Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 062052
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
352 PM CDT SUN JUL 6 2014

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 328 PM CDT SUN JUL 6 2014

COLD FRONT HAS BEEN MAKING STEADY PROGRESS TO THE EAST AT ABOUT 20
KTS ACROSS MN TODAY...AND AT 3PM WAS IN THE PROCESS OF WORKING
ACROSS THE TWIN CITIES. MORNING CLOUDS SLOWED DOWN THE WARMING IN
THE TWIN CITIES...BUT THERE IS STILL HOPE FOR OUR FIRST 90 DEGREE
TEMP THIS YEAR AS THERE WILL BE ABOUT A 2 HOUR WINDOW WHERE WE CAN
STILL WARM BEHIND THE FRONT BEFORE THE CAA KICKS IN. WE HAVE SEEN
PLACES LIKE REDWOOD FALLS...GLENCOE...AND NEW ULM HIT 90 IN THIS
ZONE AND IT WILL BE HITTING THE TWIN CITIES STILL DURING PEAK
HEATING BETWEEN 3 AND 5 PM...SO DON/T GIVE UP HOPE ON THAT FIRST
90 JUST YET!

AS FOR STORM POTENTIAL...ACTIVITY OVER WI HAS BEEN ELEVATED...WITH
THE ATMO STILL CAPPED WITH RESPECT TO SFC BASED CONVECTION PER THE
STABLE CU FIELD /AT 230 PM/ STILL IN PLACE OVER WHAT IS A VERY JUICY
WARM SECTOR...WHERE DEWPS HAVE BEEN COMMONLY RISEN UP INTO THE MID
70S. STILL LOTS OF DISAGREEMENT WITH WHETHER OR NOT THIS FRONT WILL
EVEN GENERATE CONVECTION...BUT GIVEN THE DEGREE OF INSTABILITY
PRESENT...ALONG WITH THE SHORTWAVE MOVING INTO WRN MN AS EVIDENCED
BY DRYING ON WATER VAPOR BACK ACROSS THE DAKOTAS...PREFER THE IDEA
THE HRRR AND MEMBER1 OF THE 15Z HOPWRF SHOW WITH A SCT LINE OF
STORMS DEVELOPING ALONG THE FRONT AROUND 20Z AND QUICKLY SPREADING
EAST. THIS WOULD PLACE THE THUNDER THREAT MAINLY ALONG AND EAST OF
AN ALBERT LEA TO RICE LAKE LINE. SFC WINDS HAVE VEERED CONSIDERABLY
DURING THE DAY...WHICH WILL RESULT IN A MINIMAL TORNADO THREAT...BUT
2K-4K J/KG OF MLCAPE...H7-H5 LAPSE RATES UP OVER 7 DEG C/KM...AND
EFFECTIVE SHEAR AROUND 40 KTS WILL BE MORE THAN ENOUGH TO SUPPORT A
WIND/HAIL THREAT...ESPECIALLY TOWARD THE IOWA BORDER WHERE
INSTABILITY AND LAPSE RATES ARE BETTER.

WILL SEE SKIES CLEAR OUT TONIGHT...BUT CONSISTENT NW WINDS WILL
BRING IN DEWPS IN THE LOWER/MID 60S...WHICH WILL LIMIT THE FOG
POTENTIAL. IN ADDITION...A VERY POTENT SHORTWAVE CURRENTLY OVER NRN
SASKATCHEWAN WILL DROP INTO NODAK TONIGHT...WITH ACTIVITY EXPECTED
TO DEVELOP OVER CENTRAL NODAK THIS EVENING. THIS WILL LIKELY SEND
SHOWERS/STORMS TOWARD CENTRAL MN LATE TONIGHT INTO MONDAY
MORNING...THOUGH MORE ROBUST STORM COVERAGE OVER THE MPX CWA IS NOT
EXPECTED UNTIL MONDAY AFTERNOON AS THAT STRONG SASKATCHEWAN WAVE
MOVES INTO WRN MN. FOR THIS WAVE...PREFERRED A GEM/ECMWF/GFS BLEND
FOR ITS TIMING. THE NAM IS ABOUT 6 HOURS FASTER WITH THE
WAVE...PLACING IT OVER ERN MN BY THE END OF THE SHORT TERM AS
OPPOSED TO WRN MN AS THE OTHER GUIDANCE SHOWS. DETERMINISTIC MODELS
SHOW FAIRLY WIDESPREAD CONVECTION DEVELOPING BASED ON THEIR QPF
FIELDS...BUT THE CAMS SHOW ACTIVITY BEING NOTICEABLY MORE SCATTERED
OVER MN MONDAY AFTERNOON. THIS IS LIKELY DUE TO THE FACT THAT THERE
REALLY IS NO STRONG SFC FEATURE TO FOCUS ACTIVITY DURING THE
AFTERNOON...SO THE CAMS ARE SIMPLY GENERATING CONVECTION WHERE THEY
CAN DEVELOP ENOUGH INSTABILITY.

