Area Forecast Discussion Issued by NWS Twin Cities, MN
000
FXUS63 KMPX 142343 AAA
AFDMPX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
643 PM CDT FRI JUN 14 2013
.UPDATE...
ISSUED AT 630 PM CDT FRI JUN 14 2013
CONFIDENCE FOR WIDESPREAD CONVECTION LATER TONIGHT IS DECREASING.
NOT SEEING A WHOLE LOT OF AGITATED CU OVER ERN SD WHICH IS
CONCERNING. ALSO CONCERNING IS THE LACK OF DECENT FORCING. MUCH OF
THE FORCING IS REMAINING NORTH WITH THE NEWD ADVANCING TROUGH
NEAR THE CANADIAN BORDER...AND TO THE SOUTH ACROSS NEB AND IA. THE
CONVECTION TO THE SOUTH WILL STEER EWD/ESEWD AROUND THE PERIPHERY
OF THE CENTRAL PLAINS RIDGE AND SHOULD BYPASS SRN MN. THE
ATMOSPHERE REMAINS PRETTY UNSTABLE ACROSS WRN MN AND ERN SD...SO
CANNOT RULE OUT ISO-SCT COVERAGE LATER THIS EVENING...AND EVEN A
SEVERE STORM OR TWO...BUT NOT ANTICIPATING ANYTHING TOO
WIDESPREAD GIVEN THE LACK OF SIGNIFICANT FORCING.
WILL DROP POPS INTO THE CHC CATEGORY TONIGHT AND DRIVE THEM FROM
WEST TO EAST AHEAD OF THE COLD FRONT. GIVEN THE PROXIMITY OF THE
IA MCS...WILL HOLD ONTO THE FLASH FLOOD WATCH FOR FARIBAULT AND
FREEBORN COUNTIES BUT THAT COULD BE DROPPED BEFORE 10 PM.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 357 PM CDT FRI JUN 14 2013
DURING THIS PERIOD...AN H5 LOW WILL SLOWLY MOVE FROM SASKATCHEWAN
OVER TO MANITOBA...HELPING TO FLATTEN OUT THE RIDGE CURRENTLY
EXTENDING FROM TX UP THROUGH MANITOBA. PRIMARY SFC LOW WILL REMAIN
OVER THE CANADIAN PRAIRIES...BUT THE INCREASING ZONAL FLOW ALOFT
WILL HELP DRIVE A COLD FRONT INTO WRN MN AROUND 6Z TONIGHT...THE
I-35 CORRIDOR NEAR 15Z SAT...AND CLEARING THE EAU AREA BY 21Z SAT.
STILL LOTS OF UNCERTAINTY TONIGHT AS TO CONVECTIVE POTENTIAL ACROSS
THE MPX AREA. TWO ISSUES TO WATCH THIS EVENING WILL BE THE IMPACT OF
THE WARM THERMAL RIDGE/CAP MOVING INTO SW AND HOW FAR NORTH DOES THE
LLJ MAKE IT TONIGHT. FOR THE CAP...HAVE SEEN +12C AT H7 MOVE UP TO
ABOUT THE NE EDGE OF THE BUFFALO RIDGE. AS FOR THE LLJ...30+ KT
WINDS AT H85 ARE IN PLACE ACROSS THE WRN HALF OF MN...BUT THE FOCUS
OF THE STRONGEST MOISTURE TRANSPORT IS CURRENTLY DOWN IN THE OMAHA
AREA...WHICH HAS HELPED DRIVE A CLUSTER OF ELEVATED STORMS OVER WRN
IA THAT WILL CONTINUE EAST ACROSS IOWA THE REST OF THE AFTERNOON.
