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000
FXUS63 KMPX 161028
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
528 AM CDT THU MAY 16 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 253 AM CDT THU MAY 16 2013

INITIAL SHORT TERM TRENDS INDICATE INCREASE IN HIGH/MID LEVEL
CLOUDS FROM WEST TO EAST DURING THE DAY.  SOME RESIDUAL MID CLOUDS
AND SPRINKLES ASSOCIATED WITH DEPARTING UPPER LEVEL JET SHOULD
EXIT TO THE EAST THIS MORNING. OVER RIDGING ALOFT SHOULD
CONTINUE TO PROMOTE WARM CONDITIONS WITH 70S TO SOME MID 80S IN
THE SOUTH. THREAT OF SHOWERS MINIMAL TODAY...LEFT THE SLIGHT
CHANCES GOING FOR THE EXTREME SOUTHWEST AFTER 22Z.

DETERMINISTIC MODELS DIVERGE SOMEWHAT ON HANDLING CONVECTION
TONIGHT. BOTH THE 00Z NAM AND GFS DEVELOP MCS LIKE CONVECTION OVER
SOUTHEAST SOUTH DAKOTA THIS EVENING AND RIDE IT NORTHEAST ALONG
BETTER H85 MOISTURE TRANSPORT/TEMPERATURE ADVECTION MAXIMA FROM
WEST CENTRAL INTO CENTRAL MN. PWATS INCREASE TO 1.25 PLUS
OVERNIGHT AS SYSTEM MOVES IN...SO WHEREVER WE CAN GET CONVECTION
TO INITIATE... THERE SHOULD BE SOME GOOD QPF AMOUNTS. THE 00Z
ECMWF AND PREVIOUS RUN OF THIS MODEL...CONTINUED ITS TREND OF
DEVELOPING THE CONVECTION MORE ALONG/AHEAD OF THE SURFACE WARM
FRONT WHICH WILL LIFT NORTHEAST PERHAPS CLOSE TO SOUTHWEST MN BY
12Z FRI. THIS SHOULD DEVELOP CONVECTION FARTHER TO THE SOUTH AND
WEST ALONG AND AHEAD OF THIS BOUNDARY...AS THE UPPER SHORT WAVE
LIFTS ACROSS THE REGION. AFTER COLLABORATION WITH WPC_QPF...WILL
CONTINUE THE HEAVIER QPF OVER FAR SOUTHERN MN TONIGHT.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 253 AM CDT THU MAY 16 2013

A WET ACTIVE PATTERN WILL BE UPON THE AREA FROM THE END OF THIS
WEEK THROUGH THE MIDDLE OF NEXT DUE TO THE ARRIVAL OF A HIGHLY
AMPLIFIED RIDGE-TO-TROUGH PATTERN FOLLOWED BY THE DEVELOPMENT OF
SEVERAL AREAS OF SFC LOW PRESSURE. ALL THIS WILL CULMINATE IN
PLENTY OF RAIN THROUGH THE PERIOD...SEVERAL ROUNDS OF
THUNDERSTORMS...AND A SMALL POTENTIAL OF SEVERE WX FOR SATURDAY.

