Flooding in Minnesota, May 26 to 31, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
344 AM CDT SAT MAY 26 2012

.SHORT TERM...

TODAY THROUGH SUNDAY AFTERNOON...

MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND RAIN SHOWERS
EXPECTED TO MOVE IN FROM THE SW THROUGH THE DAY TODAY...WITH A FEW
THUNDERSTORMS IN THE AFTERNOON...MOST LIKELY OVER THE SWRN
COUNTIES...AND THEN A BETTER CHANCE OF STRONGER SHOWERS AND STORMS
TONIGHT WITH THE POTENTIAL FOR LOCALLY HEAVY RAIN INTO EARLY SUNDAY
MORNING. THEN BY LATE SUNDAY AFTERNOON...THE NEXT CHANCE FOR
CONVECTIVE SHOWERS AND STORMS RETURNS AS A COLD FRONT MOVES IN
FROM THE WEST.

THERE IS A THREAT OF SEVERE WEATHER LATE TONIGHT AND AGAIN LATE SUN
AFTERNOON. HOWEVER...THE MAIN AREA OF CONCERN WILL BE ON THE
POTENTIAL FOR HEAVY RAIN ON TOP OF AN ALREADY SATURATED NEAR SFC
SOIL LAYER AND THE ADDED RUNOFF INTO AREA RIVERS AND STREAMS
ALREADY ELEVATED. AT THIS TIME HOWEVER...WILL KEEP WITH THE
HYDROLOGIC OUTLOOK TO HIGHLIGHT THE HYDRO CONCERNS UNTIL A BETTER
HANDLE CAN BE OBTAINED ON THE PLACEMENT OF THE CONVECTION TONIGHT
AND TOMORROW NIGHT.

CURRENT SYNOPTIC SET UP PLACES A DEEPENING UPPER LOW OVER THE
GREAT BASIN AND A BROAD UPPER RIDGE OVER THE DEEP SOUTH INTO THE
MID MS VALLEY. AT THE SFC...CYCLOGENESIS IS CURRENTLY TAKING PLACE
OVER SERN CO/WRN KS...AS A WARM/STATIONARY FRONT EXTENDS TO THE
EAST INTO NRN MO AND A LARGE AREA HIGH PRESSURE MOVES INTO ONTARIO
FROM THE WEST. A RATHER ROBUST AREA OF CONVECTION HAS DEVELOPED
NORTH OF THE WARM FRONT IN NRN IA/FAR SRN MN AND CONTINUES TO
TRACK TO THE E/NE.

THROUGH THIS AFTERNOON...THE SFC LOW WILL DRIFT TO THE NE INTO
FAR WRN NEB AND THE WARM FRONT WILL LIFT TO THE NORTH INTO SRN
MN/WI. AS THIS OCCURS...A WARM MOIST UNSTABLE AIR MASS WILL BE
ADVECTED NWD INTO THE UPPER MIDWEST AND ALLOW FOR SHOWERS AND
STORMS TO CONTINUE ACROSS MUCH OF THE REGION. WILL LIKELY SEE THE
INTENSITY OF THE CURRENT STORMS TO THE SOUTH DIMINISH SLIGHTLY AS
THE MAIN AREA OF CONVECTION MOVES INTO A MORE STABLE AIR MASS THIS
MORNING AND EARLY AFTERNOON.

BY LATE THIS AFTERNOON AND INTO THE EVENING...AS THE LLJ
INTENSIFIES AGAIN AND NOSES FURTHER NORTH INTO CENTRAL MN...AND
THE WARM FRONT BECOMES POSITIONED JUST TO THE NORTH OF THE
MOISTURE/INSTABILITY AXIS...EXPECT CONVECTION TO INITIATE
THROUGHOUT THE SRN COUNTIES OF THE NORTHLAND AND PROPAGATE
NORTHWARD THROUGH THE NIGHT. STEEP MID LEVEL LAPSE RATES...MU CAPE
VALUES 1000-2000 J/KG...COMBINED WITH A STRONG LLJ AND A ROBUST
INFLUX OF MOISTURE FROM THE SOUTH SHOULD BE ENOUGH TO TRIGGER A
FEW STRONG TO POSSIBLY SEVERE STORMS. THE AVAILABLE MOISTURE FOR
PRECIP WITH THESE STORMS WILL BE THE OTHER CONCERN. WITH PWATS
NEAR AND POSSIBLY OVER 1.5 INCHES ACROSS A GOOD PORTION OF THE
CWA...THE POTENTIAL FOR LOCALLY HEAVY RAINFALL AMTS REMAINS HIGH.
THE BIG QUESTION WILL BE HOW FAST THE WARM FRONT LIFTS NWD...AND
ALSO IF ANY CONVECTION TO THE SOUTH IN THE WARM SECTOR ROBS THE
STORMS TO THE NORTH OF MOISTURE/INSTABILITY.

