Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 030610
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
110 AM CDT FRI JUL 3 2015

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 317 PM CDT THU JUL 2 2015

EARLY AFTERNOON VISIBLE SATELLITE IMAGERY SHOWED ANOTHER MURKY SKY
ACROSS THE UPPER MIDWEST OWING TO THE FOREST FIRES OF WESTERN
CANADA. THE FILTERED SUNSHINE COUPLED WITH LIGHT WINDS RESULTED IN
COOL TEMPERATURES ACROSS THE REGION WITH AFTERNOON HIGHS EXPECTED TO
REMAIN IN THE 70S AT MOST LOCATIONS TODAY. A WEAK SURFACE TROUGH
ACROSS THE EASTERN DAKOTAS WILL BE THE FOCUS FOR A FEW AFTERNOON
THUNDERSTORMS...BUT THESE STORMS WILL REMAIN NORTHWEST OF THE
FORECAST AREA.

THE FORECAST IS DRY THROUGH MID DAY FRIDAY...UNTIL A FEW AFTERNOON
SHOWERS AND STORMS ARE AGAIN EXPECTED TO REDEVELOP ALONG A SAGGING
FRONTAL WEST/EAST ORIENTED FRONTAL BOUNDARY. THESE STORMS WILL BE
SCATTERED IN NATURE...SO ALTHOUGH CONFIDENCE IS FAIRLY HIGH IN THERE
EXISTENCE...THE AREAL COVERAGE WILL BE SUCH THAT ONLY HAVE 20-30
PERCENT CHANCE OF PRECIP AT ANY 3HR PERIOD FRIDAY AFTERNOON.
INSTABILITY WILL ONLY BE ON THE ORDER OF 500 TO 1000 J/KG...AND DEEP
LAYER SHEAR WILL ONLY BE AROUND 25 TO 30 KTS...SO NOT ANTICIPATING
SEVERE WEATHER WITH FRIDAYS STORMS.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 317 PM CDT THU JUL 2 2015

THE LONG TERM CONCERNS REMAIN BOUNDARY WHICH SAGS SOUTH INTO THE AREA
INTO THE 4TH AND THE COLD FRONTAL PASSAGE SUNDAY AFTERNOON INTO
MONDAY.

INITIALLY...THE FRIDAY BOUNDARY SAGS INTO THE AREA AND BECOMES
QUASISTATIONARY INTO SATURDAY.  WILL CONTINUE TREND OF SMALL CHANCE
POPS WITH THIS FEATURE AS IT MOVES INTO THE CWA FRIDAY NIGHT.  MAIN
QUESTION IS HOW QUICKLY IT WASHES OUT INTO SATURDAY.  VARIOUS MODELS
INDICATE MUCAPES AROUND 1500 J/KG IN THE VICINITY OF THE BOUNDARY
IN THE AFTERNOON. STILL CONCERNED THERE COULD BE ISOLATED
DEVELOPMENT WITH THIS FEATURE INTO THE AFTERNOON. WE INCLUDED AN
ISOLATED TRW MENTION FOR EASTERN AREAS THROUGH THE AFTERNOON.  BY
THAT TIME...WE SHOULD SEE ENOUGH RIDGING ALOFT TO HOLD DOWN MORE
WIDESPREAD ACTIVITY INTO THE EVENING. WILL HAVE TO CONTINUE TO
MONITOR THIS HOWEVER...WITH THE GFS STRONGEST IN OVERALL
PRECIPITATION COVERAGE LINGERING INTO SATURDAY NIGHT.

