Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 131139
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
539 AM CST SAT FEB 13 2016

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 313 AM CST SAT FEB 13 2016

QUITE THE CHILLY LOW LEVEL ARCTIC AIRMASS CENTERED ACROSS THE REGION
EARLY THIS MORNING...AS EVIDENCED BY SURFACE PRESSURES RISING TOWARD
THE 1040MB MARK AND ACTUAL AIR TEMPS TAKING A TUMBLE BELOW THE ZERO
MARK IN MANY SPOTS. WINDS HAVE BEEN A TOUCH SLOW TO SUBSIDE WITH
JUST A SLIGHT COUPLE HOUR DELAY TO THE APPROACH OF THE RIDGE
AXIS...WITH REMNANT WINDS OF 5 TO 10 MPH AT TIMES HELPING DROP WIND
CHILL READINGS DOWN INTO THE -15 TO -25F RANGE. GIVEN TRENDS AND
EXPECTED LIGHTER WINDS THROUGH MID MORNING...STILL DO SEE A WINDOW
FOR ACTUAL AIR TEMPS TO TAKE A TUMBLE...ESPECIALLY WESTERN AREAS...
BUT WITH ENOUGH OF A BREEZE AT TIMES TO MAINTAIN THE GOING ADVISORY
AS READINGS IN MANY SPOTS EITHER COME REALLY CLOSE TO OR EXCEED
CRITERIA.

OUTSIDE OF THAT...NOT MUCH TO TALK ABOUT TODAY...SAVE FOR SOME
PASSING CIRRUS AT TIMES AND HIGHS STRUGGLING THROUGH THE SINGLE
DIGITS WITH VERY SHALLOW MIXING AS THE RIDGE AXIS SLIDES OVERHEAD.
THE FOCUS THEN SHIFTS TOWARD OUR NEXT INCOMING UPPER WAVE LATER
TONIGHT INTO SUNDAY MORNING...CURRENTLY JUST COMING ASHORE INTO
WASHINGTON STATE. THAT FEATURE WILL NUDGE A SURFACE/ELEVATED WARM
FRONT FROM THE NORTHERN PLAINS THROUGH IOWA INTO MIDDAY SUNDAY...
WITH A NICE UPTICK IN DEEPER LAYER WARM ADVECTION ASCENT DRIVING TOP
DOWN SATURATION FROM THE WEST WITH TIME. GIVEN THAT SETUP...HAVE NO
TROUBLES ENVISIONING A BAND OF SNOW WORKING INTO THE REGION LATE
TONIGHT THROUGH SUNDAY MORNING...WITH SOME MODEST PRECIP RATES GIVEN
SOME IMPRESSIVE 40-50 KNOTS OF UPGLIDE FOR A TIME AHEAD OF THAT
BOUNDARY...PARTICULARLY ACROSS FAR WESTERN/SOUTHERN COUNTIES.

THE TROUBLE STEMS FROM JUST HOW MUCH INITIAL DRY AIR RESIDES ACROSS
EASTERN AREAS...ESPECIALLY INTO CENTRAL WISCONSIN COUNTIES...AS
THERE LOOKS TO BE A VERY SHARP SOUTHWEST-NORTHEAST CUTOFF TO HEAVIER
PRECIP POTENTIAL FROM THIS EVENT. GIVEN THAT SETUP AND THE FACT THAT
FORCING WILL BE WEAKENING WITH TIME...REALLY HAVE TO WONDER JUST HOW
MUCH SNOW WILL OCCUR ALONG/NORTH OF I-94. MEANWHILE...GIVEN STRONGER
FORCING AND WHAT SHOULD BE SOME DECENT RATIOS WITH A QUITE DEEP DGZ
BISECTED BY MODEST OMEGA...WESTERN/SOUTHERN AREAS (SAY GENERALLY
SOUTH OF A LINE FROM DODGE CENTER MN TO BOSCOBEL WI) HAVE A DECENT
SHOT AT A COUPLE OF INCHES OF FLUFFY ACCUMULATION. WITH THAT IN MIND
AND WITH COORDINATION OF SURROUNDING OFFICES...HAVE ELECTED TO FIRE
OFF A WINTER WEATHER ADVISORY...THOUGH HONESTLY BIGGER IMPACTS MAY
BE MITIGATED BY THE LONGER DURATION OF SNOW AND EXPECTED LIGHTER/
FLUFFY NATURE OF THE SNOW. FARTHER TO THE NORTH AND EAST...AMOUNTS
SHOULD TAPER QUICKLY BUT EVEN NORTH OF I-94 DO ULTIMATELY ANTICIPATE
SOME LIGHTER SNOWS INTO SUNDAY AFTERNOON/EVENING AS THE UPPER TROUGH
AND DEEPER MOISTURE WORK ACROSS THE AREA.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 313 AM CST SAT FEB 13 2016

