Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 291725
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1225 PM CDT MON SEP 29 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM CDT MON SEP 29 2014

ITS BACK TO REALITY THIS MORNING IN THE TEMPERATURE DEPARTMENT.
AFTER A BEAUTIFUL DAY ON SUNDAY WITH HIGHS IN THE 80S...WHICH BY THE
WAY WAS THE FOURTH DAY IN A ROW WITH HIGHS SOME 10 TO 15 DEGREES
ABOVE NORMAL...HIGHS TODAY WILL BE MORE IN THE 55 TO 65 DEGREE RANGE
FROM NORTH TO SOUTH ACROSS THE FA. THIS WILL RESULT IN TODAY BEING
20 TO 30 DEGREES COOLER THAN THE HIGHS ON SUNDAY.

THE COOL DOWN TODAY IS THE RESULT OF A STRONG COLD FRONT THAT
STRETCHED FROM NEAR KEAU TO FSD EARLY THIS MORNING. THE FRONT WILL
PUSH WELL SOUTH OF THE REGION TODAY WITH HIGH PRESSURE BUILDING OVER
THE WESTERN GREAT LAKES AND UPPER MISSISSIPPI VALLEY TONIGHT.

BANDS OF SHOWERS EXIST TO THE REAR OF THE FRONT AND STRETCH FROM FAR
NORTHERN WI TO NEAR BIS. THE SHOWERS ARE WELL DEFINED BY A BAND OF
MID LEVEL FRONTOGENESIS. THE ARW/NMM WRFS AS WELL AS THE HRRR ARE
LAGGING BY A FEW HOURS ON THE SOUTHEAST PROPAGATION OF THE SHOWERS
EARLY THIS MORNING. ONE EXCEPTION IS THE HOPWRF...WHICH HAS HANDLED
THE OVERNIGHT DEVELOPMENT AND MOVEMENT MUCH BETTER. THEREFORE...THE
FORECAST THROUGH THE MORNING WAS MODELED TOWARDS THE HOPWRF. THIS
BRINGS SCT-NUMEROUS SHOWERS THROUGH CENTRAL MN...THE TWIN CITIES
METRO AS WELL AS WEST CENTRAL WI. THE SHOWERS WILL DIMINISH HEADING
SOUTHEAST THIS AFTERNOON AS MID LEVEL MOISTURE AND FORCING DIMINISH.
RATHER EXTENSIVE LOW CLOUDINESS ACROSS MUCH OF THE FA EARLY THIS
MORNING WILL GRADUALLY DIMINISH TO THE NORTH AND EAST OF THE TWIN
CITIES DURING THE AFTERNOON. THE LOW CLOUDS WILL LIKELY HOLD TO THE
WEST AND SOUTH EVEN THROUGH TONIGHT AS THE LOW LEVEL FLOW BECOMES
SOUTHEAST IN ADVANCE OF AN APPROACHING LOW PRESSURE SYSTEM. LOWS
TONIGHT WILL RANGE FROM THE MIDDLE AND UPPER 30S IN OUR NE CWA
AROUND RICE LAKE AND LADYSMITH TO THE LOWER 50S ACROSS SOUTHWEST
MN.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 403 AM CDT MON SEP 29 2014

THE WORK WEEK WILL BE DOMINATED BY A LARGE SCALE THROUGH THAT WILL
BE WORKING ACROSS CENTRAL NOAM...BRINGING WITH IT ENHANCED CHANCES
FOR PRECIP TUESDAY AFTERNOON/NIGHT...WEDNESDAY AFTERNOON/NIGHT...AND
AGAIN THURSDAY NIGHT INTO FRIDAY. FOR THE WEEKEND...WE WILL GET INTO
NW FLOW THAT WILL FEATURE US GETTING INTO THE WARM SECTOR OF A
CLIPPER ON SUNDAY.

FOR THE WORK WEEK SYSTEM...THERE A 3 WAVES OF INTEREST THAT WILL
IMPACT THE MPX AREA AS THE MEAN THROUGH WORKS THROUGH. THE FIRST
WAVE WILL BE ASSOCIATED WITH THE CLOSED LOW CURRENTLY OVER THE FOUR
CORNERS AND WILL WORK ACROSS THE ERN DAKOTAS AS A COMPACT NEGATIVELY
TILTED TROUGH ON TUESDAY. WAVE TWO WILL BE A MORE SUBTLE FEATURE
COMING OUT OF THE CENTRAL PLAINS WEDNESDAY THAT WILL WORK INTO THE
GREAT LAKES BY THURSDAY. THE FINAL SHORT WAVE TO IMPACT THE AREA
WILL COME DOWN ON THE BACK SIDE OF THE TROUGH THU NIGHT INTO FRIDAY.
MODEL AGREEMENT IS HIGH WITH THE FIRST WAVE. WAVE TWO STILL HAS
SIGNIFICANT DIFFERENCES IN HOW FAR WEST IT WILL TRACK...WITH
DISCREPANCIES IN THE FINAL WAVE DEALING WITH HOW STRONG IT WILL BE.

