Area Forecast Discussion
Issued by NWS Twin Cities, MN

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 102349
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
649 PM CDT THU JUL 10 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 325 PM CDT THU JUL 10 2014

MAIN CONCERN FOR THE SHORT TERM IS TURNING OUT TO BE THE POTENTIAL
FOR HEAVY RAIN TONIGHT OVER WESTERN MN BASED ON LATEST HI-RES CAMS.

THIS AFTERNOON...SRLY LOW LEVEL WINDS HAVE BECOME WELL ESTABLISHED
AS HIGH PRESSURE HAS NOW PUSHED OFF TO MICHIGAN. THESE SRLY WINDS
HAVE FINALLY BROUGHT THE CANADIAN SMOKE PLUME THAT WAS LINGERING
JUST TO OUR SW THE PAST COUPLE OF DAYS UP INTO CENTRAL AND SRN
MN...HENCE THE MILKY COLOR IN THE SKY AND OCCASIONAL HAZE REPORTS
ACROSS THE AREA THIS AFTERNOON. BACK TO THE WEST...A SHORT WAVE CAN
BE SEEN APPROACHING WRN MN...THOUGH THIS HAS DONE NOTHING MORE THAN
CREATE MAINLY VIRGA...AND THIS IS EXPECTED TO BE THE CASE AS IT
WORKS ACROSS MN THIS EVENING. INSTEAD...THE MAIN WAVE DRIVING THE
WEATHER ACROSS THE NRN PLAINS IS THE CUT-OFF H5 LOW CURRENTLY
SPINNING FROM ALBERTA INTO SASKATCHEWAN. THIS WAVE IS WHAT IS
FORCING THE LLJ TO BE BACK MORE ACROSS CENTRAL INTO THE ERN DAKOTAS
TODAY.

FOR THIS AFTERNOON INTO TONIGHT...FAVORED THE FORECAST FOR POPS AND
QPF TOWARD THE RAP/ECMWF ALONG WITH JUST ABOUT ANY HI-RES CAM YOU
CAN FIND THAT WAS RUN AT 12Z OR LATER. ALL OF THESE MODELS SHOW
THUNDERSTORMS DEVELOPING OVER NE SODAK AROUND 21/22Z AND SLOWLY
WORKING EAST INTO WRN MN THIS EVENING. ALL HI-RES MODELS SHOW 2-4
INCHES OF RAIN FALLING IN THE GENERALLY VCNTY OF THE NE SODAK/WRN MN
BORDER. LOOKING AT THE RAP...THIS LOOKS TO BE TIED TO WHAT IS
HAPPENING IN THE 925-850MB LAYER. THE RAP HAS BEEN PRETTY CONSISTENT
WITH SHOWING MOISTURE TRANSPORT IN THIS LAYER INCREASING THIS
AFTERNOON ACROSS SE SODAK...WITH THE EDGE OF IT UP INTO NE SODAK. IN
ADDITION TO THAT...THE RAP SHOWS A STRONG FGEN SIGNAL AT THE NOSE OF
THIS LLJ. THE REASON FOR THE HEAVY PRECIP SIGNAL IS THIS LLJ AND ITS
ASSOCIATED FGEN REMAIN MORE OR LESS STATIONARY OUT NEAR THE MN/SD
BORDER THROUGH ABOUT 6Z. WITH THIS FORCING REMAINING
STATIONARY...THERE WILL BE A PERIOD THROUGH ABOUT 6Z WHERE THE
ACTIVITY CAN TRAIN OUT THERE...BEFORE EVERYTHING STARTS TO BECOME
MORE PROGRESSIVE LATE TONIGHT AS THE CANADIAN UPPER LOW MOVES TOWARD
MANITOBA. QPF GRIDS USED WERE A BLEND OF THE SHORT TERM CAMS
TEMPERED WITH THE 12Z ECMWF. THIS RESULTED IN 1-2 INCHES OF QPF
THROUGH FRI MORNING OUT IN WRN MN...WHICH MAY STILL BE CONSERVATIVE
CONSIDERING SOME OF THE HI-RES MODELS HAVE BEEN SHOWING THE
POTENTIAL FOR ISOLATED RAINFALL AMOUNTS OVER 5 INCHES TONIGHT...SO
THIS IS SOMETHING THAT CERTAINLY BEARS SOME WATCHING.

THROUGH THE REST OF THE SHORT TERM...THE LLJ AND SFC FRONT WILL
SLOWLY WORK EAST WITH TIME DURING THE MORNING ON FRIDAY...WITH BEST
RAINFALL CHANCES FOR ERN MN/WRN WI LIKELY COMING DURING THE MORNING
AS REMNANTS OF TONIGHTS ACTIVITY SHIFTS EAST. BACKED OFF SOME ON
POPS FRIDAY AFTERNOON...AS CAMS ARE FAIRLY SPARSE WITH ACTIVITY AS
WE LOOSE THE DEFINITION ON THE SFC FRONT...WHICH WILL COINCIDE WITH
A WEAKENING OF THE LLJ AS WE GET INTO SUBSIDENCE ASSOCIATED WITH THE
RIGHT ENTRANCE REGION OF THE UPPER JET WORKING ACROSS THE
INTERNATIONAL BORDER. WITH LESS ACTIVITY  EXPECTED...ALSO BOOSTED
TEMPS A FEW DEGREES OUT IN WRN WI AS IT IS NOT LOOKING AS LIKELY FOR
FRIDAY TO BE DOMINATED BY CLOUDS AND RAIN AS WAS PREVIOUSLY
ANTICIPATED.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 325 PM CDT THU JUL 10 2014

