Area Forecast Discussion
Issued by NWS La Crosse, WI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KARX 172310
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
610 PM CDT FRI APR 17 2015

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 220 PM CDT FRI APR 17 2015

SEVERAL CONCERNS COMING IN THE NEXT SEVERAL DAYS...INCLUDING
ELEVATED FIRE POTENTIAL SATURDAY...AND ONSET OF RAIN SATURDAY
NIGHT INTO SUNDAY.

HIGH PRESSURE AND LAX WIND RESULTING IN A PLEASANT DAY WITH
SATELLITE LOOPS SHOWING SOME DIURNAL CUMULUS. BUT THINGS WILL
CHANGE WITH LARGE CLOSED SYSTEM FILLING AND EJECTING ACROSS THE
AREA THIS WEEKEND. CLOUD COVER AND MOISTURE WILL BE INCREASING
AHEAD OF THIS FEATURE...BUT NOT BEFORE ONE MORE DAY OF WARM
WEATHER. SOUTHERLY FLOW WILL BE BRINGING MORE MOISTURE INTO THE
REGION...BUT THAT WILL NOT REALLY ARRIVE EN MASS UNTIL SATURDAY
NIGHT. PRIOR TO THAT...DRY EASTERLY WINDS AND DEEP MIXING WILL
ALLOW FOR VERY LOW DEWPOINTS FOR MUCH OF WI. HUMIDITY LEVELS WILL
BE DROPPING BELOW 30 PERCENT AND THERE IS CONCERN FOR ELEVATED
FIRE DANGER. MORE ON THAT IN THE FIRE WEATHER SECTION BELOW.

MOISTURE WILL FIGHT THE DRY AIR INITIALLY...BUT EVENTUALLY THE
SATURATION WILL WIN OUT AND SHOWERS/TSRA WILL BEGIN IN EARNEST.
SHORT TERM MODEL SOLUTIONS ALL IN AGREEMENT SHOWING THAT THE
CLOSED SYSTEM WILL OPEN UP AND PHASE INTO THE LONG WAVE TROUGH
THAT IS MOVING ACROSS THE UPPER MIDWEST. BUT SOME OF THE DETAILS
ARE DIFFERENT IN HOW THIS PHASING AND THE FORCING WILL MANIFEST
THEMSELVES. THERE IS A GENERAL CONSENSUS IN A BROAD AREA OF
SHOWERS AND EMBEDDED TSRA IN THE DEFORMATION AND FRONTOGENETIC
AREAS. WENT WITH CATEGORICAL RAIN CHANCES FROM SATURDAY NIGHT ALL
THE WAY INTO SUNDAY EVENING...BUT RAIN AMOUNTS DO NOT APPEAR TO
BE TOO EXCESSIVE.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 220 PM CDT FRI APR 17 2015

RAIN AREA FINALLY SHIFTS EAST OUT OF THE AREA LATE SUNDAY NIGHT OR
EARLY MONDAY. BUT STRONG COLD ADVECTION BEHIND THE TROUGH WILL
RESULT IN A VERY BLUSTERY DAY ON MONDAY. THERE WILL ALSO BE SOME
LIFT IN THE CYCLONIC FLOW BEHIND THE SYSTEM...AND COLD SHOWERS ARE
A POSSIBILITY. WITH TEMPERATURE PROFILES SHOWING PLENTY OF COLD
AIR JUST OFF THE DECK...IT IS NOT OUT OF THE REALM OF
POSSIBILITIES WE COULD SEE SOME SNOW SHOWERS OR FLURRIES MIXED IN.
GFS IS MOST BULLISH WITH THE PRECIP RISK.

COLD AIR INVADES BY TUESDAY MORNING. 850 MB TEMPERATURES FALL TO
-2 TO -4 RANGE OVER THE FORECAST AREA. DEPENDING ON HOW MUCH THE
WINDS SLACKEN WE COULD HAVE A RISK FOR SOME FROST. MORE ON THAT AS
WE GET CLOSER. ANOTHER SHORT WAVE TROUGH ROTATES AROUND THE MAIN
UPPER TROUGH TUESDAY NIGHT...SO STILL COULD HAVE SOME LIGHT MIXED
PRECIP ISSUES. BEYOND THAT IT LOOKS TO BE DRY...BUT IT WILL STAY
COLD THROUGH THE WEEK.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 610 PM CDT FRI APR 17 2015

HIGH PRESSURE OVER SOUTHERN CANADA WILL MOVE SOUTHEAST AND OVER
THE GREAT LAKES THROUGH SATURDAY. THIS WILL MAINTAIN VFR
CONDITIONS ACROSS THE AREA BUT LOOK FOR MID LEVEL CEILINGS TO
DEVELOP SATURDAY AT KRST AS MOISTURE CONTINUES TO WORK NORTH AHEAD
OF A STORM SYSTEM SLOWLY APPROACHING FROM THE SOUTHWEST. ANY
RAINFALL FROM THIS SYSTEM LOOKS TO HOLD OFF UNTIL SATURDAY
EVENING AT THE EARLIEST. THE GRADIENT WILL TIGHTEN UP BETWEEN THE
HIGH OVER THE GREAT LAKES AND THE APPROACHING STORM SYSTEM TO
PRODUCE EAST TO SOUTHEAST WINDS SATURDAY BETWEEN 10 AND 15 KNOTS
WITH GUSTS OF 20 TO 25 KNOTS FROM THE MIDDLE OF THE MORNING
THROUGH THE AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 220 PM CDT FRI APR 17 2015

THERE IS A RISK FOR HIGHER FIRE DANGER SATURDAY AFTERNOON THANKS
TO THE CONTINUED DRY AIR FEED ON EASTERLY WINDS. HUMIDITY LEVELS
WILL DROP BELOW 25 PERCENT...AND PERHAPS DOWN AROUND 20 PERCENT.
HIGH TEMPERATURES LOOK TO BE BORDERLINE...ONLY REACHING THE 65-70
RANGE...AND WINDS WILL ALSO BE BORDERLINE WITH SPEEDS IN THE 10-15
MPH RANGE. BUT WITH THE PRIMARY FUEL CONCERN BEING GRASS WHICH
DRIES QUICKLY AND BURNS EASILY...WE HAVE ALREADY SEEN THAT THESE
CRITERIA ARE NOT TERRIBLY IMPORTANT FOR FIRE POTENTIAL.

&&

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

$$

SHORT TERM...MW
LONG TERM...MW
AVIATION...04
FIRE WEATHER...MW



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.