National Weather Service Raw Text Product

751 
FXUS63 KMPX 020914
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
414 AM CDT TUE SEP 2 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT TUE SEP 2 2014

A COOL AND DRY DAY IS EXPECTED ACROSS EASTERN MN AND WESTERN WI WITH 
ISOLATED SHOWERS THIS MORNING MOVING EAST AND OUT OF THE FORECAST 
AREA WITH TIME.

VAD WIND PROFILES FROM KABR...TO KMSP...TO ARX ARE ALL SHOWING 
NORTHWEST FLOW FROM 2-10KFT THIS MORNING. THERE IS ONGOING WEAK 
LOW-LEVEL COLD ADVECTION THIS MORNING WHICH SHOULD KEEP HIGH TEMPS 
TODAY SLIGHTLY COOLER THAN YESTERDAY EVEN WITH EXPECTED AFTERNOON 
SUNSHINE. THE HIGH CLOUDS THIS MORNING ARE THE REMNANTS OF A COMPLEX 
OF THUNDERSTORMS THAT DEVELOPED IN SD/NE LAST EVENING. THE CLOUDS 
ARE THINNING WITH TIME WITH NO NEW UPDRAFTS AND ARE ALSO MOVING 
EAST AT GOOD CLIP /35-40KTS/. SO...THE CLOUDS SHOULD BE OUT OF THE 
PICTURE QUICKLY THIS MORNING. PLEASANT TEMPERATURE-DEWPOINT 
COMBINATION TODAY IS TYPICAL FOR EARLY SEPTEMBER WITH 70S OVER 50S. 
THERE IS GOOD COVERAGE IN LIGHT SHOWERS ACROSS FAR SOUTHERN MN AND 
IN NORTH CENTRAL IA EARLY THIS MORNING TIED TO PV ADVECTION AND THE 
UPPER JET OVER IA. THE VORTICITY ADVECTON WILL ALSO QUICKLY MOVE 
EAST OF THE FORECAST AREA THIS MORNING. THE LIGHTNING HAS REALLY 
DROPPED OFF...WITH JUST A COUPLE STRIKES IN IA WHERE THERE ARE STILL 
MUCAPE VALUES BETWEEN 500-1000J/KG. THE NORTHWEST FLOW WILL BE SHORT 
LIVED...HOWEVER...WITH THE LOW LEVEL FLOW TURNING BACK TO THE 
SOUTHWEST BY 12Z WEDNESDAY ACROSS WESTERN MN. THE WARM ADVECTION HAS 
THE POTENTIAL TO GENERATE ISOLATED TO SCATTERED WEAK THUNDERSTORMS 
LATE TONIGHT ACROSS THE WESTERN FORECAST AREA.   

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 410 AM CDT TUE SEP 2 2014

WARM AND HUMID WEATHER IN THE MIDDLE OF THE WEEK WILL GIVE WAY TO A 
COOL CRISP FALL AIRMASS FOR THE WEEKEND. TEMPERATURES WILL RUN FROM 
ROUGHLY 5 TO 10 DEGREES ABOVE NORMAL ON WEDNESDAY...TO 5 DEGREES 
BELOW NORMAL OVER THE WEEKEND.

EARLY MORNING WATER VAPOR IMAGERY WITH GFS 02.00 500MB HEIGHTS AND 
WINDS IDENTIFIED A VIGOUROUS SHORTWAVE CRAWLING DOWN THE BRITISH 
COLUMBIA COAST. OVER THE NEXT 36 HOURS THIS PV ANOMALY WILL
TRANSITION EASTWARD ALONG THE INTERNATIONAL BORDER AND CAUSE A
SURFACE LOW TO DEVELOP OVER THE HIGH PLAINS...WITH THE WARM SECTOR
OVERSPREADING THE UPPER MIDWEST DURING THE DAY ON WEDNESDAY. A
SURFACE WARM FRONT WILL LIFT NORTHWARD...AND BOUNDARY LAYER
DEWPOINTS OF NEAR 70F WILL BECOME WIDESPREAD ACROSS SOUTHERN MN BY
WEDNESDAY EVENING.

