Areal Flood Warning 9, NWS Twin Cities, MN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1214 PM CDT SUN APR 10 2011

.AVIATION... /18Z TAF ISSUANCE/

SURFACE LOW PRESSURE NEARING ST CLOUD AT THIS TIME WITH A COLD
FRONT EXTENDING SOUTH TO NEAR FAIRMONT. THUNDERSTORMS EXPECTED TO
DEVELOP QUICKLY BETWEEN 18Z AND 20Z ALONG THIS FRONT PER THE HRRR
AND VSREF FROM THE TWIN CITIES TO BLUE EARTH. BEST CHANCE FOR
STORMS AT KMSP IS BETWEEN 18Z AND 21Z. KRNH HAS THEIR BEST CHANCE
BETWEEN 19Z AND 22Z WITH KEAU 21Z TO 24Z. DID INCLUDE WIND GUSTS
TO 35 KNOTS AND HAIL IN THE KEAU TERMINAL WHERE PROBABILITIES FOR
SEVERE STORMS ARE MUCH HIGHER DURING THE MID TO LATE AFTERNOON
HOURS. TO THE WEST OF THE BOUNDARY...CEILINGS PLUMMET BELOW 010
ALONG WITH VISIBILITIES GENERALLY LESS THAN 2 MILES IN BR. THESE
CONDITIONS WILL LIKELY CONTINUE THROUGH THE EVENING HOURS AT
KAXN...KRWF AND KSTC. LAMP GUIDANCE ALSO SHOWING IFR OR LOWER
CONDITIONS SPREADING INTO KMSP...KRNH AND KEAU BY EARLY THIS
EVENING. CONCERN IS THAT THIS MAY NOT BE FAST ENOUGH AND TRENDS
WILL BE MONITORED. IN ADDITION...NORTHWEST WINDS AT 15-20 KNOTS
WITH GUSTS TO 25 KNOTS...WILL MOVE INTO KAXN AND KRWF BY 21Z AND
INTO THE EASTERN TAF SITES THIS EVENING. THE STRONGER WINDS WILL
PERSIST OVERNIGHT AND MONDAY MORNING.

KMSP...NARROW WINDOW EARLY THIS AFTERNOON FOR STORMS. BY
21Z...BELIEVE THE THREAT WILL BE EAST OF THE AIRPORT WITH MVFR
CEILINGS QUICKLY SPREADING IN. MAIN CONCERN IS THAT CEILINGS
MAY DROP BELOW 010 BETWEEN 21Z-24Z AND A TEMPO GROUP WAS INSERTED
TO ADDRESS THIS. CONFIDENCE HIGH FOR CEILINGS UNDER 010 FOR MUCH
OF THE NIGHT AHEAD AS VERY MOIST CYCLONIC LOW LEVEL CONDITIONS
PREVAIL IN THE WAKE OF THE LOW. SOUTH WINDS 12-15 KNOTS VEERING
WEST 15 TO 20 KNOTS BY 11/00Z AND NORTHWEST OVERNIGHT AND MONDAY
MORNING. GUSTS 25 TO 30 KNOTS EXPECTED TONIGHT AND MONDAY MORNING.

&&

.DISCUSSION... /ISSUED 332 AM CDT SUN APR 10 2011/

OVERNIGHT CONVECTION LIFTING NORTHEAST AND WEAKENING. STILL HAVE
STRONG LLJ IMPINGING ON SURFACE WARM FRONT LIFTING INTO SOUTHERN
MINNESOTA AT THIS TIME. STILL MAINTAIN A HAIL THREAT BUT HEAVY
RAIN MORE OF A PROBLEM. EXPECT THIS ACTIVITY TO LIFT INTO
CENTRAL MINNESOTA THROUGH EARLY MORNING AND CONTINUE TO WEAKEN.
MAIN PROBLEM IS TIMING/LOCATION OF CONVECTIVE INITIATION FOR THE
AFTERNOON/EARLY EVENING. 00Z NAM SHIFTED SYSTEM A BIT FARTHER TO
THE WEST...CLOSER TO THE PREVIOUS GFS RUNS. WILL FOLLOW THIS MORE
CLOSELY TODAY. THIS WOULD BRING THE SURFACE LOW AND COLD FRONT TO
EAST CENTRAL MINNESOTA THROUGH 18Z TODAY. CONVECTION SHOULD
INITIATE ABOUT THAT TIME WITH STRONG INSTABILITY AND LOW LEVEL
SHEAR INDICATED. ACTIVITY SHOULD BECOME SEVERE QUICKLY AND MOVE
EAST QUICKLY AS WELL. SPC MODERATE RISK LOOKS PRETTY GOOD WITH
WEST CENTRAL WISCONSIN SEEING THE GREATEST THREAT OF AN ISOLATED
TORNADO OR TWO LATE AFTERNOON/EVENING. TEMPERATURES SHOULD SURGE
INTO THE 70S OVER THE EASTERN CWA WITH THICKER CLOUDS/UPPER TROUGH
SWINGING INTO WESTERN AREAS...READINGS MAY REMAIN IN THE 50S.
SOUTH WINDS SHOULD REV THIS MORNING OVER THE EAST AS
WELL...DRAWING SURFACE DEWPOINTS AROUND 60F.

