Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 251047
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
547 AM CDT SAT JUL 25 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 341 AM CDT SAT JUL 25 2015

SOME FOG AN HR OR TWO AFT SUNSET IS POSSIBLE DUE TO THE RECENT HEAVY
RAINFALL AND LIGHT WINDS NEAR THE SFC.

THE MAIN FORECAST CONCERN DEALS WITH A SHORTWAVE MOVING EASTWARD
ACROSS WYOMING INTO THE SOUTH DAKOTA LATER TODAY...AND ACROSS
SOUTHERN MN TONIGHT. A STRONG PVA ANOMALY IS ASSOCIATED WITH THIS
SHORTWAVE IN THIS FAST WEST-EAST MID LEVEL FLOW ALOFT. ALTHOUGH
MLCAPES WILL BE MARGINAL DURING THE AFTN/EVENING...MID LEVEL LAPSE
RATES ASSOCIATED WITH THIS SHORTWAVE MAY ALLOW FOR ISOLD/SCATTERED
SHRA/TSRA TO DEVELOP AND MOVE ACROSS SOUTHERN MN DURING THE NIGHT.

THE STRONGEST INSTABILITY GRADIENT IS FORECAST TO REMAIN IN SW/SC MN
DURING THE OVERNIGHT HRS...SO BASED ON THIS...AND THE MOISTURE
GRADIENT/TRANSPORT AIMING TOWARD THE SW CWA OF MPX...KEPT THE BEST
CHC/S OF RAINFALL IN THIS AREA...THEN TAPER IT OFF TO THE NE ACROSS
THE REST OF MN/WC WI.

TEMPS WILL ONCE AGAIN RISE INTO THE 80S...WITH A 90 DEGREE TEMP
POSSIBLE IN WC/SW/SC MN DURING PEAK HEATING. HEAT INDICES WILL
LIKELY RISE AGAIN INTO THE MID 90S.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 341 AM CDT SAT JUL 25 2015

MULTIPLE OPPORTUNITIES FOR PRECIPITATION MARK THE LONG TERM
FORECAST PERIOD...ALTHOUGH TIMING/LOCATION DETAILS ARE STILL IN
THE REALM OF LOW CONFIDENCE.

SUNDAY STILL LOOKS TO HAVE A WASHED-OUT WARM FRONT JUST
WEST/SOUTH OF THE FORECAST AREA. CONSISTENCY REGARDING THE PROGGED
POSITION OF THIS BOUNDARY HAS BEEN POOR OVER THE LAST SEVERAL
MODEL RUNS. WHILE INSTABILITY LOOKS SUFFICIENT TO SUPPORT
INCLUSION OF CHANCE POPS...DEEP LAYER SHEAR AND MOISTURE TRANSPORT
ARE MODEST AT BEST. WILL KEEP POPS AT 20-30 PERCENT FOR NOW GIVEN
THOSE FACTORS AND THE POOR RUN-TO-RUN CONSISTENCY.

A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS STILL LOOKS TO
ARRIVE ON MONDAY NIGHT AND TUESDAY AS A MORE DEFINED SURFACE
FRONTAL SYSTEM MOVES ENTERS THE AREA. A DECENT POCKET OF 925-850MB
MOISTURE TRANSPORT CENTERS ITSELF OVER THE FORECAST AREA BETWEEN
06Z AND 12Z TUESDAY. HAVE INCLUDED 50-60 POPS DURING THIS
TIMEFRAME. MID LEVEL CAPPING BUILDS OVER THE AREA ON
TUESDAY...WITH A STEAMY DAY AS TEMPERATURES CLIMB INTO THE UPPER
80S TO LOWER 90S AND HEAT INDICES RISE INTO THE MID TO UPPER 90S.

THE RELATED COLD FRONT MOVES ACROSS THE AREA LATE TUESDAY
AFTERNOON AND EVENING. MID LEVEL HEIGHT FALLS ASSOCIATED WITH
APPROACHING SHORTWAVE ENERGY ATOP THE SOUTHERN PLAINS RIDGE SHOULD
ACT TO ERODE THE CAP. THIS WOULD BE THE TIME FRAME THAT SEVERE
WEATHER WOULD BE POSSIBLE.

IN THE WAKE OF THE FRONT...THE REMAINDER OF THE UPCOMING WORK WEEK
LOOKS TO BE COOLER AND DRY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 545 AM CDT SAT JUL 25 2015

AN HR OR TWO OF IFR/MVFR VSBY DUE TO LIGHT WINDS IN THE BOUNDARY
LAYER...ESPECIALLY FOR KRNH. THE FOG IS VERY SHALLOW SO IT SHOULD
QUICKLY DISSIPATE AFT SUNRISE. OTHERWISE...VFR CONDS WILL PREVAIL
OVER THE NEXT 24 HRS WITH WINDS SLOWLY BECOMING E/SE THIS AFTN.

KMSP...

VFR CONDS WILL PREVAIL OVER THE NEXT 24-30 HRS. WINDS WILL BE
LIGHT FROM THE N/NE THIS MORNING...THEN SHIFT TO THE E/ESE BY THE
AFTN. A MORE SE WIND IS EXPECTED OVERNIGHT AND SUNDAY MORNING.

/OUTLOOK FOR KMSP/

SUN AFTN...MAINLY VFR. CHC MVFR/IFR IN TSRA. WINDS SE 5-10 KTS.
MON...VFR. CHC OF TSRA LATE. WINDS SE 5-10 KTS.
TUE...MAINLY VFR. CHC MVFR/IFR IN TSRA. WINDS S 10-15 KTS.

&&

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

$$

SHORT TERM...JLT
LONG TERM...LS
AVIATION...JLT



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