Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 281826
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
126 PM CDT SUN JUN 28 2015

.UPDATE...FOR 18Z AVIATION DISCUSSION BELOW

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 404 AM CDT SUN JUN 28 2015

TODAY AND TONIGHT...SFC ANALYSIS SHOWS A LOW PRES CENTER CROSSING
FROM ERN SD INTO SWRN MN EARLY THIS MRNG WITH A TRAILING CDFNT
EXTENDING TO THE SW. A WEAK WMFNT LOOKS TO PRECEDE THE SFC LOW...
BUT ASIDE FROM CONTRIBUTING MODEST ASCENT TO THE SWATH OF
SHWRS/TSTMS SHIFTING FROM ERN MN INTO WRN WI...THE WMFNT IS OF
LITTLE CONSEQUENCE...PARTICULARLY WITH RESPECT TO TEMPERATURES.
THE SFC LOW IS EXPECTED TO SLOWLY MEANDER TO THE ESE THRU THE
DAY... RELOCATING ITSELF TO NEAR KRST THIS AFTN THEN CONTINUE INTO
N- CENTRAL IL OVERNIGHT. IN CONCERT WITH THIS SFC LOW...AN H5 OPEN
SHTWV TROF AND AN H7 CUTOFF LOW WILL DROP SE FROM NRN MN INTO SWRN
WI THRU THE DAY TDA...THEN CONTINUE MOVG TWD LAKE MICHIGAN TNGT.
THE SLOW PROGRESSION OF THE LOW PRES FEATURES...BOTH AT THE SFC
AND ALOFT...WILL MAINTAIN LOW-MID LVL CONVERGENCE ALONG WITH BROAD
DIVERGENCE ALOFT. PLENTY OF RESIDUAL MOISTURE /PWATS ARND 1.25
INCHES/ INVOF THESE FEATURES WILL ALLOW FOR RE-DEVELOPMENT OF
SHWRS/TSTMS LATER THIS MRNG THRU THIS AFTN FOR MAINLY ERN PORTIONS
OF THE WFO MPX CWFA. THIS FOCUS AREA IS IN CONJUNCTION WITH THE
LOW PRES FEATURES...SO HAVE MAINTAINED LIKELY POPS FOR WRN WI INTO
FAR ERN MN...WITH POPS TRENDING DOWN SHARPLY GOING W OF I-35. THE
LACK OF INSOLATION DUE TO ONGOING ACTIVITY...MITIGATING STRONG
INSTABILITY...ALONG WITH THE LACK OF APPRECIABLE SHEAR WILL
PREVENT DEVELOPMENT OF SEVERE WX SO AM NOT EXPECTING AS SUCH.
HOWEVER...AN ISOLD STRONG STORM WITH GUSTY WINDS/HVY RAIN/SMALL
HAIL CANNOT BE RULED OUT. AS THE LOW PRES FEATURES SHIFT AWAY TO
THE SE LATER TDA INTO TNGT...ANY SHWR/TSTM ACTIVITY WILL ALSO
SHIFT AWAY FROM THE REGION...GRADUALLY ALLOWING PRECIP TO DIMINISH
OVER THE COVERAGE AREA.

AS FOR TEMPERATURES...CLOUD/RAIN COMPLICATIONS OVER THE ERN
PORTION OF THE CWFA WILL MAKE FOR THAT PORTION SEEING THE
COOLEST TEMPS. MEANWHILE...THE EXIT OF THE LOW PRES FEATURES WILL
ALLOW FOR PLENTY OF SUNSHINE ALONG THE DAKOTA BORDERS. WILL LOOK
FOR HIGHS TO RANGE FROM THE MID-70S IN WRN WI TO THE LWR 80S IN
WRN MN.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 404 AM CDT SUN JUN 28 2015

THE THEME OF THE LONG TERM PERIOD IS THE PERSISTENT NORTHWEST FLOW
WE WILL EXPERIENCE AS THE STRONG RIDGE ACROSS THE WESTERN CONUS
LOOKS TO REMAIN IN PLACE FOR THE FORESEEABLE FUTURE. WITH THIS
SETUP...A COUPLE SHORTWAVES IN THE UPPER FLOW WILL PUSH ACROSS OUR
AREA DURING THE LONG TERM FORECAST PERIOD AND OFFER CHANCES FOR
MORE THUNDERSTORMS.

