000
FXUS63 KMPX 132027
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
327 PM CDT THU JUN 13 2013

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 327 PM CDT THU JUN 13 2013

UPPER LEVEL RIDGE AXIS WILL BE MOVING OVERHEAD TONIGHT AS THE SFC
HIGH SLIDES INTO WI. IT WILL BE A DRY AND COOL NIGHT...WITH
READINGS IN W WI DIPPING INTO THE UPPER 40S. CLOUDS WILL BE ON THE
INCREASE AFTER MIDNIGHT AHEAD OF A DEVELOPING FRONTAL SYSTEM
ACROSS THE NRN ROCKIES. THIS FRONT...IN ASSOCIATION WITH A
SHORTWAVE COMING UP THE BACKSIDE OF THE RIDGE WILL SPARK SCATTERED
ELEVATED CONVECTION IN NEB/SD LATE TONIGHT. THIS ACTIVITY IS
EXPECTED TO RIDE ALONG THE EDGE OF A SUBSTANTIAL MID-LEVEL CAP
INTO CENTRAL MN DURING THE MORNING HRS. BY THE TIME THE ACTIVITY
MOVES INTO MN...IT SHOULD PRIMARILY BE LIGHT RAIN SHOWERS...BUT A
FEW TSTMS CANNOT BE RULED OUT. FOR THIS REASON...POPS WILL BE ON
THE INCREASE THROUGHOUT THE MORNING FROM SW-NE...THEN MAINTAINING
CHC/SCT POPS INTO THE AFTN. BY AFTN...SFC HEATING ALONG WITH A
MID-LEVEL SPEED MAX SHOULD BE ENOUGH TO FIRE OFF SFC-BASED
CONVECTION ALONG THE FRONT IN E SD. THIS ACTIVITY WILL FOLLOW THE
FRONT AS IT SLOWLY SAGS SOUTH AND EAST. THE GREATEST THREAT FOR
SEVERE TSTMS WILL MOVE INTO WESTERN MN BY LATE AFTN. LIKE ON
WED...PWATS WILL RISE TO WELL ABOVE NORMAL LEVELS (> 1.5
INCHES)...SO HEAVY RAIN IS AGAIN A DISTINCT POSSIBILITY. THERE IS
PLENTY OF SHEAR ALONG THE BOUNDARY...SO SUPERCELLS ARE
POSSIBLE...WHICH BRINGS INTO PLAY THE TREAT FOR HAIL...WIND...AND
EVEN TORNADOES.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 327 PM CDT THU JUN 13 2013

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE IN PROGRESS
ACROSS THE WESTERN HALF OF MN FRIDAY EVENING. THE ACTIVITY WILL
INCREASE IN COVERAGE WHILE SPREADING INTO EASTERN MN AND WEST
CENTRAL WI DURING THE LATE EVENING AND OVERNIGHT HOURS. THERE IS
CERTAINLY A THREAT FOR SEVERE WEATHER ACROSS WESTERN AND SOUTHERN
MN DURING THE EVENING/NIGHT WITH PLENTY OF SHEAR AND CAPE
FORECAST. HOWEVER...RATHER WARM MID LEVEL AIR IS FORECAST TO
BE IN PLACE ACROSS THE WEST AND SOUTH AT THE START OF THE PERIOD
WHICH MAY INHIBIT MORE THAN ISOLATED SEVERE FOR A TIME. THE
VARIOUS CAMS FOCUS MORE OF THE CONVECTION AROUND THE NORTHERN AND
EASTERN PERIPHERY OF THE WARM AIR BUBBLE THROUGH MUCH OF THE
NIGHT. SO NO CLEAR CUT SOLUTION AT THIS TIME.

