Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 012108
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
408 PM CDT WED OCT 1 2014

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 316 PM CDT WED OCT 1 2014

AFTERNOON ANALYSIS SHOWS A STACKED LOW OVER MANITOBA...WITH THE
ASSOCIATED BOUNDARY STRADDLING THE MN/DAKOTAS BORDER. THE FIRST
RELATED WAVE OF LIFT GENERATED A HEALTHY AREA OF SHOWERS THAT WILL
CONTINUE TO LIFT FROM EAST CENTRAL MN AND WEST CENTRAL WI TOWARD
LAKE SUPERIOR. IN ITS WAKE...RESIDUAL LOW LEVEL MOISTURE AND LIGHT
WINDS WILL CONTRIBUTE TO PESKY STRATUS AND FOG DEVELOPMENT TONIGHT
INTO THURSDAY. WILL NEED TO WATCH WEST CENTRAL WISCONSIN WHERE
CONDITIONS COULD LEAD TO DENSE FOG OVERNIGHT...PARTICULARLY NEAR EAU
CLAIRE.

ON THURSDAY...THE NEXT WAVE EJECTS NORTHEAST ACROSS THE AREA FROM
THE SOUTHERN STREAM SYSTEM. EXPECT ANOTHER ROUND OF RAIN WITH A FEW
THUNDERSTORMS TO BLOSSOM OVER SOUTH/EAST CENTRAL MN AND WEST CENTRAL
WI THURSDAY AFTERNOON. THE PRIMARY UNCERTAINTY IS HOW FAR WEST THE
PRECIPITATION SHIELD WILL EXTEND. HAVE LEANED TOWARD THE NAM/ECMWF
WHICH RESTRICT THE CATEGORICAL POPS EAST OF A REDWOOD FALLS TO ST
CLOUD MN LINE. HAVE INCLUDED 70-80 POPS ALONG AND EAST OF THE
INTERSTATE 35 CORRIDOR FOR THURSDAY AFTERNOON.

TEMPERATURES TONIGHT WILL HANG IN THE UPPER 40S TO MID 50S UNDER THE
EXTENSIVE CLOUD COVER...WITH LOW/MID 60S ANTICIPATED FOR THURSDAY.


.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 PM CDT WED OCT 1 2014

THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE LONG TERM FORECAST PICKS UP
DURING QUITE AN ACTIVE PERIOD OF WEATHER.  AN IMPRESSIVE FALL LOW
PRESSURE SYSTEM WILL BE COMING TOGETHER ACROSS THE MIDWEST BY
THURSDAY EVENING...AND WILL SPREAD MODERATE TO HEAVY RAIN AT TIMES
INTO SOUTHEASTERN MINNESOTA THROUGH WESTERN WISCONSIN.  AT THIS
TIME...AN UPPER LEVEL TROUGH THAT IS POSITIONED OVER THE FOUR
CORNERS REGION TODAY...WILL LIFT NORTHEAST AS IT BEGINS TO PHASE
WITH A DEEPLY AMPLIFIED NORTHERN TROUGH DROPPING SOUTHEAST FROM
ALBERTA THROUGH SASKATCHEWAN. STRONG FRONTOGENESIS...ACCOMPANIED BY
DECENT DIFFERENTIAL DIVERGENCE AND STRONG ISENTROPIC LIFT WILL BE
FOCUSED FROM A LINE NEAR FAIRMONT...THROUGH THE EAST METRO TOWARD
TAYLORS FALLS AND AREAS TO THE EAST.  THE SURFACE LOW WILL ADVANCE
NORTHEAST FROM MISSOURI TO NEAR GREEN BAY BY MIDNIGHT THURSDAY
NIGHT...AND WILL RAPIDLY DEEPEN OVERNIGHT THROUGH MUCH OF FRIDAY AS
THE NORTHERN AND SOUTHERN TROUGHS PHASE TOGETHER.  FOR MUCH OF
CENTRAL AND ESPECIALLY WESTERN MINNESOTA...FRIDAY WILL BE MOSTLY
DRY.  HOWEVER...THE DEEPENING SURFACE LOW WILL CREATE VERY WINDY
CONDITIONS AS A 1030MB SURFACE HIGH MOVE IN TO MONTANA...MEANING
QUITE A TIGHT PRESSURE GRADIENT IS EXPECTED ACROSS THE UPPER MIDWEST
THROUGH THE DAY.  THE CENTER OF THE UPPER TROUGH WILL BE OVERHEAD BY
MID DAY...AND STRONG COLD AIR ADVECTION WILL HOLD DAYTIME
TEMPERATURES ABOUT 20 DEGREES BELOW SEASONAL NORMALS.  COLD AIR
ADVECTION LOOKS STRONGER AT THIS POINT WITH 850H TEMPS OF -4 TO
-6...SO COOLED HIGH TEMPS FRIDAY BY ABOUT TWO TO THREE DEGREES
EVERYWHERE...MEANING MOST WILL SEE HIGHS IN THE 40S...WITH WIND
CHILL VALUES LOWER THAN THAT.  ON FRIDAY NIGHT...MODELS INDICATE AN
AREA OF DECENT THETA-E ADVECTION MOVING THROUGH ON THE BACKSIDE OF
THE SYSTEM WHICH MAY PRODUCE LIGHT PRECIP ACROSS THE EASTERN HALF OF
THE CWA.  TEMPERATURES LOOK TO BE COLD ENOUGH FOR MIXING IN SOME
SNOWFLAKES OVERNIGHT...ESPECIALLY ACROSS WESTERN WISCONSIN...BUT AT
THIS TIME NO ACCUMULATION IS EXPECTED.