THOUGH NW FLOW IS EXPECTED...1.5-2.5K J/KG OF MLCAPE COMBINED WITH
50-60 KTS OF BULK SHEAR WILL BE MORE THAN ENOUGH TO SUPPORT A SEVERE
THREAT. HODOGRAPHS FOR MONDAY ARE MOSTLY LONG STRAIGHT
LINES...INDICATING THE MAIN THREAT WOULD BE LARGE HAIL FROM
SPLITTING SUPERCELLS. IF ENOUGH STORMS CAN INITIATE...WE WOULD
LIKELY END UP WITH A COMPLEX OF STORMS OR TWO THAT WOULD HAVE A WIND
TREAT AS WELL. HIGHER LCLS /DUE TO THE DRIER BOUNDARY LAYER AIR
EXPECTED/ ALONG WITH THE SHEAR BEING MAINLY OF THE SPEED VARIETY
/WITH LITTLE DIRECTION CHANGE/ WILL GREATLY LIMIT ANY TORNADO
THREAT.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 328 PM CDT SUN JUL 6 2014

WHILE THE BEST STORM COVERAGE SHOULD GENERALLY BE BETWEEN 21-00Z
IN WESTERN MN...EASTERN MN WILL HAVE THE BEST SHOT AT THUNDER
BETWEEN 00-03Z...AND SHORTLY THEREAFTER IN WESTERN WI. THE MID-
LEVEL DRYING ARRIVES QUICKLY BETWEEN 03-06Z IN THE EASTERN
FORECAST AREA...SO THE PRECIP SHOULD GET QUICKLY SHUFFLED OFF TO
THE EAST LATE TOMORROW EVENING.

DRIER AND SLIGHTLY COOLER AIR ARRIVES BEHIND THE STORM SYSTEM ON
TUESDAY WITH SURFACE HIGH PRESSURE EXPANDING INTO THE PLAINS AND
UPPER LEVEL NORTHWEST FLOW. NORTHWEST WINDS WILL BE A LITTLE
BREEZY...OTHERWISE EXPECT MOSTLY SUNNY SKIES AND MILD TEMPERATURES
IN THE 70S TO NEAR 80 DEGREES. UPPER LEVEL RIDGING FLATTENS AS IT
SHIFTS INTO THE HIGH PLAINS ON WEDNESDAY...HOWEVER WITH RETURN
FLOW DEVELOPING IN WESTERN MN IN THE AFTERNOON HIGH TEMPERATURES
WILL IMPROVE A FEW DEGREES. THE EAST WILL REMAIN ON THE FRINGE OF
AN 850MN COLD POCKET CENTERED ROUGHLY OVER LAKE SUPERIOR. MID AND
HIGH CLOUDS BUILDING INTO THE AREA FROM THE WEST. MODEL
CONSISTENCY ISN`T AS GOOD LATER IN THE WEEK WITH WEST TO NORTHWEST
UPPER FLOW AND THE POSSIBILITY OF A FEW WEAK WAVES TO TRACK
THROUGH THE AREA. THE TIMING OF THESE WAVES REMAIN TOO DIFFICULT
TO PINPOINT WITH EACH MODEL SHOWING SLIGHTLY DIFFERENT
TIMING AND LATITUDINAL PLACEMENT - DID NOT REALLY ALTER THE POPS
MUCH WEDNESDAY NIGHT AND BEYOND. TEMPERATURES ARE EXPECTED TO
REMAIN WITHIN A FEW DEGREES OF CLIMATE NORMALS DURING THE PERIOD.
AFTER MONDAY...THE NEXT SUBSTANTIAL PROBABILITY FOR PRECIP ARRIVES
ON THURSDAY WHEN THE FLOW BECOMES A LITTLE MORE W-SW AND WARM
ADVECTION ARRIVES FROM THE DAKOTAS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1243 PM CDT SUN JUL 6 2014