THROUGH THE DAY SUNDAY...THE WARM FRONT WILL CONTINUE TO LIFT NWD
WITH MUCH OF THE REGION SEEING SHOWERS AND STORMS END FROM SOUTH
TO NORTH AND DRY OUT BRIEFLY BEFORE THE NEXT ROUND OF CONVECTION
MOVES IN FROM THE WEST ALONG A COLD FRONT. THE SFC LOW IS EXPECTED
TO MOVE FROM THE ERN DAKOTAS INTO NRN MN SUNDAY AFTERNOON AS THE
COLD FRONT SLIDES EWD INTO WRN MN. WILL LIKELY SEE CONVECTIVE
INITIATION ALONG THE FRONT IN THE LATE AFTERNOON...WITH THE
PRIMARY AREA OF CONVECTION EXPECTED OVER W-CNTRL MN...AND FURTHER
DEVELOPMENT ALONG THE FRONT TO THE SOUTH THROUGH THE EARLY
EVENING. THE CO-LOCATION OF THE UPPER S/W AND RE-INTENSIFYING LLJ
INTO CNTRL MN WILL PRODUCE VERY FAVORABLE SHEAR PROFILES. A VERY
WARM AND MOIST BDY LYR WILL ALLOW THE LOW LEVELS TO BECOME VERY
UNSTABLE. THE COMBINATION OF SHEAR...INSTABILITY AND LIFT FROM THE
FRONT WILL YIELD A SLIGHT CHANCE OF SEVERE WEATHER.

.LONG TERM...

SUNDAY NIGHT THROUGH FRIDAY...

MAIN FOCUS WILL OCCUR EARLY IN THE EXTENDED PERIOD AS A COLD
FRONT STARTS TO MOVE INTO THE CWA. A WARM AND MOIST AIRMASS WILL
OCCUR AHEAD OF THIS FRONT WITH PWATS AROUND 1.5 INCHES. DEEP LAYER
SHEAR WILL SUPPORT SEVERE CONVECTION...AND INSTABILITY AND FORCING
ALSO SUPPORT SEVERE STORMS. SWODY2 HAS MOST OF OUR CWA IN THE RISK
FOR SEVERE STORMS...AND WE AGREE WITH THAT OUTLOOK. ACROSS OUR
CWA...IT APPEARS THE THREATS WILL BE MAINLY LARGE HAIL...DAMAGING
WINDS AND HEAVY RAIN. MOST OF THE MODELS AGREE PUTTING THE MAIN
AXIS OF RAIN RIGHT THROUGH THE HEART OF OUR CWA. GIVEN STRONG
STORMS ARE EXPECTED...RAINFALL COULD EASILY BE FROM 1-2 INCHES
JUST SUNDAY NIGHT INTO MONDAY MORNING OVER THE BULK OF OUR CWA.
THIS WOULD CONTINUE THE THREAT FOR FLOODING...AND MANY RIVERS ARE
ALREADY RUNNING HIGH. A FLASH FLOOD/FLOOD WATCH MAY BE
NEEDED...BUT WE STILL DO HAVE SOME CONCERNS. THE MAIN CONCERN IS
EXACTLY HOW MUCH PRECIPITATION WILL OCCUR PRIOR TO THE SUNDAY
NIGHT/MONDAY CONVECTION...WITH A SECOND CONCERN ON HOW
SEVERE/WIDESPREAD PRECIP WILL BE SUNDAY NIGHT-MONDAY. WE WILL
CONTINUE TO HIGHLIGHT POTENTIAL HEAVY RAIN AND FLOODING IN THE ESF
OUTLOOK AND HWO.

THE UPPER LOW/SURFACE LOW WILL STILL BE OVER NORTHWESTERN ND AT
12Z MON...THEN MOVE EAST-NORTHEAST DURING THE DAY. SHOWERS/STORMS
WILL CONTINUE MONDAY...ALTHOUGH CHANCES WILL BE LOWER OVER THE
SOUTHWEST...AND HIGHEST OVER THE NORTHEAST. SOME SEVERE STORMS
COULD STILL BE POSSIBLE MONDAY OVER OUR EASTERN WI CWA.

THE THREAT FOR RAIN WILL CONTINUE INTO TUESDAY WITH AN UPPER
TROUGH REMAINING OVER THE CWA...BUT RAIN INTENSITY SHOULD BE MUCH
LOWER. TEMPS WILL ALSO COOL TUESDAY BACK INTO THE LOWER FIFTIES TO
LOWER SIXTIES.

MUCH OF THE REMAINING PERIODS LOOK TO BE DRY...OR ONLY CONTAIN
LOW CHANCES FOR LIGHT RAIN. TEMPS WILL GRADUALLY MODERATE AS
WELL...REACHING INTO THE UPPER SIXTIES TO LOWER SEVENTIES BY
FRIDAY.

