Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 131722
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1222 PM CDT SUN JUL 13 2014

.UPDATE...
ISSUED AT 1214 PM CDT SUN JUL 13 2014

UPDATED TO INCLUDE 18Z AVIATION DISCUSSION BELOW.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 250 AM CDT SUN JUL 13 2014

SFC ANALYSIS SHOWS A CDFNT STEADILY SAGGING SWD THRU CENTRAL MN
AND NWRN WI...AS EVIDENCED BY WINDS SHARPLY SHIFTING TO THE NW
WITH THE FROPA AND WINDS STILL WSW IN ADVANCE OF THE CDFNT.
TEMPS/DEWPOINTS ALSO DROP OFF NOTICEABLY BEHIND THE CDFNT... AND
THIS CDFNT WILL CONTINUE TO STEADILY DROP SEWD AS THE DAY
PROGRESSES. VERY LITTLE PRECIP TO SPEAK OF WITH THIS
FRONT...MAINLY JUST A OF KDLH THIS MRNG...BUT THERE ARE SOME AREAS
OF FOG OVER SRN MN INTO W-CENTRAL WI BUT THIS WILL DISSIPATE
SHORTLY AFTER SUNRISE AND AM NOT LOOKING FOR IT TO GO DENSE WITH
WINDS WILL CLOSE TO 5 MPH THRU DAYBREAK. AS THE FRONT EXITS...VERY
LITTLE CLOUD COVER WILL BE LEFT IN ITS WAKE...ALLOWING FOR MOCLR
SKIES TDA. THE COOLER AND DRIER AIR ASSOCIATED WITH THIS FRONT
WILL SLOWLY INVADE FROM THE N BUT AM NOT LOOKING FOR THE TRUE CAA
TO COMMENCE UNTIL LATE TONIGHT INTO EARLY SUNDAY MRNG. HIGHS WILL
STILL GENERALLY RANGE THROUGH THE MID 70S TDA...THOUGH SOME SPOTS
IN FAR NRN PORTIONS OF THE MPX CWFA MAY HOLD IN THE LWR 70S. LATER
THIS EVE AND TNGT IS WHEN THE COLDER AIR WILL MAKE ITS MOVE INTO
THE AREA AS H85 TEMPS DROP INTO THE SINGLE DIGITS. THIS WILL
TRANSLATE TO LOW TEMPS TNGT HITTING THE LOW-MID 50S.
HOWEVER...THERE WILL BE A POST-FRONTAL TROF IN ADVANCE OF THE
LARGE UPR LVL LOW PRES CENTER DROPPING INTO THE GRT LKS FROM
CENTRAL CANADA TNGT INTO EARLY MON. THIS TROF WILL BE THE LEADING
EDGE FOR A BATCH OF SHOWERS MOVING IN FROM THE N. THOUGH MUCH OF
THE MPX CWFA WILL REMAIN DRY THRU TMRW MRNG...A TIER OR TWO IN NRN
PORTIONS OF THE CWFA MAY BE SUSCEPTIBLE TO SOME RAIN SHWRS SO HAVE
INCLUDED 20-30 POPS OVERNIGHT TO ACCOUNT FOR THIS. THE OTHER ISSUE
WITH THE FROPA WILL BE AN INCRS IN WIND SPEEDS...MAINLY THIS AFTN
AND EVE WITH A TIGHTER PRES GRADIENT POST-FRONT...BUT NOTHING
EXCESSIVE.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 250 AM CDT SUN JUL 13 2014

THE WELL ADVERTISED COOL DOWN FOR MONDAY AND TUESDAY STILL LOOKS
ON TRACK...SO DIDN`T CHANGE THE PREVIOUSLY ISSUED FORECAST ALL
THAT MUCH. THE TEMPERATURES ON MONDAY WILL BE DICTATED BY STRONG
COLD ADVECTION AND THE ASSOCIATED CLOUDS/SHOWERS. IN THESE
STRONG ADVECTION CASES...IT IS OFTEN DIFFICULT TO IMPROVE UPON
/OR BEAT/ CONSENSUS MODEL GUIDANCE IF THERE IS A TIGHT CLUSTERING
OF TEMPERATURE OUTPUT AMONG MULTIPLE MODELING SYSTEMS...WHICH
THERE IS IN THIS CASE. IN GENERAL...MODEL FORECAST HIGHS RANGE
BETWEEN 59-68 ACROSS THE FORECAST AREA...INCLUDING THE TWIN
CITIES/ST.CLOUD/EAU CLAIRE. OUR FORECAST HIGHS ON MONDAY ARE NEAR
THE MEDIAN OF THE AVAILABLE GUIDANCE. THIS WOULD STILL PUT US
UNDER THE RECORD LOW MAX TEMP OF 68 AT MSP...STC AND EAU FOR JULY
14. COINCIDENTALLY...JULY 14 /IN 1936/...IS THE HOTTEST DAY ON
RECORD FOR MUCH OF MINNESOTA...INCLUDING 108 IN THE TWIN CITIES
AND 111 AT EAU CLAIRE. THE ST. CLOUD RECORD IS ACTUALLY JULY 13
WHERE IN 1936 IT REACHED 107 DEGREES. SO...WE`LL BE ABOUT 50
DEGREES SHY OF THOSE VALUES ON MONDAY AND ABOUT 20 DEGREES BELOW
NORMAL. IN FACT...IT WILL FEEL EVEN COOLER WITH THE CLOUD
COVER...SCATTERED SHOWERS AND BREEZY NORTHWEST WINDS THAT SHOULD
GUST BETWEEN 25 AND 35 MPH IN MOST LOCATIONS. THE COLD ADVECTION
OF 850MB TEMPS SUGGESTS WE WILL HAVE NO PROBLEM BRINGING DOWN THE
WINDS NEAR THE TOP OF THE MIXED LAYER.