A BROAD UPPER RIDGE WILL SLOWLY GLIDE THROUGH THE REGION FRIDAY
THROUGH SATURDAY NIGHT. HOWEVER...WITHIN THIS RIDGE WILL BE
SEVERAL PROMINENT SHORTWAVE TROUGHS THAT WILL PROMOTE POCKETS OF
LIFT ACRS THE AREA. AT THE SFC...A QUASI-STNRY SFC FRONT S OF THE
REGION WILL TRANSITION TO A WMFNT AND LIFT N WITHIN THE INCRG H5
HEIGHTS. EVEN WITH THE RISING HEIGHTS...CAPPING IS NOWHERE NEAR
IMPRESSIVE THUS ALLOWING FOR CONVECTION TO SPAWN NEAR AND ALONG
THE NWD-MOVING FNT. PLENTY OF GULF OF MEXICO MOISTURE WILL BE
ADVECTED WELL N INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION DUE
TO A PROLONGED SLY FLOW...AND THIS WILL PUSH PWATS INTO THE
1.25-1.50 INCH RANGE. POPS REMAIN IN THE LIKELY CATEGORY WITH A
CHC THUNDER MENTION SINCE LARGE-SCALE RIDGING WILL STILL BE THE
GENERALIZED PATTERN. THERE WILL BE A BIT OF A LULL IN THE ACTION
FRI NIGHT INTO SAT MRNG AS THE UPPER RIDGE BRIEFLY REASSERTS
ITSELF...BUT THE RIDGE WILL QUICKLY SHIFT TO THE E ON
SAT...ALLOWING A BROAD LONGWAVE TROUGH COMING ONSHORE THE WRN
CONUS TO SHIFT INTO THE CENTRAL CONUS SAT-SUN. MUCH MORE
BROADSCALE LIFT ALONG WITH MORE IMPRESSIVE UPPER JETTING WILL
ALLOW MORE ORGANIZED CONVECTION TO DEVELOP FOR SAT NIGHT AND
CONTINUING THROUGH TUE AS THE UPPER LEVEL TROUGH SETTLES OVER THE
CENTRAL CONUS. UNDER THIS TROUGH...A SLOW-MOVING BUT WELL-
DEVELOPED LOW PRES CENTER WILL MEANDER EWD...PROMOTING ENHANCED
LOW-LEVEL JETTING MAINLY LATE SAT INTO EARLY SUN. THERE IS SOME
MODEL DISAGREEMENT AS TO THE PLACEMENT OF THE JETTING AND THE BEST
INSTABILITY AXES. ATTM...BEST PLACEMENT FOR LARGE-SCALE ASCENT IS
IN THE DAKOTAS...AND THIS IS HIGHLIGHTED IN THE SPC ASSESSMENT OF
ITS SWODY3. THERE IS A SMALL CHC SOME ISOLD STRONG-TO-SEVERE
STORMS COULD LAST SAT EVENING INTO SUN MRNG INTO FAR WRN MN...BUT
THE DIURNALLY DRIVEN NATURE WOULD SEEM TO MITIGATE THIS
POSSIBILITY DUE TO THE TIMING. BEYOND THE SEVERE WX THREAT...THE
PERSISTENT RAIN EXPECTED FROM THIS MEANDERING SYSTEM WILL PRODUCE
PERIODS OF STEADY RAIN...SOMETIMES MOD-HVY AT TIMES...SAT NIGHT
THRU TUE. CUMULATIVE QPF FORECASTS ARE IN THE 1-2 INCH RANGE WITH
ISOLATED AMOUNTS UP TO 3 INCHES...ESPECIALLY IN WRN MN. THE
RAINFALL WILL SLOWLY TAPER OFF ACRS THE REGION TUE INTO WED AS THE
UPPER LOW GRADUALLY LIFTS NE OUT OF THE REGION. THE FORECAST THEN
INCLUDES A COUPLE DAYS OF DRYING OUT GOING INTO THE LATTER PORTION
OF THE WEEK AS AN UPPER RIDGE AND BROAD SFC HIGH PRESSURE ARE
EXPECTED TO MOVE ACRS THE REGION.

AS FOR TEMPERATURES...THERE WILL BE GENERALLY LITTLE DAY-TO-DAY
VARIATIONS THROUGH THE WEEKEND INTO EARLY NEXT WEEK SINCE THERE
WILL BE PLENTY OF CLOUD/RAIN COMPLICATIONS ALONG WITH THE LACK OF
PRONOUNCED AIRMASS CHANGES. HIGHS WILL GENERALLY RUN IN THE
70S WITH LOWS IN THE 50S AND 60S. ONCE THE CDFNT FROM THE
ORGANIZED LOW PRES SYSTEM SWINGS THRU BY EARLY TUE...TEMPS WILL
BECOME A BIT COOLER AND DROP SLIGHTLY BELOW NORMAL. HIGHS WILL
DROP TO THE 60S WITH LOWS AROUND 50 STARTING TUE AND GOING INTO
THE MIDDLE OF THE WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 512 AM CDT THU MAY 16 2013

VFR THROUGH 06Z/17 WITH MVFR CIGS POSSIBLE AT KRWF AS THUNDER
MOVES INTO THE REGION. WHENT 3-5SM -SHRA AT KAXN AND KSTC LATER
TONIGHT AS WELL. THE REMAINDER OF THE REGION WILL REMAIN VFR WITH
THREAT OF THUNDER LIMITED TO MAINLY WEST OF KMSP TONIGHT. SURFACE
WIND FLOW BECOMING MORE EAST IN DIRECTION THIS MORNING AHEAD OF
DEVELOPING LOW PRESSURE SYSTEM AND FRONT TO THE SOUTH. NOT
ANTICIPATING SUSTAINED GUSTS DURING THE PERIOD.

KMSP...VFR DURING THE PERIOD. BEST CHANCE OF RAIN COMES IN MAINLY
AFTER 08Z AND MAY LINGER WELL INTO FRIDAY MORNING...IF MODELS ARE
CLOSE. LEFT THUNDER OUT FOR NOW...AS SPC OUTLOOK AND VARIOUS SREF
FORECAST TOOLS INDICATING BETTER THREAT REMAINS TO THE WEST.
KEEPING WIND DIRECTION MORE EAST AND GENERALLY 10 KTS OR LESS.

/OUTLOOK FOR KMSP/
FRI...VFR WITH MVFR IN TSRA MAINLY IN THE MORNING. E-SE WINDS
10-15 KTS. SAT...VFR/MVFR CIGS. CHC IFR IN HEAVIER TSRA. SE WINDS
5-10 KTS. SUN...VFR/MVFR CIGS. CHC IFR IN HEAVIER TSRA. SE WINDS
8-12 KTS.

&&

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

$$

SHORT TERM...DWE
LONG TERM...JPC
AVIATION...DWE