000
FXUS63 KMPX 240548
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1248 AM CDT FRI MAY 24 2013

.UPDATE...

06Z AVIATION DISCUSSION ADDED BELOW.

&&

.SHORT TERM...THROUGH MONDAY
ISSUED AT 204 PM CDT THU MAY 23 2013

23.12Z RAOBS SHOW GOOD 925-850MB COLD ADVECTION ACROSS THE WRN GREAT
LAKES THIS MORNING IN MODERATE NORTHEAST FLOW. FRONTAL SLOPE OVER
THE STATE IS SOMETHING THAT WILL COME INTO PLAY FOR UPCOMING
FORECAST AND HOW FAR IT SLIDES SOUTHWEST. AT 12Z KINL-KABR HAD A 7C
TEMPERATURE DIFFERENCE AT 850MB /12C AT 925MB/. A MASSIVE DRYING
ACROSS MN OCCURRED OVERNIGHT WITH PRECIPITATELY WATER VALUES
PLUMMETING FROM 0.90 TO 0.32 INCHES...OR 136 TO 48 PERCENT NORMAL.
THE SURFACE RIDGE NOSING IN IS QUITE DRY WITH PRECIPITABLE WATER
VALUES IN THE 30 PERCENT RANGE ACROSS SRN CANADA. THIS GAVE WAY TO A
SUNNY BUT COOL DAY TODAY. A HIGHER AMPLITUDE RIDGE AXIS IS
ANCHORED IN THE DAKOTAS AND SOUTH...WHILE A DEEPER CYCLONE HAS NOW
SHIFTED ONSHORE INTO THE NWRN U.S. NUMEROUS SPOKES OF ENERGY ARE
CIRCULATING AROUND THAT LOW...ONE OF WHICH IS QUITE STRONG OVER
NEVADA WITH RAP ANALYSIS SHOWING A TROPOPAUSE FOLD TO NEAR
500MB...ON THE POLEWARD SIDE OF A MEASURED 100KT 250MB JET CORE
NOSE. THIS IS DRIVING HEIGHT FALLS ACROSS MT/ID/UT. SURFACE DEW
POINTS OF MEANING FOR CONVECTION ARE LOCATED IN OKLAHOMA...SOON TO
RETURN NORTHWARD.

FORECAST IS ON TRACK FOR CALMING WINDS TONIGHT AND CLEAR SKIES.
WIDESPREAD FROST SHOULD OCCUR WITH LOWER 30S FORECAST ACROSS NWRN
WI. WITH LOWER DEW POINTS OVER NWRN WI COUNTIES CURRENTLY...HAVE
DECIDED TO JUST ADD ALL OF THOSE COUNTIES INTO THE FROST ADVISORY.

BIG PICTURE DURING THIS PERIOD IS FALLING HEIGHTS AND PRESSURE IN
THE FRONT RANGE WITH SOUTHERLY FLOW INCREASING AND A RETURN OF
MOISTURE TO NEB/SD FRIDAY NIGHT. THIS WILL PLACE THE LOW-LEVEL
THERMAL BOUNDARY ACROSS THE FORECAST AREA FROM 850-925MB...SLIGHTLY
DISPLACED SWWRD...FROM KABR-KMLI. THE CONSENSUS NCEP MODELS AT
23.12Z REMAIN CONSISTENT WITH THEIR PREVIOUS RUNS ON THE FRONTAL
BOUNDARY BECOMING ACTIVE IN THE DAKOTAS/NEB FRIDAY EVENING AND
SHIFTING EAST INTO MN/IA OVERNIGHT. THE 23.00Z ECMWF/UKMET
SOLUTIONS DO AS WELL...HOWEVER THEY REMAIN FURTHER WEST.

THE 300/305K SURFACE IN THE NCEP SOLUTIONS REMAINS CONSISTENT WITH
AN 8G/KG MOISTURE SURGE ISENTROPICALLY LIFTING AND CONVERGING INTO
CENTRAL AND ERN MN FRIDAY OVERNIGHT WITH A FETCH OF ABOUT 500 J/KG
OF MUCAPE FEEDING IT. THE NAM SEEMS TO BE THE MOST AGRESSIVE. NOT
OVERLY IMPRESSIVE FOR SEVERE WEATHER...BUT RATHER THERE IS ENOUGH
FORCING TO GENERATE RA/TSRA SWWRD OF MSP. THE ECMWF SOLUTIONS
SUGGEST MORE OF A FOCUS IN SRN/SWRN MN. THE MAIN QUESTION IS HOW
FAR EAST DOES THIS CONVECTIVE COMPLEX TRACK FRIDAY NIGHT AND HOW FAR
EAST DOES THE FRONTAL BOUNDARY LIFT. HAVE INCREASED RAIN CHANCES
FURTHER EAST FOR FRIDAY NIGHT AND SATURDAY...HOWEVER WITH THE
VERIFICATION RECORD OF THE ECMWF...THERE IS STILL A CHANCE THE
EASTERN AREAS WILL BE DRY. CONFIDENCE IS LOW ON THE EXACT
LOCATION OF THE WEATHER...BUT HIGHER THAT IT WILL BE AN ACTIVE
FRONTAL ZONE WITH SHRA/ISO TSRA.

