Special Weather Statement, NWS Twin Cities, MN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1116 PM CDT WED AUG 12 2015

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 227 PM CDT WED AUG 12 2015

PRIMARY CONCERN IN THE SHORT TERM IS THETA-E RIDGE AND ASSOCIATED
INSTABILITY WORKING INTO THE AREA ON THE BACKSIDE OF THE SURFACE
HIGH... AND A WEAK SURFACE TROUGH DROPPING THROUGH THE AREA
TONIGHT AND THURSDAY. THE PRIMARY LARGE SCALE FORCING FOR ASCENT
LOOKS TO REMAIN NORTH/NORTHEAST OF OUR AREA... WHICH SHOULD BE THE
FOCUS FOR MORE WIDE SPREAD PCPN AND HIGHER POPS. HOWEVER...
SCATTERED CONVECTION STILL LOOKS LIKE IT SHOULD BE ABLE TO GET
GOING TO OUR NORTHWEST BY EARLY EVENING... WHICH WOULD THEN MOVE
SOUTHEAST THROUGH THE OVERNIGHT HOURS. THE ACTIVITY LOOKS LIKE IT
WOULD BE MOVING OUT OF THE BEST MOISTURE TRANSPORT... AND WOULD BE
GETTING OUT AHEAD OF ANY LOW LEVEL FORCING... BUT WOULD LIKELY BE
ABLE TO SUSTAIN ITSELF AT LEAST INTO THE CENTRAL PORTION OF THE
AREA OVERNIGHT. SO... ALLOWED FOR CHANCE POPS TO MOVE ACROSS A
GOOD PART OF THE AREA FROM LATE EVENING THROUGH THE OVERNIGHT.
SUBSEQUENT UPDATES MAY NEED TO BUMP THINGS UP DEPENDING UPON HOW
ACTIVITY EVOLVES TONIGHT. ANY SEVERE WEATHER THREAT SHOULD BE
CONFINED TO THE NORTHERN PORTION OF THE AREA AND BE MAINLY A HAIL
AND WIND ISSUE. IF CONVECTION IS ABLE TO GROW UPSCALE INTO AN
MCS... WHICH DOESN/T APPEAR TOO LIKELY AT THIS POINT... THEN A
WIND THREAT COULD PERSIST FARTHER SOUTH/EAST INTO THE AREA THROUGH
THE OVERNIGHT HOURS. WE MAY SEE SOME REDEVELOPMENT OVER THE
SOUTHERN PORTION OF THE AREA THURSDAY AFTERNOON NEAR THE SURFACE
THROUGH... THEN ACROSS MORE OF THE AREA THURSDAY EVENING AS A
SHORTWAVE MOVES INTO THE AREA FROM THE PLAINS.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 227 PM CDT WED AUG 12 2015

THE MAIN THEME OF THE EXTENDED PERIOD WILL BE FOR THE
WESTERN/CENTRAL CONUS RIDGE TO BE FLATTENED OUT AS SUCCESSIVE
SHORTWAVES MOVE EAST ALONG THE INTERNATIONAL BORDER... WITH
HEIGHTS CONTINUING TO LOWER ACROSS THE NORTHERN CONUS THROUGH THE
MIDDLE OF NEXT WEEK. THIS WILL INITIALLY LEAD TO OUR INCREASING
WARMTH AND HUMIDITY FOR A COUPLE OF DAYS... THEN COOLER
TEMPERATURES FOR NEXT WEEK. THE MAIN FEATURE OF INTEREST STILL
LOOKS LIKE IT WILL BE A COLD FRONT MOVING THROUGH THE REGION ON
SUNDAY. THE GFS HAS SLOWED DOWN... AND IS NOW VERY SIMILAR TO THE
ECMWF AND GEM WITH THE TIMING OF THE FROPA ON SUNDAY... WITH IT IN
THE WESTERN FORECAST AREA AROUND 12Z THEN INTO THE EASTERN AREA BY
00Z. ITS PROGRESSION DOES LOOK TO SLOW WITH TIME AS THE MID-LEVEL
WINDS BECOME MORE PARALLEL TO THE FRONT. HOWEVER... IT DOESN/T
LOOK LIKE IT WILL STALL OUT TOO CLOSE TO THE AREA... SO WE SHOULD
HAVE DRY WEATHER OVER MOST OF THE AREA FROM MONDAY THROUGH A GOOD
PART OF TUESDAY. DID KEEP SOME LOW POPS OVER THE SOUTH ON
MONDAY... WITH THE BOUNDARY BEING CLOSEST TO THAT PORTION OF THE
AREA... BUT WOULDN/T BE SURPRISED IF SUBSEQUENT FORECASTS ARE ABLE
TO REMOVE THAT. THE NEXT ITEM OF CONCERN COMES AT THE TAIL END OF
THE FORECAST PERIOD... WITH DECENT AGREEMENT BETWEEN THE GFS...
ECMWF... AND GEFS ON A STRONG SHORTWAVE MOVING INTO THE PLAINS ON
WEDNESDAY WITH AN ASSOCIATED SURFACE LOW. WARM FRONTAL BOUNDARY
LOOKS LIKE IT WOULD BE LIFTING NORTH THROUGH THE AREA DURING THE
DAY ON WEDNESDAY... AND THE SYSTEM APPEARS AS LOW IT MIGHT BE
SOMEWHAT SLOW TO MOVE EASTWARD GIVEN THE AMPLITUDE OF THE UPPER
WAVE... SO IT COULD BE A WET PERIOD SOMEWHERE IN THE REGION FROM
LATE TUESDAY INTO THURSDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1104 PM CDT WED AUG 12 2015

