Special Weather Statement, NWS Twin Cities, MN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
706 AM CDT THU AUG 23 2012

.UPDATE...

UPDATED FOR 12Z AVIATION DISCUSSION BELOW.

&&

.PREV DISCUSSION...
/ISSUED 409 AM CDT THU AUG 23 2012/

OVERVIEW...SEVERAL CHANCES FOR RAIN IN THE COMING DAYS WITH NEAR
TO ABOVE NORMAL TEMPS THROUGH THE WEEKEND.

SURFACE LOW IN THE PLAINS NOT SHOWING MUCH CHANGE IN INTENSITY BUT
IT IS SLIDING EAST WITH TIME. 3MB 6-HR MSLP CHANGE IN WEST
CENTRAL MN THIS MORNING. PRESSURE FALLS NEARLY CO-LOCATED WITH NOSE
OF THE LLJ AND MOISTURE TRANSPORT. ALSO IN THIS VICINITY IS A NICE
POCKET OF MUCAPE INCREASE OVER THE LAST 3 HOURS...ROUGHLY 400-600
J/KG TO GO ALONG WITH THE THICKNESS RIDGE. NO SURPRISE WE ARE
GENERATING SHOWERS AND STORMS THIS MORNING. THE 850MB JET TAKES
ITS TIME BEFORE SLIDING EAST...BUT THINK THE PRECIP FOCUS WILL BE
ACROSS THE NORTHERN FORECAST AREA AND INTO NORTHERN MN AND
NORTHWEST WI. THESE SHOWER WILL TAKE QUITE SOME TIME TO CLEAR
ESPECIALLY WITH THE WARM FRONT IN THE AREA.

EVEN WITH THE PRECIP LARGELY MOVING OUT DURING THE
AFTERNOON...THIS RAIN WILL PLAY A HUGE ROLE IN THE TEMPERATURE
FORECAST TODAY. THERE IS LARGE BUST POTENTIAL HERE. THE TEMP
PROFILE AND EXPECTED CLEARING IN FAR SOUTHERN MN WARRANTS LOWER
90S...BUT THERE SHOULD BE A SHARP CUTOFF BETWEEN LOWER 80S AND
LOWER 90S DEPENDING ON WHERE THE CLOUDS END UP...PERHAPS EVEN
BISECTING THE METRO.

AFTER A RELATIVE LULL IN ACTIVITY ON FRIDAY...STRONG UPPER LOW
CURRENTLY OFF THE COAST OF BRITISH COLUMBIA DIVES INTO NORTH
DAKOTA AND THEN LIFTS OFF TOWARD LAKE WINNIPEG BY MID DAY
SATURDAY. STRONG DYNAMICAL FORCING IS NORTH...BUT GOOD THETA-E
ADVECTION EXTENDS WELL SOUTH INTO THE MID/UPPER MISSISSIPPI RIVER
VALLEY. THERE IS A SECONDARY AND MUCH WEAKER SURFACE LOW IN THE
SOUTHERN PLAINS THIS WEEKEND...BUT THAT WASHES OUT WITH TIME.

IN THE EXTENDED...LONGWAVE FLOW FAVORS AN UPPER RIDGE OR WEAK
UPPER HIGH PREVAILING OVER THE SOUTHWEST CONUS AND PORTIONS OF THE
CENTRAL CONUS...AND A MEAN LONGWAVE TROUGH ALONG THE EAST COAST.
THIS FAVORS ABOVE NORMAL TEMPS OVER A LARGE PORTION OF THE COUNTRY
OUT SIDE OF THE EAST COAST...WHICH ALSO SHOULD BE FAIRLY WET.

&&

.AVIATION.../12Z TAF ISSUANCE/

A SOMEWHAT LOW CONFIDENCE FORECAST FOR THE NEXT 24 TO 30 HOURS
WITH THE POSSIBILITY OF THUNDERSTORMS THIS AFTERNOON/EVENING FOLLOWED
BY LOW CIGS AND FOG POTENTIAL LATE TONIGHT AND FRIDAY MORNING.
SHOWERS HAVE BEEN ON A DIMINISHING TREND EARLY THIS MORNING WITH
DRY CONDITIONS EXPECTED FROM LATE THIS MORNING INTO MID TO LATE
AFTERNOON. INSTABILITY WILL BUILD AS A COLD FRONT PUSHES EAST INTO
MINNESOTA...GENERATING SCATTERED THUNDERSTORMS ALONG AND AHEAD OF
THE FRONT. LEFT TEMPO GROUPS OUT FOR NOW DUE TO UNCERTAINTY...BUT
MAINTAINED VCTS MENTION. FOLLOWING THE PASSAGE OF THE FRONT...ONE
MODEL BRINGS A SLUG OF LOW LEVEL MOISTURE NORTHWARD INTO SRN MN
AND WCTRL WI LATE TONIGHT WITH MVFR CIGS OR LOWER POSSIBLE.
HOWEVER...ANOTHER MODEL REMAINS VERY DRY. FOR NOW WILL SIDE WITH
THE FORMER SOLUTION WHICH SEEMS TO BE HANDLING THE CURRENT
SITUATION A BIT BETTER AND INTRODUCE TEMPOS FOR MVFR OR IFR CIGS
LATE TONIGHT BUT CONFIDENCE REMAINS LOW.

