800 
FXUS63 KMPX 080754
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
254 AM CDT FRI JUN 8 2012

.DISCUSSION...
THINGS HAVE NOT CHANGED TOO MUCH WITH RESPECT TO FORECAST
EXPECTATIONS AND CONCERNS IN COMPARISON TO YESTERDAY AFTERNOON.
THE MAIN FORECAST ISSUE STILL LOOKS TO BE THE POTENTIAL FOR MORE
WIDESPREAD CONVECTION AND THE POSSIBILITY OF SOME SEVERE WEATHER
SUNDAY AFTERNOON INTO SUNDAY NIGHT. HOWEVER... IN THE SHORTER
TERM WE WILL CONTINUE TO SEE SOME CONVECTION TODAY INTO THIS
EVENING AS SOME ISENTROPIC LIFT PERSISTS OVER THE THE REGION WITH
SOME ELEVATED CAPE STILL IN PLACE. AS THE UPPER RIDGE TO OUR WEST
FLATTENS AND IS KICKED EASTWARD IN ADVANCE OF THE WESTERN TROUGH
WE SHOULD SEE THE MAIN 850MB THETA-E RIDGE GET DISPLACED TO OUR
NORTH AND EAST TONIGHT... WITH WARMER AIR CONTINUING TO WORK IN AT
LOW LEVELS. THAT SHOULD ALLOW FOR ANY PCPN TO END TONIGHT AND
ALLOW FOR A DRY SATURDAY. THE GFS AND ECMWF HAVE TRENDED TOWARD
ONE ANOTHER TO SOME EXTENT... WITH SOME NOTABLE DIFFERENCES STILL
EVIDENT BEYOND MONDAY... ALTHOUGH LESS THAN WITH PREVIOUS
FORECASTS. WILL STICK CLOSE TO THE PREVIOUS FORECAST... AND MAINLY
JUST BLEND WITH THE LATEST MIDDLE OF THE ROAD COMPROMISE BETWEEN
THE ECMWF AND GFS. THE MAIN DIFFERENCE THAT LOOKS TO IMPACT OUR
POTENTIAL FOR SEVERE WEATHER ON SUNDAY IS THAT BOTH SOLUTIONS NOW
AGREE ON A SOMEWHAT SLOWER ARRIVAL OF THE COLD FRONT ON SUNDAY...
WHICH WILL ALLOW FOR GREATER DESTABILIZATION. IN ADDITION... BOTH
WOULD IMPLY BETTER AND MORE FOCUSED LARGE SCALE FORCING ACROSS A
GOOD PORTION OF THE AREA AS A STRONG UPPER JET WRAPS AROUND THE
SOUTHERN PERIPHERY OF THE UPPER TROUGH MOVING THROUGH THE NORTHERN
PLAINS SUNDAY INTO SUNDAY EVENING.

FOR TODAY... CONTINUED TO MENTION SOME CHANCE FOR SHRA/TSRA OVER
THE NORTHERN AND EASTERN CWFA WITH THE AFOREMENTIONED BROAD WARM
ADVECTION AND INSTABILITY IN PLACE. 850-500MB DIFFERENTIAL THETA-E
PROGS SHOW CONVECTIVE INSTABILITY IN PLACE FOR ESSENTIALLY THE
NEXT SEVERAL DAYS... ALTHOUGH UNTIL SUNDAY TODAY INTO THIS EVENING
IS THE ONLY TIME FRAME WHEN IT LOOKS TO COINCIDE WITH SOME LARGE
SCALE FORCING AND SATURATION NEAR THE LFC. THE WARM SECTOR REALLY
SURGES NORTH THROUGH THE AREA ON SATURDAY... AND TEMPERATURES AOA
90 DEGREES STILL LOOK LIKE A GOOD BET FOR MOST OF THE AREA... WITH
SOME MID 90S NOT OUT OF THE QUESTION DEPENDING ON THE DEPTH OF
MIXING. WITH THE WARM FRONTAL BOUNDARY PUSHED WELL NORTH OF THE
AREA WE SHOULDN/T HAVE ANY PCPN TO WORRY ABOUT... AND ANY DEBRIS
CLOUDINESS FROM UPSTREAM CONVECTION SHOULD STAY TO OUR NORTH AND
WEST BASED UPON EXPECTED MID-UPPER LEVEL WINDS. THE PRESSURE
GRADIENT INCREASES THROUGH THE DAY... SO SOME FAIRLY GUSTY WINDS
WILL ACCOMPANY THE WARM TEMPERATURES... WITH MAY HELP KEEP IT FROM
FEELING TOO UNCOMFORTABLE.