WILL RUN WITH VFR CONDS AT ALL TAF SITES BUT THERE ARE A COUPLE OF
CAVEATS. FIRST...THE ONGOING CONVECTION AT INITIALIZATION MAY DROP
FAR ENOUGH S TO IMPACT KAXN-KSTC WITH MVFR-IFR TSTMS PRIOR TO 12Z
THIS MRNG. SECONDLY...RE-DEVELOPMENT OF CONVECTION MAY IMPACT
KMSP-KRNH-KEAU MID-TO-LATE DAY TMRW. CHCS ARE TOO LOW ATTM TO
INCLUDE CB/TS FOR EITHER SCENARIO SO WILL MAINTAIN A DRY FCST BUT
WILL MONITOR AND AMEND IF/AS NEEDED. OTHERWISE...HIGH CLOUDS WILL
PREVAIL THROUGHOUT THIS SET WITH WINDS SHIFTING FROM S TO NW OVER
THE NEXT 18 HRS BEFORE GOING LGT TMRW EVE.

KMSP...VFR CONDS EXPECTED THROUGHOUT THIS SET THOUGH THERE IS A
SMALL WINDOW LATE MRNG INTO EARLY AFTN OF HAVING ISOLD CONVECTION
IMPACT THE AIRPORT. CHCS ARE TOO LOW AND TIMING IS TOO DIFFICULT
TO PINPOINT ATTM SO WILL RUN WITH A DRY TAF UNLESS RADAR TRENDS
DICTATE OTHERWISE.

/OUTLOOK FOR KMSP/
FRI...VFR. WINDS NW 5 KTS.
SAT...VFR. WINDS S 5-10 KTS.
SUN...MAINLY VFR. CHC MVFR-IFR CONDS WITH SHRA/TSRA. WINDS SW 10
KTS.

&&

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

SHORT TERM...
LONG TERM...
AVIATION...JPC

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1018 PM CDT WED AUG 12 2015

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
131800-
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-
1018 PM CDT WED AUG 12 2015

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

.DAY ONE...TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

THERE IS A CHANCE FOR THUNDERSTORMS THURSDAY INTO THURSDAY NIGHT
AND AGAIN SATURDAY NIGHT INTO SUNDAY. THE THREAT FOR SEVERE
WEATHER APPEARS LOW AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION IS NOT EXPECTED TO BE NEEDED THROUGH
THE REST OF TONIGHT.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1247 AM CDT THU AUG 13 2015

MNZ042-130615-
TODD-
1247 AM CDT THU AUG 13 2015

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN TODD COUNTY...

AT 1246 AM CDT...A STRONG THUNDERSTORM WAS OVER CLARISSA...OR 26
MILES NORTHEAST OF ALEXANDRIA...MOVING SOUTHEAST AT 30 MPH.

WINDS IN EXCESS OF 40 MPH AND NICKEL SIZE HAIL ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
BROWERVILLE...CLARISSA AND EAGLE BEND.

THIS INCLUDES U.S. HIGHWAY 71 BETWEEN MILE MARKERS 191 AND 203.

LAT...LON 4612 9509 4628 9485 4621 9465 4594 9465
TIME...MOT...LOC 0546Z 305DEG 27KT 4616 9497

CLF

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
204 AM CDT THU AUG 13 2015

MNZ042-043-049-130730-
STEARNS-MORRISON-TODD-
204 AM CDT THU AUG 13 2015

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NORTHERN STEARNS...
SOUTHWESTERN MORRISON AND SOUTHERN TODD COUNTIES...

AT 203 AM CDT...A LINE OF STRONG THUNDERSTORMS WAS ALONG A LINE
EXTENDING FROM NEAR BOWLUS TO PLEASANT BEACH TO WEST UNION...AND
MOVING SOUTHEAST AT 50 MPH.

WIND GUSTS UP TO 50 MPH AND HALF INCH HAIL ARE POSSIBLE WITH THESE
STORMS.

LOCATIONS IMPACTED INCLUDE...
SARTELL...ST. JOSEPH...SAUK CENTRE...COLD SPRING...MELROSE...
COLLEGEVILLE...ALBANY...RICHMOND...AVON...HOLDINGFORD...FREEPORT AND
UPSALA.

THIS INCLUDES THE FOLLOWING HIGHWAYS...
 INTERSTATE 94 IN MINNESOTA BETWEEN MILE MARKERS 120 AND 161.
 U.S. HIGHWAY 71 BETWEEN MILE MARKERS 151 AND 182.

LAT...LON 4563 9421 4545 9443 4546 9496 4592 9512
      4592 9476 4594 9447
TIME...MOT...LOC 0703Z 329DEG 46KT 4588 9442 4579 9473 4580 9505

CLF