PICKING UP THE FORECAST ON MONDAY...OUR FIRST SHORTWAVE OF THE
LONG TERM PERIOD WILL BE ADVANCING SOUTH THROUGH MANITOBA. A
STRENGTHENING JET STREAK FROM MANITOBA THROUGH THE DAKOTAS WILL
AID IN UPPER LEVEL DIVERGENCE ACROSS MINNESOTA AND WESTERN WI.
THIS AND THE PV ADVECTION THAT WILL MOVE THROUGH WITH THE
SHORTWAVE WILL PROVIDE LIFT...AND DAYTIME HEATING WILL HELP
DESTABILIZE THE ATMOSPHERE...SO EXPECT FAIRLY WIDESPREAD
THUNDERSTORM ACTIVITY BY THE AFTERNOON...WHICH WILL LIKELY FADE
OVERNIGHT.

THE NEXT WAVE WILL PUSH INTO OUR REGION TUESDAY NIGHT...BUT
APPEARS TO BE A SLIGHTLY SLOWER AT THIS TIME. LOW LEVEL WARM
ADVECTION WILL PUSH INTO WESTERN MN LATE IN THE NIGHT WITH SHOWERS
PUSHING IN FROM THE DAKOTAS. INSTABILITY LOOKS VERY LIMITED...SO
THUNDER WILL LIKELY BE ISOLATED. ANOTHER SIMILAR WAVE WILL BE ON
ITS HEELS WEDNESDAY NIGHT...WITH ADDITIONAL THUNDERSTORM CHANCES.

LOOKING AHEAD TO THE WEEKEND...FRIDAY AND SUNDAY BOTH OFFER MORE
THUNDERSTORM CHANCES...AND THE GFS/ECMWF BOTH INDICATE A DRY
INDEPENDENCE DAY. HIGH TEMPERATURES THROUGH THE PERIOD WILL VARY
FROM THE MID 70S TO MID 80S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 126 PM CDT SUN JUN 28 2015

MVFR CLOUDS AND SHOWER/THUNDERSTORM POTENTIAL ARE THE PRIMARY
CONCERNS THIS TAF PERIOD...WITH THE SECONDARY BEING THE POTENTIAL
FOR FOG DEVELOPMENT OVERNIGHT.

THE CU FIELD WILL CONTINUE TO BECOME MORE EXTENSIVE ACROSS THE
AREA...WITH SHOWERS AND THUNDERSTORMS BECOMING MORE NUMEROUS AS
CONVECTIVE TEMPS ARE REACHED /MID 70S/. AT LEAST WIDELY SCATTERED
ACTIVITY WILL BE POSSIBLE AT ALL SITES...EXCEPT KAXN AND KRWF
WHICH SHOULD BE FAR ENOUGH WEST. ATTENDANT MVFR VSBY/CIG
REDUCTIONS WILL OCCUR.

ELSEWHERE...BKN-OVC CIGS AROUND 3KFT-4KFT SHOULD
PREVAIL...ALTHOUGH SCT-BKN CIGS AS LOW AS 2.5KFT WILL LINGER THIS
AFTERNOON.

SHOWERS AND THUNDERSTORMS DIMINISH THROUGH THE EVENING
HOURS...WITH FOG BECOMING A CONCERN. WILL LARGELY DEPEND ON THE
EXTENT OF RAINFALL TODAY. HAVE INCLUDED A MENTION AT WI SITES
WHERE THE PROBABILITY OF RAINFALL AND AN OVERALL BETTER FOG
SCENARIO EXISTS.

ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED ON MONDAY.
THESE STORMS WILL HAVE THE POTENTIAL OF HAIL AND GUSTY WINDS.

KMSP...
SCATTERED SHOWER AND ISOLD THUNDERSTORM ACTIVITY SHOULD BLOSSOM
BETWEEN 19Z AND 20Z...PERSISTING INTO EARLY EVE. MVFR CIGS/VSBYS
WILL BE POSSIBLE WITH THE ACTIVITY. COULD SEE SOME BR DEVELOPMENT
OVERNIGHT...BUT NEED TO SEE HOW THIS AFTERNOON PANS OUT BEFORE
CONFIDENCE IS HIGH ENOUGH TO INCLUDE.

/OUTLOOK FOR KMSP/
TUE...VFR. WINDS NE 5-10 KTS.
WED...VFR WITH MVFR -TSRA POSSIBLE. WINDS E 5-10 KTS.
THU...VFR WITH MVFR -TSRA POSSIBLE. WINDS SE 5-10 KTS.

&&

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

$$

SHORT TERM...JPC
LONG TERM...SPD
AVIATION...LS


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