Area Forecast Discussion
Issued by NWS Twin Cities, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KMPX 260832
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
332 AM CDT SUN JUL 26 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CDT SUN JUL 26 2015

THE MAIN SHORT TERM CONCERN IS THE POTENTIAL FOR DIURNALLY DRIVEN
SHOWER AND THUNDERSTORM DEVELOPMENT TODAY.

THE AREA OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO TRACK
EASTWARD ACROSS THE SOUTHERN THIRD OF MINNESOTA EARLY THIS
MORNING. IN THE WAKE OF SAID ACTIVITY...HI-RES MODELS SHOW
700 MB TEMPS/HEIGHTS BUILDING ACROSS SOUTHWEST MN...WITH AN H7
TEMP CIRCA +11C OR GREATER DEVELOPING GENERALLY ALONG AND
WEST/SOUTH OF THE MN RIVER VALLEY BY 18Z. THE MAJORITY OF CAMS
MODELS INDICATE SPOTTY CONVECTION DEVELOPING THIS AFTERNOON ALONG
THE EASTERN PERIPHERY OF THIS CAPPING INVERSION. WHILE THERE IS
NOT ANY SORT OF WELL-DEFINED FOCUSING MECHANISM TO SPARK SHOWERS
AND THUNDERSTORMS OTHER THAN THE INSTABILITY THAT IS PROGGED TO
DEVELOP WITH SFC DEWPOINTS IN THE 70S AND FAINT MIDLEVEL ENERGY
OVERHEAD...FEEL A 20 POP IS WARRANTED.

ANY CONVECTION WOULD COME TO AN END AROUND SUNSET...WITH A MUGGY
SUMMER NIGHT AHEAD...AS LOW TEMPS HOLD UP IN THE UPPER 60S TO
LOWER 70S WITH DEWPOINTS NOT TOO FAR BELOW THAT.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 333 AM CDT SUN JUL 26 2015

THE EXTENDED PERIOD CAN BE CHARACTERIZED AS HOT/HUMID AND UNSETTLED
AT THE BEGINNING...THEN TURNING COOLER AND DRIER BY THE END OF THE
WEEK.

AN ABNORMALLY STRONG UPPER LOW IS FORECAST TO DEEPEN AND MOVE ACROSS
THE NORTHERN ROCKIES AND EASTWARD ALONG THE CANADIAN BORDER FROM THE
NORTHERN PLAINS AND UPPER MIDWEST BY WEDNESDAY.

AHEAD OF THIS SYSTEM...SOUTHERLY FLOW WILL KEEP CONDS VERY
WARM AND HUMID WITH HEAT INDICES BOTH MONDAY/TUESDAY AFTN IN THE
MID TO UPPER 90S. I WOULD NOT BE SURPRISED IF THE URBAN AREA OF THE
TWIN CITIES METRO AREA WOULD GET A HEAT ADVISORY FOR BOTH MONDAY AND
TUESDAY BASED ON THESE CONDS. THE ONLY QUESTION IS WHETHER MORE
CLOUD COVER WILL INHIBIT FULL SUNSHINE AND LOWER AFTN HIGHS.

THERE IS ENOUGH INSTABILITY AND A STRONG SW FLOW ALOFT AHEAD OF THE
UPPER LOW MONDAY TO WARRANT ISOLD TSRA IN EC MN/WC WI...ESPECIALLY
CONSIDERING MID LEVEL LAPSE RATES ARND 7.0 TO 7.5C.

THE MAIN FOCUS FOR ACTIVE WX AND THE POTENTIAL OF SVR WX WILL BEGIN
LATE MONDAY NIGHT AS MOISTURE ADVECTION...ALONG THE INCREASING LLJ
SURGES NORTHWARD ACROSS THE UPPER MIDWEST. HEIGHT FALLS WITH THE
UPPER LOW AND A STRENGTHENING SFC LOW IN THE DAKOTAS SHOULD WARRANT
THIS SIGNIFICANT LLJ AND ASSOCIATED MOISTURE ADVECTION. THIS WILL
LEAD TO A BROAD AREA OF CONVECTION DEVELOPING NEAR MPX CWA. STEEP
LAPSE RATES/AMPLE INSTABILITY ALONG THE STRONG LLJ SHOULD BE ENOUGH
TO WARRANT SVR POTENTIAL. AT THIS TIME...SPC IS NOT HIGHLIGHTING
OUR REGION...WITH MAINLY A MARGINAL RISK OF SVR WX. A BETTER CHC OF
SVR WX IS LIKELY TUESDAY AFTN AHEAD OF THE COLD FRONT. THE PROBLEM
WITH TUESDAY IS A VERY STRONG CAP DEVELOPING DURING THE DAYTIME WITH
70H TEMPS RISING TO NEAR 14C. IT MAYBE LATE IN THE EVENING BEFORE
THIS CAP BEGINS TO BREAK WHICH LEADS TO MORE SVR WX SE OF MPX CWA.
THE MAIN PVA ASSOCIATED WITH THE UPPER LOW IS NOT FORECAST TO MOVE
INTO MN UNTIL AFT TUESDAY EVENING. SO...THE STRONG CAP COULD
PRECLUDE AN ACTIVE TUESDAY EVENING IN MN...AND THE MAIN FOCUS IN
WI/IA DURING THE LATE EVENING ONCE THE CAP BREAKS.

PAST TUESDAY NIGHT...THE ABNORMALLY STRONG UPPER LOW WILL MOVE NORTH
OF THE GREAT LAKES...BRING DRIER WX AND COOLER TEMPS FOR THE SECOND
HALF OF THE WORK WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1159 PM CDT SAT JUL 25 2015

MUCH OF THE THUNDERSTORM ACTIVITY IS SOUTHWEST OF RWF...WITH A
LARGE AREA OF LIGHT TO MODERATE RAIN EXTENDING NORTHEAST ACROSS
THE MN RIVER INTO CENTRAL MN. THIS AREA WILL DROP SOUTHEAST
OVERNIGHT...LIKELY ERODING ON THE NORTHERN EDGE SOMEWHAT AS IT
DOES SO. REGARDLESS...VFR CONDITIONS EXPECTED THROUGH THE PERIOD.

KMSP...IT APPEARS MSP SHOULD SEE A PERIOD OF LIGHT RAIN LATE
TONIGHT...BUT VFR CONDITIONS EXPECTED TO PREVAIL AND AMOUNTS WILL
BE A FEW HUNDREDTHS OR LESS.

/OUTLOOK FOR KMSP/
MON...VFR. CHC OF TSRA LATE. WINDS SE 5-10 KTS.
TUE...MAINLY VFR. CHC MVFR/IFR IN TSRA. WINDS S 10-15 KTS.
WED...VFR. WINDS W 15-20 KTS.


&&

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

$$

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



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.