Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 170948
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
348 AM CST WED DEC 17 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM CST WED DEC 17 2014

QUIET WEATHER THIS PERIOD WITH MAIN FOCUS BEING THE EXTENT OF THE
LOW CLOUD COVER /AND SUBSEQUENT SNOW SHOWERS/ AND THE TEMPERATURES.
EARLY THIS MORNING...WATER VAPOR IMAGERY EASILY DEPICTED AN UPPER
LOW ADVANCING SOUTHEASTWARD THROUGH NORTHERN WISCONSIN. SIGNIFICANT
MID LEVEL DRYING WAS OBSERVED DIRECTLY THROUGH THE HEART OF THE
FA...BUT THE REAL CONCERN IS WHETHER OR NOT THE LOW LEVELS ARE
SATURATED.  THE LOW CLOUDS OVERNIGHT HAVE BEEN A LITTLE LESS
WIDESPREAD THAN EXPECTED...WITH A SOLID CLEARING LINE FROM
ALEXANDRIA THROUGH ST CLOUD...TO NEAR NEW RICHMOND WISCONSIN...WITH
CLEAR SKIES SOUTHWEST OF THIS LINE AT THE CURRENT TIME.
TEMPERATURES HAVE HENCE DROPPED INTO THE SINGLE DIGITS ACROSS MOST
OF WESTERN MINNESOTA WHILE TEMPERATURES REMAIN IN THE TEENS FURTHER
NORTHEAST THANKS TO THE CLOUD COVER THERE.  THE UPPER LOW WILL
CONTINUE ROTATING SOUTHEASTWARD TOWARD LAKE MICHIGAN /NORTH OF
CHICAGO/ TODAY AND THE STRATUS IN NORTHEASTERN MN WILL ADVANCE
SOUTHWARD DUE TO THE COUNTERCLOCKWISE CIRCULATION OF THE UPPER LOW.
ITS NOT AS SIMPLE AS JUST TIMING IN THE CLOUDS TO SOUTHERN MN
HOWEVER...BECAUSE CONTINUED SUBSIDENCE HAS PROVEN IT CAN SCOUR OUT
SOME OF THE CLOUD COVER.  WHILE THIS IS OCCURRING...A SURFACE HIGH
WILL BE PUSHING IN FROM THE WEST. MODEL SOUNDINGS INDICATE A FINE
LINE BETWEEN OVERCAST AND CLEAR SKIES...WITH A DEW POINT DEPRESSION
OF 3 DEGREES BEING ALL THAT MAY BE REQUIRED TO SEE THE CLOUDS
SCATTER OUT. SO...AS THE CLOUDS CONTINUE SOUTH...SCATTERING SHOULD
OCCUR.  SOUTHWESTERN MN SHOULD REMAIN MOSTLY CLEAR TO PARTLY
CLOUDY...WHILE GLENWOOD THROUGH THE TWIN CITIES MAY BE IN THAT
TRANSITION ZONE THIS MORNING...AND IT LOOKS LIKE A GOOD BET THAT
CLOUDS WILL LINGER MOST OF THE DAY TO NORTH AND EAST OF THIS LINE.
THE AREAS THAT DO SEE CLOUD COVER CAN ALSO EXPECT TO SEE FLURRIES OR
A FEW SNOW SHOWERS SIMILAR TO YESTERDAY AFTERNOON.  WITH THE HIGH
PUSHING IN FROM THE WEST...WE`RE ALREADY SEEING WIND SPEEDS DROP DUE
TO THE WEAKENING PRESSURE GRADIENT OUT WEST. THIS TREND WILL ONLY
CONTINUE THROUGH TONIGHT AS WINDS BECOME CALM.  WITH THE CALM
WINDS...SKY COVER TONIGHT WILL BE IMPORTANT IN PREDICTING THE
OVERNIGHT LOWS.  WENT WITH A CONSERVATIVE FORECAST IN EASTERN MN AND
WESTERN WI IN REGARDS TO TEMPS BECAUSE CLOUDS MAY STILL LINGER.  NOT
CONFIDENT IN THAT THOUGH DUE TO THE SHALLOW LAYER OF SATURATION
EXPECTED.  IN ADDITION...THE NAM SHOWS A STRONG SIGNAL OF SATURATION
UNDER 3K FEET...BUT THE GFS AND EC ARE MORE OPTIMISTIC IN REGARDS TO
CLOUD COVER. IF SKIES DO CLEAR...LOW TEMPS MAY BE A FEW DEGREES
COOLER THAN CURRENTLY ADVERTISED.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 348 AM CST WED DEC 17 2014

THE LONG TERM IS CHOCK FULL OF CLOUDS AND TEMPERATURES NEAR OR
ABOVE AVERAGE. BENIGN WEATHER WILL CONTINUE UNTIL NEXT WEEK WHEN
THE PATTERN BECOMES MORE ACTIVE...INCLUDING THE LIKELIHOOD FOR A
CLIPPER EARLY IN THE WEEK...POSSIBLY MORPHING A LARGE AND STRONG
SYSTEM SOMEWHERE NEARBY FOR CHRISTMAS EVE AND DAY.

