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 220549
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
149 AM EDT FRI AUG 22 2014

.SYNOPSIS...
A STRONG UPPER RIDGE WILL LEAD TO CONTINUED HOT CONDITIONS
FRIDAY. A BACK DOOR COLD FRONT WILL MOVE SW INTO THE NORTHERN AND
CENTRAL MIDLANDS SATURDAY...AND SHIFT TOWARDS THE CSRA SUNDAY.
THIS WILL LEAD TO A CHANCE OF THUNDERSTORMS ALONG AND AHEAD OF THE
FRONT...WITH TEMPERATURES RETURNING TO MORE NORMAL LEVELS BEHIND
IT. THE FRONT WILL SHIFT TO OUR SOUTH EARLY TO MID NEXT
WEEK...LEADING TO GENERALLY FAIR WEATHER WITH NEAR NORMAL
TEMPERATURES.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPPER RIDGE AND SURFACE HIGH PRESSURE CENTERED OVER THE LOWER
MISSISSIPPI VALLEY/GULF COAST CONTINUE TO DOMINATE THE WEATHER
ACROSS THE MIDLANDS AND CSRA. THIS WILL CONTINUE INTO FRIDAY. 88D
REGIONAL RADAR COMPOSITE SHOWS DECAYING LINE OF SHOWERS MOVING
SOUTHEAST ACROSS CENTRAL/EAST NC. THIS WAS ONCE A PART OF A LARGER
LINE OF SHOWERS AND THUNDERSTORMS THAT BOTH THE HRRR AND WRF
INDICATED WOULD WEAKEN THROUGH THE EVENING HOURS. SATELLITE LOOP
SHOWS SOME DEBRIS CLOUDS FROM THIS CONVECTION THAT WILL BE
SPREADING ACROSS THE REGION OVERNIGHT...ESPECIALLY ALONG THE NC/SC
BORDER. OTHERWISE...SKIES WILL REMAIN MOSTLY CLEAR AND
TEMPERATURES FALLING INTO THE LOWER/MIDDLE 70S BY SUNRISE.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
LITTLE CHANGE FRIDAY. UPPER RIDGE WILL REMAIN CENTERED JUST TO OUR
WEST...WITH SURFACE TROUGH ACROSS THE COASTAL CAROLINAS. THIS AND
A LOW LEVEL DOWNSLOPE FLOW WILL LEAD TO CONTINUED HOT MAX TEMPS.
MODELS CONTINUE TO INDICATE MAX TEMPS NEAR 100 DEGREES AGAIN MOST
AREAS...AND ALSO CONTINUES TO INDICATES DEW POINTS MIXING DOWN
INTO THE 60S ACROSS MOST OF OUR FA TO NEAR 70 SE FA...KEEPING HEAT
INDICES BELOW OUR HEAT ADVISORY CRITERIA OF 110F. ONLY ISOLATED TO
SLIGHT CHANCE DIURNAL TSTMS AT BEST DUE TO BUILDING RIDGE
ALOFT...AND FAIRLY DRY LOW LEVEL AIR LEADING TO HIGH LEVELS OF
FREE CONVECTION/HIGH CONVECTIVE TEMPS.

MAIN ISSUE FOR SATURDAY AND INTO SUNDAY IS TIMING OF APPROACHING
BACK DOOR FRONT. LATEST NAM A LITTLE FASTER THAN GFS. GUIDANCE
BLEND AND SHORT RANGE ENSEMBLE SUGGEST FRONT WITH ASSOCIATED BAND
OF THUNDERSTORMS MOVING INTO THE NORTHERN AND CENTRAL FA SATURDAY
AFTERNOON. CHANCE POPS SHOULD GENERALLY SUFFICE.

WARM MAX TEMPS STILL POSSIBLE SAT AHEAD OF THE FRONT...WITH
WARMEST TEMPS FAVORING THE CSRA WHERE TEMPS COULD REACH 100 AGAIN.
WITH NAM BEING SLIGHTLY FASTER THAN GFS WITH THE BACK DOOR FRONT...THE
NAM MOS IS SLIGHTLY COOLER THAN THE GFS MOS FOR SAT MAX
TEMP...ESPECIALLY NORTH AND CENTRAL. EVEN IF TEMPS NEAR 100
REACHED AGAIN SAT...GUIDANCE STILL SUGGESTS DEWPOINTS LOW ENOUGH
TO PRECLUDE HEAT INDEX VALUES FROM REACHING OUR HEAT ADVISORY
CRITERIA OF 110F.

FRONT EXPECTED TO SHIFT SW THRU THE FA SAT NT THRU SUN NT. EXPECT
CHANCE POPS NEAR AND JUST AHEAD OF THE FRONT...WITH COOLING TEMPS
ALONG AND NORTH OF IT. SO...POPS SUN AFTN FAVORING THE CSRA. HIGH
TEMPS SUNDAY SHOULD BE NOTICEABLY LESS BEHIND THE FRONT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
FRONT TO PUSH TO OUR SOUTH EARLY TO MID NEXT WEEK WITH SURFACE HIGH
PRESSURE BUILDING DOWN THE EASTERN SEABOARD...WITH UPPER RIDGE
ALOFT. SLIGHTLY COOLER AND DRIER AIR BEHIND THE FRONT ALONG WITH
RIDGE ALOFT WILL REDUCE CONVECTIVE CHANCES...TO SLIGHT CHANCE AT
BEST. TEMPS EXPECTED TO BE GENERALLY NEAR NORMAL.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS EXPECTED THROUGH THE PERIOD...WITH EARLY MORNING MVFR
POSSIBLE AT AGS/OGB.

SOME CONVECTIVE DEBRIS CONTINUES TO CROSS THE REGION WITH MOSTLY
CLEAR SKIES ACROSS THE SOUTHERN MIDLANDS AND CSRA. EXPECT THE
DEBRIS CLOUDS TO LIMIT FOG POTENTIAL...HOWEVER THERE IS ENOUGH
POTENTIAL TO INCLUDE A TEMPO GROUP FOR AGS/OGB BETWEEN 08 AND 12Z
THIS MORNING. FOG WHICH DEVELOPS WILL RAPIDLY ERODE WITH SUNRISE
WITH SOME DIURNAL CUMULUS FORMING THROUGH THE LATE MORNING AND
AFTERNOON HOURS. CHANCES FOR CONVECTION AT THE TAF SITES REMAINS
TOO LOW TO INCLUDE ATTM. WINDS THROUGH THE PERIOD WILL BE WEST TO
NORTHWEST AT 7 KNOTS OR LESS.

EXTENDED AVIATION OUTLOOK...MVFR OR IFR CONDITIONS POSSIBLE IN LATE
NIGHT AND EARLY MORNING FOG SATURDAY THROUGH MONDAY. ISOLATED
AFTERNOON AND EVENING THUNDERSTORMS MAY ALSO BRING RESTRICTIONS.

&&

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

$$






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