PRECIP CHANCES WILL FOLLOW THIS WARM FRONT...BUT BY WEDNESDAY 
AFTERNOON BUFR SOUNDINGS SHOW A STOUT CAP DEVELOPING ACROSS SOUTHERN 
MN...SO HAVE BROKE POP GRIDS INTO 3HR BLOCKS TO BETTER DEPICT THE 
TIMING AND LOCATION OF EXPECTED CONVECTION. THE 02.00 WRFARW AND 
WRFNMM HAVE PRECIP FOCUSED NORTH OF THE WARM FRONT...SO FEEL 
COMFORTABLE SHAVING OFF POPS FROM SOUTH TO NORTH THROUGHOUT THE DAY 
ON WEDNESDAY. LATE WEDNESDAY EVENING THE BOUNDARY LAYER WILL 
DECOUPLE AND SHOULD SEE AN MCS DEVELOP ON THE NOSE OF THE LOW LEVEL 
JET ACROSS CENTRAL MN WHICH SHOULD SHIFT EAST SOUTHEAST OVERNIGHT.
VEERING WINDS IN THE EFFECTIVE LAYER WILL SUPPORT ORGANIZED
CONVECTION SO SUSPECT TO SEE A FEW STRONG/SEVERE STORMS...WITH THE
BEST CHANCES ALONG AND NORTH OF I-94.

THIS CONVECTION WILL EXIT THE REGION BY THURSDAY MORNING...AND
WILL SEE TEMPERATURES SURGE ACROSS SOUTHEASTERN MN AND WESTERN
WI AHEAD OF A COLD FRONT THAT IS FORECAST TO PASS THROUGH THE
REGION DURING THE DAY ON THURSDAY. FORECAST SOUNDINGS SHOW AN
EXTREMELY UNSTABLE ENVIRONMENT BY LATE AFTERNOON ACROSS
WISCONSIN...SO COULD SEE ANOTHER ROUND OF SEVERE STORMS IF THE
SURFACE CONVERGENCE ALONG THE FRONT IS ENOUGH TO BREAK THROUGH THE
CAP.

IN THE WAKE OF THIS FRONT IS A MUCH COOLER...DRIER AIRMASS. LOW 
TEMPERATURES THURSDAY NIGHT WILL FALL INTO THE 40S ACROSS THE 
NORTHWEST CWA. NORTHWEST FLOW AND SURFACE HIGH PRESSURE SUPPORT DRY 
WEATHER THROUGH THE WEEKEND. 

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1050 PM CDT MON SEP 1 2014

ISOLATED SHOWERS AND THUNDERSTORMS WILL WORK THEIR WAY EASTWARD
ACROSS CENTRAL/SOUTHERN MN AND WEST CENTRAL WI OVERNIGHT AND
TUESDAY MORNING. DUE TO THE NATURE OF THE PRECIPITATION ONLY VCSH
WAS USED. A CONCERN FOR THE OVERNIGHT IS THE POTENTIAL FOR FOG TO
DEVELOP...ESPECIALLY ACROSS WEST CENTRAL WI INCLUDING KRNH AND
KEAU. THE LIMITING FACTOR IS HOW FAST MID/HIGH LEVEL CLOUDINESS
INCREASES AFTER MIDNIGHT. CONFIDENCE IS LOW SO KEPT THE MENTION
OUT FOR NOW. LIGHT WINDS OVERNIGHT WILL INCREASE TO 10-14 KNOTS BY
LATE TUESDAY MORNING FROM THE WSW. WINDS WILL DIMINISH ONCE AGAIN
TUESDAY EVENING. 

KMSP...ONLY EXPECT ISOLATED SHRA/TSRA DURING THE OVERNIGHT HOURS
(08Z-12Z) WITH A MORE SOLID AREA OF PRECIPITATION PASSING ACROSS
IA AND FAR SOUTHERN MN. VFR THROUGH THE PERIOD. 

/OUTLOOK FOR KMSP/

WED...VFR. CHC MVFR/TSRA. WINDS S 10-15 KTS.
THU...VFR. CHC MVFR/TSRA LATE. WINDS S 10-15 KTS BCMG W LATE.
FRI...VFR. WINDS NW 10 KNOTS.


&&

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

$$

SHORT TERM...CLF
LONG TERM...JRB
AVIATION...RAH