Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 292119
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
419 PM CDT MON SEP 29 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 420 PM CDT MON SEP 29 2014

SHORT TERM CONCERNS ARE THE EXTENT OF CLEARING OVERNIGHT AND THREAT
OF LOW CLOUDS AND FOG OR PATCHY FROST DEVELOPING LATE.  THEN TIMING
OF INCOMING TROUGH AND ASSOCIATED AREAS OF RAIN AND THUNDER MAINLY
DURING THE AFTERNOON OUT WEST.

SOME BREAKS IN THE OVERCAST AND DRYING TREND MAINLY ACROSS NORTHWEST
MN AND PORTIONS OF WEST CENTRAL WISCONSIN.  NORTHEAST FLOW CONTINUES
TO DRAW MOISTURE IN FROM THE GREAT LAKES/  WILL HAVE TO MONITOR THIS
TREND INTO THE EVENING.  THERE MAY LEFTOVER CLOUD COVER ACROSS MUCH
OF THE WESTERN CWA INTO THE NIGHT.  THE FAR EAST MAY CLEAR
SOMEWHAT...AND IF IT DOES...THERE REMAINS A THREAT OF LOWER STRATUS
DEVELOPMENT AFTER MIDNIGHT.  FOG MAY BE A PROBLEM AS WELL...BUT MAY
NOT DEVELOP LOWER VSBYS.  AIR IS COLD ENOUGH FOR SOME FROST
POTENTIAL IN THE FAR NORTHEAST PORTION OF THE CWA...BUT CONFIDENCE ON
ANYTHING WIDESPREAD NOT HIGH ENOUGH TO INCLUDE FOR NOW.

NEXT TROUGH IS PROGGED TO MOVE FROM THE FOUR CORNERS AREA AT THIS
TIME TO THE DAKOTAS BY TUESDAY EVENING.  SYSTEM APPEAR QUITE STRONG
ON SATELLITE WATER VAPOR IMAGERY WITH SIG DRYING AT THE BASE OF THE
TROUGH. THIS LIFTS NORTHEAST AND BECOMES NEGATIVELY TILTED INTO
SOUTHEAST SOUTH DAKOTA BY 00Z WED.  SHOULD SEE DECENT RESPONSE WITH
INCREASING MOISTURE/INSTABILITY OVER THE SOUTHWEST PORTION OF THE
CWA TUESDAY AFTERNOON.  THUNDER THREAT INCREASES SOUTHWEST INTO
AFTERNOON AS WELL WITH STEEPENING LAPSE RATES AND BEST LI`S
INCREASING TO AROUND MINUS 4.  BEST SEVERE THREAT REMAINS TO THE
SOUTHWEST OF THE CWA.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 420 PM CDT MON SEP 29 2014

SEVERAL BOUTS OF PRECIPITATION ARE EXPECTED DURING THE LONG TERM
PORTION OF THE FORECAST...AS A LARGE SCALE MID/UPPER TROUGH DOMINATES
CENTRAL NORTH AMERICA. TEMPERATURES WILL RANGE AROUND NEAR NORMAL
VALUES THROUGH MOST OF THE WORK WEEK...WITH COLDER AIR FILTERING
IN FOR FRIDAY AND THE START OF THE WEEKEND.

THE FIRST ROUND OF WIDESPREAD RAIN IS EXPECTED LATE TUESDAY...AS
THE TROUGH CURRENTLY NOTED OVER THE FOUR CORNERS REGION /ON 21Z WATER
VAPOR IMAGERY/ EJECTS NORTHEAST AND BECOMES NEGATIVELY TILTED OVER
THE NORTHERN PLAINS...SENDING A COLD FRONT ACROSS THE AREA. WEST
CENTRAL MN SHOULD SEE SHOWERS AND THUNDERSTORMS BY MID AFTERNOON
TUESDAY...REACHING THE WI BORDER BY SUNSET...THEN SPREADING ACROSS
WEST CENTRAL WISCONSIN OVERNIGHT. THE FORCING IS FAIRLY
PROGRESSIVE...SO RAINFALL AMOUNTS WITH THIS FIRST WAVE SHOULDN/T
BE MORE THAN ONE QUARTER TO ONE HALF INCH.