SATURDAY THROUGH MONDAY...DURING THIS PERIOD...THE AFOREMENTIONED
FALL SYSTEM WILL ADVANCE NORTH TOWARD HUDSON BAY AND CONTINUE
DEEPENING INITIALLY.  MAINLY DRY CONDITIONS ARE IN THE FORECAST FOR
OUR AREA.  THE UPPER TROUGH WILL KEEP THE STRONG NORTHWEST WIND
FLOWING OVER OUR AREA DURING THIS TIME...MEANING QUITE A COLD
WEEKEND IS IN STORE.  EARLY SATURDAY MORNING...TEMPERATURES IN THE
30S WILL BE COMMON...WITH AREAS IN THE NORTHWEST POTENTIALLY
DROPPING BELOW FREEZING. FROM SUNDAY THROUGH MONDAY...THE STRONG
SYSTEM WILL RETROGRADE TO JUST SOUTHWEST OF THE HUDSON BAY AND
BECOME VERTICALLY STACKED.

MONDAY NIGHT THROUGH WEDNESDAY...THE WEAKENING SYSTEM WILL BEGIN
PUSHING EAST AND 850H TEMPS WILL BE ON THE RISE. TEMPERATURES ARE
EXPECTED TO RETURN TO THE 60S FOR HIGHS ON TUESDAY. DISAGREEMENT
REMAINS BETWEEN THE GFS/EC ABOUT THE UPPER PATTERN TOWARD THE MIDDLE
AND END OF NEXT WEEK...WHICH WILL DICTATE TEMPERATURES ACROSS THE
MIDWEST.


&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1158 AM CDT WED OCT 1 2014

THE TROUGH OVER NORTH DAKOTA THAT HAS FACILITATED A SOLID AREA OF  RAIN
SHOWERS OVER CENTRAL/EASTERN MN AND WESTERN WI ALONG WITH LIFR/IFR
CONDITIONS WILL LIFT NORTH ACROSS MANITOBA DURING THE TAF PERIOD.
PERIODIC WAVES OF SHORTWAVE ENERGY AND WEAK SURFACE TROUGHING WILL
MAINTAIN REDUCTIONS TO FLYING CONDITIONS THROUGH THE PERIOD. IN
THE WAKE OF THE SHOWERS THIS AFTERNOON...THE CONCERN WILL SHIFT TO
THE POTENTIAL FOR FOG DEVELOPMENT AND STRATUS THROUGH THE
OVERNIGHT HOURS. THE CIGS LOOK TO BE THE WORST FOR WEST CENTRAL WI
SITES...WHERE LIFR AND EVEN VLIFR CONDITIONS ARE EXPECTED TO
DEVELOP OVERNIGHT. CONDITIONS WILL BE SLIGHTLY LESS IMPACTFUL WITH
WESTWARD PROGRESSION TOWARD KAXN/KSTC/KRWF.

THE NEXT SLUG OF MOISTURE AND ROBUST LIFT ARRIVE ON THURSDAY
AFTERNOON AND EVENING...PRIMARILY AFFECTING KMSP/KRNH/KEAU...WITH
KSTC AND KRWF ON THE WESTERN FRINGES.

SOUTH-SOUTHEAST WINDS GRADUALLY VEER TONIGHT...WITH NORTHWEST
WINDS EXPECTED FOR THURSDAY. SPEEDS GENERALLY AROUND OR UNDER 6
KTS THROUGH THE PERIOD.

KMSP...
CIGS ARE ADMITTEDLY TRICKY FOR THIS AFTERNOON/EVE. EXPECT THE AREA OF
RAIN TO EXIT THE AIRPORT BY 20Z. THERE WILL BE THE POTENTIAL FOR
SCT BREAKS IN THE SUB-1000FT DECK THIS AFTERNOON...BUT OVERALL
CIGS SHOULD REMAIN BELOW 1700 FT THROUGH 22Z. WILL THEN HAVE A
WINDOW OF TIME UNTIL 02Z WHEN CIGS COULD IMPROVE TO OVC020...BUT
THEN SHOULD DROP BACK TO AROUND 1500FT AROUND/AFTER SUNSET AND
REMAIN IFR OVERNIGHT. FOG IS EXPECTED TO DEVELOP OVERNIGHT...WITH
POCKETS OF 1/2SM VSBYS NEAR THE AIRPORT. NOT CONFIDENT IF KMSP
WILL GO THAT LOW DIRECTLY AT THE SITE...SO WILL STICK WITH 1SM
PREVAILING FOR NOW.

/OUTLOOK FOR KMSP/

FRI...MAINLY MVFR WITH CHC -SHRA. WINDS WNW 20G30 KTS.
SAT...VFR. WINDS NW 10-15 KTS.
SUN...VFR. WINDS NW 10 KTS.


&&

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

$$

SHORT TERM...LS
LONG TERM...SPD
AVIATION...LS






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