 AM EDT MON APR 21 2014

.SYNOPSIS...
A PRESSURE RIDGE WILL EXTEND THROUGH THE FORECAST AREA TODAY AND
TONIGHT. A WEAK COLD FRONT WILL MOVE THROUGH THE AREA TUESDAY
AFTERNOON AND EVENING. HIGH PRESSURE BEHIND THE FRONT WILL DOMINATE
WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
A DRY SURFACE PRESSURE RIDGE WILL EXTEND THROUGH THE FORECAST
AREA TODAY. AN H5 RIDGE WILL ALSO BE OVER THE AREA. IT WILL BE A
SUNNY AND WARM DAY. THE TEMPERATURE GUIDANCE WAS CLOSE WITH HIGHS
IN THE MIDDLE AND UPPER 70S. THE SURFACE PRESSURE RIDGE WILL
WEAKEN IN THE AREA TONIGHT. ALOFT...AN UPPER TROUGH WILL APPROACH
WITH AN INCREASE IN HIGH CLOUDINESS. OVERNIGHT LOW TEMPERATURES
ARE FORECAST IN THE LOWER 50S.

&&

.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
THE NAM AND GFS SHOW THE COLD FRONT MOVING THROUGH THE AREA
TUESDAY AFTERNOON OR EVENING. THE NAM WAS A LITTLE SLOWER WITH THE
TIMING. BOTH MODELS INDICATE H85 WESTERLY FLOW WITH GULF MOISTURE
PARTLY CUT OFF. THE NAM AND GFS MOS POPS HAVE TRENDED HIGHER BUT
ARE STILL IN THE CHANCE CATEGORY. KEPT CHANCE POPS BELIEVING
COVERAGE WILL BE LIMITED BECAUSE OF A LACK OF DEEP MOISTURE AND
WEAK CONVERGENCE ALONG THE FRONT. THE DIURNAL TIMING FAVORS
THUNDERSTORMS. LIMITED MOISTURE WILL LIKELY KEEP INSTABILITY WEAK.
THE NAM INDICATES SURFACE-BASED LI/S AROUND -3. THE MODELS
INDICATE WEAK SHEAR WITH H85 WINDS NEAR 20 KNOTS. THEREFORE...THE
CHANCE OF SEVERE THUNDERSTORMS IS LOW. DRYING BEHIND THE FRONT
SHOULD DOMINATE LATE TUESDAY NIGHT. THE GUIDANCE TEMPERATURES WERE
CONSISTENT.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE MODELS WERE CONSISTENT SHOWING DRY RIDGING DOMINATING WEDNESDAY
AND THURSDAY. THE GFS AND ECMWF SHOWED SOME MOISTURE INCREASE
ASSOCIATED WITH A DIFFUSE FRONT FRIDAY. THE MODELS HAVE NOT BEEN
CONSISTENT FOR SATURDAY AND SUNDAY. THE GFS SHOWED A COLD FRONT
WITH LIMITED MOISTURE SATURDAY. THE ECMWF KEPT THE FRONT WELL
NORTHWEST OF THE AREA THROUGH SUNDAY...ALTHOUGH PREVIOUS RUNS WERE
MORE PROGRESSIVE. THE GFS...ECMWF...AND EKD MOS PLUS GFS ENSEMBLE
MEAN POPS WERE VERY LOW THROUGH THE PERIOD. WE KEPT THE DRY
FORECAST BUT CONFIDENCE IS LOW BECAUSE OF THE MODEL INCONSISTENCY.
THE GFS...ECMWF...AND EKD MOS INDICATED NEAR OR ABOVE NORMAL
TEMPERATURES DURING THE PERIOD.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
HIGH CONFIDENCE FOR VFR CONDITIONS THROUGH 12Z TUESDAY.

AN UPPER RIDGE AND WEAK SURFACE HIGH PRESSURE WILL DOMINATE THE
PATTERN TODAY PROVIDING MOSTLY SUNNY SKIES. WINDS WILL GENERALLY
BE OUT OF THE NORTH THIS MORNING AND WILL ROTATE TO NORTHWESTERLY
THIS AFTERNOON. INCREASING HIGH CLOUDS EXPECTED OVERNIGHT AS AN
UPPER DISTURBANCE APPROACHES FROM THE WEST. LIGHT SOUTHWESTERLY
WINDS OVERNIGHT.

.EXTENDED AVIATION OUTLOOK...A WEAK FRONT WILL MOVE THROUGH
TUESDAY AFTERNOON AND EVENING...WITH A CHANCE OF SHOWERS AND
ASSOCIATED MVFR RESTRICTIONS.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$