594
FXUS62 KCAE 281040
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
640 AM EDT SUN JUN 28 2026
WHAT HAS CHANGED
UPDATED BOTH KEY MESSAGES BUT THE OVERALL PATTERN REMAINS THE
SAME. AVIATION DISCUSSION UPDATED FOR 12Z TAFS.
KEY MESSAGES
- 1. SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS POSSIBLE ON
TODAY AND TOMORROW. A FEW STRONG THUNDERSTORMS ARE POSSIBLE
LATER TODAY.
- 2. DANGEROUS HEAT POSSIBLE TODAY AND TOMORROW, WITH A SIGNAL
FOR A MORE IMPACTFUL AND INTENSE HEAT EVENT DURING THE
OPENING DAYS OF JULY.
DISCUSSION
KEY MESSAGE 1: SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS
POSSIBLE ON TODAY AND TOMORROW. A FEW STRONG THUNDERSTORMS ARE
POSSIBLE LATER TODAY.
THE UPPER RIDGE CENTERED OVER THE MISSISSIPPI RIVER WILL
STRENGTHEN SIGNIFICANTLY TODAY. IN RESPONSE TO THE BUILDING
RIDGING, UPPER LEVEL WINDS WILL BE OUT OF THE NORTHWEST TODAY
WHILE A SHORTWAVE CAUGHT IN THE FLOW PASSES THROUGH THE REGION.
FIRST A DECAYING SHORTWAVE AND ASSOCIATED MCS WILL PASS INTO THE
MOUNTAINS, GENERALLY WEAKENING THROUGHOUT THE MORNING. THIS MAY
YIELD SOME MORE WIDESPREAD CLOUD COVER THAN GUIDANCE ALLOWS FOR
AND COMPLICATES THE REST OF THE FORECAST A BIT. THE CAMS HAVE A
DECENT HANDLE OF THE MORNING CONVECTION AND CONTINUE TO
INDICATE THAT A SECOND COMPLEX OF THUNDERSTORMS WILL MOVE INTO
THE CWA FROM THE UPSTATE THIS AFTERNOON AND WILL MAINLY IMPACT
AREAS ALONG THE I-26 CORRIDOR AND POINTS TO THE NORTH AND EAST.
THESE SAME LOCATIONS ARE OUTLOOKED IN A MARGINAL (1/5) RISK FOR
SEVERE WEATHER FROM THE SPC. MODELED SOUNDINGS CONTINUE TO SHOW
AN INVERTED-V PROFILE AND ADEQUATE DCAPE BETWEEN 750 AND 1000
J/KG INDICATING THE POTENTIAL FOR STRONG DOWNBURST WINDS. LONG,
SKINNY CAPE PROFILES AND HIGH PWATS ALSO SHOW THE POTENTIAL FOR
HEAVY RAINFALL. WHILE EVERYONE HAS THE CHANCE OF SEEING A SHOWER
OR THUNDERSTORM TODAY, CHANCES DROP OFF QUICKLY TOWARDS THE
CSRA.
LINGERING MOISTURE IS EXPECTED TO BRING ANOTHER CHANCE FOR
SCATTERED SHOWERS AND THUNDERSTORMS ON MONDAY, THOUGH CONFIDENCE
AND COVERAGE IS LOWER. THE THREAT FOR SEVERE WEATHER IS ALSO
LOWER ON MONDAY AS THE AFOREMENTIONED UPPER RIDGE CONTINUES TO
BUILD AND SLIDE EAST TOWARDS THE REGION.
KEY MESSAGE 2: DANGEROUS HEAT POSSIBLE TODAY AND TOMORROW, WITH
A SIGNAL FOR A MORE IMPACTFUL AND INTENSE HEAT EVENT DURING THE
OPENING DAYS OF JULY.
ANOTHER HOT AND HUMID DAY IS IN THE FORECAST TODAY, THOUGH THE
TIMING OF TODAY'S THUNDERSTORM COMPLEX WILL IMPACT HOW HOT
LOCATIONS ACROSS THE NORTHERN HALF OF THE FORECAST AREA GET. THE
CURRENT FORECAST HAS HIGHS IN THE UPPER 80S AND LOWER 90S IN THE
NORTH AND LOWER TO MID 90S IN THE SOUTH. THE HEAT WILL COMBINE
WITH DEWPOINTS IN THE LOWER TO MID 70S TO PRODUCE PEAK HEAT
INDEX VALUES AS HIGH AS 107 IN A FEW SPOTS THIS AFTERNOON. WHILE
WE ARE NOT EXPECTING TO MEET HEAT ADVISORY CRITERIA TODAY, THESE
VALUES ARE HIGH ENOUGH THAT CAUTION NEEDS TO BE USED IF YOU PLAN
TO BE OUTDOORS FOR AN EXTENDED PERIOD OF TIME. A HEAT ADVISORY
MAY BE NEEDED FOR A PORTION OF THE CSRA ON MONDAY WHEN HEAT
INDEX VALUES MAY APPROACH 110 DEGREES IN THE AFTERNOON.
