Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 282350
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
650 PM CDT MON JUL 28 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 337 PM CDT MON JUL 28 2014

SHORT TERM CONCERNS REMAIN TIMING OF SHOWERS THIS EVENING AND THE
THREAT OF SHOWERS/THUNDER FOR MAINLY TUESDAY AFTERNOON.

THE INITIAL SHORT WAVE ACROSS SOUTHWEST MN IS SHEARING/WEAKENING
TO THE SOUTHEAST. HEAVY CUMULUS NOTED...AND PERHAPS A LIGHT
SHOWER AFFECTING SOUTH CENTRAL MN PER LATEST RADAR TREND.
OVERALL...THIS SHOULD EXIT THROUGH 00Z TUE. WATER VAPOR IMAGERY
SHOWS ANOTHER SHORT WAVE DROPPING SOUTHEAST OVER THE WESTERN GREAT
LAKES WITH SOME SHRA ASSOCIATED. SEVERAL DETERMINISTIC MODELS SHOW
SOME WEAK CONVECTION AFFECTING WEST CENTRAL WISCONSIN OVERNIGHT.
SEVERAL HIRES MODELS INDICATED THIS AS WELL. INSTABILITY IS WEAK
BUT THERE MAY BE ENOUGH FORCING WITH THE WAVE TO GENERATE A FEW
SHOWERS/ISOLATED THUNDER. CLOUDS WILL THIN SOME...BUT DO EXPECT AT
LEAST SOME SCATTERED CLOUDS TO REMAIN OVERNIGHT.

ON TUESDAY...MODELS CONTINUE TO SUGGEST ANOTHER MORE POTENT SHORT
WAVE AFFECTING AT LEAST WEST CENTRAL WISCONSIN MAINLY DURING THE
AFTERNOON. MUCAPES INCREASE TO AROUND 1500 J/KG OVER EASTERN MN
AND WESTERN WI WITH DEEP LAYER SHEAR AROUND 30KTS. MID LEVEL
LAPSE RATES NOT THAT UNSTABLE...SO SEVERE THREAT NOT THAT HIGH.
PERHAPS SOME MARGINAL SEVERE HAIL. SHOULD SEE HIGH TEMPERATURES
WARM THROUGH THE 70S TO SOME LOWER 80S ACROSS THE AREA.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 337 PM CDT MON JUL 28 2014

THE PREVAILING UPPER LEVEL PATTERN THROUGH SATURDAY WILL BE A
LARGE RIDGE OVER THE WRN CONUS...A DEEP LONGWAVE TROUGH OVER THE
ERN CONUS...WITH THE CENTRAL CONUS CAUGHT IN THE MIDDLE UNDERNEATH
FAIRLY PERSISTENT NW FLOW. AT THE SFC...THIS WILL RESULT IN MAINLY
SFC HIGH PRESSURE. ALTHOUGH OCCASIONAL SHORTWAVE DISTURBANCES WILL
SWING AROUND THE WRN FRINGES OF THE LONGWAVE TROUGH...THROUGH THE
UPR MISS RIVER VALLEY AND GREAT LAKES...THE LACK OF MOISTURE
COMBINED WITH WEAK SFC SUPPORT DUE TO HIGH PRES KEEPING ANY
ORGANIZED FRONTAL SYSTEMS AWAY WILL MEAN ONLY ISOLD PRECIP
DEVELOPMENT FOR MAINLY FAR ERN MN INTO WRN WI.

GOING INTO THE WEEKEND...THIS LONGWAVE PATTERN BEGINS TO BREAK
DOWN AS THE WRN RIDGE SHIFTS INTO THE CENTRAL CONUS. THIS WILL
ALSO MEAN A BREAKDOWN OF THE PERSISTENT HIGH PRES...ALLOWING WEAK
SFC LOW PRES AREAS TO INFILTRATE THE CENTRAL CONUS. THIS MEANS A
SLIGHT INCRS IN POPS FOR THE ENTIRE CWFA /AS OPPOSED TO MAINLY ERN
PORTIONS OF THE WFO MPX CWFA/ FOR THE WEEKEND INTO EARLY NEXT
WEEK. STILL NOT LOOKING AT MUCH IN THE WAY OF QPF...SO POPS ARE
KEPT IN THE 20-30 RANGE. IN FACT...OVERALL QPF OVER THE NEXT WEEK
WILL STRUGGLE TO REACH A QUARTER INCH AND MANY PORTIONS OF THE
CWFA WILL REMAIN DRY.

AS FOR TEMPERATURES...THE PATTERN STILL ALLOWS FOR VERY LITTLE DAY
TO DAY VARIATION IN TEMPERATURES DUE TO THE LACK OF AIRMASS
CHANGE. HIGHS THROUGH THE WEEKEND WILL HIT THE UPR 70S TO LWR 80S
WHILE LOWS DROP TO THE UPR 50S TO LWR 60S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 650 PM CDT MON JUL 28 2014

VFR CONDITIONS EXPECTED THROUGH THE PERIOD. THERE WILL CONTINUE TO BE
STRATOCU AROUND 5000-6000 DROPPING SOUTHWARD FROM THE WESTERN
LAKE SUPERIOR AREA. SOME OF THIS MAY GO BROKEN IN PARTS OF WESTERN
WISC LATER THIS EVENING OR OVERNIGHT. OTHERWISE LITTLE WEATHER
TONIGHT. LEFT FOG OUT FOR THE KEAU AREA...DUE TO LIKELIHOOD FOR
THE CLOUDS TO INHIBIT WIDESPREAD FOG FORMATION.

SOME SHOWERS ARE POSSIBLE IN WESTERN WISC TUESDAY AFTERNOON AND
MAYBE THUNDER AS WELL. THREAT IS NOT YET STRONG ENOUGH TO INCLUDE
TSRA IN THE KEAU TAF. NW WIND MIGHT GUST ABOVE 10 KNOTS AMID
DAYTIME HEATING.

KMSP... VFR THROUGH THE PERIOD. THERE IS A VERY SMALL CHANCE OF
BROKEN CLOUDS AROUND 5K-6K FEET LATER TONIGHT AS CLOUDS DROP
SOUTHWARD BUT MOST OF THE BROKEN CLOUDS WILL BE IN WISCONSIN. MORE
CU WILL DEVELOP LATE TUESDAY MORNING AND THIS IS ALSO WHEN THERE
MAY BE A FEW GUSTS 10-15 KTS.

/OUTLOOK FOR KMSP/

WED...VFR. WINDS NW 5-10 KTS.
THU...VFR. WINDS NW 5 KTS.
FRI...VFR. WINDS NW 5 KTS.

&&

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

$$

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





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