GUSTY SOUTH WINDS TODAY WILL BECOME LIGHT TONIGHT WITH THE PASSAGE
OF THE FRONT.

KMSP...

MOST OF THE SHOWER ACTIVITY HAS REMAINED WEST AND NORTH OF THE
TERMINAL THIS MORNING. THERE SHOULD BE A BREAK IN PRECIPITATION
POTENTIAL UNTIL LATE AFTERNOON AS THE FRONT APPROACHES. VCTS
EXPECTED EARLY THIS EVENING...BUT NOT YET CONFIDENT ENOUGH TO
INCLUDE PREVAILING TS OR TEMPOS. MVFR CIGS ALSO POSSIBLE LATE
TONIGHT AND ESPECIALLY FRIDAY MORNING AS LOW LEVEL MOISTURE
SURGES BACK NORTH.

/OUTLOOK FOR KMSP/

FRIDAY...MVFR CIGS POSSIBLE IN THE MORNING. VFR EXPECTED BY
AFTERNOON. WINDS SSW AT 5 TO 10 KTS.
SATURDAY...VFR/MVFR WITH TSRA POSSIBLE. WINDS S 5 TO 10 KTS.
SUNDAY...VFR. WINDS W AT 5 KTS.

&&

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

CLF/BORGHOFF

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
455 AM CDT THU AUG 23 2012

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
241000-
DOUGLAS-TODD-MORRISON-MILLE LACS-KANABEC-STEVENS-POPE-STEARNS-
BENTON-SHERBURNE-ISANTI-CHISAGO-LAC QUI PARLE-SWIFT-CHIPPEWA-
KANDIYOHI-MEEKER-WRIGHT-HENNEPIN-ANOKA-RAMSEY-WASHINGTON-
YELLOW MEDICINE-RENVILLE-MCLEOD-SIBLEY-CARVER-SCOTT-DAKOTA-
REDWOOD-BROWN-NICOLLET-LE SUEUR-RICE-GOODHUE-WATONWAN-BLUE EARTH-
WASECA-STEELE-MARTIN-FARIBAULT-FREEBORN-POLK-BARRON-RUSK-
ST. CROIX-PIERCE-DUNN-PEPIN-EAU CLAIRE-
455 AM CDT THU AUG 23 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL AND
SOUTHERN MINNESOTA... AND WEST CENTRAL WISCONSIN.

.DAY ONE...TODAY AND TONIGHT

A FEW THUNDERSTORMS ARE POSSIBLE ACROSS CENTRAL MINNESOTA AND
WESTERN WISCONSIN THIS MORNING AND EARLY AFTERNOON. THERE SHOULD
BE A BREAK IN THE ACTION FOR A FEW HOURS BEFORE MORE THUNDERSTORMS
ARE POSSIBLE THIS EVENING. THE THREAT FOR SEVERE WEATHER LOOKS
LOW.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE WEATHER WILL BE ACTIVE OVER THE NEXT FEW DAYS WITH MULTIPLE
CHANCES FOR THUNDERSTORMS. THE THREAT FOR SEVERE WEATHER THIS
WEEKEND IS ALSO LOW.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1116 AM CDT THU AUG 23 2012

MNZ055-056-231645-
CHIPPEWA-SWIFT-
1116 AM CDT THU AUG 23 2012

AT 1111 AM CDT...WEATHER SERVICE RADAR WAS TRACKING A STRONG
THUNDERSTORM NEAR MILAN. THIS STORM WAS MOVING NORTHEAST AT 20 MPH.

HAIL UP TO NICKEL SIZE AND WINDS UP TO 30 MPH ARE EXPECTED WITH THIS
STORM.

* LOCATIONS IN OR NEAR THE PATH OF THIS STORM INCLUDE...
  MILAN.
  BIG BEND CITY.

LAT...LON 4527 9579 4515 9565 4506 9590 4512 9599
TIME...MOT...LOC 1616Z 235DEG 16KT 4513 9588

SPD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1124 AM CDT THU AUG 23 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1111 AM     HAIL             ESE MILAN               45.11N 95.91W
08/23/2012  M0.88 INCH       CHIPPEWA           MN   TRAINED SPOTTER

&&

SPD

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1130 AM CDT THU AUG 23 2012

MNZ055>057-231715-
CHIPPEWA-KANDIYOHI-SWIFT-
1130 AM CDT THU AUG 23 2012

AT 1127 AM CDT...WEATHER SERVICE RADAR WAS TRACKING STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM 3 MILES SOUTHEAST OF
APPLETON TO 7 MILES SOUTHEAST OF DANVERS TO 4 MILES EAST OF DE GRAFF.
THESE STORMS WERE MOVING NORTHEAST AT 30 MPH.

HAIL UP TO NICKEL SIZE AND WINDS UP TO 30 MPH ARE EXPECTED WITH THESE
STORMS.

* LOCATIONS IN OR NEAR THE PATH OF THESE STORMS INCLUDE...
  BENSON
  MURDOCK.
  DE GRAFF.
  DANVERS.
  BENSON.
  SUNBURG.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS THUNDERSTORM COULD INTENSIFY QUICKLY...SO BE READY TO ACT IF A
WARNING IS ISSUED.

&&

LAT...LON 4541 9578 4540 9529 4540 9494 4512 9520
      4512 9552 4515 9598
TIME...MOT...LOC 1630Z 246DEG 28KT 4519 9595 4522 9561
          4525 9536

SPD