COLD FRONT MAKING STEADY PROGRESS ACROSS MN THIS AFTERNOON AND AT
18Z STRETCHED FROM ABOUT MILLE LACS LAKE DOWN TO WORTHINGTON...SO
JUST ABOUT READY TO MOVE INTO THE WRN TWIN CITIES METRO AREA. SCT
STORMS OVER WRN WI ARE ELEVATED...WITH SFC BASED STORMS EXPECTED
TO DEVELOP ALONG THE COLD FRONT AROUND 20Z. BY THEN THE FRONT WILL
LIKELY BE JUST CLEARING MSP AND NEARING RNH...SO STILL LOOKS LIKE
FIELD WITH BEST CHANCE FOR TS WITH THE FROPA THIS AFTERNOON IS
EAU...WHERE A VCTS WAS MAINTAINED...BUT SHIFTED AN HOUR LATER TO
BETWEEN 21Z AND 23Z. TONIGHT IS EXPECTED TO BE QUIET...WITH VFR
CONDS AND WNW-NW WINDS PREVAILING. OVERNIGHT...STORMS ARE EXPECTED
TO DEVELOP OVER CENTRAL NODAK...WITH REMNANTS OF THAT ACTIVITY
LIKELY DRIFTING INTO CENTRAL MN LATE TONIGHT/EARLY MON MORNING.
CONFIDENCE ON HOW THIS POTENTIAL ACTIVITY WILL EVOLVE IS LOW...SO
STUCK WITH NOTHING MORE THAN A VCSH TOWARD THE END OF THE AXN/STC
TAFS. MORE ROBUST TSRA ACTIVITY ACROSS THE MPX AREA IS EXPECTED
AFTER 18Z MON AS A STRONG SHORTWAVE COMES OUT OF THE DAKOTAS.

KMSP...LOOKS LIKE SFC BASED CONVECTION ALONG THE COLD FRONT WILL
START TO DEVELOP JUST AS THE FRONT IS CLEARING MSP...SO ACTIVITY
THIS AFTERNOON WILL REMAIN EAST OF THE FIELD. NEXT CHANCE FOR
PRECIP WOULD COME BETWEEN 12Z AND 16Z MON MORNING AND THAT WOULD
BE ASSOCIATED WITH ANY REMNANTS OF STORMS THAT ARE EXPECTED TO
DEVELOP OVER NODAK TONIGHT. AT THIS POINT...SPREAD IN MODELS IS
HIGH ENOUGH TO KEEP ANY PRECIP MENTION OUT OF THE TAF MON MORNING.
BETTER TSRA CHANCES EXPECTED MON AFTERNOON AS A STRONG SHORTWAVE
MOVES INTO WRN MN. FAVORED THE TIMING OF THE GFS/ECMWF/GEM WITH A
SLOWER PROGRESSION OF THE WAVE AND RESULTANT SLOWER ARRIVAL OF
AFTERNOON ACTIVITY THAN WHAT THE NAM HAS. ONCE THESE PESKY LOW
CLOUDS CLEAR OUT TODAY...CONFIDENCE IS HIGH IN REST OF TAF BEING
VFR OUTSIDE OF ANY PRECIP.

/OUTLOOK FOR KMSP/
TUE...VFR. WIND NW 10 TO 20 KT.
WED...VFR. WIND NW 5 TO 15 KT.
THU...VFR. CHC TSRA OVERNIGHT. WIND S 10 TO 15 KT.


&&

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

$$

SHORT TERM...MPG
LONG TERM...CLF
AVIATION...MPG






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