ON SUNDAY INTO SUNDAY EVENING... ATTENTION WILL TURN TOWARD THE
MAIN UPPER TROUGH MOVING OUT INTO THE NORTHERN PLAINS. THIS
FEATURE WILL INTENSITY A SURFACE LOW ACROSS SOUTHERN MANITOBA BY
SUNDAY EVENING... WITH A SHARP COLD FRONT EXTENDING SOUTH THROUGH
CENTRAL MINNESOTA. THE AIRMASS AHEAD OF THIS FRONT LOOKS TO BE
QUITE JUICY... WITH PROGGED MLCAPE VALUES FROM THE GFS AND ECMWF
BOTH AOA 1500 J/KG AND QUITE POSSIBLY ABV 2500 J/KG. THE BEST DEEP
LAYER SHEAR WILL BE STARTING TO ARRIVE AS THE COLD FRONT MOVES
INTO THE AREA... AND IT APPEARS WE SHOULD HAVE SUFFICIENT DEEP
LAYER SHEAR FOR STORM ORGANIZATION... PERHAPS INITIALLY AS
SUPERCELLS BUT WITH A TRANSITION TO A LINEAR MODE SEEMING LIKELY
GIVEN A GOOD MODEL CONSENSUS ON A RAPIDLY WEAKENING CAP THROUGH
THE LATE AFTERNOON AND EARLY EVENING WITH FAIRLY WIDESPREAD TSRA
ACTIVITY DEVELOPING. LOW LEVEL SHEAR LOOKS TO BE MAXIMIZED TO OUR
NORTH... WHERE WINDS WILL HAVE A MUCH BETTER CHANCE OF BEING
BACKED DUE TO PROXIMITY TO THE SURFACE LOW AND WARM FRONTAL
BOUNDARY. HOWEVER... THERE WOULD STILL BE SOME CHANCE FOR A
TORNADO FARTHER SOUTH INTO OUR AREA INITIALLY PRIOR TO ANY
TRANSITION TO A LINEAR MODE OF CONVECTION. BUT... THE PRIMARY
THREATS STILL LOOK TO BE THE POTENTIAL FOR LARGE HAIL AND DAMAGING
WIND GUSTS SUNDAY AFTERNOON INTO SUNDAY NIGHT.

SOME PCPN MAY LINGER INTO MONDAY AS THE COLD FRONT SLOWLY WORKS
ITS WAY EAST THROUGH THE FORECAST AREA. ALLOWED FOR DRY WEATHER
FROM MONDAY NIGHT THROUGH TUESDAY NIGHT... ALTHOUGH THERE IS SOME
POTENTIAL FOR A FEW SHRA DEPENDING ON HOW LONG THE UPPER TROUGH
AND ASSOCIATED MID-LEVEL COLD POOL LINGER IN THE AREA. THE GFS HAS
QUICKENED ITS DEPARTURE IN COMPARISON TO ITS PREVIOUS RUNS WHILE
THE ECMWF HAS SLOWED ITS DEPARTURE. GIVEN THE UNCERTAINTY AND THE
EXPECTATION THAT THINGS WOULD MAINLY BE SCATTERED SHOWERS OVER
ONLY A PORTION OF THE AREA... OPTED TO LEAVE ANY MENTION OUT FOR
NOW. HOWEVER... DID BRING BACK A CHANCE OF SHRA/TSRA FOR WEDNESDAY
INTO THURSDAY AS WE LOOK TO GET ON THE BACKSIDE OF THE SURFACE
HIGH AND SEE SOME RETURN FLOW SETUP ACROSS THE REGION IN ADVANCE
OF THE NEXT SHORTWAVE.

&&

.AVIATION.../06Z TAF ISSUANCE/ 
/ISSUED 1236 AM CDT FRI JUN 8 2012/
OUTSIDE OF WEST CENTRAL WI...JUST MID/HIGH CLOUDS THIS MORNING. A
LINE OF SHOWERS AND THUNDERSTORMS ARE EXPECTED IN WI...BUT SHOULD
LARGELY BE OUT OF THE AREA AFTER SUNRISE. VFR EXPECTED TODAY WITH
STRONG SOUTHERLY WINDS.

KMSP...VFR EXPECTED WITH THE SHOWER AND THUNDERSTORM ACTIVITY
REMAINING WELL NORTHEAST OF THE AIRPORT. MUCH STRONGER S-SW WINDS
EXPECTED BY THE EARLY AFTERNOON.

.OUTLOOK 
SATURDAY AND SUNDAY...VFR. 
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.

&&

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

$$