THEN FOCUS TURNS TO MORE WIDESPREAD ACTIVITY WITH THE COLD FROPA
SUNDAY NIGHT INTO MONDAY. APPEARS THE 12Z ECMWF HAS CAUGHT UP TO
THE GFS IN OVERALL MOVEMENT OF THE FRONT...NOT 6 HOURS SLOWER LIKE
PREVIOUS MODEL RUNS. THE FRONT MOVES ALONG THE MN/DAKOTAS BORDER
BY 00Z MON. THIS SHOULD BRING LIKELY POPS INTO THE LATE AFTERNOON
INTO THE FAR WEST. THEN GUIDANCE INDICATES CATEGORICAL/LIKELY
EVENT AS THE FRONT MOVES EAST DURING THE NIGHT. INSTABILITY IS
STRONGEST INTO THE LATE AFTERNOON/EVENING...WITH WARMING OUT AHEAD
OF THE FRONT SOME UPPER 80S LIKELY JUST AHEAD OF THE FRONT TO THE
WEST SUNDAY AFTERNOON. MUCAPES IN EXCESS OF 1500 J/KG ARE LIKELY.
AT THIS TIME...THE SEVERE WEATHER THREAT IS LOW...WITH THE BETTER
SHEAR LAGGING THE FRONT AND ANCHORED FARTHER NORTH WITH THE UPPER
JET. STILL HAVE SOME THREAT INTO THE EVENING ALONG THE FRONT WITH
MULTICELL ACTIVITY. EXPECT THE LINE TO WEAKEN AS IT MOVES EAST
DURING THE NIGHT. THE FRONT IS PROGGED TO BE NEAR KMSP BY 12Z
MONDAY WITH MAIN ACTIVITY/THREAT FOR REDEVELOPMENT MAINLY OVER THE
EASTERN PORTION OF THE CWA INTO MONDAY. SHOULD SEE ACTIVITY END IN
THE WESTERN AREAS FOR MONDAY AFTERNOON.

COOLER AND DRIER CONDITIONS MOVE INTO THE AREA THEREAFTER AS
CANADIAN HIGH PRESSURE DOMINATES THE WEATHER AT LEAST THROUGH THE
DAY WEDNESDAY.  MODELS DIVERGE ON TIMING OF NEXT FRONTAL SYSTEM.
THE GFS DRAGS ANOTHER FRONT THROUGH ON THURSDAY WITH THE ECMWF MORE
OF A SPLIT FLOW PATTERN WITH ENERGY TRAVELING TO THE SOUTH AND
WEAKENING TO THE NORTH. WILL MAINTAIN THE GFS TIMING OF SYSTEM FOR
NOW.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 109 AM CDT FRI JUL 3 2015

WEAK COLD FRONT DROPPING DOWN THIS AFTERNOON WILL PROVIDE ONLY
ISSUE FOR TAFS. EXPECT ISO/SCT TSRA TO DEVELOP AROUND 18-20Z IN
CENTRAL MN THAT WILL DRIFT SE TOWARD WRN WI INTO THE EVENING. AT
THIS POINT COVERAGE IS EXPECTED TO BE SPARSE ENOUGH THAT ANY
MENTION OF PRECIP HAS BEEN LEFT OUT OF TAFS. ONLY FIELD THAT YOU
CAN SAY FOR SURE NO PRECIP IS POSSIBLE AT THIS POINT IS RWF...BUT
CHANCES ARE PRETTY LOW EVERYWHERE ELSE AS WELL. WINDS WILL START
OF SWRLY THIS MORNING AND BACK TOWARD THE NW AS THE FRONT WORKS
INTO THE AREA.

KMSP...VFR CONDS WILL DOMINATE. MAY SEE SHRA/TSRA IN THE
AREA THIS AFTERNOON...BUT STILL EXPECT SCARCE COVERAGE...SO
CONTINUED TO LEAVE ANY PRECIP MENTION OUT. TIME PERIOD FOR SEEING
ANY ACTIVITY WOULD BE 23Z TO 03Z.

/OUTLOOK FOR KMSP/
SAT...VFR. WINDS SW 5-10 KTS.
SUN...VFR. TSRA WITH MVFR LIKELY OVERNIGHT. WINDS S 10-15 KTS.
MON...MVFR/IFR WITH TSRA EARLY. THEN VFR. WINDS NW 10 KTS.

&&

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

$$

SHORT TERM...JRB
LONG TERM...DWE
AVIATION...MPG


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