FXUS63 KMKX 240936
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
336 AM CST THU DEC 24 2009
.DISCUSSION...FORECAST FOCUS IS ON PRECIP TRENDS THIS MORNING...THEN
DECENT RAINS FOR LATER TODAY/TONIGHT AND THEN DAY OF TRANSITION ON
FRIDAY WITH COLD AIR WRAPPING BACK IN FROM THE SOUTHWEST AROUND
SLOW MOVING LOW.
TODAY- CONFIDENCE...MEDIUM
WATER VAPOR/RUC COMBO SHOW ONE STRONG SHORT WAVE WITH IMPRESSIVE JET
MAX...SHIFTING NORTHWARD INTO NORTHERN MN AND THE UPPER PENINSULA.
285-290K ISENTROPIC PLOTS SHOWS THE DECENT/STEEP UPGLIDE BECOMING
MORE GRADUAL THIS MORNING. WILL LIKELY KEEP AN ADVISORY IN PLACE FOR
THE MORNING HOURS. SURFACE TEMPS STILL RIGHT AROUND OR SLIGHTLY
BELOW 32 IN MANY LOCATIONS. AS THIS INITIAL SHORT WAVE AND
ISENTROPIC LIFT SHIFT NORTH AND DIMINISH...THINK PRECIP WILL
BECOME LIGHTER...BUT ANY BREAK WILL BE SHORT LIVED. THE INVERTED
TROUGH AXIS TO OUR WEST WILL MOVE SLOWLY EAST. BY LATER TODAY...A
MORE IMPRESSIVE LOW LEVEL JET MAX...65 KNOTS FROM THE NAM...45-50
KNOTS OFF THE GFS...TAKES AIM ON THE CWA. RAIN WILL BE ON THE
INCREASE.
TONIGHT- CONFIDENCE...MEDIUM
STRONG SHORTWAVE ENERGY IN THE SOUTHERN PLAINS WILL DEVELOP DEEP LOW
INTO WC IL BY 12Z FRI. THE SHORTWAVE APPROACHES WITH A STRONGLY
NEGATIVE TILT. PREFER THE NAM 850 PROFILE WHICH SHOWS A MORE
PRONOUNCED THERMAL RIDGE INTO THE CWA WHEREAS THE GFS WHICH SHOWS
COOLING 850 TEMPS. A COUPLE OF CONCERNS...IF THE GFS WERE TO PAN OUT
WE WOULD BE LOOKING AT A MIXY SCENARIO. ALSO...2 METER TEMPS FROM
BOTH GFS AND NAM ARE BARELY ABOVE FREEZING ALL NIGHT. OVERALL WILL
SIDE WITH THE WARMER LOOK TO THE 3 HOURLY MOS TEMPS. AS LOW LEVEL
JET STRENGTHENS FROM THE SOUTHEAST...ANTICIPATE ENOUGH MODIFICATION
IN THE LOW LEVELS TO DISCOUNT MIXY PRECIP. HIGH PRECIPITABLE WATER
VALUES/MIXING RATIOS...QPF AMOUNTS OVER AN INCH. WILL MENTION
HEAVY RAIN POTENTIAL IN THE SE CWA.
CHRISTMAS- CONFIDENCE...LOW TO MEDIUM
THE SHORTWAVE ENERGY SWINGS AROUND GETS CAUGHT UP IN THE
CIRCULATION OF THE UPPER LOW DROPPING SOUTHEAST FROM THE NORTHERN
PLAINS. 850 THERMAL RIDGE ACROSS THE CWA TO START OFF THE DAY SO WILL
GO WITH MORNING HIGHS. STRONG COLD AIR ADVECTION GETS GOING DURING
THE DAY AND WILL HAVE A SOUTHWEST TO NORTHEAST CHANGOVER IN PRECIP
TYPES. HEAVIEST QPF PAINTED WITHIN THE WARMER THERMAL FIELDS.
SATURDAY AND SUNDAY- CONFIDENCE...MEDIUM
UPPER LOW WILL BE SLOWLY PLODDING AROUND THE AREA WITH SEVERAL
VORTICITY LOBES EMBEDDED WITHIN THE CIRCULATION. LIGHT SNOW/SNOW
SHOWERS A GOOD BET. 850 TEMPS IN THE MINUS TEENS. EXPECTING A FEW
INCHES OF ACCUMULATION ALONG THE WAY.
MONDAY- CONFIDENCE...MEDIUM
UPPER LOW PULLING FURTHER AWAY WITH FLOW BECOMING GRADUALLY LESS
CYCLONIC. ECMWF BRUSHES THE FAR EAST WITH LIGHT QPF. FOR NOW WILL
MAINTAIN THE COOD COLLAB AND LEAN TOWARDS THE DRIER GFS.
&&
.AVIATION...GENERALLY MVFR AND LWR CIGS EXPECTED THRU THE TAF
PD...BUT MAY BE A BRIEF PD OF CIGS RISING TO VFR...ESPECIALLY IN
EAST WHERE DRY AIR PERSISTS. AREAS OF -FZRA/PL TO PERSIST THIS MRNG
AND POSSIBLY INTO THE EARLY AFTN UNTIL SECOND STRONG SURGE OF
MOISTURE AND WARM AIR ASSOCD WITH STRONG LOW LEVEL JET BEGINS THIS
AFTN AND EVE. MOSTLY RAIN EXPCD WITH THIS SECOND PERIOD OF STRONG
FORCING...TRANSITIONING TO -SN AS COLD AIR WRAPS IN FROM SOUTH
ON FRI.
&&
.MARINE...TIGHTENING PRES GRADIENT IN RESPONSE TO STRENGTHENING
PLAINS LOW PRESSURE STILL EXPECTED TO ALLOW WIND GUSTS TO GALE
WARNING CRITERIA TO DEVELOP THIS AFTERNOON...WITH BETTER CHANCE FOR
HIGHER GUSTS TNGT INTO FRI MRNG. LOST KNSW3 WIND SENSOR DUE TO
ICING...AND MAY LOSE SEVERAL MORE. HOPING SLIGHTLY WARMER WINDS WILL
RESULT IN SOME MELTING ON WIND SENSOR...OTRW WL BE DIFFICULT TO
VERIFY STRONG WINDS. WL CONTINUE SMALL CRAFT ADVY THIS MRNG
TRANSITIONING TO GALE WARNING STARTING AT 18Z THRU FRI MRNG.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR WIZ046-047-051-
052-056>060-062>072.
LM...SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR LMZ643>646.
GALE WARNING FROM NOON TODAY TO NOON CST FRIDAY FOR LMZ643>646.
&&
$$
SHORT/LONG TERM...PC
AVIATION/MARINE...MBK