IT APPEARS THAT DRIER AIR WILL FILTER INTO THE REGION DURING THE
MID-WEEK PERIOD, DECREASING HEAT INDEX VALUES, THOUGH IT WILL
REMAIN HOT AS THE STRONG UPPER RIDGE ANCHORS ITSELF OVER THE
EASTERN CONUS. BY LATE WEEK, AND INTO THE HOLIDAY WEEKEND,
GUIDANCE CONTINUES TO MAINTAIN A STRONG UPPER RIDGE, WITH 850-MB
TEMPERATURES APPROACHING OR EXCEEDING 20C. THIS PATTERN FAVORS
TEMPERATURES INCREASING AGAIN, WITH SEVERAL DAYS OF HIGHS AT OR
ABOVE 100 DEGREES POSSIBLE DURING THE THURSDAY TO SUNDAY
PERIOD. IF TRENDS CONTINUE, HEAT PRODUCTS MAY BE NEEDED SEVERAL
DAYS IN A ROW. BE SURE TO MAKE HEAT SAFETY PREPARATIONS NOW AND
HAVE A PLAN TO MONITOR CHILDREN, THE ELDERLY, PETS, AND ANYONE
WITHOUT ADEQUATE INDOOR COOLING.
ONE POTENTIAL CAVEAT TO THIS EXTENDED PERIOD OF HEAT COULD BE
DEVELOPMENT IN THE TROPICS. THE NHC MAINTAINS A 20% CHANCE FOR
CYCLONE FORMATION OVER THE NEXT 7 DAYS OFF THE SC COAST.
GUIDANCE INDICATES THAT THUNDERSTORMS THAT MOVE THROUGH THE
CAROLINAS TODAY WILL DRIFT OVER THE GULF STREAM AND COULD
ACQUIRE TROPICAL CHARACTERISTICS BEFORE HEADING BACK WEST
TOWARDS THE UNITED STATES. IT IS IMPORTANT TO NOTE THAT
CONFIDENCE IN ANY ORGANIZED TROPICAL DEVELOPMENT REMAINS LOW, AS
ENSEMBLE GUIDANCE CONTINUES TO SHOW CONSIDERABLE SPREAD ON
DEVELOPMENT AND TRACK. HAVING SAID THAT ANY CLOUDS AND RAIN,
TROPICAL OR OTHERWISE, WOULD LIMIT THE IMPACT OF THE HEAT SO THE
POTENTIAL BEARS WATCHING IN THE COMING DAYS.
AVIATION /12Z SUNDAY THROUGH THURSDAY/
VFR CONDITIONS LIKELY OUTSIDE OF AFTERNOON CONVECTION SUNDAY.
THE ACTIVE SUMMER PATTERN CONTINUES SUNDAY WITH WEST-SOUTHWEST
WINDS DEVELOPING, GUSTS TO 20-22 KNOTS AND TYPICAL SUMMER CU
AROUND 5-6K FEET; SOME MORNING MIFG IS LINGERING MAINLY AT AIK
AND CAE THROUGH 12Z, WITH SOME PERIODIC DROPS TO MVFR POSSIBLE.
SOME STRONG THUNDERSTORMS WILL MOVE INTO THE REGION BY LATE
MORNING INTO THE AFTERNOON- EVENING, BUT COVERAGE WILL BE FAIRLY
SCATTERED. PROB30 GROUPS INCLUDED FOR THIS POTENTIAL THROUGHOUT
MUCH OF THE AFTERNOON FOR TSRA AND WIND GUST POTENTIAL.
CONFIDENCE IN COVERAGE IS NOT TERRIBLY HIGH GIVEN SOME MORNING
CLOUD COVER FROM UPSTREAM CONVECTION HOWEVER. THUNDERSTORM
COVERAGE SHOULD CLEAR OUT AROUND 00-01Z MONDAY.
EXTENDED AVIATION OUTLOOK...AFTERNOON CONVECTION WILL DEVELOP
AGAIN MONDAY BUT IS LESS LIKELY FOR THE REMAINDER OF THE WEEK
AS RIDGING BUILDS OVERHEAD. BRIEF EARLY MORNING RESTRICTIONS
ALSO POSSIBLE EARLY NEXT WEEK.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
DISCUSSION...7
AVIATION...42
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