WITH THE FRONT TO THE WEST...EXPECT A SFC LOW TO MOVE UP INTO ERN
NEB...WHICH SEVERAL CAMS AND MOST MEMBERS OF THE HOPWRF SHOW
GENERATING A LARGE AMOUNT OF CONVECTION WEST OF OMAHA BETWEEN 21Z
AND 00Z THIS AFTERNOON. THIS SHOULD AUGMENT THE MOISTURE
TRANSPORT...KEEPING IT FARTHER SOUTH OF THE AREA...WITH
HEAVIEST/MOST WIDESPREAD STORMS STAYING DOWN ACROSS IA. ABOUT THE
ONLY MODELS THAT DO NOT GO ALONG WITH THE IDEA OF THE HEAVIEST RAIN
STAYING IN IA TONIGHT ARE 14.12 NAM AND THE LAST SEVERAL RUNS OF THE
RAP BRING THE NOSE OF THE JET INTO SRN MN. AS FOR TONIGHT...STILL
PREFER THE 14.12 ARW-EAST SOLUTION AND MOST HOPWRF MEMBERS...WHICH
SHOW JUST A BKN AREA OF STORMS MOVING ACROSS THE AREA THIS EVENING
WITH THE COLD FRONT. GIVEN H7 TEMPS IN WRN MN...COMBINED WITH THE
NOCTURNAL STRENGTHENING OF THE LLJ A BIT FARTHER EAST OF ITS CURRENT
LOCATION...STILL EXPECT THE GREATEST COVERAGE OF STORMS TONIGHT TO
BE EAST OF A STC TO MKT LINE.
AS FOR THE SEVERE THREAT TONIGHT...WITH MUCAPE STILL LIKELY TO BUILD
UP TO 3500 J/KG...CAN NOT RULE OUT A HAIL/WIND THREAT THROUGH THE
NIGHT. SEE LATEST SWOMCD FROM THE SPC FOR MORE ON THAT POTENTIAL.
ALSO KEPT THE FLOOD WATCH GOING...BUT CONFIDENCE IS DECREASING IN
ANY ISSUES HAPPENING THIS PERIOD AS HEAVIER RAINS ARE LOOKING TO BE
CONFINED TO IOWA TONIGHT. HOWEVER...PWAT IS UP BETWEEN 1.5 AND 2
INCHES...SO A HEAVY RAIN THREAT IS STILL THERE...SO WILL CONTINUE
WITH THE FLASH FLOOD WATCH GIVEN THE RECENT WETNESS DOWN TOWARD
ALBERT LEA...PLUS ANY NRN DEVIATION IN WHERE THE LLJ SETS UP COULD
PUT THEM IN THE POSITION TO GET A COUPLE INCHES OF RAIN OVERNIGHT.
LOOKING AHEAD TO SATURDAY...IS LOOKING LIKE A MID LEVEL DRY SLOT
WILL MOVE IN WITH THE INCREASINGLY ZONAL FLOW...WHICH MEANS SATURDAY
IS BEGINNING TO LOOK DRIER FOR THE MPX AREA. STILL ENOUGH
INSTABILITY LINGERING IN THE EARLY AFTERNOON FROM ALBERT LEA UP
TOWARD LADYSMITH TO WARRANT A CHANCE OF THUNDERSTORM MENTION...BUT
EVEN THEN...IS LOOKING LIKE BRUNT OF ACTIVITY FOR SATURDAY WILL BE
SOUTHEAST OF THE MPX AREA. AS A RESULT...IN ALL LIKELIHOOD...IF
CURRENT FLASH FLOOD WATCH AREA DOES NOT SEE RAIN TONIGHT...CAN
PROBABLY CANCEL THE WATCH SATURDAY MORNING.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 357 PM CDT FRI JUN 14 2013
RESIDUAL SHOWER/TSTM ACTIVITY ACROSS WEST CENTRAL WI THROUGH
SOUTHEAST MN SATURDAY EVENING WILL END EARLY IN THE NIGHT AS HIGH
PRESSURE RIDGING BUILDS ACROSS THE FA. SUNDAY STILL LOOKS LIKE A
FINE DAY WEATHER WISE WITH ABUNDANT SUNSHINE WITH HIGH PRESSURE OVER
