Area Forecast Discussion
Issued by NWS La Crosse, WI

Home | Current Version | Previous Version | Text Only | 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 151754
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1154 AM CST MON DEC 15 2014

.UPDATE...
ISSUED AT 1154 AM CST MON DEC 15 2014

VISIBILITIES IMPROVING SOUTH OF I-94 WITH RAIN MOVING IN.
HOWEVER...ACROSS CLARK/TAYLOR AND THE REST OF NORTHERN
WISCONSIN...VISIBILITIES STILL NEAR ZERO IN SOME SPOTS. WILL KEEP
DENSE FOG ADVISORY GOING ACROSS THOSE COUNTIES UNTIL 6PM.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 229 AM CST MON DEC 15 2014

FOG STILL PRIMARY CONCERN INITIALLY...BUT A CHANGE IS COMING AS
THE LARGE CLOSED SYSTEM EJECTS NORTHEAST THROUGH THE REGION. FOG
WILL GIVE WAY TO RAIN...AND THEN A TRANSITION TO SNOW AS THE
COOLER AIR SURGES IN BEHIND THE SYSTEM.

08Z SURFACE ANALYSIS SHOWS CENTER OF THE LOW PRESSURE SYSTEM OVER
KS...WITH AN INVERTED TROUGH STRETCHING NORTH THROUGH OMAHA AND
INTO WESTERN IA/MN AND WESTERN ONTARIO. EXTENSIVE LOW CLOUD AND
FOG CONTINUES TO PLAGUE THE AREA EAST OF THE SYSTEM AND DENSE FOG
ADVISORIES CONTINUE THROUGH NOON. SHIELD OF RAIN ROTATING AROUND
THE SYSTEM AND AS IT MOVES IN...SHOULD HELP TO IMPROVE THE FOG
SITUATION. THUS THE PLAN IS TO LET THE ADVISORY RUN UNTIL NOON.

SYSTEM TRACKS SLOWLY NORTHEAST ACROSS IA TODAY...AND TO NEAR
CHICAGO BY TUESDAY MORNING. DEFORMATION AREA WITH MOST
SIGNIFICANT PRECIPITATION LOOKS TO BE FROM THE SIOUX FALLS
AREA...UP TOWARD THE TWIN CITIES AND DULUTH. ENOUGH COLD AIR
AVAILABLE FOR SOME OF THAT TO FALL IN THE FORM OF SNOW. FOR OUR
FORECAST AREA...APPEARS THAT THE HEAVIEST PRECIPITATION WILL BE
OVER BEFORE THE COLD AIR ARRIVES. SO WHILE THERE WILL LIKELY BE
SOME WINTRY PRECIPITATION... IT SHOULDN`T AMOUNT TO TOO MUCH THIS
TIME. LAST ITEM TO DIAGNOSE IS THE POTENTIAL FOR A MIX AS THE COLD
AIR SURGES IN TO CHANGE THE RAIN OVER TO SNOW. COULD BE A SHORT
PERIOD OF SLEET OR EVEN FREEZING RAIN AS THE TRANSITION OCCURS.
FOR NOW DO NOT FORESEE THE NEED FOR AN ADVISORY...BUT WE WILL HAVE
TO KEEP AND EYE ON THE TIMING OF THE COLD AIR ARRIVAL.

THE WARM TEMPERATURES OF THE PAST FEW DAYS WILL BE DISAPPEARING
BEHIND THE SYSTEM AS WELL. TEMPERATURES WILL HOVER IN THE 40S
TODAY...BUT LOOK TO DIVE BELOW THE FREEZING MARK BY MORNING.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 229 AM CST MON DEC 15 2014

SYSTEM PULLS AWAY ON TUESDAY...BUT ANOTHER TROUGH DROPS SOUTH OUT
OF ONTARIO BEHIND IT...HELPING TO DIG A LARGER TROUGH. DYNAMIC
LIFT AHEAD OF THIS SECOND SYSTEM WILL ACT ON RESIDUAL MOISTURE AND
LOOKS TO GENERATE SOME FLURRIES TUESDAY NIGHT. ADDED TO THE
FORECAST. THIS ONE ALSO HAS ANOTHER REINFORCING SHOT OF COLD AIR
WITH IT...SO EXPECT A RETURN TO MORE TYPICAL DECEMBER TEMPERATURES
FOR THE REMAINDER OF THE WEEK. HIGH PRESSURE THEN SETTLES IN FOR
THURSDAY INTO EARLY FRIDAY...PROVIDING TRANQUIL BUT COOL WEATHER.
THE NEXT WEATHER DISTURBANCE MOVES THROUGH THE SOUTHERN PORTION OF
THE COUNTRY FRIDAY INTO SATURDAY. ECMWF KEEPS THE SYSTEM WELL
SOUTH OF OUR AREA...BUT THE GFS IS A BIT FURTHER NORTH. SIDING
WITH THE ECMWF AT THIS POINT BUT BEARS WATCHING WITH MANY PEOPLE
HAVING WEEKEND TRAVEL PLANS. BEYOND THAT...THE UPPER LEVEL FLOW
PATTERN LOOKS TO KEEP THE MAIN STORM TRACKS EITHER NORTH OR SOUTH
OF THE LOCAL AREA.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1154 AM CST MON DEC 15 2014

RAIN HAS FINALLY SCOURED OUT PESKY DENSE FOG ACROSS THE AREA. THIS
RAIN WAS FALLING IN ADVANCE OF A DEEPENING LOW PRESSURE SYSTEM
OVER SOUTHWEST IA. LOOK FOR THE RAIN TO CONTINUE INTO
TONIGHT...WITH A TRANSITION TO SNOW AFTER 08Z AT KRST AND 12Z AT
KLSE AS COLD AIR IS DRAWN IN BEHIND THE LOW MOVING THROUGH
NORTHERN IL. COULD BE A BRIEF PERIOD OF SOME SOME SLEET IN THE
TRANSITION...BUT FELT NOT SIGNIFICANT ENOUGH TO INCLUDE IN THE
BODY OF THE TAF. OTHERWISE...LOOK FOR LIFR CONDITIONS AT
KRST...IMPROVING INTO IFR BY 05Z...AND MVFR AFTER 14Z. AT
KLSE...IFR CONDITIONS EXPECTED TO IMPROVE INTO MVFR AFTER 12Z.
RELATIVELY LIGHT WINDS WILL BECOME GUSTY OUT OF THE
NORTH/NORTHWESTAS THE LOW PULLS INTO IL OVERNIGHT. EXPECT GUSTS
IN THE 25 TO 35KT RANGE LATE TONIGHT THROUGH TUESDAY MORNING.
SNOWFALL LATE TONIGHT THROUGH TUESDAY MORNING EXPECTED TO BE 1/4
INCH OR LESS.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ017-029.

MN...NONE.
IA...NONE.
&&

$$

UPDATE...DAS
SHORT TERM...MW
LONG TERM...MW
AVIATION...DAS


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