000
FXUS63 KMPX 140023 AAA
AFDMPX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
723 PM CDT MON MAY 13 2013

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 315 PM CDT MON MAY 13 2013

MAIN CONCERNS IN THE SHORT TERM REVOLVE AROUND FIRE WEATHER CONCERNS
BOTH THIS AFTERNOON AND ESPECIALLY FOR TUESDAY. THERE IS ALSO A
SMALL OUTSIDE CHANCE FOR THUNDERSTORMS LATE TUESDAY AFTERNOON...BUT
THAT THREAT STILL LOOKS QUITE MINIMAL THANKS TO DRY AIR AND A STRONG
CAP. THOUGH IF ANYTHING WERE TO GO...GIVEN DEGREE OF SHEAR AND
INSTABILITY...IT WOULD BE SEVERE WITH LARGE HAIL AND WIND BEING THE
THREATS.

WARM FRONT THIS AFTERNOON RAPIDLY APPROACHING WRN MN. HAD A NARROW
BAND OF SHOWERS DEVELOP OVER MN THIS MORNING WITHIN STRONG WAA
REGIME AROUND H85 THAT IS NOW PUSHING INTO WRN WI. THESE SHOWERS ARE
MOVING EAST AT ABOUT 30 MPH AND SHOULD BY OUT OF THE MPX CWA BY
AROUND 00Z. VERY DRY AIR IN THE LOW LEVELS /SEE MORNING SOUNDING
FROM MPX/ HAS MADE IT DIFFICULT TO ACTUALLY GET MEASURABLE RAIN OUT
OF THESE SHOWERS...WITH MAJORITY OF STATIONS ONLY REPORTING A TRACE
OR 0.01. THEREFORE HAVE CAPPED POPS AT 50 OR LESS THE REST OF THE
DAY AND MAINTAINED A SCT SHOWER WORDING.

FOR TONIGHT INTO TUESDAY MORNING THE BIG QUESTION IS WHAT HAPPENS
WITH POTENTIAL CONVECTION COMING OUT OF NODAK. STORMS LOOK TO
INITIATE ON THE NOSE OF A LLJ AROUND 00Z THIS EVENING OVER NE MT AND
SPEND THE REST OF THE NIGHT WORKING ACROSS NODAK. BY THE
MORNING...WHAT IS LEFT OF THEM WILL BE WORKING INTO MN. BASED ON THE
13.12 NAM HANDLING OF THE LLJ...FAVORED THESE STORMS TO STAY NORTH
OF THE MPX CWA. HOWEVER...SEE THAT BY THE END OF THE 13.18
RAP...SAID LLJ IS A BIT FURTHER SOUTH...WHICH WOULD BRING THE
POTENTIAL FOR SOME SORT OF REMNANT SHOWERS WORKING TOWARD THE AXN
AREA. SPCWRF/NMM/ARW ALL SHOW SOME SORT OF REMNANT SHOWERS MOVING
ACROSS CENTRAL MN IN THE MORNING AS WELL...BUT GIVEN HOW DRY THINGS
ARE TURNING BEHIND THE SHOWERS OVER WI...FAVORED A DRY FORECAST FOR
TONIGHT. INSTEAD...WILL LIKELY START THE MORNING WITH EXTENSIVE
MID/UPPER LEVEL DEBRIS CLOUDS...THAT LOOK TO QUICKLY BLOW OUT OF
HERE BY THE AFTERNOON.

FOR FIRE WEATHER...WAS VERY CLOSE TO ISSUING A RED FLAG WARING OUT
WEST FOR TODAY...BUT SHIED AWAY AFTER WATCHING DEWPS CLIMB INTO THE
40S. HOWEVER...PLAYING HINDSIGHT FORECASTER...STARTING TO SEE MORE
AND MORE HUMIDITIES OUT WEST DROP TO NEAR OR BELOW 25 PERCENT...AND
GIVEN NEAR WIND ADVY STRENGTH WINDS OUT THERE NOW...A RED FLAG
WARNING MAY HAVE BEEN A GOOD IDEA AFTER ALL. WHAT THIS DOES DO
THOUGH IS INCREASE CONFIDENCE IN POTENTIAL FOR RED FLAG CONDITIONS
TUESDAY.