THIS LEADS INTO THE SECOND PROBLEM FOR FRIDAY NIGHT... WHICH
STRETCHES INTO SATURDAY... AND THAT IS THE THREAT FOR FLASH FLOODING
ACROSS FAR SOUTHERN MN... ESPECIALLY ALONG AND SOUTH OF I-90.
NAM/GFS PROFILES SHOW ANOTHER POTENTIAL WARM RAIN PROCESS...
SIMILAR TO WHAT WE SAW ON WEDNESDAY FROM HUTCHINSON TO ALBERT LEA
WITH 3+ INCHES OF RAIN FALLING. PW VALUES ARE PROGGED TO BE NEAR 1.75
INCHES...WHICH IS BETTER THAN 2 STANDARD DEVIATIONS ABOVE NORMAL
AS WELL AS NEAR THE 99TH PERCENTILE. NAM/GFS/ECMWF ARE ALL
FOCUSED ON THE BEST 925-850MB MOISTURE TRANSPORT INCREASING ACROSS
IA FRIDAY EVENING AS THE LOW LEVEL JET STRENGTHENS WITH THE NOSE
OF THE TRANSPORT POKING INTO SOUTHERN MN. THE MOISTURE FLUX
CONVERGENCE IS MAXIMIZED OVER SOUTH CENTRAL MN. FLASH FLOOD GUIDANCE
VALUES ARE AROUND 1.75 INCHES IN 3 HOURS WITH 2 INCHES IN 1 HOUR
FOR THE I-90 CORRIDOR. COORDINATION WITH OFFICES TO THE EAST AND
SOUTH RESULTED IN HOLDING OFF ON A WATCH FOR ONE MORE CYCLE TO SEE
IF WE CAN GET A BETTER HANDLE ON THE CONVECTION. THE SHOWERS
GRADUALLY DIMINISH ACROSS WEST CENTRAL THROUGH SOUTH CENTRAL MN ON
SATURDAY AS WE GET MORE OF A WESTERLY PUSH OF DRIER AIR ALONG WITH
FRONTAL BOUNDARY MOVING EAST AND SOUTH.

FOLLOWED THE PREVIOUS SHIFT AND KEPT SUNDAY DRY. THERE IS PRETTY
GOOD CONSENSUS BETWEEN THE MODELS OF A DRY DAY BEFORE SOME SHOWERS
AND THUNDERSTORMS DROP IN FROM THE NORTHWEST SUNDAY NIGHT AND
MONDAY. WE ARE STILL HOLDING ON TO DRY WEATHER FROM MONDAY NIGHT
THROUGH WEDNESDAY (2 1/2 DAYS)... BEFORE SHOWERS AND THUNDERSTORMS COME
BACK ON THURSDAY. THE LAST TIME MSP HAD THREE DAYS IN A ROW WITH NO
PRECIPITATION WAS MAY 5-7TH. AT LEAST LOWS/HIGHS THROUGH THE
PERIOD WILL BE NEAR OR ABOVE SEASONAL VALUES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1239 PM CDT THU JUN 13 2013

VFR CONDS WILL DOMINATE AS HIGH PRESSURE ALONG THE MN/DKTS BORDER
THIS MORNING MOVES TO E WI BY 18Z FRI. AS THE HIGH SHIFTS
EAST...WINDS WILL TURN FROM NE TO SE...WITH SPEEDS INCREASING TO
10-15KTS OUT W TOMORROW MORNING WITH GUSTS AOA 20KTS AFT 16Z. A
FEW PASSING HIGH CLOUDS AND SCT FAIR WX CUMULUS IS ALL THAT WILL
BE SEEN TODAY. MID/HI LEVEL CLOUDS INCREASE FROM THE W BEGINNING
LATER THIS EVENING AS A FRONTAL SYSTEM DEVELOPS ACROSS THE NRN
HIGH PLAINS. CLOUD BASES SHOULD REMAIN AOA 8 KFT THROUGH 18Z FRI.
SCATTERED HI-BASED -SHRA MAY AFFECT THE WRN TAF SITES AFT
15Z...BUT NOTHING THAT WILL CAUSE ANY RESTRICTIONS. THERE MAY EVEN
BE A TSTM SOMEWHERE ACROSS W CENTRAL MN...BUT CONFIDENCE IS TOO
LOW TO PIN-POINT ANY SPECIFIC TAF SITE (OR TIME) AT THIS POINT.

KMSP...VFR. WINDS WILL DIE DOWN THIS EVENING AS THEY START TO SHIFT
SE. SPEEDS WILL INCREASE TO ABV 7KTS BY 11Z, WITH HIGHER GUSTS BY
MID TO LATE MORNING. CLOUDS WILL BE ON THE INCREASE LATER
TONIGHT...BUT SHOULD REMAIN AOA 100. THERE IS A SMALL POSSIBILITY
FOR -SHRA TOMORROW MORNING...MAINLY AFT 16Z, BUT SINCE CONFIDENCE
IS NOT REAL HIGH AND IMPACT WOULD BE MINIMAL...HAVE DECIDED TO
LEAVE IT OUT FOR NOW. MORE SIGNIFICANT CONVECTION SHOULD HOLD OFF
UNTIL AFT SAT/00Z.

/OUTLOOK FOR KMSP/
FRI NGT...MVFR POSSIBLE. TSRA POSSIBLE. S BCMG W 10KTS.
SAT...MVFR POSSIBLE EARLY. WINDS BECOMING WEST 5-10 KTS.
SUN...VFR. SW WINDS 5-10KTS.

&&

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

$$

SHORT TERM...JCA
LONG TERM...RAH
AVIATION...JCA