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 221939
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
240 PM CDT MON SEP 22 2014

.SHORT TERM...(TONIGHT)
ISSUED AT 240 PM CDT MON SEP 22 2014

WEAK SURFACE TROUGH SPARKED A BAND OF FAIR WEATHER CU ACROSS
CENTRAL. THESE WILL DIE OFF QUICKLY AROUND SUNSET. HIGH PRESSURE TO
THE SOUTH AND A LIGHT WIND FIELD SETS THE STAGE FOR SOME VALLEY FOG
IN THE RIVER VALLEYS.

.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 240 PM CDT MON SEP 22 2014

MODELS REMAIN IN VERY GOOD AGREEMENT WITH AMPLIFYING AN UPPER LEVEL
RIDGE ACROSS THE CENTRAL U.S. THIS WEEK. NAEFS 500 MB HEIGHT
ANOMALIES INTO THE WEEKEND AVERAGE +2-3 ACROSS THE NORTHERN PLAINS-
UPPER MISSISSIPPI RIVER VALLEY. MEANWHILE...850 MB TEMP ANOMALIES
HOVER FROM 0-1...NOT RECORD TERRITORY...BUT CERTAINLY SUGGEST ABOVE
NORMAL TEMPERATURES INTO THE WEEKEND. ALL IN ALL...LOOKS LIKE A
FABULOUS EARLY FALL WEEK/WEEKEND WITH WARM TEMPERATURES AND DRY
CONDITIONS.

THAT SAID...IT MAY NOT BE COMPLETELY DRY. YESTERDAY...MODELS WERE
MOVING A SHORTWAVE TROUGH FROM THE WEST COAST...ACROSS THE
NORTHERN/CENTRAL PLAINS TUE/WED. SOLUTIONS THEN SUGGESTED THIS BIT
OF UPPER LEVEL ENERGY WOULD SPLIT...WITH A PIECE MOVING INTO
NORTHERN MN AND SOUTHERN CANADA...AND THE SOUTHERN PIECE
RETROGRADING BACK TO THE WEST. THIS WOULD HAVE LEFT THE LOCAL
FORECAST AREA DRY.

LATEST MODEL RUNS TREND BACK TO A PREVIOUS ECMWF SOLUTION WHICH KEPT
THE SHORTWAVE TOGETHER...AND SPUN IT ACROSS THE REGION. LITTLE IF
ANY FRONTOGENETIC CONVERGENCE WITH THE FEATURE...BUT WEAK WARM AIR
ADVECTION AND MOISTURE TRANSPORT WOULD HELP FUEL SCATTERED RAIN
SHOWERS. MOST OF THIS WOULD HOLD WEST OF THE MISSISSIPPI RIVER. THE
STRONG RIDGE EVENTUALLY KILLS THE FEATURE AS IT TRIES TO WORK
FARTHER EAST...AND KICKS IT BACK WEST AS IT DIES OUT. HAVE HAD A DRY
FORECAST GOING FOR THE WED/WED NIGHT PORTION OF THE FORECAST...WITH
ONLY SMALL CHANCES IN THE FAR WEST TUE NIGHT. GOING TO HOLD THIS FOR
NOW. HOWEVER...SMALL CHANCES MAY HAVE TO BE EXPANDED EAST FOR
WED/WED NIGHT IF TRENDS CONTINUE TO SUGGEST THE SHORTWAVE WILL HOLD
TOGETHER AS IT MOVES IN.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1216 PM CDT MON SEP 22 2014

HIGH PRESSURE WILL REMAIN OVERHEAD THROUGH TONIGHT. THIS WILL
PROVIDE FOR CLEAR SKIES AND LIGHT WINDS WITH IDEAL RADIATIONAL
COOLING CONDITIONS. THIS IS EXPECTED TO LEAD TO FAIRLY EXTENSIVE
EARLY MORNING FOG AND STRATUS IN THE RIVER VALLEYS WHICH WILL IMPACT
KLSE AIRPORT. EXPECTING LIFR CONDITIONS AT KLSE TO DEVELOP BETWEEN
09-10Z...THEN LASTING THROUGH 14Z. SOUTH-SOUTHWEST WINDS OVERNIGHT
AT KRST AIRPORT  ARE EXPECTED TO KEEP THE NEAR SURFACE/LOWER
BOUNDARY LAYER MIXED TO PREVENT WIDESPREAD FOG FORMATION. WILL
INCLUDE A 6SM BR MENTION IN THE 09-13Z TIME FRAME. OTHERWISE...
AFTER THE FOG/STRATUS LIFTS IN THE MORNING...PLAN ON VFR CONDITIONS
THROUGH THE REST OF THE DAY.

&&

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

$$

SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION.....DAS


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