GIVEN THE AFORMENTIONED NEGATIVELY-TILTED NATURE OF THE FIRST
WAVE...THE COLD FRONT WILL LOSE ITS EASTWARD PUSH. THEREFORE IT
WILL LIKELY BECOME SLOWED UP ACROSS WESTERN MN ON WEDNESDAY INTO
THURSDAY...AS A REINFORCING SOUTHERN STREAM SHORTWAVE ARRIVES.
HAVE THEREFORE MAINTAINED THE CHANCE POPS FOR AREAS ALONG/EAST OF
INTERSTATE 35. ANOTHER ONE HALF INCH APPEARS POSSIBLE FOR THESE
AREAS...BRINGING TWO DAY TOTALS TO NEAR ONE INCH.

ON THURSDAY NIGHT AND FRIDAY...A NORTHERN STREAM WAVE DIPS
SOUTHEAST FROM CANADA...AND FACILITATES ONE MORE LOW CHANCE OF
PRECIPITATION /ALONG-NORTH OF INTERSTATE 94/ PRIOR TO OVERALL DRY
WEATHER ARRIVING FOR THE WEEKEND.

HIGH TEMPERATURES WILL MOSTLY BE IN THE 60S THROUGH
THURSDAY...WITH HIGHS IN THE 50S FOR FRIDAY AND SATURDAY AND LOWS
IN THE 30S FRIDAY NIGHT AS COLDER AIR WORKS IN BEHIND THE NORTHERN
STREAM WAVE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1211 PM CDT MON SEP 29 2014

LOW CONFIDENCE CIG FORECAST INTO THE AFTERNOON. ABUNDANT LOW LEVEL
MOISTURE AND CAA CONTINUING SHOULD PRECLUDE RAPID CLEARING. WILL
TRY AND SCATTER CLOUDS OUT AFTER 23Z MOST LOCATIONS IN THE EAST.
FARTHER WEST A BIT MORE PROBLEMATIC. THERE IS EROSION GOING ON
TO THE SOUTHWEST BUT DONT KNOW HOW EXTENSIVE THIS WILL BE
OVERNIGHT. IF IT DOES CLEAR OUT AROUND 00Z...THEN SOME RISK OF
STRATUS/FOG DEVELOPING. WILL CONTINUE PREVIOUS TREND OF BRINGING
IN THE STRATUS/FOG/LIFR TO THE WEST AND AT KEAU FOR NOW. STILL
CONFIDENCE LOW ON THIS OVERALL DEVELOPMENT. ANY LOW CLOUDS WILL
DISSIPATE THROUGH 15Z TO THE WEST WITH MORE MID/HIGH LEVEL CLOUDS
MOVING IN DURING THE MORNING TO THE MN PORTION OF THE CWA. MAIN
RAIN THREAT HOLDS OFF AT WESTERN TAF SITES UNTIL AFTER 18Z TUE.
EAST TO SOUTHEAST WINDS DURING THE PERIOD. A FEW GUSTS MOVING
ACROSS WITH THE COLD AIR MOVING THROUGH. THEN INCREASING AGAIN
TUESDAY AFTERNOON AHEAD OF THE NEXT FRONTAL BOUNDARY.

KMSP...LOW CONFIDENCE ON CEILING BREAKING OUT. WILL TRY AND BREAK
CEILING THROUGH 21Z...AND SCATTER IT OUT THROUGH 00Z. SOME THREAT
OF STRATUS DEVELOPING LATER TONIGHT...BUT LOW CONFIDENCE REMAINS
SO WILL LEAVE SCT012 FOR NOW. THEN SOME MID/HIGH LEVELS CLOUDS
MOVING IN DURING THE MORNING...WITH THE MAIN RAIN THREAT HOLDING
OFF UNTIL AFTER 00Z WED.

/OUTLOOK FOR KMSP/

TUE...VFR. MVFR/SHRA LIKELY TUE NIGHT. WINDS E-SE 10-15 KTS.
WED...MAINLY VFR. CHANCE MVFR IN SHRA/TSRA. WINDS S-SE 10-15 KTS.
THU...MAINLY VFR. CHANCE MVFR IN SHRA. WINDS W-NW 5-10 KTS.


&&

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

$$

SHORT TERM...DWE
LONG TERM...LS
AVIATION...DWE





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