THIS QUESTION REMAINS THROUGH MONDAY...HOW FAR EAST WILL THE
FRONTAL BAND BE LOCATED. THE FRONT WILL LIKELY REMAIN ACTIVE WITH
SHOWERS/STORMS AND CLOUDS...AND HIGHS QUITE A BIT COOLER THAN OUTSIDE
THE BAND. OVERALL...HAVE INCREASED RAIN CHANCES IN THE WRN/SRN
FORECAST AREA AND TRIED TO REMAIN NEARLY DRY IN THE EAST. SEEMS
LIKE IT WILL BE A CLOUDY WEEKEND...AND THUS HAVE LOWERED HIGHS
SUNDAY AND MONDAY AS WELL. SEVERE WEATHER THREATS ARE MOST
POSSIBLE IN SWRN MN CLOSER TO THE CAPE POOL...AND MONDAY LOOKS
MOST FAVORABLE SHOULD THE INSTABILITY INCREASE AS THE WARM FRONT
MOVES TOWARD MN. HOWEVER...ACTIVITY ALONG THAT FRONT THIS WEEKEND
MAY HAVE MUCH TO DO WITH HOW THE ENVIRONMENT/FRONT EVOLVES MONDAY.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 241 PM CDT THU MAY 23 2013

IT CONTINUES TO LOOK LIKE WE/LL UNFORTUNATELY NEED TO KEEP A
PROLONGED PERIOD OF CHANCE POPS IN THE FORECAST THROUGH THE WEEK
AS THE BAROCLINIC ZONE LINGERS IN THE AREA... WITH ELEVATED
INSTABILITY AND PERSISTENT WARM ADVECTION WORK TO GENERATE
SCATTERED SHRA/TSRA. THERE WILL UNDOUBTEDLY BE SOME DRY PERIODS...
WITH PCPN FOCUSED WHEN INDIVIDUAL SHORTWAVES RIPPLE SOUTHEAST
THROUGH THE UPPER FLOW... BUT AT THIS POINT IT IS IMPOSSIBLE TO
TRY AND PIN POINT WHEN SUCH DRY PERIODS MIGHT OCCUR. THE 12Z ECMWF
HAS COME AROUND MORE IN LINE WITH THE GFS IN KEEPING THINGS MORE
ACTIVE IN OUR AREA THROUGHOUT THE TIME PERIOD... ALTHOUGH BOTH
SUGGEST WE SHOULD FINALLY BRING THE UPPER TROUGH EAST TOWARD THE
REGION BY THE END OF THE WEEK. DEPENDING ON HOW THAT UNFOLDS... WE
COULD HAVE A POSSIBILITY FOR FOCUSED CONVECTION AND POSSIBLE
SEVERE WEATHER DURING THE THURSDAY-FRIDAY TIME FRAME. BUT... UNTIL
THAT POINT THE MAIN ISSUES WOULD LIKELY BE LOCALLY HEAVY RAIN AND
PERHAPS SOME HAIL. IN GENERAL... TEMPERATURES WILL WARM THROUGH
THE WEEK AS THE BONAFIDE WARM SECTOR SLOWLY LIFTS NORTH INTO THE
AREA.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1248 AM CDT FRI MAY 24 2013

HIGH PRESSURE SLIDING INTO WI TONIGHT WILL PROVIDE EXCELLENT
CONDITIONS THROUGH MUCH OF THE DAY FRIDAY...BUT GOING THROUGH THE
DAY...WILL START TO SEE AN AREA OF SHRA/TSRA MOVE EAST THROUGH
THE DAKOTAS. BASED ON MPX SOUNDING LAST NIGHT...AIRMASS OVER THE
MPX AIRSPACE IS VERY DRY...WHICH SHOULD DELAY THE ONSET OF ANY
PRECIP. DID NOT INTRODUCE ANY VCSH UNTIL AFTER 00Z...BUT QUICKLY
SPREAD IT EAST ACROSS MN AS THE LLJ BEGINS NOSING INTO IOWA THIS
EVENING. GIVEN DRY ANTECEDENT CONDITIONS...KEPT CONDS VFR AS IT
WILL TAKE A WHILE TO MOISTEN THE LOW LEVELS...BUT BY 12Z
SATURDAY...PROBABILITIES FOR MVFR OR LOWER CIGS WILL BE INCREASING
PRECIPITOUSLY ACROSS MN. FOR WINDS...HIGH PRESSURE WILL BE SLIDING
OVER TOWARD MICH OVER THE DAY...WITH GRADIENT INCREASING AS A
RESULT. WINDS WILL BE STRONGEST WEST...WEAKEST EAST. BASED ON
SOUNDINGS...EXPECT SOME STRONG SUSTAINED WINDS...WITH MINIMAL
GUSTING. A 16G21KT TYPE DAY LOOKS TO AHEAD FOR WRN MN.

KMSP...CONFIDENCE HIGH IN TAF PARAMETERS UNTIL THE TAIL END OF THE
TAF. AT THIS POINT...KEPT ONLY A VCSH MENTION...THOUGH AT SOME
POINT LATE FRIDAY NIGHT...DO EXPECT THERE TO BE A PERIOD OF
SHRA/ISO TSRA. THIS WOULD BE MOST LIKELY BETWEEN 8Z AND 12Z. AS
FOR CIGS...KEPT THEM VFR...THOUGH CHANCE FOR MVFR...INCLUDING SUB
017 CIGS INCREASES AFTER 8Z SAT.

/OUTLOOK FOR KMSP/
SAT...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10-15 KTS.
SUN...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10-15 KTS.
MON...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10 KTS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FROST ADVISORY UNTIL 7 AM CDT THIS MORNING FOR MNZ045-052-053-
     063.

WI...FROST ADVISORY UNTIL 7 AM CDT THIS MORNING FOR WIZ014>016-
     023>028.

&&

$$

SHORT TERM...BAUMGARDT/ARX
LONG TERM...
AVIATION...MPG