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 130735
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
235 AM CDT SAT SEP 13 2014

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 235 AM CDT SAT SEP 13 2014

WATER VAPOR IMAGERY/RAP 500MB ANALYSIS SHOWING DEEP MID-LEVEL TROUGH
THAT GAVE THE AREA A CHILLY DAMP FRIDAY NOW OVER UPPER MI. RADAR
MOSAIC SHOWING LINGERING RAIN FROM CENTRAL UPPER MI INTO OVER FAR
EASTERN WI. IR SATELLITE SHOWED BULK OF LOW CLOUDS ASSOCIATED WITH
THIS TROUGH NOW NORTHEAST OF I-94. SURFACE HIGH PRESSURE/CLEARING
WAS WORKING INTO THE FORECAST AREA. ARX WEBCAM SHOWING EXTENSIVE
MISSISSIPPI RIVER VALLEY FOG WITH THE CLEARING/LIGHT WINDS. FOG WAS
HIT AND MISS ACROSS THE REST OF THE FORECAST AREA. OTHERWISE...
TEMPERATURES AS OF 2 AM WERE IN THE MIDDLE 30S TO MIDDLE 40S.

PLAN ON CONTINUING FROST ADVISORY THROUGH 8 AM THIS MORNING AS
TEMPERATURES FALL INTO THE LOWER/MIDDLE 30S. OTHERWISE...PLAN ON A
DRY/COOL SATURDAY AS A RIDGE OF HIGH PRESSURE PASSES OVERHEAD. LOOK
FOR HIGHS IN THE 55-65 DEGREE RANGE WHICH IS SOME 10-15 DEGREES
BELOW THE NORMAL...BUT MUCH BETTER THAN THE CHILLY CONDITIONS SEEN
ON FRIDAY.

LIGHT SOUTH WINDS/WARM AIR ADVECTION WILL THEN SET UP ACROSS THE
AREA TONIGHT AS THE HIGH MOVES INTO THE GREAT LAKES REGION AND A MID-
LEVEL/SURFACE TROUGH PUSHES FROM THE NORTHERN PLAINS INTO MN. SOME
MID/HIGH CLOUD WILL ALSO BE SEEN MAINLY NORTH OF I-94 IN THE WARM
AIR ADVECTION. LOOK FOR LOWS IN THE UPPER 30S TO THE LOWER 40S.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 235 AM CDT SAT SEP 13 2014

MID-LEVEL/SURFACE TROUGH PUSHES INTO THE AREA ON SUNDAY. MODELS
SHOWING WEAK 850MB MOISTURE TRANSPORT AND BEST SURFACE CONVERGENCE
NORTHEAST OF I-94 FOR A CHANCE OF SHOWERS IN THE AFTERNOON. THE REST
OF THE AREA LOOKS TO REMAIN DRY. OTHERWISE...PLAN ON ANOTHER EARLY
AUTUMN-LIKE DAY WITH HIGHS TOPPING OFF IN THE 60S.

SHOWER CHANCES WILL SPREAD ACROSS THE REST OF THE AREA SUNDAY NIGHT
AS THE TROUGH SLIPS SOUTHEAST. LOOK FOR LOWS IN THE 40S TO LOWER
50S. SHOWER CHANCES LOOK TO LINGER INTO MONDAY AS ANOTHER MID-LEVEL
TROUGH DROPS INTO THE AREA FROM THE NORTHERN PLAINS. THIS TROUGH
INTERACTS WITH THE BAROCLINIC ZONE ACROSS THE SOUTH WITH WEAK
FRONTOGENESIS IS NOTED IN THE 850-500MB LAYER PER THE NAM. THE GFS
IS A BIT STRONGER WITH THIS. WILL GO WITH A 20-50 POPS FOR NOW
MAINLY ALONG/SOUTH OF I-90. PLAN ON HIGHS MONDAY GENERALLY IN THE 60-
65 DEGREE RANGE.

FOR THE PERIOD TUESDAY THROUGH FRIDAY...

COOL/DRY NORTHWEST FLOW ALOFT WILL PREVAIL TUESDAY INTO WEDNESDAY
WITH HIGHS IN THE 60S AND LOWS IN THE UPPER 30S TO MIDDLE 40S.

SOME WARMING LOOKS TO TAKE PLACE THURSDAY INTO FRIDAY AS HIGH
PRESSURE MOVES OFF TO THE EAST AND A TROUGH MAKES ITS WAY OUT OF THE
INTERMOUNTAIN WEST INTO THE PLAINS. INCREASING WARM AIR
ADVECTION/MOISTURE TRANSPORT INTO THE REGION MAY PUSH A FEW SHOWERS
INTO THE AREA  LATER THURSDAY NIGHT INTO FRIDAY. LOOK FOR HIGHS
THURSDAY IN THE 60S AND MID 60S TO THE LOWER 70S ON FRIDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1140 PM CDT FRI SEP 12 2014

WITH CLOUDS HOLDING T/TD SPREADS CLOSE THROUGH THE DAY...AND
CLEARING SKIES JUST IN TIME FOR NIGHTTIME...ITS A FAVORABLE SETUP
FOR DIURNAL COOLING INDUCED RIVER VALLEY FOG. NOT AS MUCH T/TD
SPREAD TO MAKEUP - ONLY 3 DEGREES AT 04Z. SFC WINDS WILL BE LIGHT
THROUGH THE NIGHT. HOWEVER...A SIGNIFICANT DRAWBACK WILL BE THE
DEPTH OF THE LIGHT WIND LAYER. RAP BUFKIT SOUNDINGS CONTINUE TO
BRING 10+ KTS OF WIND BY 300 FT FOR MOST OF THE NIGHT. THE NAM HAS A
SLIGHTLY DEEPER LIGHT WIND FOR THE FIRST PART OF THE
OVERNIGHT...DECREASING BEFORE 12Z. GENERALLY - THE SHALLOWER THE
LIGHT WIND LAYER...THE LESS FAVORABLE FOR DENSE FOG. CLOUDS AREN/T
COMPLETELY CLEAR EITHER...WITH SCATTERED PATCHES MOVING OVERHEAD.
CERTAINLY...SOME VSBY RESTRICTIONS ARE LIKELY...AND COULD SEE
THICKER FOG/STRATUS BANK SITTING ON THE MISSISSIPPI RIVER...BUT
UNSURE IF IT WILL SPREAD ACROSS KLSE. THIS COULD BE A SCENARIO WHERE
VSBYS DO DROP TO 1/4SM BRIEFLY...THEN BACK UP TO P6SM...THEN
2SM...AS FOG SLOSHES AROUND. CONFIDENCE LOW IN HOW THIS WILL
PLAYOUT...SO WILL LIKELY HOLD WITH MVFR VSBYS AND BCFG FOR NOW.
SOMETHING TO WATCH CLOSELY TONIGHT.

HIGH PRESSURE BUILDS IN SATURDAY...AND WILL RESULT IN VFR CONDITIONS
OUTSIDE OF THE EARLY MORNING FOG POTENTIAL. WINDS WILL GRADUALLY
SWING FROM WEST TO SOUTHWEST. LATER SAT NIGHT...SOME CIGS NEAR 4KFT
COULD RETURN AS LOW LEVEL WARM AIR ADVECTION AND WEAK MOISTURE
TRANSPORT LEAD A SHORTWAVE MOVING EAST ACROSS THE NORTHERN PLAINS.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR WIZ017-029-033-
     034-042>044.

MN...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR MNZ086-087-094-
     095.

IA...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR IAZ008>010-018-
     019-029.

&&

$$

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



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