Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 240454
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1154 PM CDT WED JUL 23 2014

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 309 PM CDT WED JUL 23 2014

NEAR NORMAL TEMPERATURES AND A MOSTLY DRY FORECAST IS STILL EXPECTED
IN THE SHORT TERM WITH THE EXCEPTION OF THUNDERSTORM POTENTIAL
FROM WEST CENTRAL TO SOUTH CENTRAL MN TOMORROW MORNING.

THE REGIONAL RADAR SCOPE IS QUIET THIS AFTERNOON WITH ALL THE
CONVECTIVE ACTIVITY EITHER TIED TO THE COLD FRONT ACROSS THE
EASTERN GREAT LAKES...OHIO RIVER VALLEY AND MID MISSISSIPPI RIVER OR
ON THE EAST SIDE OF THE UPPER RIDGE EMBEDDED IN THE ANTICYCLONICALLY
ROTATING MOISTURE PLUME AND THICKNESS DIFFLUENCE IN KS AND NE.  THE
SURFACE HIGH IS BUILDING ACROSS THE AREA THIS AFTERNOON...BUT THIS
HIGH SHOULD WEAKEN AND SLIDE EAST TONIGHT. THE LLJ QUICKLY
STRENGTHENS THIS EVENING OVER THE HIGH PLAINS AND THE RESULT WILL BE
THETA-E ADVECTION INTO THE EASTERN DAKOTAS AND FAR WESTERN MN BY
SUNRISE TOMORROW MORNING. THE 23.12Z NAM/GFS/GEM AND MOST OF THE
AVAILABLE CAM GUIDANCE FROM LAST NIGHT AND THIS MORNING WANT TO
DRIVE ANY CONVECTION THAT FORMS ON THE NOSE OF THE LLJ SOUTH WITH
TIME AND WEAKEN THE ACTIVITY BEFORE IT PENETRATES TOO FAR INTO
MINNESOTA. THIS WOULD MEAN MOST OF THE AREA WOULD REMAIN DRY
TOMORROW /AT LEAST DURING THE DAYLIGHT HOURS/. THE 23.00Z ECMWF WAS A
BIT OF AN OUTLIER WITH THE WESTERN EXTENT OF THE PRECIP DURING THE
DAY TOMORROW...THE 23.12Z IS A LITTLE SLOWER THAN ITS 00Z
COUNTERPART BUT IT WOULD STILL SUGGEST CHANCE-TO-LIKELY POPS IN WEST
CENTRAL MN BETWEEN 18-00Z.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 309 PM CDT WED JUL 23 2014

THE MAIN THEME FOR THE EXTENDED PERIOD IS A CHG FROM AN UNSETTLED
PATTERN AT THE BEGINNING...TO A MORE LATE SUMMER TYPE PATTERN
WITH DRIER AND COOLER THAN NORMAL WX SCENARIO BY NEXT WEEK.

THURSDAY NIGHT/EARLY FRIDAY MORNING WILL REMAIN PROBLEMATIC IN
TERMS OF WHERE THE NOCTURNAL LLJ WILL DEVELOP AND VEER DURING THE
MORNING HRS...WHICH WILL TRANSLATE TO HIGHER POPS AND QPF AMTS IN
THE REGION. CURRENT MODELS INDICATE THAT THE NOSE OF THE LLJ WILL
DEVELOP SOMEWHERE IN SOUTHERN MN/NORTHERN IA THURSDAY
EVENING...WITH WINDS VEERING MORE W/WSW BY FRIDAY
MORNING...CHANGING THE MAXIMUM CONVERGENCE IN THE LOW LEVELS
ACROSS IA BY FRIDAY MORNING. BEST CHC/S OF RAINFALL WILL OCCUR
DURING THIS TIME FRAME...ESPECIALLY WHERE THE BEST CONVERGENCE
ALONG THIS LLJ REMAINS.

AFT FRIDAY MORNING...A SFC TROUGH WILL MOVE ACROSS MN/WESTERN WI
LEADING TO SOME AFTN/EVENING SHRA/TSRA. BEST CHC/S WILL OCCUR LATE
SATURDAY/SUNDAY AS THE MAIN UPPER LOW THAT IS CURRENTLY MOVING
INTO THE PACIFIC NW THIS AFTN...MOVES ALONG THE CANADIAN BORDER
TRACKING SOME UPPER LEVEL ENERGY EASTWARD ALONG THIS FAST MOVING
WEST TO EAST FLOW ALOFT FRI/SAT.

ONCE THIS FEATURE ALONG THE CANADIAN BORDER MOVES EAST OF MN AND
BEGINS TO DIG SOUTH/SE ACROSS THE EASTERN U.S. OUR WX WILL TURN
COOLER THAN NORMAL. IN ADDITION...N/NW FLOW ALOFT WILL MEAN A
DRIER PATTERN WITH MOST OF THE ACTION ALONG THE GULF COAST STATES
AND EASTERN U.S.

THIS TRANSITION TO A COOLER PATTERN WILL LIKELY CONTINUE THRU THE
BEGINNING OF AUGUST AS A STRONG UPPER RIDGE ANOMALY IS CURRENTLY
ADVERTISE IN THE EXTENDED MODELS BUILDING OFF THE EASTERN COAST OF
THE U.S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1141 PM CDT WED JUL 23 2014

FEW PROBLEMS EXPECTED IN THE NEAR TERM AS HIGH PRESSURE MAINTAINS
CONTROL OF THE WEATHER ACROSS THE UPPER MIDWEST THROUGH THE
MORNING HOURS. THE ONLY ISSUE MAY BE FOG DEVELOPMENT IN THE PRONE
AREAS ESPECIALLY TO THE EAST WHERE WINDS WILL BE LIGHTER TOWARD
DAYBREAK. OTHERWISE...SHOWERS WILL BE APPROACHING WESTERN
MINNESOTA IN THE MORNING AFTER A STRONG LLJ DEVELOPS OVERNIGHT
ACROSS THE DAKOTAS. STILL EXPECT THESE SHOWERS TO BE DIMINISHING
SO NOT CONFIDENT IN ACTUALLY SEEING RAIN AT A SPECIFIC LOCATION
SUCH AS RWF...SO REMOVED THE CHANCE THERE. THEN...A MORE ROBUST
CHANCE OF PRECIPITATION COMES LATE THURSDAY NIGHT WHICH IS
INDICATED AT MSP AND RWF. MSP MAINLY BECAUSE OF THE EXTRA 6 HOUR
WINDOW. LIGHT WINDS TONIGHT WILL CONTINUE TURNING EAST AND NEARLY
SOUTH THROUGH TOMORROW.

KMSP...MAIN FOCUS WILL BE THE THUNDERSTORMS EXPECTED IN THE
OVERNIGHT PERIOD THURSDAY INTO FRIDAY. OTHERWISE VFR CONDITIONS
EXPECTED WITH LITTLE CHANGES FROM THE PREVIOUS FORECAST.

/OUTLOOK FOR KMSP/
THU NIGHT...VFR. CHANCE MVFR CONDS W/ TSRA OVERNIGHT. WINDS SE AT
10KTS.
FRI...VFR. CHANCE TSRA. WINDS SSE AT 5-10KTS.
SAT...VFR. WINDS W AT 10KTS.

&&

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

$$

SHORT TERM...CLF
LONG TERM...JLT
AVIATION...SPD





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