592
FXUS63 KMPX 301140
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
640 AM CDT WED SEP 30 2026
KEY MESSAGES
- QUIET AND DRY WEATHER BEGINS, WITH A WARMER DAY TODAY FOLLOWED BY
COOLER TEMPERATURES FOR THE REST OF THE PERIOD.
- ISOLATED SHOWERS POSSIBLE SATURDAY AFTERNOON/EVENING,
OTHERWISE A DRY FORECAST. AMOUNTS GENERALLY LESS THAN A TENTH
OF AN INCH, MOST REMAIN DRY.
DISCUSSION
ISSUED AT 305 AM CDT WED SEP 30 2026
MOST MORNINGS WE BRING UP THE NIGHTTIME MICROPHYSICS RGB AS THE
PRODUCT TO LOOK AT, MAINLY BECAUSE IT HELPS US PICK OUT AREAS OF LOW
LEVEL CLOUD COVER AND FOG, AND WHILE THAT IS ALSO THE CASE TODAY I'D
LIKE TO PUT SOME FOCUS ON THE DIFFERENTIAL WATER VAPOR RGB. THERE IS
A TREMENDOUS SIGNAL BETWEEN THE CLOUDS AND MOISTURE FLOWING
SOUTHEAST OF THE AREA DOWN WHERE THERE ARE STILL SHOWERS ONGOING IN
EASTERN IOWA THROUGH SOUTHERN WI AND NORTHERN IL AND WHERE THERE IS
A BIT OF DRY AIR JUST NORTHWEST OF THE THIS LINE AS EVIDENT BY THE
TAN/BROWN. NORTHWEST OF THE THIN LINE OF DRY AIR IS AIR THAT ONCE
AGAIN CONTAINS A BIT MORE MOISTURE DESPITE THE LACK OF CLOUD COVER,
MAINLY DUE TO THE SUBSIDENCE AS HIGH PRESSURE MOVES IN. OUR LOWER
LEVEL TEMPERATURES FROM THE SURFACE TO AROUND 850MB CONTINUES TO BE
ON THE WARMER SIDE, ESPECIALLY FOR THIS TIME OF YEAR, WHICH WILL
ALLOW TEMPERATURES TO REACH INTO THE MID 70S THIS AFTERNOON WITH
SOME 80S IN WESTERN MN POSSIBLE IN OUR NORMAL WARM SPOTS. THIS WILL
BE RELATIVELY SHORT LIVED AS AFTER TODAY WE SHOULD DROP BACK INTO
THE 60S FOR HIGH FOR THE REST OF THE PERIOD, WITH LOWS LIKEWISE
DROPPING FROM NEAR 60 THIS MORNING TO MID TO UPPER 50S TOMORROW
MORNING DOWN TO THE UPPER 40S BY FRIDAY MORNING. KEEP IN MIND THAT
FOR SEP 30TH FOR THE TWIN CITIES, OUR NORMAL HIGH IS 67 AND LOW IS
48; THESE NUMBERS WILL ONLY CONTINUE TO FALL INTO THE FIRST WEEK OF
OCTOBER SO WE WILL BE ESSENTIALLY NEAR NORMAL TEMPERATURE WISE
DESPITE IT SEEMING COLDER SIMPLY DUE TO HAVING BEEN WARMER THAN
NORMAL RECENTLY. TAKING ANOTHER QUEUE FROM CLIMATOLOGY, OUR AVERAGE
FIRST 32 OR COLDER DAY IN THE TWIN CITIES IS OCTOBER 12TH AND THE
LONGER RANGE GUIDANCE FAVORS CONTINUED 60S FOR HIGHS AND 40S FOR
LOWS THROUGH THE FIRST HALF OF OCTOBER, MEANING WE PROBABLY END UP
ON THE LATER SIDE FOR A FIRST HARD FREEZE. WHETHER OR NOT WE MAKE A
RUN AT THE LATEST ON RECORD BEING NOV 18TH BACK IN 2016 REMAINS TO
BE SEEN.