ALTHOUGH THE FIRST WAVE WILL BE PASSING US BY TO THE WEST...IT WILL
SEND A COLD FRONT INTO MN TUESDAY NIGHT. ALL MODELS FROM
DETERMINISTIC...PROBABILISTIC...TO CONVECTIVE ALLOWING SHOW A BAND
OF SHOWERS/STORMS WORKING ACROSS THE AREA BEGINNING TUESDAY
AFTERNOON IN WRN MN AND EVENTUALLY ENDING UP OVER IN WRN WI BY
WEDNESDAY MORNING. USED THE SREF TO TIME A N-S ORIENTED BAND OF
LIKELIES ACROSS THE AREA TUESDAY AFTERNOON THOUGH THE NIGHT. FROM
THE QPF PERSPECTIVE...INSTABILITY LOOKS PRETTY LIMITED WITH THE
BAND...SO NOT ANTICIPATING ANY EXCESSIVE RAIN RATES...WITH A GENERAL
QUARTER TO HALF INCH LOOKING LIKELY WITH THIS BAND OF SHOWERS. THE
BIGGER QUESTION WITH THIS FIRST WAVE...IS WHERE DOES THE COLD FRONT
END UP. GIVEN THE TRACK OF THE UPPER WAVE TO THE WEST OF THE MPX
AREA...THIS FRONT WILL BE SLOWING DOWN AS IT WORKS ACROSS MN AS THE
UPPER FORCING DRIVING IT INITIALLY HEADS UP THROUGH MANITOBA. BY
WEDNESDAY MORNING...THIS FRONT ONLY LOOKS TO BE ABOUT HALF WAY
ACROSS MN.

THIS FRONT AND ITS POSITION WILL BE OF IMPORTANCE FOR WAVE TWO
COMING UP FROM THE SW WED AFTERNOON...AS A HEALTHY SLUG OF RAIN
LOOKS TO TRAVEL NORTH ALONG THE FRONT AS THE UPPER WAVE LEADS TO AN
ENHANCEMENT IN THE LLJ AND ASSOCIATED MOISTURE TRANSPORT. THIS
EVENING...THE GEM/GFS KEPT THE BULK OF THE SECOND WAVES PRECIP
ENTIRELY EAST OF THE MPX CWA...THE ECMWF WAS BRINGING THE CORE OF
THE PRECIP RIGHT UP I-35...WHILE THE NAM WAS IN BETWEEN...THOUGH
CLOSER TO THE ECMWF THAN THE GEM/GFS. GIVEN THE LOCATIONAL
DISCREPANCIES...HAVE HELD POPS DOWN IN THE LIKELY CATEGORY
WEDNESDAY/WEDNESDAY NIGHT IN THE EAST. A BLEND OF THE NAM/ECMWF FOR
QPF WOULD SAY ANOTHER GOOD HALF TO ONE INCH OF RAIN WOULD BE
POSSIBLE WITH THIS WAVE FROM MANKATO UP THROUGH THE WRN TWIN CITIES
METRO AND UP INTO DULUTH. BESIDE WHERE THE PRECIP END UP...THERE ARE
ALSO DISCREPANCIES WITH HOW QUICKLY THIS PRECIP EXITS THE
AREA...WITH THE ECMWF KEEPING WRN WI WET RIGHT THROUGH THURSDAY
MORNING. NOT TO IGNORE THE WEST SIDE OF THE CWA...DID START REMOVING
POPS WEDNESDAY/WEDNESDAY NIGHT FOR THE WRN THIRD OF THE CWA AS
PRECIP THIS PERIOD WILL BE ALONG/EAST OF THE COLD FRONT...WHICH WILL
BE WELL EAST OF WRN MN.