AS WE PROGRESS THROUGH THE SATURDAY-THURSDAY PERIOD WE/LL SEE QUITE
THE EVOLUTION OF LARGE SCALE FEATURES AND WEATHER ACROSS THE AREA.
THINGS WILL START OUT WARM WITH THE UPPER JET NORTH OF THE AREA...
BUT AN UNSEASONABLY DEEP UPPER LOW WILL DROP SOUTH/EAST FROM CENTRAL
CANADA INTO THE UPPER MIDWEST AND GREAT LAKES REGION DURING THE
SUNDAY NIGHT THROUGH TUESDAY PERIOD. THIS WILL BRING VERY COOL
TEMPERATURES TO MUCH OF THE REGION... WITH THE HEART OF THE COLD AIR
TRACKING ACROSS MINNESOTA AND POINTS EAST. SOME PCPN CHANCES WILL
LOITER ACROSS THE REGION SATURDAY INTO SUNDAY PRIOR TO THE ARRIVAL
OF THE COLD FRONT AND UPPER TROUGH... WITH DIURNAL CHANCES FOR PCPN
AFTER THAT AS THE UPPER COLD POOL SWINGS ACROSS THE REGION. BEST
CHANCES FOR PCPN PRIOR TO FROPA WILL BE ACROSS THE SOUTHERN PORTIONS
OF THE AREA WHERE THE BAROCLINIC ZONE AND BEST INSTABILITY ARE
PROGGED... WITH CHANCES FOR DIURNAL SHRA FOLLOWING FROPA LOCATED
OVER EASTERN AREAS WHERE BOUNDARY LAYER CYCLONIC FLOW WILL BE MOST
PREVALENT AND LOW-MID LEVEL LAPSE RATES WILL BE STEEPEST BENEATH THE
MID-UPPER LEVEL COLD POOL. WE WILL SEE RIDGING BEGIN TO WORK INTO
THE AREA AFTER TUESDAY... WITH DRY WEATHER AND MODERATING
TEMPERATURES FOR THE LAST FEW DAYS OF THE FORECAST PERIOD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 649 PM CDT THU JUL 10 2014

INSTABILITY CONTINUES TO INCREASE ALONG AND WEST OF THE DAKOTAS/MN
BORDER EARLY THIS EVENING AS A SHORT WAVE MOVES INTO THE CENTRAL
DAKOTAS. SHOWERS ARE INCREASING IN COVERAGE AND INTENSITY OVER
EASTERN SOUTH DAKOTA. THIS SHOULD LEAD TO THUNDERSTORMS BECOMING
LIKELY EARLY THIS EVENING FOR KAXN AND DURING THE LATE EVENING FOR
KRWF. IT WILL PROBABLY BE CLOSER TO MIDNIGHT BEFORE THUNDER
REACHES KSTC. SHORT TERM GUIDANCE POINTS TO THE ACTIVITY REACHING
THE TWIN CITIES BEFORE DAYBREAK WITH WEAKENING AS IT PUSHES ACROSS
WEST CENTRAL WI. HOWEVER...MORE DEVELOPMENT IS SHOWN ACROSS EASTERN
MN LATER IN THE MORNING. AN UNSETTLED PERIOD FOR SURE. MAINLY VFR
BUT BOUTS OF MVFR OR LOWER ARE CERTAINLY LIKELY IN THE HEAVIER
STORMS. CONCERN IS ALSO INCREASING FOR MVFR CEILINGS DEVELOPING
FRIDAY AFTERNOON FROM KSTC AND KMSP ON EAST IN THE MOIST
SOUTHERLY FLOW AHEAD OF AN APPROACHING COLD FRONT IN THE EASTERN
DAKOTAS. CONFIDENCE IS NOT HIGH AT THIS TIME WITH BKN-OVC050
INSERTED. SOUTHERLY WINDS (170-210) NEAR 10 KNOTS THROUGH THE
PERIOD.

KMSP...SOME SPRINKLES ARE CERTAINLY POSSIBLE LATER THIS EVENING
WITH MORE ROBUST SHOWERS AND THUNDERSTORMS EXPECTED IN THE 08Z-12Z
TIME FRAME. SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL LIKELY
LINGER THROUGH THE MORNING. A FEW SHOWERS AND THUNDERSTORMS ARE
POSSIBLE FRIDAY EVENING AHEAD OF AN APPROACHING COLD FRONT.

/OUTLOOK FOR KMSP/

SAT...VFR WITH MVFR/SHRA/TSRA POSSIBLE. WIND NW AT 5 KTS.
SUN...VFR WITH MVFR/SHRA/TSRA POSSIBLE. WINDS W AT 5-10 KTS.
MON...VFR WITH MVFR CIGS/SHRA POSSIBLE. WIND NW AT 10-20 KTS.

&&

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

$$

SHORT TERM...MPG
LONG TERM...TRH
AVIATION...BORGHOFF




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