Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 130345
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1045 PM CDT SAT JUL 12 2014

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 308 PM CDT SAT JUL 12 2014

RADAR IMAGERY CONTINUES TO SHOW RAIN WITH EMBEDDED THUNDERSTORMS
OVER THE AREA AS OF 330 PM. PCPN WAS FOCUSED OVER TWO AREAS... ONE
NEAR THE IOWA BORDER AND ANOTHER FROM EAST CENTRAL INTO WEST CENTRAL
MINNESOTA. THE FORMER AREA WAS BEING SUPPORTED BY A SHORTWAVE
EVIDENT IN WATER VAPOR IMAGERY OVER FAR SOUTHERN MINNESOTA AND THE
MAIN INSTABILITY GRADIENT/BAROCLINIC ZONE. HOWEVER... THE LATTER WAS
BEING AIDED BY THE SECONDARY FRONT/DEWPOINT GRADIENT DROPPING
SOUTHEAST THROUGH THE AREA AHEAD OF THE SHORTWAVE TROUGH PUSHING
EAST FROM THE DAKOTAS INTO MINNESOTA. MLCAPE VALUES OF 250-1000 J/KG
WERE APPARENT IN THE SPC MESOANALYSIS OVER THE EASTERN PORTION OF
THE AREA... WHERE EMBEDDED STORMS WITH HIGH RAINFALL RATES WERE
PRESENT. SOME PEA SIZED HAIL WAS OCCURRING WITH THE STRONGEST
STORMS... WHICH HAD SOME BETTER CORES ABV 25K FT AGL. THE HRRR HAS
HAD A DECENT HANDLE ON THINGS THROUGH THE DAY... SO GENERALLY
FOLLOWED ITS GUIDANCE TOGETHER WITH NEIGHBORHOOD PROBABILITIES FROM
THE HOPWRF. THAT BEING SAID... EXPECT THINGS TO SHIFT EAST/SOUTH
THROUGH EARLY EVENING... WITH MOST OF THE CWFA BECOMING PCPN FREE
BETWEEN 00Z AND 03Z. WE COULD SEE SOME SHRA SNEAK BACK INTO THE
NORTHWEST/NORTH CENTRAL PORTION OF THE AREA LATER THIS EVENING AND
OVERNIGHT BEHIND THE FRONTAL BOUNDARY AS THE MID-UPPER LEVEL PV LOBE
SWINGS THROUGH THAT AREA. COLD ADVECTION WILL ASSERT ITSELF OVER THE
AREA ON SUNDAY. SUBSIDENCE WITH THE COLD ADVECTION SHOULD BE
SUFFICIENT TO KEEP ANY SHRA FROM DEVELOPING ON SUNDAY GIVEN THAT THE
BETTER LOW-MID LEVEL LAPSE RATES WILL STILL BE UPSTREAM AND CLOSER
TO THE UPPER LOW AT THAT POINT. SO... EXPECT MAINLY JUST DIURNAL CU
WITH TEMPERATURES GETTING INTO THE LOWER TO MIDDLE 70S.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 308 PM CDT SAT JUL 12 2014

THE UPPER LOW WILL BEGIN DIGGING SOUTH AGGRESSIVELY SUNDAY NIGHT
AND WILL REACH THE CENTRAL GREAT LAKES MONDAY. CLOUDS AND
SCATTERED TO NUMEROUS SHOWERS WILL ACCOMPANY THE LOW
MONDAY...GREATEST COVERAGE NEAR THE LOW OVER WESTERN WI. STEEP LOW
LEVEL LAPSE RATES IN THE STRONG CAA REGIME MAY RESULT IN SOME
ISOLATED THUNDER...BUT NOTHING THAT WILL BE TOO STRONG GIVEN THE
RELATIVELY SHALLOW INSTABILITY/MOIST LAYER - MORE LIKE AN ISOLATED
STRIKE OR TWO AT BEST.

