948
FXUS62 KCAE 071041
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
641 AM EDT TUE JUL 7 2020
SYNOPSIS
MOISTURE CONTINUES TO STREAM INTO THE REGION FROM THE SOUTH
AHEAD OF AN AREA OF LOW PRESSURE MOVING EASTWARD THROUGH
SOUTHERN GEORGIA. THIS WILL BRING INCREASING CHANCES OF SHOWERS
AND THUNDERSTORMS INTO THE MIDDLE OF THE WEEK WITH HEAVY RAIN
POSSIBLE. SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE FROM
LATE THIS WEEK THROUGH THE WEEKEND AS A MOIST AIR MASS REMAINS
OVER THE REGION.
NEAR TERM /THROUGH TONIGHT/
MID-LEVEL TROUGH WILL EXTEND OVER THE REGION TODAY AND BECOME
CENTERED OVER THE REGION TONIGHT. AT THE SURFACE, A FRONTAL
BOUNDARY WILL BE STALLED ACROSS THE AREA. SURFACE LOW PRESSURE
WILL MOVE INTO THE AREA FROM THE SOUTHWEST THIS MORNING AND SET
UP OVER THE CSRA BY TONIGHT. DEEP MOISTURE WILL BE IN PLACE WITH
PRECIPITABLE WATER VALUES AROUND 2.4 INCHES WITH THE HIGHEST
VALUES EAST. INSTABILITY APPEARS LIMITED WITH LI VALUES PEAKING
AROUND -1 OR -2. WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS
ARE EXPECTED DURING THE AFTERNOON WITH NUMEROUS SHOWERS
CONTINUING INTO TONIGHT. THE MAIN THREAT IS LOCALLY HEAVY
RAINFALL AND POTENTIAL FOR FLASH FLOODING. THE FORECAST AREA IS
OUTLOOKED IN A MARGINAL RISK FOR EXCESSIVE RAINFALL BY WPC. THE
AREAS THAT RECEIVED THE HEAVIEST RAINFALL ON MONDAY WILL BE
PARTICULARLY SUSCEPTIBLE INCLUDING AIKEN AND EDGEFIELD COUNTIES
AND EASTERN SUMTER, LEE, CLARENDON, AND SOUTHERN CHESTERFIELD
COUNTIES. FLOODING IS NOT EXPECTED TO BE WIDESPREAD ENOUGH TO
WARRANT A FLASH FLOOD WATCH. CLOUDS AND RAIN WILL KEEP
TEMPERATURES AROUND 10 DEGREES BELOW NORMAL, WITH HIGHS ONLY IN
THE LOWER TO MIDDLE 80S. OVERNIGHT LOWS IN THE LOWER 70S.
SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/
THE UPPER LOW OVER THE REGION WEDNESDAY WILL MOVE OFF THE COAST
WEDNESDAY NIGHT. THE SURFACE LOW WILL LINGER OVER THE COASTAL PLAIN.
ALTHOUGH PWAT VALUES WILL REMAIN AT OR ABOVE 2 INCHES OVER MUCH OF
THE AREA, THE DEEPEST MOISTURE WILL SHIFT TO THE COASTAL PLAIN.
SHOWERS AND THUNDERSTORMS WILL BECOME MORE DIURNAL GIVEN LACK OF
FORCING. INSTABILITY WILL LIKELY BE SLIGHTLY GREATER WITH SOME DRY
AIR MOVING IN ALOFT AND STEEPER LOW LEVEL LAPSE RATES WHICH MAY BE
SUFFICIENT TO POSE A THREAT FOR ISOLATED STRONG DOWNBURSTS. WE KEPT
CATEGORICAL POPS FOR WEDNESDAY AFTERNOON AND CHANCE POPS INTO
WEDNESDAY NIGHT. HIGH TEMPERATURES WILL REMAIN BELOW NORMAL IN THE
MID 80S WITH OVERNIGHT LOWS IN THE LOW 70S.
LONG TERM /THURSDAY THROUGH MONDAY/
A NEGATIVELY TILTED UPPER TROUGH SLOWLY MOVE EAST, THOUGH UPPER
TROFINESS LINGERS OVER THE EASTERN CONUS. A POTENTIAL TROPICAL LOW
WILL KEEP A CHANCE OF SHOWERS AND THUNDERSTORMS IN THE AREA AS IT
DRIFTS ALONG THE COAST THURSDAY NIGHT INTO FRIDAY. THE NHC CONTINUES
TO GIVE THIS AREA OF LOW PRESSURE A 40 PERCENT CHANCE OF DEVELOPMENT
AS IT MOVES INTO THE WARMER CAROLINA COASTAL WATERS BUT AT THAT
POINT, WITH OUR AREA BEING ON THE WEST SIDE OF THE SYSTEM, IT WOULD
POSE LITTLE THREAT. MOISTURE WILL LIKELY STAY IN THE AREA INTO EARLY
NEXT WEEK AND WITH TEMPERATURES CLIMBING BACK TO NEAR NORMAL WITH
MAINLY DIURNAL SHOWERS AND THUNDERSTORMS.
AVIATION /12Z TUESDAY THROUGH SATURDAY/
A SURFACE LOW IS SLOWLY TRACKING EASTWARD THROUGH SOUTHERN GA
TOWARDS SOUTHERN SC, CONTINUING TO BRING SHOWERS AND
THUNDERSTORMS TO OUR REGION INTO EARLY WEDNESDAY. SCATTERED
SHOWERS CURRENTLY REMAIN IN OUR AREA, WITH MORE MOVING IN FROM
THE SOUTH AS THE EARLY MORNING PROGRESSES. MVFR/IFR CONDITIONS
EXPECTED AS VISIBILITIES ARE FORECAST TO GO DOWN TO 4-5SM BY
EARLY MORNING. VISIBILITIES WILL REMAIN LOW INTO THE AFTERNOON.
WINDS GENERALLY CALM UNTIL DAYBREAK, BECOMING EASTERLY AT 5-10
KNOTS. IN ADDITION TO SHOWERS, ISOLATED THUNDERSTORMS ARE
EXPECTED TO DEVELOP IN THE AFTERNOON. EXPECT HIGHER RESTRICTIONS
WITHIN THESE POCKETS OF INSTABILITY.
EXTENDED AVIATION OUTLOOK
THE CHANCE FOR RESTRICTIONS FROM
MAINLY DIURNAL CONVECTION AND EARLY MORNING FOG WILL PERSIST THROUGH
THE WEEKEND.
CAE WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page