328
FXUS63 KMPX 122336
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
636 PM CDT WED AUG 12 2026
KEY MESSAGES
- SCATTERED THUNDERSTORMS POSSIBLE (30-50% CHANCE) FOR SOUTHERN
MINNESOTA LATE TONIGHT INTO THURSDAY MORNING. THERE IS A
MARGINAL (LEVEL 1 OF 5) RISK THAT A FEW STORMS MAY BE SEVERE.
- TEMPERATURES TO GO ON A COOLING TREND DOWN TO NORMAL
TEMPERATURES TOMORROW THROUGH THE WEEKEND INTO EARLY NEXT
WEEK.
DISCUSSION
ISSUED AT 225 PM CDT WED AUG 12 2026
A SUBTLE SHORTWAVE FEATURE IS EXPECTED TO TRACK FROM THE
NORTHERN PLAINS INTO THE UPPER MIDWEST TONIGHT INTO TOMORROW.
THIS WILL HELP TO PROVIDE SOME SYNOPTIC SUPPORT FOR STORM
CHANCES. WITH THE STATIONARY BOUNDARY EXPECTED TO REMAIN TO OUR
SOUTH, MOISTURE WILL BE ONE THE MAIN QUESTIONS. MODEL GUIDANCE
AND WPC QPF CONTINUE TO KEEP THE AXIS OF THE HIGHEST RAIN WELL
TO OUR SOUTH DRIVEN BY THIS FEATURE. EVEN LOOKING AT THE CURRENT
STATE OF DEW POINTS ACROSS MINNESOTA IT IS MAINLY DOWN NEAR THE
BORDER WITH IOWA THAT WE STILL HAVE HIGH DEW POINTS WITH MUCH
LOWER VALUES AS YOU HEAD NORTH. HOWEVER THIS MOISTURE CONCERN IS
LIMITED SOMEWHAT BASED ON THE TIMING OF WHEN STORMS ARE
EXPECTED, OVERNIGHT. WITH THE DIURNAL DROP IN TEMPERATURE, THIS
WILL MAKE SATURATION EASIER TO ACHIEVE. STILL STORM CHANCES,
ESPECIALLY WHEN YOU TAKE WHERE UPSTREAM CI IS MOST LIKELY TO
OCCUR REMAIN MUCH HIGHER TO OUR SOUTH. THEREFORE, IT IS
SOUTHERN MINNESOTA WITH THE BEST CHANCES TO SEE SOME SCATTERED
STORMS. SPC HAS MAINTAINED A MARGINAL (1 OUT OF 5) RISK WITH A
HIGHLY CONDITIONAL RISK. OVERALL TRENDS HAVE BEEN FARTHER SOUTH
IN RECENT CAM RUNS AS THE INSTABILITY ENVIRONMENT LOOKS ON THE
MORE MARGINAL SIDE. ENOUGH FOR STORM STORMS TO FORM, BUT DEEP
CONVECTION IS MORE UNCERTAIN WITH THIS LEVEL OF INSTABILITY. SOME
RUNS HAVE SHOWN ON FAVORABLE DEEP LAYER SHEAR, SO IF DEEP
CONVECTION CAN INITIATE THEN A STORM COULD BE SEVERE, THUS THE
HIGHLY CONDITIONAL MARGINAL RISK.
A MORE ZONAL FLOW PERIOD LOOKS TO SETTLE IN THURSDAY. THIS WILL
START A COOLING TREND THROUGH THE WEEKEND WITH TEMPERATURES
EVENTUALLY SETTLING WITH HIGHS NEAR 80 AND LOWS IN THE LOWER
60S. SO WHILE THIS IS A COOLING TREND IT IS US FALLING DOWN TO
NORMAL TEMPERATURES FROM A WARMER THAN NORMAL PERIOD. RAIN AND
STORM CHANCES CONTINUE TO BE FOCUSED DOWN TO OUR SOUTH WITH SOME
CHANCES IN REGIONS NEAR THE IOWA BORDER. LOOKING AHEAD TO
FRIDAY, WHICH HAD BEEN THE NEXT CHANCE FOR A WIDESPREAD RAIN,
CHANCES HAVE COME DOWN. LOOKING TOWARDS BOTH THE DETERMINISTIC
MODELS AND THEIR ENSEMBLE SYSTEMS THERE IS MUCH MORE SPREAD NOW
WITHIN THE SOLUTIONS. THE PAST DISCUSSION NOTED A DOWNWARD
TREND AND THIS HAS CONTINUED. TOMORROW THIS WILL START TO GET
MORE INTO THE CAM WINDOW AND THAT SHOULD PROVIDE SOME USEFUL
ADDITIONAL GUIDANCE TO SEE IF THIS DOWNWARD TREND CONTINUES.
SOME GUIDANCE THOUGH, MOST NOTABLY THE ECMWF, STILL HAS THIS
CHANCE BUT IT HAS SHIFTED TEMPORALLY MORE INTO LATE SATURDAY
FROM THE MORNING. SO INCREASED UNCERTAINTY WITH BOTH SPATIAL AND
TEMPORAL GAPS BETWEEN ENSEMBLE MEMBERS. WITH THE CHANCES FOR
SOME LATER TIMES NOW DURING PEAK HEATING THIS DOES ALSO INCREASE
THUNDERSTORM CHANCES. WE SHOULD HAVE A BREAK IN ACTIVITY FOR
THE START OF THE WEEK BEFORE A MORE ACTIVE PERIOD STARTS AGAIN.
AS EXPECTED THOUGH THERE IS SIGNIFICANT SPREAD FOR NEXT WEEK.
AVIATION /00Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 636 PM CDT WED AUG 12 2026
INCREASING MID LEVEL CLOUDS EXPECTED THIS EVENING AS A
DISTURBANCE ACROSS THE NORTHERN PLAINS HEADS EAST. SHOWERS ARE
EXPECTED TO REACH WESTERN MN LATE TONIGHT, AND MAY SPREAD INTO
EASTERN MN AND WI EARLY THURSDAY MORNING. VFR CONDITIONS WILL
LIKELY CONTINUE, DESPITE ANY SHOWER ACTIVITY. WINDS WILL BE
LIGHT TONIGHT, SHIFTING EASTERLY THURSDAY AND INCREASING TO 5 TO
10 KTS.
KMSP...NO ADDITIONAL CONCERNS. CONFIDENCE IS NOT HIGH ENOUGH TO
INTRODUCE ANY SHOWERS IN THE TAF YET, BUT A PROB30 MAY BE
INCLUDED WITH THE NEXT ISSUANCE.
/OUTLOOK FOR KMSP/
SAT...VFR, CHC -SHRA AND MVFR/IFR. WIND SE 10 KTS SHIFTING TO W.
SUN...VFR. WIND NW 5-10 KTS.
MON...VFR. WIND WSW 5-10 KTS.
MPX WATCHES/WARNINGS/ADVISORIES
MN...NONE.
WI...NONE.
DISCUSSION...NDC
AVIATION...BORGHOFF
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