&&

.AVIATION.../06Z TAF ISSUANCE/

VFR CONDITIONS WILL PREVAIL THROUGH THE FIRST HALF OF THIS TAF
PERIOD. WINDS WILL INCREASE OUT OF THE EAST BY DAYBREAK. CONDITIONS
BEGIN TO DETERIORATE AT BRD AFTER 18Z AS SHOWERS WITH A FEW
EMBEDDED THUNDERSTORMS WILL MOVE NORTHWARD AHEAD OF A WARM FRONT.
BEST LIKELIHOOD FOR THUNDER WILL BE ACROSS THE SOUTHERN TERMINALS.
HAVE LIGHT RAIN WITH THUNDER IN THE VICINITY AT ALL AERODROMES
STARTING AT 0Z WITH MVFR CEILINGS.

&&

.POINT TEMPS/POPS...
DLH  54  47  59  53 /  50  80  80  90
INL  58  46  59  54 /  30  80  80  80
BRD  61  54  78  59 /  50  80  60  80
HYR  65  56  82  62 /  50  70  60  90
ASX  57  50  72  56 /  50  80  70  80

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 10 PM CDT SUNDAY
     FOR LSZ121-144>148.

     SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 10 PM CDT
     SUNDAY FOR LSZ140>143.

&&

SHORT TERM...TENTINGER
LONG TERM....MELDE
AVIATION...KK

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
137 PM CDT FRI MAY 25 2012

MNZ010>012-018>021-025-026-033>038-WIZ001>004-006>009-261845-
KOOCHICHING-NORTHERN ST. LOUIS-NORTHERN COOK/NORTHERN LAKE-
NORTHERN ITASCA-CENTRAL ST. LOUIS-SOUTHERN LAKE/LAKESHORE-
SOUTHERN COOK/LAKESHORE-NORTHERN CASS-SOUTHERN ITASCA-
SOUTHERN CASS-CROW WING-NORTHERN AITKIN-SOUTHERN AITKIN-
CARLTON/SOUTHERN ST. LOUIS-PINE-DOUGLAS-BAYFIELD-ASHLAND-IRON-
BURNETT-WASHBURN-SAWYER-PRICE-
137 PM CDT FRI MAY 25 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST MINNESOTA AND
NORTHWEST WISCONSIN.

.DAY ONE...THIS AFTERNOON AND TONIGHT

RIVERS ACROSS MUCH OF THE NORTHLAND...ESPECIALLY NORTHEAST
MINNESOTA... WILL REMAIN HIGH. PARTICULARLY THE SAINT LOUIS RIVER
AROUND SCANLON AND THE MISSISSIPPI RIVER NEAR AITKIN...WHICH WHERE
APPROACHING FLOOD STAGE. THOSE WITH OUTDOOR PLANS NEAR A RIVER OR
STREAM SHOULD MONITOR CONDITIONS CLOSELY. SEE THE LATEST FLOOD
STATEMENTS FOR FURTHER INFORMATION.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

MORE RAIN WILL FALL THIS WEEKEND AND COULD BE UPWARDS OF ONE OR
TWO INCHES. THIS RAIN COULD CAUSE ADDITIONAL FLOODING
ACROSS THE NORTHLAND...AND KEEP RIVER LEVELS HIGH. SEE THE LATEST
FLOOD STATEMENTS FOR FURTHER INFORMATION. THOSE CAMPING THIS
WEEKEND NEAR A RIVER OR STREAM SHOULD MONITOR CONDITIONS CLOSELY.

THUNDERSTORMS WILL BE POSSIBLE SATURDAY THROUGH SUNDAY NIGHT. THE
STORMS ON SATURDAY AND SATURDAY NIGHT COULD BE SEVERE IN SOUTHERN
AREAS OF THE NORTHLAND...GENERALLY SOUTH OF A LINE FROM PARK
RAPIDS THROUGH MOOSE LAKE MINNESOTA AND IN WISCONSIN MAINLY SOUTH
OF STATE HIGHWAY 77. SEVERE STORMS ARE ALSO POSSIBLE SUNDAY AND
SUNDAY NIGHT. WITH LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN
THREATS.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED THIS AFTERNOON OR
TONIGHT.

LSZ121-140>148-261845-
BAYFIELD TO OAK POINT WI-GRAND PORTAGE TO GRAND MARAIS MN-
GRAND MARAIS TO TACONITE HARBOR MN-
TACONITE HARBOR TO SILVER BAY HARBOR MN-
SILVER BAY HARBOR TO TWO HARBORS MN-TWO HARBORS TO DULUTH MN-
DULUTH MN TO PORT WING WI-PORT WING TO SAND ISLAND WI-
SAND ISLAND TO BAYFIELD WI-OAK POINT TO SAXON HARBOR WI-
137 PM CDT FRI MAY 25 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE NEARSHORE WATERS OF
WESTERN LAKE SUPERIOR.

.DAY ONE...THIS AFTERNOON AND TONIGHT

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

CLC

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING WEB ADDRESS:
HTTP://WWW.WEATHER.GOV/DULUTH (ALL LOWER CASE)