Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 211002
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
402 AM CST SUN DEC 21 2014

.SHORT TERM...

TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM.

AREAS OF VERY LIGHT FREEZING DRIZZLE AND A FEW SNOWFLAKES ARE
OVERSPREADING MUCH OF THE CWA FROM THE SW VIA LOW LEVEL WARM...MOIST
ADVECTION. SFC TEMPS TO WARM ABOVE FREEZING BY 16Z. DO NOT BELIEVE
THERE WILL BE ENOUGH OF AN IMPACT ON ROADWAYS FOR A FREEZING RAIN
ADVISORY AT THIS TIME. THE RESIDUAL CHEMICALS AND SALT ON ROADWAYS
FROM THE PAST SEVERAL DAYS MAY BE ENOUGH TO KEEP THE ROADS IN OKAY
CONDITION.

AS A WEAK SHORTWAVE TROUGH APPROACHES FROM THE PLAINS
TODAY AND PASSES TNT...THE 850 MB BAROCLINIC ZONE WILL SHIFT NEWD
ACROSS THE CWA THROUGHOUT THE DAY. FCST SOUNDINGS CONTINUE TO SHOW A
MID LEVEL DRY LAYER BUT STILL EXPECT THE LIFT TO RESULT IN SEEDER
FEEDER MECHANISM OR OUTRIGHT SATURATION IN SOME AREAS. THUS HAVE
CHANCE POPS FOR RAIN AND SNOW FROM LATE THIS MORNING THROUGH THE
AFTERNOON. THE CHANCES OF RAIN...SNOW...AND POSSIBLY FREEZING
DRIZZLE CONTINUE TNT WITH THE PASSAGE OF THE WEAK SHORTWAVE TROUGH
AND CONTINUED MOISTURE IN THE LOW LEVELS.


MONDAY-FORECAST CONFIDENCE HIGH

MODELS IN GOOD AGREEMENT IN STACKED AND FILLING LOW MOVING FROM
SOUTHEAST DAKOTA INTO IOWA.  THERE HAS BEEN A TREND FOR THERMAL
PROFILES AROUND 850MB TO BE COOLER WITH THIS SYSTEM...WITH 850 MB
TEMPS HOVERING AROUND 0C.  HOWEVER...JUST ENOUGH OF A LAPSE RATE IN
BOUNDARY LAYER WITH STALE COLD AIR AT SURFACE TO PERMIT TEMPERATURES
TO RISE WELL INTO THE 30S.  CERTAINLY COULD BE MIX OF RAIN AND WET
SNOW...BUT IMPACTS SHOULD BE MINIMAL WITH BULK OF PRECIPITATION
FALLING AS RAIN.

LOOKS LIKE AFTERNOON AND EVENING RUSH HOUR WILL BE WETTEST PERIOD.

.LONG TERM...

TUESDAY AND WEDNESDAY-FORECAST CONFIDENCE LOW

NOT SURE HOW TO WORD THIS...BUT IT HAS BEEN A LONG TIME SINCE I HAVE
SEEN THIS MUCH UNCERTAINTY IN A DAY 3 FORECAST.  OPERATIONAL GFS AND
SREF HAVE TRENDED SLOWER AND SOUTH TOWARD LOWER MISSISSIPPI RIVER
VALLEY WITH 2ND LOW PRESSURE WAVE...WHILE ECMWF AND PARALLEL GFS
FOCUS ON MORE NORTHERN SOLUTION NEAR THE GREAT LAKES.

AT FIRST GLANCE THE GEFS AND SREF SOLUTIONS SHOW POTENTIAL FOR A
DREADED GULF LOW TRACK WITH HEAVY WET SNOW POTENTIAL.
HOWEVER...WITH TREND OF OTHER RELIABLE MODELS LIKE ECMWF TOWARD
ABSENCE OF DEEP LOW OVER GREAT LAKES...SEE POTENTIAL FOR VERY LITTLE
PRECIPITATION OR SNOW BEING GREATER OVER SOUTHERN WISCONSIN THAN
POTENTIAL FOR SIGNIFICANT STORM.

RIGHT NOW A CONSERVATIVE CONSENSUS FORECAST IS THE ONLY VIABLE
OPTION I SEE.  IT LOOKS LIKE GRADUAL COOLING OF THE COLUMN WITH
CHANCE OF RAIN GOING TO SNOW WITH LARGE RANGE OF POSSIBLE
PRECIPITATION AMOUNTS...BUT LEANING TOWARD DRIER SOLUTIONS.

THURSDAY THROUGH SATURDAY-FORECAST CONFIDENCE MEDIUM

GFS AND ECMWF ARE IN BETTER AGREEMENT ON FAST MOVING LOW COMING OUT
OF KANSAS AHEAD OF A POLAR SURGE AND THEN HEADING FOR THE GREAT
LAKES. A FRONTOGENETIC SNOW BAND IS SHOWN TO PUSH FROM NEBRASKA TO
IOWA AND WISCONSIN THURSDAY INTO EARLY FRIDAY.

THIS BAND WOULD BE RATHER NARROW...SO MIGHT ONLY AFFECT 2-3 COUNTY
WIDE AREA AND COULD EASILY MISS MOST AREAS.  BEST GUESS RIGHT NOW IS
LIGHT AMOUNTS ESPECIALLY IN NORTHERN HALF OF AREA.
&&

.AVIATION/12Z TAFS/...CIGS WILL RANGE FROM JUST A FEW HUNDRED FEET
OR LESS OVER SOUTH CENTRAL WI TO A 1000 FEET IN THE EAST TODAY AS
AREAS OF FREEZING DRIZZLE...RAIN...SNOW MOVE ACROSS THE AREA. SFC
TEMPS TO WARM ABOVE FREEZING BY 10 AM...ENDING THE ICING
THREAT...BUT A LIGHT COATING OF ICE ON SURFACES WILL OCCUR
BEFOREHAND. THE CIGS WILL LIFT TO 1-3 KFT FOR TNT. VSBYS OF 3-5SM
WILL PREVAIL WEST OF THE MILWAUKEE METRO AREA FOR MOST OF SUN AND
SUN NT. RAIN...SNOW...AND PATCHY FREEZING DRIZZLE WILL REMAIN IN THE
FORECAST FOR TNT.

&&

.MARINE...A SMALL CRAFT ADVISORY GOES INTO EFFECT LATER THIS
AFTERNOON FROM PORT WASHINGTON AND NWD AND STARTS AT 10 PM SOUTH OF
PORT WASHINGTON. AS LOW PRESSURE APPROACHES FROM THE NORTHERN
PLAINS...BREEZY SOUTH TO SOUTHEAST WINDS WILL DEVELOP LATER TODAY
INTO MONDAY NIGHT. THE SOUTHERLY FETCH WILL GENERATE HIGH WAVES
DURING THIS PERIOD. THE WINDS AND WAVES WILL SUBSIDE ON TUESDAY AS
THE WEAKENING LOW PRESSURE AREA MOVES ACROSS THE REGION. THE SMALL
CRAFT ADVISORY WILL EXPIRE EARLY TUE AM.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 3 AM CST TUESDAY
     FOR LMZ644>646.

     SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM CST
     TUESDAY FOR LMZ643.

&&

$$

TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
MONDAY THROUGH SATURDAY...CRAVEN


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