THE BIGGER STORY MONDAY WILL BE THE MUCH COOLER THAN NORMAL
TEMPERATURES EXPECTED. 925 MB TEMPS OF ONLY ABOUT +10C AND 850 MB
TEMPS AT BEST A FEW DEGREES ABOVE 0C WILL ALLOW HIGHS TO ONLY
REACH THE LOW TO MID 60S...EVEN IF THE SUN CAN MAKE A BRIEF
APPEARANCE. RECORD LOW MAX TEMPS ARE 68 AT MSP...STC AND EAU AND
RECORD LOWS MONDAY NIGHT ARE MID TO UPPER 40S. THE RECORD LOWS MAY
BE A BIT OF A STRETCH...BUT THE COLD HIGHS SHOULD BE RELATIVELY
EASILY ATTAINABLE IF HIGHS ARE NOT REACHED AT 06Z MONDAY.

THE TROUGH WILL SLOWLY LIFT OUT FOR MID TO LATE WEEK...BUT THE
MOISTURE WILL EXIT AS EARLY AS MONDAY NIGHT. THEREFORE...EXPECTING
A MOSTLY CLEAR REST OF THE WEEK WITH SLOWLY MODERATING TEMPERATURES.
FOR MOST...THIS MAY BE CONSIDERED THE NICEST WEEK OF THE SUMMER
THUS FAR.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1045 PM CDT SAT JUL 12 2014

TWO ISSUES TO DEAL WITH OUT THE GATE WITH THE 06Z TAFS. THE FIRST
IS PATCHY FOG FORMING ACROSS SOUTHERN MN THROUGH WEST CENTRAL WI
WHERE WINDS HAVE BECOME QUITE LIGHT AHEAD OF AN APPROACHING COLD
FRONT ALONG WITH DEW POINTS HOLDING IN THE MIDDLE TO UPPER 60S.
THIS IS ON TOP OF THE RAIN THAT FELL TODAY. THIS AFFECTS
KRWF...KRNH AND KEAU. NOT TOO KEEN ON KMSP HAVING MVFR BR WITH A
BIGGER SPREAD BETWEEN THE TEMP AND DEW POINT (HEAT ISLAND). HAVE
INCLUDED MVFR CIGS AS WELL FOR KRNH AND KEAU FOR A FEW HOURS
BEFORE THE COLD FRONT MOVES THROUGH. THE AFOREMENTIONED FRONT WILL
PUSH THROUGH KAXN BY THE START OF THE PERIOD AND WORK IT WAYS TO A
POSITION SOUTH OF A KRWF TO KEAU LINE BY 12Z. WINDS WILL BRIEFLY
TURN DUE NORTH AND PERHAPS EVEN A LITTLE NORTHEAST BEHIND THE
FRONT BEFORE SETTLING BACK TO A NW DIRECTION. A FEW SHOWERS AND
ISOLATED THUNDERSTORMS ALONG THE FRONT CONTINUE TO WEAKEN...BUT A
FEW BOGEYS MAY MAKE IT INTO CENTRAL MN AND WEST CENTRAL WI DURING
THE EARLY MORNING HOURS. VCSH INCLUDED. VFR ON SUNDAY WITH
INCREASING NORTHWEST WINDS. SPEEDS 12-16 KNOTS FOR THE LATE
MORNING AND AFTERNOON ALONG WITH GUSTS UP TO 25 KNOTS.

KMSP...A COLD FRONT ACROSS NORTHERN MN WILL PASS THE AIRFIELD IN
THE 09Z-10Z TIME FRAME. A DRY PASSAGE FORECAST WITH BKN-OVC VFR
CLOUDS. SCT CLOUDS ON SUNDAY WITH BREEZY NORTHWEST WINDS
(16G23KTS) FOR THE AFTERNOON AND EARLY EVENING.

/OUTLOOK FOR KMSP/

MON...MVFR PSBL WITH CHC OF SHRA/TSRA. NW WINDS 15-30 KTS.
TUE...VFR. NW WINDS 10-15 KTS.
WED...VFR. NW WINDS 5-10 KTS.

&&

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

$$

SHORT TERM...TRH
LONG TERM...BORGHOFF
AVIATION...RAH






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