Area Forecast Discussion
Issued by NWS La Crosse, WI

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806
FXUS63 KARX 092338
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
538 PM CST TUE FEB 9 2016

.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 131 PM CST TUE FEB 9 2016

A TYPICALLY BENIGN FEBRUARY FORECAST HEADING INTO LATE WEEK...WITH
THE MAIN CONCERN BEING TEMPERATURE TRENDS...AND SOME SMALL CHANCES
FOR MAINLY LIGHT SNOW...PARTICULARLY THURSDAY NIGHT INTO EARLY
FRIDAY. AS DISCUSSED QUITE A BIT RECENTLY...THE OVERALL FLAVOR OF
OUR WEATHER PATTERN INTO LATE WEEK (AND REALLY INTO THE WEEKEND) IS
ONE OF BELOW NORMAL TEMPERATURES...AS SHARP WESTERN RIDGING AIDS IN
PERSISTENT TROUGHING OVER THE EASTERN THIRD TO HALF OF THE CONUS.
ALL THE WHILE...PRONOUNCED MID LEVEL CONFLUENCE BETWEEN THOSE TWO
FEATURES WILL HELP STEER SEVERAL BOUTS OF LOW LEVEL RIDGING DOWN
FROM CENTRAL CANADA THROUGH THE MISSISSIPPI VALLEY...KEEPING MOST OF
THE AREA MAINLY ON THE DRY AND CHILLY SIDE RIGHT ON INTO FRIDAY. OF
COURSE...IN TYPICAL FASHION...THERE`S ALWAYS SOMETHING TO LOOK
AT...AND THAT "SOMETHING" THIS GO AROUND IS THE PLACEMENT OF A
RATHER TIGHT THERMAL GRADIENT JUST OFF TO OUR WEST...AS LEE
TROUGHING AND SUBSEQUENT WARMING THERMAL PROFILES INTERACT WITH THAT
PERSISTENT COLD STUCK OVER OUR AREA.

THAT SETUP OF COURSE WILL HELP STRENGTHEN A FRONTOGENETIC RESPONSE
AT VARIOUS TIMES...WITH THE FIRST SHOT OF THAT ALREADY TAKING SHAPE
THIS AFTERNOON OVER WESTERN NORTH DAKOTA. A SECOND SHOT OF STRONGER
FORCING LOOKS TO DRIVE A SNOW BAND SOUTHWARD THROUGH EASTERN ND/SD
INTO WESTERN IA LATER TONIGHT INTO WEDNESDAY MORNING...BUT WITH OUR
LOCAL AREA DOMINATED BY LOW LEVEL RIDGING AND MAINLY CLEAR
CONDITIONS. THAT SHOULD DELIVER SOME CHILLY OVERNIGHT LOWS...
ESPECIALLY WESTERN HALF OF THE AREA WHERE WINDS HAVE A SHOT TO
DECOUPLE IN THE WEAKEST GRADIENT. WIND CHILL VALUES MIGHT PUSH
ADVISORY CRITERIA FOR A FEW HOURS TOWARD SUNRISE...BUT NOT PLANNING
ANY HEADLINES GIVEN THE RELATIVELY ISOLATED NATURE OF SUCH
CONDITIONS.

THEREAFTER...SHOULD SEE SOME PASSING MID CLOUDS INTO WEDNESDAY BUT
WITH RIDGING IN FULL CONTROL THROUGH THURSDAY...LIKELY DELIVERING A
GOOD DEAL OF SUNSHINE FOR THAT DAY. STILL WATCHING THE PASSAGE OF
ANOTHER WEAKER WAVE INTO THURSDAY NIGHT AND EARLY FRIDAY...BUT
QUESTIONS REMAIN ABOUT HOW MUCH OUR THERMAL TROUGHING WILL RELAX TO
ALLOW ANY BETTER WARM ADVECTION ASCENT UP IN THIS DIRECTION. LATEST
09.12Z GFS HAS REALLY BACKED AWAY FROM THE IDEA OF A RELAXATION OF
THE PATTERN...THOUGH THE GGEM/ECMWF REMAIN STEADFAST...SUPPORTING
CHANCES FOR MAINLY LIGHT SNOW. TEMPS SOLIDLY BELOW NORMAL RIGHT ON
THROUGH FRIDAY...WITH WED/THU MORNINGS BEING THE COLDEST AS SOME OF
THE USUAL "ICE BOX" AREAS ARE LIKELY TO END UP IN THE TEENS BELOW
ZERO.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 131 PM CST TUE FEB 9 2016

QUIET AND CHILLY WEATHER CONTINUES INTO FRIDAY NIGHT AND SATURDAY
WITH ONE LAST REINFORCING SHOT OF COLD AIR ARRIVING...COURTESY OF
IMPRESSIVE 1040+ MB SURFACE RIDGING SLIDING ACROSS THE REGION. GIVEN
THAT SETUP...SHOULD SEE HIGHS ON SATURDAY STUCK IN THE SINGLE DIGITS
(MAYBE EVEN NEAR ZERO IN SOME SPOTS?) AND LOWS WELL BELOW ZERO...
POTENTIALLY DOWN BELOW -15F PENDING CLOUD TRENDS AND THE SURFACE
HIGH PLACEMENT. PRETTY GOOD AGREEMENT REGARDING THE ARRIVAL OF OUR
NEXT STRONGER SHORTWAVE TOWARD SUNDAY/SUNDAY NIGHT...WITH A CHANCE
FOR SNOW. LOTS OF DETAILS TO BE WORKED OUT FOR THIS SYSTEM...BUT IT
DOES HAVE POTENTIAL FOR ACCUMULATING SNOWFALL. LOOKING BEYOND...HAVE
SEEN A TREND TOWARD A DE-AMPLIFICATION TO THE OVERALL PATTERN FOR
QUITE A FEW DAYS IN THE LOWER RANGE GUIDANCE...AND IT APPEARS THAT
WE MAY BE HEADED BACK INTO A MORE ZONAL FLOW REGIME FOR MUCH OF NEXT
WEEK...SUGGESTIVE OF TEMPERATURES MODERATING BACK TOWARD NORMAL OR
ABOVE NORMAL LEVELS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 538 PM CST TUE FEB 9 2016

VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. HIGH PRESSURE
WILL BUILD INTO THE TAF SITES TONIGHT PROVIDING MOSTLY CLEAR
SKIES. NORTHWEST WINDS WILL GRADUALLY DIMINISH OVERNIGHT INTO
EARLY WEDNESDAY MORNING AS THE HIGH MOVES IN. A WEAK UPPER LEVEL
DISTURBANCE WILL SLIDE ACROSS WESTERN MINNESOTA/IOWA ON WEDNESDAY
CREATING INCREASING MID LEVEL AND HIGH LEVEL CLOUD COVER AT KRST
AND KLSE...WITH CLOUD BASES IN THE 12KFT TO 20KFT RANGE.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT TERM...LAWRENCE
LONG TERM...LAWRENCE
AVIATION...WETENKAMP



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