SURFACE RIDGING WILL SLIDE A BIT TO THE EAST THURSDAY AND FRIDAY
WITH RETURN FLOW GRADUALLY STRENGTHENING. CONSIDERABLE LOW CLOUDS
ARE CURRENTLY IN PLACE TO THE WEST OF THIS RIDGE OVER MUCH OF THE
WESTERN HALF OF NORTH AMERICA. AS LOW LEVEL MOISTURE INCREASES
LATE WEEK...THINK THIS STRATUS WILL BECOME ENTRENCHED ACROSS THE
AREA AGAIN WITH LITTLE HOPE TO SEE MUCH SUN THROUGH THE REST OF
THE PERIOD. ALTHOUGH USUALLY TOO MOIST...THE NAM FORECAST
SOUNDINGS INDICATE A LITTLE FREEZING DRIZZLE POTENTIAL FRIDAY. QPF
IS VERY LIGHT...BUT NOTABLE ON ALL GLOBAL MODELS INTO SATURDAY.
THINK POTENTIAL IS TOO LOW TO MENTION AT THIS POINT BUT IT WILL BE
WATCHED.

ENERGY WILL SHIFT FROM THE SOUTHERN STREAM TO THE NORTHERN
STREAM EARLY NEXT WEEK AS A STRONG 590+ DAM MID LEVEL RIDGE BUILDS
OFF THE COAST OF CALIFORNIA. ONE SUCH PIECE OF ENERGY WILL ARRIVE
MONDAY AS A TROUGH DIGS INTO THE PLAINS DOWNSTREAM OF THE BUILDING
RIDGE. A PRETTY CHAOTIC AND DISCOMBOBULATED SYSTEM WILL PROBABLY
NOT BRING MUCH MEANINGFUL PRECIP TO THE UPPER MIDWEST...BUT
CYCLONIC FLOW AND LOW LEVEL MOISTURE WILL PRODUCE OCCASIONAL LIGHT
SNOW/FLURRIES...OR DRIZZLE/FREEZING DRIZZLE DEPENDING ON THE
MOISTURE PROFILE.

THE EVOLUTION OF THIS SYSTEM AND TROUGH GETS MORE INTERESTING AT
THE END OF THE PERIOD TUESDAY AS IT INTERSECTS A STALLED FRONTAL
BOUNDARY OVER THE GULF. THE RESULT IS A CONSOLIDATION OF ENERGY
AND A LOT OF MOISTURE BEING INGESTED INTO THE SYSTEM MIDWEEK -
FUELING A RAPIDLY DEEPENING SYSTEM SOMEWHERE OVER THE GREAT LAKES
OR EAST COAST NEAR CHRISTMAS EVE OR DAY. THIS WOULD BE A HIGH-
IMPACT SYSTEM AND CERTAINLY ONE TO WATCH.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1053 PM CST TUE DEC 16 2014

SUBSIDENCE BEHIND THE WAVE THAT GENERATED LATE AFTERNOON AND EARLY
EVENING SNOW SHOWERS ACROSS EAST CENTRAL MN AND WEST CENTRAL WI
HAS PROVEN A BIT MORE SUCCESSFUL IN SCOURING OUT THE LOW LEVEL
MOISTURE. THE RESULT HAS BEEN NOTABLE SCATTERING OF THE LOW
CLOUDS FROM WESTERN INTO CENTRAL MN. HAVE THEREFORE GONE MUCH MORE
OPTIMISTIC WITH THE 06Z SET OF TAFS. 925-850MB MOISTURE PROGS
INDICATE THE BULK OF THE LOW CLOUDS WILL REMAIN ACROSS
NORTHERN/EASTERN MN INTO WI OVERNIGHT. SO...WHILE SCATTERED SPOKES
OF LOW CLOUDS MAY PIVOT INTO KAXN/KRWF AND BRIEFLY BRING MVFR
CONDITIONS...THE PRIMARY MVFR CIGS WILL OCCUR FROM KSTC/KMSP EASTWARD
TO KRNH AND KEAU. SNOW SHOWERS WILL MAINLY OCCUR OVER WEST CENTRAL
WI. FURTHER SCATTERING OF THE LOW CLOUDS WILL COMMENCE FROM WEST
TO EAST ON WEDNESDAY MORNING AND AFTERNOON...WITH ALL SITES
EXPECTED TO BE VFR BY 00Z THURSDAY.

NORTHWEST WINDS BELOW 10KTS FOR THE OVERNIGHT HOURS...SETTLING AROUND
5 KTS FROM THE NORTH/NORTHEAST FOR WEDNESDAY.

KMSP...
EXPECTING BREAKS IN THE LOW/MVFR DECK OVERNIGHT...WITH
ATTENDANT/OCCASIONAL VFR CONDITIONS. SHOULD SEE VFR BECOME
PREVALENT BY LATE WEDNESDAY MORNING...WITH MOST OF THE LOW DECK
SCOURING OUT BY LATE AFTERNOON.

/OUTLOOK FOR KMSP/
THU...VFR. WINDS LIGHT NORTH WIND UNDER 5 KTS.
FRI...VFR. WINDS SSE 5 KTS.
SAT...VFR. WINDS SSE 5 KTS.


&&

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

$$

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










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