THURSDAY AFTERNOON SHOULD SEE THE MPX AREA BRIEFLY DRY OUT AS THE
COLD FRONT PUSHES EAST OF THE AREA...BUT A STRONG WAVE DROPPING
SOUTH OUT OF CANADA WILL BRING ANOTHER SHOT OF RAIN INTO CENTRAL MN
BY THURSDAY EVENING. THIS WAVE WILL KEEP PRECIP CHANCES GOING IN THE
EAST INTO FRIDAY BEFORE WE FINALLY DRY OUT FOR GOOD FRIDAY NIGHT AS
WE GET WEST OF THE UPPER TROUGH. FRIDAY STILL LOOKS COOL AND BRISK
WITH STRONG NW WINDS...CLOUDS AND HIGHS IN THE 40S AND 50S CERTAINLY
LIVING UP TO WHAT IS PROBABLY MOST PEOPLES PERCEPTION OF WHAT
OCTOBER IN THE UPPER MS VALLEY IS LIKE.

FOR THE WEEKEND...SFC RIDGING...BRINGING WITH IT CLEAR SKIES AND
LIGHT WINDS WILL RESULT IN A VERY CHILLY START TO SATURDAY...WITH
MOST LOCATIONS GETTING INTO THE 30S. WILL LIKELY HAVE TO DECIDE THIS
WEEK HOW FAR NORTH INTO THE CWA FROST/FREEZE HEADLINES WILL STILL BE
NECESSARY THIS WEEKEND. WE WILL QUICKLY SEE TEMPERATURES START TO
REBOUND SATURDAY NIGHT AS WE GET INTO THE WAA SIDE OF A CLIPPER THAT
WILL BE DROPPING ACROSS NRN MN SUNDAY. ALTHOUGH THE CURRENT FORECAST
IS DRY...COULD CERTAINLY SEE SOME LIGHT SHOWERS MOVING ACROSS THE
AREA SAT NIGHT/SUN MORNING WITH ISENTROPIC LIFT WORKING THROUGH. AT
ANY RATE...ANY PRECIP LOOKS LIGHT AND SHORT LIVED AND WE CURRENTLY
LOOK TO HAVE IDEAL CONDITIONS FOR SEEING SOME FAST TIMES RUN
DURING THE TWIN CITIES MARATHON ON SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1211 PM CDT MON SEP 29 2014

LOW CONFIDENCE CIG FORECAST INTO THE AFTERNOON. ABUNDANT LOW LEVEL
MOISTURE AND CAA CONTINUING SHOULD PRECLUDE RAPID CLEARING. WILL
TRY AND SCATTER CLOUDS OUT AFTER 23Z MOST LOCATIONS IN THE EAST.
FARTHER WEST A BIT MORE PROBLEMATIC. THERE IS EROSION GOING ON
TO THE SOUTHWEST BUT DONT KNOW HOW EXTENSIVE THIS WILL BE
OVERNIGHT. IF IT DOES CLEAR OUT AROUND 00Z...THEN SOME RISK OF
STRATUS/FOG DEVELOPING. WILL CONTINUE PREVIOUS TREND OF BRINGING
IN THE STRATUS/FOG/LIFR TO THE WEST AND AT KEAU FOR NOW. STILL
CONFIDENCE LOW ON THIS OVERALL DEVELOPMENT. ANY LOW CLOUDS WILL
DISSIPATE THROUGH 15Z TO THE WEST WITH MORE MID/HIGH LEVEL CLOUDS
MOVING IN DURING THE MORNING TO THE MN PORTION OF THE CWA. MAIN
RAIN THREAT HOLDS OFF AT WESTERN TAF SITES UNTIL AFTER 18Z TUE.
EAST TO SOUTHEAST WINDS DURING THE PERIOD. A FEW GUSTS MOVING
ACROSS WITH THE COLD AIR MOVING THROUGH. THEN INCREASING AGAIN
TUESDAY AFTERNOON AHEAD OF THE NEXT FRONTAL BOUNDARY.

KMSP...LOW CONFIDENCE ON CEILING BREAKING OUT. WILL TRY AND BREAK
CEILING THROUGH 21Z...AND SCATTER IT OUT THROUGH 00Z. SOME THREAT
OF STRATUS DEVELOPING LATER TONIGHT...BUT LOW CONFIDENCE REMAINS
SO WILL LEAVE SCT012 FOR NOW. THEN SOME MID/HIGH LEVELS CLOUDS
MOVING IN DURING THE MORNING...WITH THE MAIN RAIN THREAT HOLDING
OFF UNTIL AFTER 00Z WED.

/OUTLOOK FOR KMSP/

TUE...VFR. MVFR/SHRA LIKELY TUE NIGHT. WINDS E-SE 10-15 KTS.
WED...MAINLY VFR. CHANCE MVFR IN SHRA/TSRA. WINDS S-SE 10-15 KTS.
THU...MAINLY VFR. CHANCE MVFR IN SHRA. WINDS W-NW 5-10 KTS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

$$

SHORT TERM...RAH
LONG TERM...MPG
AVIATION...DWE





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