155
FXUS64 KMEG 051144
AFDMEG
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
644 AM CDT FRI SEP 5 2025
..NEW AVIATION
KEY MESSAGES
UPDATED AT 625 AM CDT FRI SEP 5 2025
- SCATTERED SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH THE
MIDSOUTH LATE EARLY THIS EVENING THROUGH OVERNIGHT TONIGHT.
SEVERE THUNDERSTORMS WILL BE POSSIBLE, PARTICULARLY THIS
EVENING. DAMAGING WINDS AND LARGE HAIL ARE THE PRIMARY THREATS.
- THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS NEAR THE
TENNESSEE RIVER. OVER THE REMAINDER OF THE MIDSOUTH, A MARGINAL
RISK FOR SEVERE THUNDERSTORMS IN PLACE, CORRESPONDING WITH A MORE
ISOLATED COVERAGE OF SEVERE THUNDERSTORMS.
- FOLLOWING STORMS TONIGHT AND A COLD FRONTAL PASSAGE TONIGHT, A
SIGNIFICANT COOLDOWN IS IN STORE THE WEEKEND. DAYTIME HIGHS IN
THE 70S AND 80S ARE FORECAST, ACCOMPANIED BY LOW HUMIDITY.
DISCUSSION
(TONIGHT THROUGH NEXT THURSDAY)
ISSUED AT 1117 PM CDT THU SEP 4 2025
WELCOMED RAINFALL IS ON THE WAY BEGINNING LATE FRIDAY AFTERNOON
INTO SATURDAY AHEAD OF A COLD FRONTAL PASSAGE. UNFORTUNATELY,
PRIOR TO THIS, RETURN FLOW AND EFFICIENT HEATING WILL ALLOW
TEMPERATURES TO CREEP INTO THE MID TO UPPER 90S. THE RETURN FLOW
WILL ALLOW FOR STRONG MOISTURE TRANSPORT AND ALLOW DEWPOINTS TO
CREEP INTO THE 60S, WITH SOME AREAS IN NORTH MISSISSIPPI REACHING
OR EXCEEDING 70 DEGREES. THIS STRONG MOISTURE COMBINED WITH LIFT
FROM THE APPROACHING FRONTAL BOUNDARY DOES BRING A LOOMING SEVERE
WEATHER THREAT. WHILE IT REMAINS <15% (LEVEL 1 OUT OF 5), THIS IS
THE FIRST TIME IN A WHILE THE THREE KEY INGREDIENTS WILL BE
AVAILABLE (MOISTURE, LIFT, AND INSTABILITY) AS THE REGION HAS
BEEN MOSTLY DOMINATED UNDER HIGH PRESSURE.
HI-RES GUIDANCE SHOWS BETWEEN 30-40KTS OF BULK SHEAR AVAILABLE
BEFORE ENHANCING TO 50-60KTS RIGHT AROUND SUNSET. WHILE SHEAR
WILL BE ENHANCED AFTER SUNSET, SURFACE BASED INSTABILITY WILL
DWINDLE. MLCAPE STILL WILL LINGER BETWEEN 1500-2000 J/KG WITH
STEEP LAPSE RATES KEEPING CONCERNS HIGH FOR LARGE HAIL AND
DAMAGING WIND GUSTS. THE PERIOD OF ENHANCED SHEAR IS RATHER SHORT
LIVED AND LARGELY CONFINED NEAR THE TN/KY BORDER. GUIDANCE
SUGGESTS A SPATIAL VARIABILITY, WITH HIGHER SHEAR AND LOWER CAPE
NORTH OF I-40, AND THE SOUTH OF I-40.
PWAT VALUES ARE AVERAGE FOR THIS TIME OF YEAR (1.8") AND ONGOING
DROUGHT CONDITIONS BRING A LIMITED FLOODING THREAT. IF A STORM
WERE TO DEVELOP OVER AN URBANIZED AREA, LOCALIZED FLOODING COULD
BECOME AN ISSUE, BUT EXCESSIVE RAINFALL AND FLASH FLOODING ARE NOT
A PRIORITY OF CONCERN. THE 90TH PERCENTILE FOR PRECIPITATION FOR
THIS EVENT IS MAXIMIZING AT 1.50" OF ACCUMULATION ALONG THE
TENNESSEE RIVER, WITH LESSER AMOUNTS ELSEWHERE. THE WORST CASE
SCENARIO, OR 10TH PERCENTILE, IS 0.30" IN THE AFOREMENTIONED AREA
AND LESSER ELSEWHERE.
POST FROPA, A MUCH COOLER AND DRIER AIRMASS WILL PREVAIL THROUGH
THE MIDDLE OF NEXT WEEK. HIGH TEMPERATURES ON SATURDAY WILL
GENERALLY BE IN THE MID TO UPPER 70S, WITH A FEW EXCEPTIONS IN
NORTH MISSISSIPPI INTO THE LOW TO MID 80S BEFORE THE COOL AIR
SINKS. CRISP, FALL LIKE MORNING WILL BE ON TAP FOR THE NEXT
SEVERAL DAYS WITH MORNING LOWS IN THE 50S AND LOW 60S. THE
WEATHER PATTERN WILL BE STABLE FROM SATURDAY EVENING FOR THE NEXT
SEVEN DAYS. WHILE COOL CONDITIONS ARE WELCOMED AS METEOROLOGICAL
FALL IS UNDERWAY, THE RAINFREE WEATHER IS UNWELCOME AS ONGOING
DROUGHT CONDITIONS ARE EXPECTED TO PERSIST. THESE ONGOING DRY
CONDITIONS WILL BRING THE RETURN OF ELEVATED FIRE DANGER AND
CONTINUED LOW STREAMFLOWS.
DNM/PWB
AVIATION
(12Z TAFS)
ISSUED AT 644 AM CDT FRI SEP 5 2025
FEW AVIATION WEATHER IMPACTS EXPECTED THROUGH LATE AFTERNOON,
OTHER THAN OCCASIONALLY GUSTY SURFACE WINDS. THESE WINDS WILL VEER
TO THE WEST IN ADVANCE OF A SLOW-MOVING COLD FRONT. PRE-FRONTAL
AIRMASS WILL REMAIN LARGELY CAPPED TO TSRA DEVELOPMENT.
TSRA CHANCES BECOME THE MAIN FOCUS BY 00Z. THERE REMAINS
RELATIVELY WIDE SPREAD IN MODEL GUIDANCE WITH RESPECT TO TSRA
TIMING AND COVERAGE. FOR THIS REASON, TSRA POTENTIAL IS STILL
BEST HANDLED WITH A PROB30. FOR MEM, ANY LATE EVENING IMPACT FROM
TSRA AT MEM SHOULD BE RELATIVELY BRIEF AND MAY SIMPLY INITIATE
EAST OF THE TRACON.
WANING CONVECTIVE INSTABILITY SHOULD LIMIT TS POTENTIAL OVERNIGHT,
EXCEPT PERHAPS AT TUP.
PWB
FIRE WEATHER
ISSUED AT 327 AM CDT FRI SEP 5 2025
A COLD FRONT WILL MOVE THROUGH THE REGION TONIGHT. THERE IS A
MEDIUM CHANCE (40-50%) OF WETTING RAINFALL. DRY CANADIAN AIR WILL
MOVE BACK INTO THE REGION THROUGH THE WEEKEND, WITH MINIMUM RELATIVE
HUMIDITY FALLING TO THE 20 TO 30 PERCENT RANGE SUNDAY AFTERNOON.
MEG WATCHES/WARNINGS/ADVISORIES
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
PUBLIC FORECAST...DNM
AVIATION...PWB
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