LOOKING LIKE A MILDER TREND IS IN THE WORKS HEADING THROUGH THE WORK
WEEK...BUT WE FIRST HAVE TO GET THROUGH A COUPLE OF ADDITIONAL
WEATHER SYSTEMS. WHILE CONFIDENCE IN THE PLACEMENT AND TIMING OF
SAID SYSTEMS REMAINS SOMEWHAT LOWER THAN DESIRED...A TREND DOES
APPEAR TO BE ARISING AMONG GUIDANCE THAT MOST OF THE IMPACTS WILL
END UP TO OUR WEST...FOCUSED WHERE YOU`D EXPECT THEM ALONG THE
TIGHTEST THERMAL GRADIENT LAID OUT WHERE IS HAS BEEN FOR DAYS NOW
FROM THE NORTHERN PLAINS DOWN THROUGH IOWA. NOT ENTIRELY READY TO
STRIP POPS COMPLETELY BUT THAT MAY BE THE WAY TO HEAD OVER COMING
DAYS. STILL LOTS OF QUESTIONS ABOUT HOW MUCH SUNSHINE WE CAN MUSTER
IN A WARMER PATTERN AS MUCH OF THE WARM ADVECTION WILL INITIALLY GO
INTO SOME SORT OF CLOUD PRODUCTION...BUT EVEN IN THE FACE OF THAT...
AN UPWARD TREND IN TEMPS DOES APPEAR IN THE WORKS...ESPECIALLY INTO
LATE WEEK AS THE RETURN OF WESTERN TROUGHING HELPS BUMP RIDGING
THROUGH MUCH OF THE CENTRAL CONUS. THERE HAVE BEEN HINTS THE PAST
FEW DAYS THAT FRIDAY COULD END UP BEING QUITE WARM AS LOW PRESSURE
SLIPS NORTH OF THE AREA AND PLACES MUCH OF THE CWA IN THE WARM
SECTOR...BUT PLENTY OF TIME FOR THOSE DETAILS TO BE WORKED OUT OR
JUST AS LIKELY...FOR THOSE DETAILS TO CHANGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 539 AM CST SAT FEB 13 2016

HIGH PRESSURE IN CONTROL ACROSS THE AREA TODAY FOR VFR CONDITIONS.
TROUGH OF LOW PRESSURE MOVES THROUGH THE REGION TONIGHT INTO
SUNDAY FOR SOME LIGHT SNOW. LOOKING AT SNOW DEVELOPING AT KRST
AROUND 07Z AND AT KLSE AROUND 11Z. WITH HEAVIEST AXIS OF SNOW
EXPECTED TO BE WEST/SOUTH OF THE TAF SITES...WENT WITH 3SM -SN AT
KRST IN THE 07-12Z TIME FRAME AND 5SM -SN AT KLSE IN THE 11-12Z
TIME FRAME. CIGS LOOK TO REMAIN AOA 3KFT IN THE RESPECTIVE TIME
FRAMES.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST
     SUNDAY FOR WIZ054-061.

     WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ017-029-
     032>034-041>044-053>055-061.

MN...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ079-
     086>088-094>096.

     WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON CST
     SUNDAY FOR MNZ086-094-095.

IA...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST
     SUNDAY FOR IAZ008>011-018-019-029-030.

     WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR IAZ008>011-
     018-019-029-030.

&&

$$

SHORT TERM...LAWRENCE
LONG TERM...LAWRENCE
AVIATION...DAS


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