ACTIVITY SHOULD MOVE QUICKLY INTO WISCONSIN THROUGH 7 PM AND EXIT
THAT REGION THROUGH 10 PM. LIGHT RAIN SHOWERS WILL WRAP AROUND THE
UPPER LOW AND WILL MOVE EAST OVERNIGHT. HIGHS POPS ALSO INCLUDED
FOR THIS. FORCING LIFTS INTO NORTHWEST MINNESOTA LATE IN THE NIGHT
AND SHOULD SEE RAIN END OVER THE WEST BY MONDAY MORNING.
CLOUDS/DRYING MOVES INTO THE REGION FOR MONDAY AFTERNOON...ALONG
WITH COOLER CONDITIONS. CLEARING AND MILD CONDITIONS TO PREVAIL
TUESDAY/TUESDAY NIGHT.

LONGER RANGE BRINGING IN ANOTHER FRONTAL BOUNDARY ABOUT WEDNESDAY
AND GFS AND ECMWF SHOWING SIGNS OF THIS STALLING OVER THE AREA AS
A DEEP UPPER LOW DEVELOPS OVER THE NATIONS MIDSECTION. IT WILL BE
INTERESTING TO SEE HOW THIS PLAYS OUT DURING TH WEEK. THE 00Z GFS
WAS COMING IN MUCH COOLER/DEEPER WITH THE. COLD ENOUGH FOR SNOW
THURSDAY NIGHT AND FRIDAY. WILL HOLD ONTO CHANCE TYPE POPS AND
RETAIN LIQUID THROUGH FRIDAY ANYWAY.

&&

.HYDROLOGY...
RADAR HAS BEEN OVERESTIMATING RAINFALL OVERNIGHT BY ABOUT A FACTOR
OF 2. SOME 1-1.5 INCH RAINS IN THE AREAS THAT HAD SOME TRAINING OF
ECHOES EARLIER IN THE NIGHT...MAINLY ALONG THE REDWOOD RIVER NEAR
REDWOOD FALLS AND OVER SOUTHEAST MN AFFECTING FREEBORN COUNTY.
HEAVER CONVECTIVE ACTIVITY WILL BE FOUND ACROSS EAST CENTRAL MN
AND PARTICULARLY WEST CENTRAL WISCONSIN INTO THE EVENING AS THE
SYSTEM COMES THROUGH. POTENTIAL FOR WIDESPREAD HEAVY RAIN IS
RATHER LIMITED AT THE MOMENT WITH RAINFALL TOTALS THE NEXT 24 HOURS
FROM ONE QUARTER TO THREE QUARTERS OF AN INCH. STILL WILL HAVE
SOME RESPONSE TO THE RIVERS.

&&

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

RAH/DWE

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1144 AM CDT SUN APR 10 2011

MNZ044-045-051>053-059>063-066>070-074>078-082>085-091>093-
WIZ014>016-023>028-111645-
MILLE LACS-KANABEC-SHERBURNE-ISANTI-CHISAGO-WRIGHT-HENNEPIN-ANOKA-
RAMSEY-WASHINGTON-MCLEOD-SIBLEY-CARVER-SCOTT-DAKOTA-BROWN-
NICOLLET-LE SUEUR-RICE-GOODHUE-WATONWAN-BLUE EARTH-WASECA-STEELE-
MARTIN-FARIBAULT-FREEBORN-POLK-BARRON-RUSK-ST. CROIX-PIERCE-DUNN-
PEPIN-CHIPPEWA-EAU CLAIRE-
1144 AM CDT SUN APR 10 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL
MINNESOTA...EAST CENTRAL MINNESOTA...SOUTH CENTRAL MINNESOTA...
SOUTHEAST MINNESOTA...NORTHWEST WISCONSIN AND WEST CENTRAL
WISCONSIN.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A MODERATE RISK OF SEVERE THUNDERSTORMS IS OUTLOOKED ACROSS PARTS
OF EAST CENTRAL AND SOUTHEAST MINNESOTA AS WELL AS ALL OF WEST
CENTRAL WISCONSIN. SEVERE THUNDERSTORMS...WITH LARGE HAIL AND
DAMAGING WINDS ARE EXPECTED TO DEVELOP EARLY THIS AFTERNOON FROM
NEAR THE TWIN CITIES TO FAIRMONT. THE STORMS WILL MOVE RAPIDLY
NORTHEAST INTO WEST CENTRAL WISCONSIN. SOME OF THE STORMS MAY
PRODUCE TORNADOES AS WELL. THE STORMS ARE EXPECTED TO BE EAST OF
THE OUTLOOK AREA BY 8 PM THIS EVENING.

MANY RIVERS REMAIN IN FLOOD. CONTINUE TO MONITOR FLOOD STATEMENTS
FOR THE LATEST UPDATES.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

RIVERS WILL LIKELY REMAIN IN FLOOD THROUGH NEXT WEEK. CONTINUE TO
MONITOR FLOOD STATEMENTS FOR THE LATEST UPDATES.

SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON INTO
EARLY THIS EVENING.

MNZ041>043-047>050-054>058-064-065-073-111645-
DOUGLAS-TODD-MORRISON-STEVENS-POPE-STEARNS-BENTON-LAC QUI PARLE-
SWIFT-CHIPPEWA-KANDIYOHI-MEEKER-YELLOW MEDICINE-RENVILLE-REDWOOD-
1144 AM CDT SUN APR 10 2011

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

AN ISOLATED THUNDERSTORM IS POSSIBLE THIS AFTERNOON.

MANY RIVERS REMAIN IN FLOOD. CONTINUE TO MONITOR FLOOD STATEMENTS
FOR THE LATEST UPDATES.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

RIVERS WILL LIKELY REMAIN IN FLOOD THROUGH NEXT WEEK. CONTINUE TO
MONITOR FLOOD STATEMENTS FOR THE LATEST UPDATES.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED.

RAH