AS FOR TUESDAY...AS MENTIONED ABOVE...EXPECT EXTENSIVE CLOUD COVER
IN THE MORNING THAT CLEARS OUT BY THE AFTERNOON...PER COLUMN
CONDENSATE FORECAST FROM THE 13.12 SPCWRF. GIVEN WARMTH OF 925-850
MB TEMPS BY THE AFTERNOON...IT WILL NOT TAKE MUCH SUN TO SEE A BIG
BOOST IN TEMPS. LOOKING TO THE SW THIS AFTERNOON...SEEING WIDESPREAD
90-95 DEGREE TEMPS ACROSS NEB INTO SODAK. THIS AIRMASS WILL BE HERE
TOMORROW...SO CONTINUED TO RUN WITH FORECAST HIGHS VERY SIMILAR TO
WHAT PREVIOUS FORECAST HAD. WITH 925 MB TEMPS PUSHING 28C PLUS IN
SRN MN...WOULD NOT BE SURPRISED IF PLACES DOWN ALONG I-90 GET INTO
THE UPPER 90S...WITH THE RECORD OF 95 AT MSP CERTAINLY WITHIN
REASON.

BESIDE THESE WARM TEMPS...GRADIENT LOOKS TO TIGHTEN WITH THE
APPROACHING COLD FRONT...WITH WINDS EXPECTED TO INCREASE AGAIN
TOMORROW TO SPEEDS VERY SIMILAR TO WHAT WE SEE NOW. SAID COLD FRONT
WILL MOVE INTO WRN MN DURING THE AFTERNOON...WITH WINDS SWITCHING TO
THE WEST AND INCREASING IN STRENGTH BEHIND IT. WITH WINDS NOT BEING
A QUESTION FOR RED FLAG POTENTIAL TOMORROW...ATTENTION TURNS TO
HUMIDITIES. THIS REMAINS DIFFICULT THANKS TO VERY POOR HANDLING OF
SFC DEWPS BY GUIDANCE IN THE PAST COUPLE OF WEEKS. CONTINUED TO
UNDERCUT GUIDANCE DEWPS BY ABOUT 10 DEGS. WITH CURRENT DEWPS...MIN
HUMIDITIES CURRENTLY FORECAST TO FALL INTO THE 20 TO 25 PERCENT
RANGE FOR MOST OF MN. THE ONLY PLACE WHERE THE HUMIDITY IS
QUESTIONABLE IS CENTRAL MN...WHERE SLIGHTLY MORE CLOUD COVER MAY
KEEP TEMPERATURES LOWER AND HUMIDITIES A BIT HIGHER. GIVEN
SIGNIFICANT NATURE OF WEATHER EXPECTED WITH THE HIGH TEMPS...STRONG
WINDS...AND LOW HUMIDITIES...DECIDED TO UPGRADE FIRE WEATHER WATCH
TO A RED FLAG WARNING FOR ALL BUT CENTRAL MN...WHERE BIGGEST
QUESTION MARKS REGARDING TEMPS/HUMIDITIES EXISTS.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 315 PM CDT MON MAY 13 2013

GIVEN THE RECENT ISSUES MODELS HAVE DISPLAYED WITH OVERDOING
SURFACE/SOIL MOISTURE...ESPECIALLY WITH RESPECT TO
DEWPOINTS...ASSESSING THE CONVECTIVE POTENTIAL FOR TUESDAY EVENING
REMAINS CHALLENGING. THEREFORE...THE 65 TO 75 DEGREE DEWPOINTS THE
GFS/NAM/SREF/ECMWF DEPICT FOR 00Z WEDNESDAY ALONG THE MN/WI BORDER
ARE NOT TRUSTED...WHICH MEANS THE 3000 TO 4000+ J/KG PROGGED
MUCAPE VALUES ARE NOT RELIABLE EITHER. HOWEVER...GIVEN THE
ANTICIPATED DIURNAL HEATING AND DEGREE OF DEEP LAYER SHEAR THAT
DOES SEEM REALISTIC...AM NOT COMFORTABLE WITH A THUNDERSTORM-FREE
FORECAST FOR TUESDAY EVENING. HAVE INCLUDED 30-40 POPS FROM WEST
CENTRAL WI TOWARD SOUTHEAST MN FOR THE POSSIBILITY OF DEVELOPMENT
AS THE CAP ERODES EARLY TUESDAY EVENING.

