Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 080522 AAA
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1222 AM CDT TUE JUL 8 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 154 PM CDT MON JUL 7 2014

STORMS HAVE STARTED TO INTENSITY ACROSS THE AREA... AND THAT TREND
SHOULD PERSIST THROUGH THE REMAINDER OF THE AFTERNOON INTO EARLY
THIS EVENING WITH MLCAPE AOA 1500 J/KG OVER MUCH OF THE AREA.
ACTIVITY HAS MAINLY BEEN FOCUSED ALONG THE NORTHERN PERIPHERY OF THE
INSTABILITY GRADIENT WHERE THE SURFACE TROUGH IS LOCATED... BUT
EXPECT TO SEE ADDITIONAL STORMS FIRE OVER MUCH OF WEST CENTRAL INTO
CENTRAL MINNESOTA AS THE SHORTWAVE OVER NORTH DAKOTA WORKS INTO THE
AREA AND HELPS DRIVE THE COLD FRONT EASTWARD. SPC MESOANALYSIS SHOWS
EFFECTIVE DEEP LAYER SHEAR OF 30 TO 40 KT... SUPPORTING THE
POTENTIAL FOR SOME ORGANIZATION... AND A FEW OF THE STRONGER STORMS
HAVE SHOWN SOME WEAK ROTATION. CAM SOLUTIONS... INCLUDING LOCAL
MPXWRF... HOPWRF... AND HRRR... SHOW A SIMILAR STORY THROUGH THE
AFTERNOON WITH THE INITIAL CLUSTER OF STORMS WE/RE SEEING NOW
FOLLOWED BY AN ADDITIONAL CLUSTER AROUND AND AFTER 21Z AS THE BETTER
FORCING WORKS INTO THE AREA. HOPWRF MEMBERS 1 AND 3 HAVE BEEN
SOMEWHAT BULLISH ON THE POTENTIAL FOR A FEW STRONGER STORMS PER
THEIR MAX UPDRAFT HELICITY FORECASTS THROUGH THIS EVENING... AND
NEIGHBORHOOD PROBABILITIES FOR UH GREATER THAN 50 SUGGESTS GREATEST
POTENTIAL FOR STRONG/SEVERE STORMS WILL GENERALLY BE FROM AROUND THE
MINNESOTA RIVER VALLEY NORTH THROUGH THE I-94 CORRIDOR BETWEEN 3 PM
AND 7 PM. MAIN CONCERN WILL BE LARGE HAIL AND LOCALLY STRONG WINDS.
MORE WIDESPREAD STRONG WINDS COULD BE AN ISSUE IF COLD POOLS CAN
ORGANIZE AND THINGS GROW UPSCALE. A FEW OF THE CAM SOLUTIONS SHOWED
UPSCALE GROWTH BY EARLY EVENING... BUT MOST LOOK TO KEEP THINGS
FAIRLY DISCRETE. LOW LEVEL SHEAR IS FORECAST TO INCREASE AS THE
SURFACE FRONT AND UPPER WAVE MOVE INTO THE AREA... WHICH COULD HELP
INCREASE THE TORNADO POTENTIAL SOME... ALTHOUGH AT THIS POINT IT
WOULD APPEAR TO BE AN ISOLATED CONCERN. DRIER AND COOLER AIR WORK IN
BEHIND THE FRONT OVERNIGHT... AND MOST OF THE AREA SHOULD SEE DRY
WEATHER ON TUESDAY. HOWEVER... SOME DIURNAL PCPN IS POSSIBLE OVER
THE EASTERN PORTION OF THE AREA ON TUESDAY WITH THE MID-LEVEL
THERMAL TROUGH OVER THE REGION.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 314 PM CDT MON JUL 7 2014

NORTHWEST FLOW AND COLD ADVECTION WILL BE ONGOING TUESDAY NIGHT
INTO WEDNESDAY MORNING. THE COLDEST POCKET OF 850MB AIR WILL BE
CENTERED NEAR AND NORTH OF LAKE SUPERIOR...BUT TEMPS WILL STILL
RANGE BETWEEN 8C AND 11C...ABOUT 5C-7C DEGREES COOLER THAN WHERE
WE ARE THIS AFTERNOON. DRIER AND COOLER WEATHER IS EXPECTED FOR
THE FORECAST AREA TUESDAY NIGHT THROUGH THURSDAY...RESULTING FROM
THE UPPER TROUGH GRADUALLY SHIFTING EAST WITH MN/WI REMAINING IN
NORTHERLY FLOW. THE UPPER RIDGING EVENTUALLY BUILDING INTO THE AREA
BY 00Z FRIDAY...WITH 925-850MB MOISTURE TRANSPORT ALSO ON THE
INCREASE THURSDAY NIGHT WITH THE LLJ. THE WEATHER REMAINS MORE
ACTIVE INTO THE WEEKEND AS A RESULT OF VERY GOOD MOISTURE
RETURN...CHARACTERIZED BY PRECIPITABLE WATER NEAR 1.5" OFF THE
GFS. ANOTHER UPPER TROUGH IS PROGGED TO DROP SOUTH OUT OF CANADA INTO
OUR REGION. SOME OF THE DETAILS WILL NEED TO WORKED OUT OVER THE
NEXT SEVERE...BUT CERTAINLY FROM LATE THURSDAY NIGHT THROUGH
SUNDAY THERE COULD BE OFF AND ON SHOWERS AND THUNDERSTORMS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1205 AM CDT TUE JUL 8 2014

VFR CONDITIONS EXPECTED IN MOST PLACES FOR THE NEXT 24 HORUS...BUT
A TOUGH NIGHT POTENTIALLY FOR EAU WHERE CIGS HAVE FALLEN ABRUPTLY
TO 200 FT IN THE LAST HOUR. IN THE RELATIVELY LIGHT WIND REGIME
AND A SATURATED ENVIRONMENT IMMEDIATELY BEHIND THE COLD
FRONT...CERTAINLY CAN SEE LOW CLOUDS AND FOG DEVELOP DURING THE
EARLY OVERNIGHT ACROSS WESTERN WISCONSIN. THINK WITH THE STRONGER
WINDS JUST ABOVE THE SURFACE AND THE LACK OF COMPLETELY CALM WINDS
AT THE SURFACE SHOULD BE MAINLY A LOW CLOUD ISSUE. HOWEVER...SINCE
CIGS WILL POSSIBLY BE IN THE LIFR RANGE...LOW CLOUD VS FOG IS
RATHER IRRELEVANT. WILL NEED TO WATCH TRENDS FOR THE NEXT FEW
HOURS. BY LATE TONIGHT...WINDS WILL BEGIN TO STRENGTHEN AND THIS
MAY LEAD TO SOME IMPROVEMENT TOWARD DAWN.

KMSP...VFR CONDITIONS EXPECTED. MAIN ISSUE WILL BE WEST/NORTHWEST
WINDS INCREASING TUESDAY MORNING. WILL LIKELY SEE GUSTS IN THE
25-30 KT RANGE BY AFTERNOON BEFORE SUBSIDING NEAR SUNSET.

/OUTLOOK FOR KMSP/
WED...VFR. WEST WIND LESS THAN 5 KT.
THU...VFR. SOUTH WIND 5 TO 10 KT.
FRI...MVFR CONDITIONS POSSIBLE WITH A CHANCE OF SHRA/TSRA. SOUTH
WIND 5 TO 10 KT.

&&

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

$$

SHORT TERM...
LONG TERM...CLF
AVIATION...BORGHOFF





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