Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 221624 AAA
AFDMKX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1024 AM CST SUN FEB 22 2015

.UPDATE...

NO CHANGES.

&&

.AVIATION/18Z TAFS/...

LOOK FOR VFR CONDITIONS THROUGH THE PERIOD AS HIGH PRESSURE BUILDS
INTO THE REGION.  NORTHWEST WINDS OF 12 TO 22 KNOTS WILL GRADUALLY
DIMINISH TONIGHT.

&&

.PREV DISCUSSION... /ISSUED 253 AM CST SUN FEB 22 2015/

TODAY AND TONIGHT...FORECAST CONFIDENCE HIGH.

THE MAIN STORY FOR THIS PERIOD ARE THE PLUMMETING TEMPERATURES AS
ARCTIC AIR FLOWS SOUTH INTO THE REGION.  SURFACE HIGH PRESSURE WILL
TRACK FROM THE DAKOTAS TO IOWA BY SUNRISE ON MONDAY.  THIS PUTS US
WITHIN THE PRESSURE GRADIENT ON THE EAST SIDE OF THE HIGH. THE COMBO
OF PERSISTENT WIND AND THE VERY COLD TEMPS WILL LEAD TO WIND CHILLS
OF 20 TO 30 BELOW TONIGHT INTO EARLY MONDAY MORNING. TEMPS TODAY
WILL LIKELY HOLD FAIRLY STEADY FROM WHERE THEY ARE BY OR SHORTLY
AFTER SUNRISE...WHICH WILL LIKELY BE IN THE SINGLE DIGITS TO AROUND
12 ABOVE.  A COLD DAY FOR SURE.  THEN TEMPS TONIGHT FALL TO 10 BELOW
TO 16 BELOW...COUPLED WITH THOSE COLD WIND CHILLS. WENT AHEAD AND
HOISTED A WIND CHILL ADVISORY FOR TONIGHT INTO MONDAY MORNING.

MONDAY AND MONDAY NIGHT - CONFIDENCE...MEDIUM
BITTERLY COLD START WITH WIND CHILLS LIKELY AT ADVISORY CRITERIA
THROUGH LATE MORNING. WILL JUST END IT NOON AT THIS POINT FOR
SIMPLICITY SAKE. AT LEAST MID MORNING. SURFACE HIGH WILL BE
POSITIONED TO OUR SOUTHWEST SO POTENTIAL FOR A LIGHT...THOUGH
ENOUGH OF A WIND TO COMBINE WITH BITTER AIRMASS TO PRODUCE WIND
CHILLS COLDER THAN BELOW -20. 925/850 WAA RAMPS UP WITH FAIRLY
TIGHT PRESSURE GRADIENT EVOLVING. SEEING SOME 50 KNOT FLAGS INTO
MONDAY NIGHT. SO EXPECTING A RATHER WINDY NIGHT WITH A NON-DIURNAL
TEMP TREND LIKELY. POTENT SHORTWAVE RIDES SOUTHEAST TOWARDS LAKE
SUPERIOR REGION. SIGNALS FOR PRECIP ARE FURTHER NORTH WITH THE NAM
MOST AGGRESSIVE IN BRINGING PRECIP BARELY INTO THE NW CWA LATER IN
THE NIGHT. WITH THE GFS AND ECMWF KEEPING PRECIP FURTHER NORTH
WILL GO WITH THE DRY FORECAST AT THIS TIME.

TUESDAY - CONFIDENCE...MEDIUM
POTENT SHORTWAVE SHIFTS FROM NEAR LAKE SUPERIOR TOWARDS
LOWER MI. SURFACE/850 TROUGH ALONG WITH A GLANCING SHOT OF DCVA
ENOUGH TO BOOST POPS A BIT ESP IN ERN/NERN CWA WHERE THERE IS MODEL
CONSENSUS WRT QPF. NAM IS QUITE AGGRESSIVE WITH PRECIP WHILE WHILE
GFS IS A NICE BLEND BETWEEN THE NAM AND DRIER LOOKING ECMWF. THE
WIND FIELDS CONTINUE TO LOOK VERY IMPRESSIVE ON THE BUFKIT SOUNDINGS
WITH THE GFS SHOWING AROUND 63 KNOTS AT 2500 FEET...ALTHOUGH
PROGGD MIXING LIMITED TO LOWEST 1K FEET. WARMEST DAY OF THE WEEK
WITH TEMPS PERHAPS ECLIPSING 30 IN A BLENDED APPROACH. ECMWF SHOWS
A -3 AT 925 WHICH IS THE WARMEST AND IF MIXED OUT WE COULD REACH
WELL INTO THE 30S...BUT WITH BOTH GFS AND NAM SHOWING SHALLOW
MIXING WITHIN THE THERMAL RIDGE/WARM SECTOR WILL STEER CLOSER TO
THE UPPER 20S/LOWER 30S FOR NOW.

