844
FXUS64 KMEG 050417
AFDMEG
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
1117 PM CDT THU SEP 4 2025
..NEW DISCUSSION, AVIATION, FIRE WEATHER
KEY MESSAGES
UPDATED AT 1117 PM CDT THU SEP 4 2025
- A LINE OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH THE MID-
SOUTH FRIDAY INTO SATURDAY, BRINGING A THREAT FOR SEVERE
WEATHER.
- A MARGINAL RISK (LEVEL 1 OUT OF 5) FOR SEVERE THUNDERSTORMS IS
IN PLACE FOR LATE FRIDAY AFTERNOON THROUGH EARLY SATURDAY
MORNING. DAMAGING WINDS AND LARGE HAIL ARE THE PRIMARY THREATS.
- A SIGNIFICANT COOLDOWN WILL FOLLOW THE FRONT, WITH PLEASANT,
FALL-LIKE TEMPERATURES FEATURING HIGHS IN THE 70S AND 80S
EXPECTED FOR SUNDAY INTO EARLY NEXT WEEK.
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. A PORTION OF THE MARGINAL
COULD BE UPGRADED TO A SLIGHT RISK IN THE SWEET SPOTWHERE THE
COMBINATION OF THESE INGREDIENTS IS HIGHEST, NEAR THE TENNESSEE
RIVER. IF A CATEGORIAL UPGRADE IS MADE, IT WOULD LIKELY BE WIND
DRIVEN. PW VALUES ARE AVERAGE FOR THIS TIME OF YEAR (1.8"), SMV
AROUND 20-25KTS, 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
AVIATION
(06Z TAFS) ISSUED AT 912 PM CDT THU SEP 4 2025
ISSUED AT 1117 PM CDT THU SEP 4 2025
VFR FOR THE NEXT 18 HOURS. WINDS WILL INCREASE TOMORROW AHEAD OF
A STRONG COLD FRONT. THE FRONT SHOULD APPROACH MEM, MKL AND JBR
AFTER SUNSET ACCOMPANIED BY A CHANCE OF RAIN/THUNDERSTORMS. ADDED
PROB30'S BETWEEN 01 AND 03Z AT THE 3 NORTHERN TAF SITES AS AN
INITIAL STARTING POINT FOR CONVECTION AND FROPA/WIND SHIFT. TUP
WILL LIKELY REQUIRE A WIND SHIFT AND MENTION OF CONVECTION IN THE
12Z TAF UPDATE.
30/SIRMON
FIRE WEATHER
ISSUED AT 1117 PM CDT THU SEP 4 2025
A COLD FRONT WILL MOVE THROUGH THE REGION FRIDAY NIGHT INTO
SATURDAY AND THERE IS A MEDIUM CHANCE (40-50%) OF WIDESPREAD
WETTING RAINFALL. MOISTURE PULL AHEAD OF THIS FRONT WILL RAISE RH
VALUES TO 40% OR HIGHER. SEASONABLY DRY AIR WILL MOVE BACK INTO
THE REGION ON SUNDAY BEHIND THE FRONT DROPPING RELATIVE HUMIDITY
BACK INTO THE 20 TO 30 PERCENT RANGE EARLY NEXT WEEK.
MEG WATCHES/WARNINGS/ADVISORIES
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
PUBLIC FORECAST...DNM
AVIATION...JDS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page