THE MAIN THING TO LOOK AT BESIDES THE TEMPERATURES MOVING FORWARD
WILL BE A CHANCE FOR SHOWERS ON SATURDAY EVENING AS A SHORTWAVE
QUICKLY SWEEPS THROUGH THE REGION, WITH ACCUMULATION GENERALLY A
TENTH OF AN INCH OR LESS WITH THE CURRENT FORECAST. THE GFS SUITE IS
MUCH DRIER THAN THE ECMWF, HOWEVER EVEN THE MOST BULLISH EPS MEMBERS
ONLY SHOW A COUPLE TENTHS OF AN INCH AT THE MOST WITH DURATION OF
PRECIP ONLY 3 TO 4 HOURS AS THE SHORTWAVE RAPIDLY MOVES THROUGH. GFS
FORECAST SOUNDINGS SHOW A CLASSIC INVERTED V LOWER LEVEL PROFILE,
ALTHOUGH LAPSE RATES BECOME POOR ABOVE 850MB SUCH THAT INSTABILITY
IS MINIMIZED. WE COULD STILL MANAGE TO SQUEEZE OUT SOME THUNDER
GIVEN THE DEGREE OF SURFACE INSTABILITY THAT WOULD BE POSSIBLE, WITH
THE MAIN QUESTION BEING HOW WELL WE CAN SATURATE THE LOWER LEVELS TO
OVERCOME THE WEAK LAPSE RATES. FOR NOW, DON'T EXPECT MUCH IN THE WAY
OF THUNDER, WITH SOME ISOLATED TO SCATTERED LIGHT SHOWERS BEING THE
EXPECTATION. AFTER SATURDAY WE RESUME OUR DRY PATTERN AS A BROAD
AREA OF HIGH PRESSURE DROPS DOWN INTO THE NORTHERN PLAINS AND INTO
THE GREAT LAKES TO START NEXT WEEK.
AVIATION /12Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 633 AM CDT WED SEP 30 2026
WIDESPREAD FG THROUGH MID MORNING WITH IFR TO LIFR VIS AND CIGS. FOG
REDUCTIONS OF LESS THAN 1 MILE WILL BE COMMON FOR MN TERMINALS, WITH
3-4 MILE REDUCTIONS AT MSP. FG WILL GRADUALLY DISSIPATE AFTER
SUNRISE, BECOMING MVFR BY 14-15Z AND VFR BY 17-18Z. WINDS BE SW AT 5-
10 KNOTS THROUGH THE PERIOD. EXPECT BKN TO OVC HIGH LEVEL CLOUDS
THROUGH THE LATE AFTERNOON AND EVENING.
KMSP...FG/BR EXPECTED THIS MORNING WITH VIS REDUCTIONS OF 3-4 MILES,
POTENTIALLY DROPPING TO AROUND 1 MILE VIS BETWEEN 12-15Z. THERE
ARE OBSERVATIONS BELOW EVEN 1/2 MILE ACROSS WESTERN HENNEPIN
COUNTY THAT COULD SPREAD AS FAR EAST AS KMSP, BUT CONFIDENCE IS
LOW. FG WILL SLOWLY DISSIPATE AFTER SUNRISE, WITH CIGS BECOMING
MVFR BY 14-15Z AND EVENTUALLY VFR BY 17-18Z. THERE IS A CHANCE
WE SEE A SIMILAR SCENARIO TO MONDAY MORNING WHERE VISIBILITIES
DROP DRAMATICALLY RIGHT AROUND SUNRISE. THIS IS DUE TO MORE
LIGHT BEING REFLECTED BY THE DROPLETS IN THE FOG, LEADING TO
REDUCED VISIBILITY. THE CURRENT TEMPO GROUP REFLECTS THIS
POSSIBILITY. WINDS WILL BE SW AT 5-10 KNOTS THIS AFTERNOON.
/OUTLOOK FOR KMSP/
THU...VFR. WIND NW 10-15G25 KTS.
FRI...VFR. WIND VARIABLE 5 KTS.
SAT...VFR. CHC MVFR SHRA. S BCMG SW WINDS 5-10KTS.
MPX WATCHES/WARNINGS/ADVISORIES
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR BROWN-
CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-MCLEOD-MEEKER-
NICOLLET-POPE-REDWOOD-RENVILLE-SIBLEY-STEARNS-STEVENS-
SWIFT-TODD-WRIGHT-YELLOW MEDICINE.
WI...NONE.
DISCUSSION...TDH
AVIATION...LPR/BED
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