646
FXUS62 KCAE 050034
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
834 PM EDT SAT JUL 4 2026
WHAT HAS CHANGED
AVIATION DISCUSSION UPDATED FOR 00Z TAFS.
KEY MESSAGES
- 1. ABOVE NORMAL TEMPERATURES CONTINUE THIS WEEKEND INTO EARLY
NEXT WEEK.
- 2. CHANCES FOR SCATTERED DIURNAL SHOWERS AND THUNDERSTORMS
START SUNDAY, CONTINUING INTO NEXT WEEK. STRONG STORMS ARE
POSSIBLE EACH AFTERNOON AND EVENING.
DISCUSSION
KEY MESSAGE 1: ABOVE NORMAL TEMPERATURES CONTINUE THIS WEEKEND
INTO EARLY NEXT WEEK.
HEADING INTO SUNDAY, THE UPPER RIDGE IS EXPECTED TO GRADUALLY
WEAKEN TOWARD 590DM AND IT'S AXIS IS EXPECTED TO START SHIFTING
A BIT EASTWARD AS A SHORTWAVE TROUGH IMPINGES ON IT ACROSS THE
UPPER MIDWEST DOWN INTO THE TENNESSEE VALLEY. THIS WILL ALLOW
LOW LEVEL FLOW TO BECOME MORE SOUTHERLY TO SOUTHWESTERLY AND
BRING SURFACE DEWPOINTS BACK INTO THE UPPER 60S TO LOW 70S WITH
AFTERNOON HIGH TEMPERATURES INTO THE MID TO UPPER 90S. OVERALL,
INCREASED MOISTURE SHOULD AID IN BRINGING HEAT INDICES BACK
TOWARD 105F ACROSS THE FA DURING THE AFTERNOON. THE MAIN CAVEAT
TO THIS IS CONVECTIVE TEMPERATURES COULD BE QUICKLY ATTAINED
EARLY IN THE AFTERNOON, BRINGING SCATTERED CONVECTION (SEE KEY
MESSAGE #2 FOR MORE INFORMATION) A BIT EARLIER THAN CURRENTLY
DEPICTED IN THE LATEST HRRR RUNS FOR EXAMPLE. THIS WOULD NOT
ALLOW TEMPERATURES TO PEAK IN THE UPPER 90S AND WOULD KEEP HEAT
INDICES IN CHECK A BIT MORE. DUE TO THIS, HAVE HELD OFF FROM
ISSUING ANOTHER HEAT ADVISORY FOR NOW, BUT THIS WILL BE
EVALUATED FOR THE NEXT FORECAST PACKAGE. THIS TREND OF DIURNAL
CONVECTION COMPLICATING TEMPERATURE/HEAT INDICES FORECASTS IS
EXPECTED TO CONTINUE INTO NEXT WEEK AS DEEP MOISTURE MOVES IN
PLACE WITH TEMPERATURES NEAR TO ABOVE NORMAL. EVEN WITH THIS
COMPLICATION, HEAT INDICES LIKELY WILL EXCEED 100F THROUGH AT
LEAST WEDNESDAY (LREF PROBABILITIES ARE OVER 70% FOR THIS),
POSSIBLY NECESSITATING ADDITIONAL HEAT PRODUCTS.
THIS ALL GOES TO SAY IT REMAINS LIKELY THAT A PROLONGED PERIOD
WITH HEAT INDICES ABOVE 100F WILL CONTINUE INTO AT LEAST THE MID
WEEK NEXT WEEK, SO HEAT SAFETY MEASURES SHOULD CONTINUE TO BE
TAKEN. THE DURATION OF THIS HEAT WILL CONTINUE TO MAKE THE
ELDERLY, YOUNG CHILDREN, PETS, AND THOSE WITHOUT INDOOR COOLING
AT PARTICULAR RISK SUNDAY AND INTO NEXT WEEK.
KEY MESSAGE 2: CHANCES FOR SCATTERED DIURNAL SHOWERS AND
THUNDERSTORMS START SUNDAY, CONTINUING INTO NEXT WEEK. STRONG
STORMS ARE POSSIBLE EACH AFTERNOON AND EVENING.
FOR SUNDAY, ROBUST SURFACE HEATING IS EXPECTED TO ALLOW
CONVECTIVE TEMPERATURES TO BE REACHED FAIRLY EARLY IN THE DAY
(BETWEEN 15-18Z), BRINGING SCATTERED SHOWERS AND STORMS ACROSS
THE FA. THIS IS FURTHER SUPPORTED IN THE MEAN HREF AND REFS
SOLUTIONS. WITH INCREASING MOISTURE FROM SOUTHERLY IVT
TRANSPORT, MUCAPE VALUES ARE EXPECTED TO NEAR 2000-2500 J/KG AND
DEEP MIXING SHOULD YIELD IMPRESSIVE DCAPE VALUES OVER 1000
J/KG. LINGERING SUBSIDENCE FROM THE WEAKENING RIDGE COULD KEEP
STORMS A BIT SHALLOW, BUT ANY MORE PERSISTENT UPDRAFT COULD
DEEPEN AND BRING THE RISK FOR A STRONG TO SEVERE STORM. THE MAIN
HAZARD FROM ANY STRONG STORM WOULD BE DAMAGING WINDS FROM
LOCALIZED DOWNBURSTS. THIS TYPE OF TYPICAL STRONG TO SEVERE
SUMMER PULSE ENVIRONMENT IS EXPECTED TO PERSIST INTO THE MID
WEEK NEXT WEEK. ENSEMBLE GUIDANCE IS IN GOOD AGREEMENT THAT THE
SUPPRESSED AND EASTWARD MOVING RIDGE WILL ALLOW PIECES OF
SHORTWAVE ENERGY TO TRAVERSE THE REGION, BRINGING A BIT MORE
FORCING THAN THAT ON SUNDAY. SCATTERED CONVECTION IS EXPECTED
EACH DAY WITH THE MAIN THREAT CONTINUING TO BE DOWNBURST WINDS.
LOCALLY HEAVY RAINFALL WILL ALSO BE POSSIBLE AS PWAT'S RAISE TO
NEAR 2.0-2.20" EARLY IN THE WEEK.
AVIATION /00Z SUNDAY THROUGH THURSDAY/
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD, INCREASED
CONVECTIVE COVERAGE SUNDAY AFTERNOON.
VFR CONDITIONS EXPECTED THROUGH TONIGHT. ISOLATED STORMS
DIMINISHED THIS EVENING AND CONVECTION IS NOT EXPECTED THROUGH
THE REST OF THE NIGHT. WHILE THERE MAY BE SOME BRIEF VISIBILITY
RESTRICTIONS TONIGHT ASSOCIATED WITH LINGERING LOW LEVEL
MOISTURE AND SMOKE FROM FIREWORKS, CONFIDENCE IS LOW IN
RESTRICTIONS DEVELOPING. SCATTERED STORMS DEVELOPING TOMORROW
AFTERNOON WITH COVERAGE HIGHER THAN THIS PAST AFTERNOON. HAVE
INCLUDED A PROB30 GROUP AT ALL TERMINALS FOR TSRA.
EXTENDED AVIATION OUTLOOK...DAILY RAIN CHANCES AND POSSIBLE
RESTRICTIONS CONTINUE INTO EARLY NEXT WEEK.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
DISCUSSION...DH
AVIATION...96
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