Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 301942
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
242 PM CDT WED JUL 30 2014

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 234 PM CDT WED JUL 30 2014

TONIGHT AND THURSDAY...SURFACE ANALYSIS CONTINUES TO SHOW EXTENSIVE
HIGH PRESSURE OVER MUCH OF THE NORTH-CENTRAL STATES. ALOFT...THE
PATTERN CONTINUES TO BE A TROUGH EAST...RIDGE WEST...WITH NORTHWEST
FLOW OVER CENTRAL NORTH AMERICA. WATER VAPOR IMAGERY SHOWS A SWATH
OF MOISTURE ROUNDING THE WESTERN FRINGES OF THE EASTERN TROUGH...
AROUND A DEVELOPING CUTOFF LOW WITHIN THE CENTER OF THE TROUGH OVER
ONTARIO. AS THIS MOISTURE DROPS SOUTH INTO NORTHERN MINNESOTA AND
LAKE SUPERIOR...ADDITIONAL CLOUD COVER CAN BE EXPECTED OVER WESTERN
WISCONSIN AND FAR EASTERN MINNESOTA THROUGH THE REST OF THE
AFTERNOON AND EARLY EVENING HOURS. GOING FURTHER WEST INTO
MINNESOTA...ASIDE FROM DIURNAL POP-UP MID-LEVEL CUMULUS CLOUDS... NO
SIGNIFICANT WEATHER IS EXPECTED. HOWEVER...FOR WESTERN WISCONSIN...
THIS ADDITIONAL MOISTURE IS IN RESPONSE TO ANOTHER WEAK SHORTWAVE
DISTURBANCE ALOFT. SIMILAR TO YESTERDAY...THIS DISTURBANCE WILL AID
IN ISOLATED SHOWER/THUNDERSTORM DEVELOPMENT FOR PORTIONS OF WESTERN
WISCONSIN. THE SHORTWAVE FOR TODAY IS NOT AS IMPRESSIVE AS THE ONE
EXPERIENCED YESTERDAY...THEREFORE AM EXPECTING LESSER COVERAGE AND
INTENSITY OF ANY STORMS THAT DO FORM. ANY AND ALL ACTIVITY IS
EXPECTED TO DISSIPATE BY SUNSET...ALLOWING FOR CLEAR SKIES
OVERNIGHT. A SIMILAR STORY IS THEN EXPECTED FOR TOMORROW AS YET
ANOTHER WEAK DISTURBANCE ALOFT COMBINED WITH THE HEATING OF THE DAY
WILL MAKE FOR ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS OVER
WESTERN WISCONSIN. AS FOR TEMPERATURES...MORE OF THE SAME IS
EXPECTED WITH NO CHANGE IN AIRMASS. HIGHS ON THURSDAY WILL BE
SIMILAR TO TODAY...REACHING THE UPPER 70S TO LOWER 80S. LOWS TONIGHT
WILL BE SIMILAR TO WHAT WAS RECORDED EARLY THIS MORNING...AGAIN
DROPPING TO THE MIDDLE 50S TO AROUND 60.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 234 PM CDT WED JUL 30 2014