ANY ACTIVITY QUICKLY LIFTS OUT OF THE FORECAST AREA BY 05Z
WEDNESDAY...WITH SPRING-LIKE CONDITIONS THEN ARRIVING FOR WEDNESDAY
AND THURSDAY AS NEARLY ZONAL FLOW DEVELOPS ACROSS THE CENTRAL CONUS.
HIGHS FOR BOTH DAYS WILL RANGE THROUGH THE 70S...WITH LOWS IN THE
UPPER 40S TO MID 50S.

FRIDAY INTO NEXT WEEKEND IS SHAPING UP TO SIGNAL A TRANSITION TO A
MUCH STORMIER PATTERN FOR THE UPPER MIDWEST. THE AFOREMENTIONED
ZONAL FLOW WILL BECOME A THING OF THE PAST AS A TROUGH DEEPENS OVER
THE SOUTHWESTERN CONUS...SHIFTS EASTWARD TOWARD THE PLAINS...AND
INDUCES SURFACE CYCLOGENENIS OVER THE PLAINS. PLENTY OF MOISTURE TO
WORK WITH THIS TIME...GIVEN THE ANTECEDENT FLOW FROM THE GULF. THE
SEVERE THREAT FOR SATURDAY CURRENTLY APPEARS TO NOSE INTO SOUTHERN
MN...ALTHOUGH...CHANGES IN THE SYNOPTIC PROGS COULD CERTAINLY SHIFT
THAT A BIT.

THE MID LEVEL TROUGH OF WESTERN ORIGIN EVENTUALLY CONGEALS WITH A
NORTHERN STREAM WAVE TO FORM ANOTHER CLOSED LOW SCENARIO OVER OUR
REGION FOR THE WEEK OF MAY 20TH...AS DEPICTED BY ENSEMBLE
MEANS...GFS...AND ECMWF. THIS COULD TRANSLATE TO HIGH TEMPERATURES
IN THE 50-60 DEGREE RANGE FOR A FEW DAYS WITH EXTENSIVE CLOUD COVER
AND SHOWERS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 702 PM CDT MON MAY 13 2013

VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS. HIGH CLOUDS WILL
SPREAD OVERHEAD THIS EVENING...OTHERWISE EXPECTING MAINLY CLEAR
SKIES TONIGHT. MID LEVEL CLOUDS WILL RETURN FOR A TIME EARLY
TUESDAY WITH A SMALL RISK FOR ISOLATED STORMS BY AFTERNOON. WINDS
ARE BE THE BIGGEST CHALLENGE TO THIS FORECAST. A WARM FRONT WAS
LOCATED FROM NEAR STC TO MSP AT TAF ISSUANCE TIME WITH WEST WINDS
BEHIND THE FRONT AND SSE WINDS ACROSS WRN WI. THE FRONT WILL WASH
OUT AND MOST LOCATIONS WILL BECOME SOUTHERLY AGAIN OVERNIGHT. A
SECONDARY WARM FRONT WILL DEVELOP AND PUSH TOWARD THE MN/WI BORDER
TUESDAY BEFORE IT TOO WASHES OUT. WEST WINDS EXPECTED AGAIN WITH
IT. FINALLY...A COLD FRONT WILL DIP SOUTH LATE TUESDAY AFTERNOON
WITH DIRECTION VEERING AGAIN TO NORTHWEST TUESDAY EVENING. SPEEDS
WILL BE LIGHT TONIGHT...BECOMING QUITE GUSTY TUESDAY.

KMSP...VFR CONDITIONS EXPECTED. SOUTH WIND TONIGHT WILL BECOME
WESTERLY LATE...THEN BECOME SOUTHERLY AGAIN TUESDAY MORNING BEFORE
VEERING THROUGH THE DAY. CONFIDENCE IS TOO LOW TO MENTION ANY
PRECIP LATE IN THE PERIOD.

/OUTLOOK FOR KMSP/
WED...VFR. NW WINDS 10 KTS.
THU...VFR. WINDS W 5 KTS.
FRI...MVFR POSSIBLE WITH CHC -TSRA. WINDS SE 5-10 KTS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...RED FLAG WARNING FROM NOON TO 8 PM CDT TUESDAY FOR MNZ047>051-
     054>070-073>078-082>085-091>093.

     FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
     EVENING FOR MNZ041>045-052-053.

WI...NONE.
&&

$$

SHORT TERM...MPG
LONG TERM...LS
AVIATION...BORGHOFF