Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 240007
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
707 PM CDT THU OCT 23 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 403 PM CDT THU OCT 23 2014

CLEARING CONTINUES TO MOVE FROM EASTERN MN INTO WESTERN WI THIS
AFTERNOON. GOOD MIXING OCCURRED THIS AFTERNOON ACROSS THE WESTERN
AND CENTRAL AREAS OF MN WITH TEMPERATURES WARMING INTO THE LOWER 70S
UNDER SUNNY SKIES. AS A RESULT OF THE MIXING AND SUBSEQUENT SUNSHINE
FOG IS NOT EXPECTED ACROSS WESTERN TO CENTRAL MN TONIGHT. THAT PART
OF THE STATE WILL SEE ABUNDANT SUNSHINE FRIDAY WITH TEMPERATURES A
COUPLE DEGREES WARMER THAN TODAY.

FOR THE WESTERN WI COUNTIES...SKIES WILL BECOME PARTLY CLOUDY BY
LATE AFTERNOON. A DENSE FOG ADVISORY WILL BE IN EFFECT OVERNIGHT FOR
THE EXTREME EASTERN MN COUNTIES AND THE WESTERN WI COUNTIES.
WIDESPREAD DENSE FOG IS EXPECTED TO FORM AFTER MIDNIGHT. THE LOWEST
VISIBILITIES WILL APPROACH 1/4 MILE. VISIBILITIES WILL IMPROVE A FEW
HOURS AFTER SUNRISE FRIDAY WITH SUNNY SKIES SKIES BY NOON.
TEMPERATURES WILL BE SEVERAL DEGREES WARMER. SKIES WILL BE CLEAR
FRIDAY NIGHT WITH TEMPERATURES IN THE 40S.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 403 PM CDT THU OCT 23 2014

A CYCLONE WILL DEVELOP ACROSS THE MIDWEST EARLY NEXT WEEK WHICH WILL
TEMPORARILY BRING AN END TO THE ABOVE NORMAL TEMPERATURES. THE
MODELS ARE IN GOOD AGREEMENT WITH THE GENERAL DEPICTION OF THE
SYSTEM...BUT THERE ARE CONSIDERABLE UNCERTAINTIES IN THE TIMING AND
INTENSITY.

UPPER LEVEL RIDGING ACROSS THE HIGH PLAINS FRIDAY NIGHT AND SATURDAY
WILL KEEP THE REGION DRY AND MILD...SO CONTINUED THE 0 POPS DURING
THAT TIME FRAME. MEANWHILE A POTENT SHORTWAVE WILL MOVE ONSHORE THE
PACIFIC NORTHWEST...AND THIS WILL BE THE WEATHER MAKER FOR THE EARLY
PART OF NEXT WEEK. THE LAST FEW RUNS OF THE GFS...IN PARTICULAR THE
23.12 HAVE BEEN VERY AGGRESSIVE IN THE DEVELOPMENT WITH THIS SYSTEM.
IT DEVELOPS A 988 LOW OVER MN...WHILE THE GEM AND ECMWF ARE
WEAKER...SLOWER...AND FARTHER EAST WITH THE LOW TRACK.