THE LONGER TERM OUTLOOK HASN/T CHANGED MUCH WITH THINGS STILL
LOOKING TO BECOME MORE ACTIVE AS WE HEAD INTO NEXT WEEK. THE
EASTERN UPPER TROUGH LOOKS TO LIFT NORTHWARD AS THE WESTERN RIDGE
FLATTENS SOME WHILE EXPANDING EASTWARD OVER TIME. OF CONCERN WITH
RESPECT TO ACTIVE WEATHER... PARTICULARLY HEAVY RAIN POTENTIAL...
IS A CUTOFF UPPER LOW BENEATH THE UPPER RIDGE WHICH IS PROGGED BY
BOTH THE ECMWF AND GFS TO SLIDE NORTHEAST/EAST INTO OUR AREA
DURING THE FIRST PART OF THE WEEK. THIS FEATURE LOOKS TO BE
ACCOMPANIED BY SOME MONSOONAL MOISTURE... WHICH HELPS TO BOOST
PRECIPITABLE WATER VALUES OVER THE REGION THAT WILL ALREADY BE
INCREASING SOMEWHAT IN SITU FROM LOCAL/REGIONAL
EVAPOTRANSPIRATION. THE MAIN TIME FRAME OF CONCERN LOOKS TO BE
FROM LATER MONDAY THROUGH LATE WEDNESDAY AS THE BAROCLINIC ZONE
LOITERS IN THE AREA WITH THE SURFACE TROUGH POSITIONED TO OUR
WEST. THE GFS AND ECMWF SHOW THE POTENTIAL FOR SEVERAL ROUNDS OF
PCPN/CONVECTION DURING THAT TIME FRAME... AND PRODUCE COPIOUS
RAINFALL IN OUR GENERAL VICINITY... RANGING FROM 2 TO AS MUCH AS 6
INCHES OR SO. THE LOCATION AND TIMING OF EACH ROUND OF PCPN IS
HIGHLY QUESTIONABLE AT THIS TIME... AND IT/S POSSIBLE THE HEAVIEST
ACTIVITY COULD BE JUST TO OUR NORTH OR SOUTH. BUT... THE OVERALL
PATTERN IS LOOKING MORE FAVORABLE FOR SOME HEAVY RAINFALL IN THE
REGION... WITH CONFIDENCE INCREASING A BIT WITH EACH SUCCESSIVE
SERIES OF DETERMINISTIC AND ENSEMBLE GUIDANCE. PRIOR TO THAT...
WE/LL HAVE SOME OCCASIONAL CHANCES FOR SCATTERED LIGHTER PCPN AS
SHORTWAVES CRUISE THROUGH THE AREA IN THE LINGERING NORTHWEST FLOW
AND WE MAINTAIN SUFFICIENT LAPSE RATES FOR SOME SHRA AND ISOLATED
TS ACTIVITY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1233 PM CDT WED JUL 30 2014

NO CONCERNS AT MN TAF SITES...BOTH FROM A FOG AND PRECIP
STANDPOINT. MIDLVL CU CLOUDS WILL FILL IN THE SKIES THE REST OF
THE AFTN HOURS...THEN SKIES CLEAR OUT OVERNIGHT...FOLLOWED AGAIN
BY LATE MRNG MIDLVL CU CLOUDS ON THU. NW WINDS 5-10 KT THIS AFTN
DROP TO NEAR CALM OVERNIGHT THEN RESUME FROM THE NW IN THE 5-10 KT
RANGE TMRW.

WI TAF SITES WILL AGAIN BE SUBJECT TO PASSING -SHRA...AND POSSIBLY
ISOLD TSTMS...LATER THIS AFTN INTO THE EARLY EVE HRS. COVERAGE IS
NOT XPCTD TO BE AS MUCH AS YDA...BUT HAVING A STRAY SHWR/TSTM
DRIFT OVER THE TERMINAL CANNOT BE RULED OUT. NO CONFIDENT ENOUGH
AT TSTM DEVELOPMENT SO HAVE OMITTED CB/TS MENTION...BUT IT MAY BE
NEEDED LATER IN AN AMD. IN ADDITION...KEAU LOOKS TO AGAIN
POTENTIALLY HAVE PRE-DAWN FOG DEVELOPMENT. CONFIDENCE NOT HIGH
ENOUGH TO DROP CONDS DOWN TO IFR-OR-WORSE ATTM BUT DID INDICATE
THE POTENTIAL BY DROPPING VSBY INTO LOW-END MVFR.

KMSP...VFR CONDS XPCTD THROUGHOUT THIS SET WITH NO PRECIP XPCTD.
MIDLVL CU WILL AGAIN DEVELOP...LASTING THRU MID-EVENING BEFORE
DISSIPATING FOR OVERNIGHT. ADDITIONAL MIDLVL CU LAT TMRW MRNG.

/OUTLOOK FOR KMSP/
FRI...VFR. WINDS NW 5 KTS.
SAT...VFR. WINDS N 5 KTS.
SUN...MAINLY VFR. SLGT CHC OF MVFR IN SHWRS/TSTMS. WINDS SW 5-10
KTS.


&&

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

$$

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





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