US. HIGHS WILL BE FROM AROUND 80 TO THE LOWER 80S ALONG WITH A
WESTERLY BREEZE. THE THREAT FOR SHOWERS AND A FEW THUNDERSTORMS
RETURNS SUNDAY NIGHT AND LINGERS ON MONDAY AS A COLD FRONT AND
FAIRLY STRONG SHORT WAVE DROP SOUTHEAST ACROSS THE REGION. IT/S
INTERESTING TO NOTE THAT ALTHOUGH THE NAM/GFS/GEM AND EC ARE
INSTEP WITH THIS SYSTEM...THE NAM/GFS HAVE MUCH MORE QPF OVER THAT
OF THE GEM/EC. IN FACT...THE LATTER SOLUTIONS HAVE VERY LITTLE
QPF. THEREFORE...LOW CHANCE POPS COVER THE AREA SUNDAY NIGHT WITH
A DIMINISHING TREND FROM WEST TO EAST ON MONDAY. WE ARE STILL
FORECASTING DRY WEATHER FROM MONDAY NIGHT THROUGH WEDNESDAY AS AN
UPPER LEVEL RIDGE BUILDS OVER THE NORTHERN PLAINS WITH SURFACE
HIGH PRESSURE EXPANDING ACROSS THE GREAT LAKES. LOWS/HIGHS DURING
THIS PERIOD ARE RIGHT NEAR SEASONAL VALUES. THE LATTER HALF OF THE
WORK WEEK WILL FEATURE INCREASING CHANCES OF RAIN. A LONG WAVE
TROUGH WILL BE SLOWLY PUSHING INTO THE WEST COAST WITH SHORT WAVE
ENERGY EMANATING TO THE NORTHEAST...KNOCKING DOWN THE RIDGE AXIS
OVER THE NORTHERN PLAINS. AT THIS TIME...PRECIPITATION CHANCES ARE
HIGHEST ACROSS WESTERN AND SOUTHERN MN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 630 PM CDT FRI JUN 14 2013
CONFIDENCE FOR THUNDERSTORM DEVELOPMENT TONIGHT HAS DECREASED FROM
THE LAST TAF ISSUANCE. THERE IS NOT A WHOLE LOT OF FORCING TO GET
INITIATION THIS EVENING OVER ERN SD/WRN MN WITH THE BEST FORCING
REMAINING TO THE NORTH NEAR THE CANADIAN BORDER...AND TO THE SOUTH
ACROSS IA AND NEB. THE ATMOSPHERE STILL REMAINS QUITE UNSTABLE IN
THOSE AREAS AND ISO-SCT COVERAGE STILL CANNOT BE RULED OUT LATER
THIS EVENING...BUT WAS NOT CONFIDENT ENOUGHT TO CONTINUE THE TS
MENTION IN ANY TAF. LATER TONIGHT CIGS WILL DROP INTO THE MVFR
CATEGORY OVER MOST OF THE AREA AS DIFFUSE COLD FRONT AND DECENT
LOW LEVEL MOISTURE PUSHES IN. CONFIDENCE WITH CIGS IS ALSO PRETTY
LOW SO DIDN/T MAKE TOO MANY CHANGES IN THAT DEPARTMENT.
KMSP...VFR UNTIL THE EARLY OVERNIGHT...THEN MVFR CIGS LIKELY TO
MOVE IN. BEST CHANCE FOR PRECIP WILL BE CENTERED AROUND MIDNIGHT
SO CONTINUED THE VCSH MENTION. MVFR CIGS ARRIVE THEREAFTER WITH
WEAK FLOW NEAR THE FRONT. CONDITIONS IMPROVE AGAIN SATURDAY
MORNING WITH THE ARRIVAL OF SOMEWHAT DRIER AIR.
/OUTLOOK FOR KMSP/
SUN...VFR. WSW WINDS 5-10KTS.
MON...CHANCE OF MVFR CONDS AND TSRA. NW WINDS 10KTS.
TUE...VFR. WINDS LGT AND VRB.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR MNZ092-093.
WI...NONE.
&&
$$
UPDATE...BORGHOFF
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...BORGHOFF