Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 282056
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
356 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 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 122 PM CDT MON JUL 28 2014

VFR CONDITIONS EXPECTED THROUGH THE PERIOD. SOME THREAT
DIMINISHING TSRA INTO WC WI PORTION OF THE AREA THIS EVENING.. BUT
BETTER CHANCE OF THUNDER DEVELOPING TUESDAY AFTERNOON. SOME
SHOWERS POSSIBLE INTO SC MN INTO THE AFTERNOON BEFORE MOVING OUT
BY EVENING. SURFACE WINDS NW-N AND GENERALLY LESS THAN 10KTS
THROUGH THE PERIOD. SURFACE RIDGE BUILDS INTO WESTERN MN LATER
TONIGHT WITH LIGHT WINDS. LEFT FOG OUT FOR THE AREA FOR NOW...WITH
ENOUGH CLOUDS/DRY AIR EXPECTED TO PROHIBIT WIDESPREAD FOG
FORMATION.

KMSP...
VFR THROUGH THE PERIOD. SOME THREAT OF ISOLD SHRA THIS
AFTERNOON/EVE BUT THAT SHOULD REMAIN TO THE SW OF THE FIELD. WINDS
NW 10KTS OR LESS THROUGH THE PERIOD.

/OUTLOOK FOR KMSP/
TUE...VFR. WINDS NW 10 KTS.
WED...VFR. WINDS NW 5-10 KTS.
THU...VFR. WINDS N 5 KTS.

&&

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

$$

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





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