TUESDAY NIGHT AND WEDNESDAY - CONFIDENCE...MEDIUM
COLD ADVECTION FOR MUCH OF TUESDAY NIGHT WITH ARCTIC THERMAL TROUGH
IN PLACE FOR WEDNESDAY. THE ECMWF IS SHOWING 925 TEMPS A BIT WARMER
THAN THE CONSENSUS OF THE NAM/GFS. 1036 MILLIBAR HIGH PRESSURE BUILDS
INTO THE DAKOTAS THIS PERIOD. ECMWF IS OUTLIER SOLUTION ATTM SHOWING
NE EDGE OF 850 BAROCLINIC SNOWS CLIPPING SW CWA LATER WED/WED NGT.
WILL GO THE CONSENSUS ROUTE FOR NOW AND LEAN WITH THE DRY
SUPERBLEND POPS.

THURSDAY - CONFIDENCE...LOW
1040 MILLIBAR HIGH RIDGES INTO THE AREA FROM THE DAKOTAS.
GFS IS ABOUT 5 DEGREES COLDER WRT 925 TEMPS AND ALSO SHOWS A NW
LOW LEVEL WIND FLOW. MEANWHILE ECMWF SHOWS A MORE ONSHORE FLOW.
WILL NOT INCLUDE AND LAKE EFFECT POPS AT THIS TIME...SOMETHING TO
WATCH WITH FUTURE MODEL RUNS.

FRIDAY - CONFIDENCE...MEDIUM
HIGH PRESSURE STILL DOMINATES AT THE SURFACE. 925 TEMPS MODIFY
A BIT FROM THURSDAY SO HIGHS A BIT DEEPER INTO THE TEENS BUT STILL
WELL BELOW NORMAL VALUES. ECMWF LOOKS A LITTLE MORE PRONOUNCED WITH
MID LEVEL TROUGH AXIS WHILE GFS SHOWING A MORE SHEARED LOOK. WILL
RETAIN DRY SUPERBLEND POPS.

SATURDAY - CONFIDENCE...LOW
BROAD ANTICYCLONIC SOUTHWEST 850 FLOW SIGNALING SOME WAA. ECMWF
HANGS ONTO THE INFLUENCE OF THE LOW LEVEL THERMAL TROUGH LONGER
THAN THE GFS WHICH RESULTS IN ABOUT A 6 DEGREE 925 TEMP DIFFERENTIAL.
MOISTURE FROM THIS RETURN FLOW REMAINS TO OUR SOUTHWEST HOWEVER WILL
GIVE A NOD TO THE GFS AND BRING SOME SNOW CHANCES IN FOR SATURDAY
NIGHT. THE ECMWF KEEPS THINGS DRY SATURDAY NIGHT WITH THE WAA INDUCED
PRECIP REMAINING FURTHER WEST IN THE PLAINS.

AVIATION/12Z TAFS/...LOOK FOR VFR CONDITIONS THROUGH THE PERIOD AS
HIGH PRESSURE BUILDS INTO THE REGION. NORTHWEST WINDS WILL INCREASE
TO 12 TO 22 KNOTS THIS MORNING...DIMINISHING TONIGHT.

MARINE...BRISK NORTHWEST WINDS ARE EXPECTED TODAY AS ARCTIC HIGH
PRESSURE SETTLES INTO THE UPPER MIDWEST. WIND GUSTS WILL APPROACH
SMALL CRAFT ADVISORY LEVELS...BUT NO ADVISORY WILL BE ISSUED.

WINDS WILL SHIFT TO THE SOUTHWEST MONDAY AFTERNOON AS THE HIGH
SLIDES INTO THE CENTRAL U.S. AND LOW PRESSURE DROPS OUT OF CENTRAL
CANADA. HIGH-END SMALL CRAFT ADVISORY WINDS AND GUSTS ARE EXPECTED
MONDAY NIGHT THROUGH TUESDAY

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 10 AM CST MONDAY
     FOR WIZ046-047-051-052-056>060-062>072.

LM...NONE.
&&

$$

UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
MONDAY THROUGH SATURDAY...COLLAR



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