Area Forecast Discussion
Issued by NWS Columbia, 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 KCAE 270410
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1210 AM EDT WED MAY 27 2015

.SYNOPSIS...
HIGH PRESSURE OFF THE MID ATLANTIC COAST WILL CONTINUE PUSHING
MOISTURE INTO THE REGION THROUGH THURSDAY. THIS WILL RESULT IN
CHANCES OF MAINLY AFTERNOON AND EVENING THUNDERSTORMS. AN UPPER
RIDGE WILL BECOME ENTRENCHED OVER THE AREA DURING THE WEEKEND
WITH DRIER AIR EXPECTED.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HIGH MOISTURE AND WEAK ISENTROPIC LIFT WILL HELP SUPPORT A
CONTINUED CHANCE OF SHOWERS OVERNIGHT. EXPECT MAINLY SHOWERS
INSTEAD OF THUNDERSTORMS BECAUSE OF NOCTURNAL COOLING AND WEAK
INSTABILITY. CLOUDINESS WILL HOLD UP TEMPERATURES. EXPECT LOWS IN
THE UPPER 60S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
SCATTERED SHOWERS WITH POSSIBLY EMBEDDED THUNDERSTORMS MAY BE
ONGOING WEDNESDAY MORNING ACROSS PARTS OF THE WESTERN MIDLANDS AND
FURTHER WEST INTO THE UPSTATE AS WEAK SHORTWAVE ENERGY SLOWLY
MOVING NORTHWARD AROUND THE PERIPHERY OF THE UPPER RIDGE INTERACTS
WITH ABUNDANT MOISTURE AND WEAK UPSLOPE SOUTHEASTERLY FLOW. WILL
KEEP CHANCE POPS EARLY WEDNESDAY ACROSS THE WESTERN MIDLANDS/CSRA
WITH A GRADIENT TO LOWER POPS TO THE EAST. PLUME OF DEEPER
MOISTURE WITH PRECIPITABLE WATER VALUES AROUND 1.5 INCHES OR
HIGHER WILL EXTEND ACROSS MUCH OF THE WESTERN HALF OF THE FORECAST
AREA ON WEDNESDAY AND WILL COMBINE WITH WEAK TO MODERATE
INSTABILITY AND RESULT IN SCATTERED CONVECTION ONCE AGAIN. HIGHEST
POPS WILL BE IN THE WEST WHERE BETTER MOISTURE EXISTS AND THERE IS
LESS INFLUENCE FROM THE UPPER RIDGE AND WILL CARRY A GRADIENT FROM
LOW LIKELY POPS WEST TO LOW CHANCE POPS EAST. SEVERE THREAT DOES
NOT APPEAR TO BE GREAT DUE TO THE MODEST INSTABILITY AND CONTINUED
WEAK SHEAR ENVIRONMENT BUT STILL CANNOT RULE OUT A POSSIBLE
ISOLATED STRONG TO SEVERE STORM. TEMPERATURES WILL BE A BIT COOLER
WEDNESDAY DUE TO EXTENSIVE CLOUDS AND MOISTURE WHICH COULD ALSO
LEAD TO WARMER OVERNIGHT LOWS.

THE UPPER RIDGE WILL TRY TO BEGIN BUILDING AGAIN ACROSS THE
SOUTHEASTERN STATES BUT THE DEEP MOISTURE PLUME WILL REMAIN ACROSS
THE UPSTATE AND MIDLANDS REGION PROVIDING ANOTHER AFTERNOON OF
SCATTERED CONVECTION WITH THE BEST CHANCES BEING ALONG AND NORTH
OF THE I-20 CORRIDOR. TEMPERATURES WILL WARM SLIGHTLY ON THURSDAY
COMPARED TO WEDNESDAY BUT CONTINUE TO GENERALLY BE IN THE MID 80S
FOR HIGHS AND MID TO UPPER 60S FOR LOWS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE UPPER RIDGE BECOMES RE-ESTABLISHED OVER THE SOUTHEASTERN STATES
FRIDAY AND CONTINUES THROUGH THE WEEKEND WHILE PERSISTENT SURFACE
RIDGING FROM THE WESTERN ATLANTIC INTO THE EAST COAST CONTINUES.
SUMMER LIKE CONDITIONS WILL EXIST WITH GENERALLY DIURNALLY INDUCED
ISOLATED TO SCATTERED CONVECTION EACH AFTERNOON/EVENING SAT-MON
WHILE THE MAIN STORM TRACK REMAINS DISPLAYED WELL TO THE NORTH
FROM THE MISSISSIPPI VALLEY ACROSS THE OHIO VALLEY INTO NEW
ENGLAND. SOME DIFFERENCES AMONG THE MEDIUM RANGE MODELS ARE NOTED
ON DAY 7 NEXT TUESDAY WITH THE GFS SHOWING A DISPLACED UPPER
TROUGH ACROSS THE WESTERN GULF COAST STATES WHILE THE ECMWF
DEVELOPS A CLOSED UPPER LOW OVER THE OHIO VALLEY WHICH ALLOWS
GREATER MOISTURE TO MOVE OVER THE AREA WITH A SOUTHWESTERLY FLOW
ALOFT RESULTING IN HIGHER RAIN CHANCES. TEMPERATURES DURING THE
PERIOD ARE EXPECTED TO BE NEAR TO ABOVE NORMAL WHILE RAIN CHANCES
WILL BE NEAR NORMAL THROUGH THE WEEKEND BUT INCREASE BY DAY 7
TUESDAY.

&&

.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
SHOWERS ARE SLOWLY DWINDLING ACROSS THE AREA EARLY THIS MORNING.
GIVEN LATEST RADAR TRENDS...EXPECT PRECIPITATION TO END AROUND
08Z-09Z.

WITH PLENTY OF MOISTURE ACROSS THE REGION LOW CLOUDS WILL RETURN
DURING THE EARLY MORNING HOURS WITH IFR EXPECTED AT ALL SITES.
LIFR CIGS WILL BE POSSIBLE FOR A FEW HOURS BEFORE SUNRISE THIS
MORNING AT ALL TAF SITES. MODELS INDICATE THAT THE MOST LIKELY
LOCATION TO SEE LIFR CIGS WOULD BE OGB. CIGS WILL GRADUALLY LIFT
LATER THIS MORNING TO VFR BY NOON. AFTERNOON CONVECTION IS
EXPECTED TO OCCUR AGAIN THIS AFTERNOON BRINGING POSSIBLE
RESTRICTIONS.

EXTENDED AVIATION OUTLOOK...EARLY MORNING RESTRICTIONS MAY CONTINUE
THROUGHOUT THE END OF THE WEEK. AFTERNOON SHOWERS AND THUNDERSTORMS
MAY ALSO BRING RESTRICTIONS THROUGH THURSDAY.

&&

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

&&

$$
99



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