BEYOND MONDAY...TUESDAY THROUGH FRIDAY LOOKS DRY IN TERMS OF
BOTH PRECIP AND HUMIDITY WITH SLOWLY WARMING TEMPERATURES. RETURN
FLOW STARTS TO DEVELOP FOR THE WEEKEND...BUT 925-850MB FLOW IS
REALLY DIRECTED MORE TOWARD NE/SD/ND. THE 13.00Z OPERATIONAL RUNS
AND PREVIOUS ENSEMBLES REALLY WANT TO HOLD THE THERMAL RIDGE BACK
TO OUR WEST UNTIL AT LEAST SUNDAY. PRECIP CHANCES IN THE EXTENDED
ARE TIED TO THE WARM/MOISTURE ADVECTION EXPECTED NEXT WEEKEND.
IGNORE THE SPURIOUS LIGHT QPF GENERATED NEAR THE LOCAL AREA THIS
WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1214 PM CDT SUN JUL 13 2014

THINGS WILL BE RELATIVELY QUIET AVIATION-WISE THROUGH THE
PERIOD... ALTHOUGH THERE WILL CERTAINLY BE MORE IN THE WAY OF
CONCERNS ON MONDAY IN COMPARISON TO TODAY. THE DEEP UPPER LEVEL
TROUGH OVER CENTRAL CANADA WILL CONTINUE ITS JOURNEY SOUTHWARD
OVER THE UPCOMING 24 HOURS... AND AS THE UPPER COLD POOL MOVES
INTO THE AREA LATE TONIGHT THROUGH MONDAY WE/LL SEE CLOUD COVER
BECOME BKN-OVC WITH SCATTERED SHRA. GIVEN EXPECTED LAPSE RATES AND
EXPLICIT MODEL OUTPUT WE SHOULD SEE A DECENT COVERAGE OF SHRA ON
MONDAY. HOWEVER... AT THIS POINT CHOSE TO JUST USE VCSH THROUGH
MOST OF THE DAY RATHER THAN BLANKETING A LONG PERIOD OF TIME WITH
A TEMPO GROUP... SINCE WE/LL CERTAINLY HAVE PERIODS OF DRY WEATHER
INTERSPERSED WITH THE PCPN CHANCES. CEILINGS SHOULD BE VFR... BUT
WEST-NORTHWEST WINDS WILL GUST ABV 20KT DURING THE DEEPER MIXING
OVER THE COURSE OF THE LATE MORNING INTO THE AFTERNOON HOURS.

KMSP...TAF REFLECTS OVERALL EXPECTATIONS WITH GOOD CONFIDENCE IN
THE GENERAL TREND OF THINGS. CEILINGS COULD WIND UP BEING A BIT
LOWER AT TIMES ON MONDAY... BUT SHOULD REMAIN VFR. IN ADDITION...
BRIEF MVFR VISIBILITIES ARE POSSIBLE DURING HEAVIER SHOWERS... BUT
TOO DIFFICULT TO TRY AND PIN THAT TIMING/OCCURRENCE DOWN AT THIS POINT.

/OUTLOOK FOR KMSP/
MONDAY NIGHT...BRIEF MVFR POSSIBLE WITH A CHANCE OF SHRA.
NORTHWEST WIND 5 TO 15 KT.
TUESDAY...VFR. NORTHWEST WIND 5 TO 10 KT.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...VFR. VARIABLE WIND LESS THAN 5
KT.
THURSDAY...VFR. SOUTHWEST WIND 5 TO 10 KT.

&&

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

$$

UPDATE...
SHORT TERM...JPC
LONG TERM...CLF
AVIATION...






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