AFTER MUCH INTERROGATION...IT APPEARS THAT THE DIFFERENCE STEM FROM
THE PHASING OF THE SOUTHERN AND NORTHERN STREAM ACROSS THE TX/OK
PANHANDLES LATE MONDAY AFTERNOON. THE NORTHERN STREAM OFF THE GFS IS
LESS AMPLIFIED AND SLIGHTLY QUICKER...SO IT PLACES THE MAIN
SHORTWAVE ON THE FOOTHILLS OF WY BY 18Z MONDAY. BY 06Z TUESDAY THIS
PV ANOMALY BECOMES PHASED WITH THE UPPER LEVEL FRONT OF THE SOUTHERN
STREAM...AND CYCLOGENESIS FOLLOWS LEADING TO A WELL DEVELOPED
CYCLONE BY TUESDAY MORNING. HOWEVER THE EC AND GEM ARE SLIGHTLY MORE
AMPLIFIED WITH THE NORTHERN STREAM...AND LESS PROGRESSIVE WITH THE
INITIAL SHORTWAVE. THE PHASING BETWEEN THE UPPER LEVEL FRONT AND THE
POLAR JET IS DELAYED AND DISPLACED...AND AS A RESULT BY 18Z TUESDAY
THE SURFACE LOW ENDS UP OVER THE EASTERN SIDE OF LAKE SUPERIOR
COMPARED TO THE WESTERN SIDE ON THE GFS. THE MAIN POINT OF THIS
DISCUSSION IS THAT THERE IS UNCERTAINTY IN THE TRACK OF THE SURFACE
LOW...AND THEREFORE HEAVIEST PRECIP. BUT CONFIDENCE IS HIGH IN A MID
LATITUDE CYCLONE DEVELOPING ACROSS CENTRAL NORTH AMERICA MONDAY
NIGHT AND TUESDAY.

THE WEATHER WILL REMAIN DRY THROUGH SUNDAY...BUT A FEW SHOWERS COULD
DEVELOP SUNDAY NIGHT WITH THE ISENTROPIC LIFT ALONG AND NORTH OF THE
WARM FRONT. USED 6HR GRIDS TO BETTER SHOW THE TIMING OF THIS PRECIP.
DID NOT MAKE CHANGES TO THE FORECAST BEYOND SUNDAY FOR THE REASONS
MENTIONED ABOVE. PRECIP CHANCES WILL LINGER THROUGH WEDNESDAY...WITH

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 707 PM CDT THU OCT 23 2014

DRIER WESTERLY LOW LEVEL AIR HAS MADE ITS WAY TO THE MN/WI BORDER
EARLY THIS EVENING AND THIS IS ABOUT AS FAR AS IT WILL GO
OVERNIGHT AS WINDS BACK AHEAD OF LOW PRESSURE DEVELOPING OVER THE
NORTHERN PLAINS. CONFIDENCE IS NOT HIGH ON KEAU CLEARING THIS
EVENING. IF THEY DO...THEY WILL LIKELY DROP QUICKLY TO LIFR OR
VLIFR. KRNH IS CURRENTLY ON THE EDGE OF STRATUS. THIS WILL LIKELY
HEAD BACK INTO FAR EASTERN MN LATE IN THE NIGHT AND FRIDAY
MORNING. KSTC...KRWF AND KAXN ARE MUCH BETTER OFF WITH VFR
FORECAST THROUGH THE PERIOD. VFR CONDITIONS EXPECTED AFTER 15Z FOR
OUR TWO WI TAF SITES.

KMSP...SOME MVFR BR LIKELY LATE TONIGHT AS MOISTURE CREEPS BACK IN
ON LIGHT SE WINDS. A CONCERN IS THAT LOW MVFR CEILINGS MAY ALSO
SPREAD IN AFTER 09Z...BUT CONFIDENCE IS NOT HIGH ON THIS. ITS JUST
A SMALL POSSIBILITY AT THIS POINT. SOME BKN-OVC035-045 MAY ALSO
PASS THROUGH DURING THE LATE MORNING HOURS...BUT AGAIN CONFIDENCE
IS NOT HIGH ON THIS WITH IT BEING MORE LIKELY ACROSS SOUTH CENTRAL
AND SOUTHEAST MN SPREADING NORTHEAST ACROSS WEST CENTRAL WI.

/OUTLOOK FOR KMSP/

SAT...VFR. WINDS W-NW AT 10-15KTS.
SUN...CHC MVFR/-SHRA LATE SUNDAY NIGHT. WINDS BECOMING SE AT
08-14KTS IN AFTERNOON.
MON...CHC MVFR/-SHRA WINDS E-NE AT 08-13KTS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT FRIDAY FOR MNZ053-063-
     070-077-078-084-085-093.

WI...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT FRIDAY FOR WIZ014>016-
     023>028.

&&

$$

SHORT TERM...DRL
LONG TERM...JRB
AVIATION...RAH







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