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 071003
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
500 AM CDT TUE JUL 7 2015

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 249 AM CDT TUE JUL 7 2015

CANADIAN WILDFIRE SMOKE STILL PREVALENT ACROSS PORTIONS OF THE
AREA...DRAGGED IN WITH NORTHERLY SURFACE FLOW/SUBSIDENCE BEHIND
DEPARTING COLD FRONT. SURFACE OBSERVATIONS ALONG/SOUTH OF A MEDFORD
WI-LA CROSSE WI-CHARLES CITY IA STILL IN THE 1-3SM RANGE WITH ACRID
SMELL OF THIS SMOKE EVIDENT OUTSIDE THE NWS LA CROSS OFFICE AT
PRESENT. OTHERWISE...SKIES WERE SLOWLY CLEARING FROM NORTHWEST TO
SOUTHEAST BEHIND THE DEPARTING COLD FRONT WHILE TEMPERATURES AT 2 AM
HOVERED IN THE MIDDLE 50S ACROSS NORTHERN WI...TO THE UPPER
50S/LOWER 60S ACROSS PORTIONS OF NORTHEAST IA INTO FAR SOUTHWEST WI.

PER EXTRAPOLATION OF IMPROVING VISIBILITIES UPSTREAM AND AIR QUALITY
FORECAST GUIDANCE...LOOKS LIKES WE WILL SEE/SMELL SMOKEY CONDITIONS
ACROSS PORTIONS OF SOUTHERN WI INTO NORTHEAST IA THROUGH THIS
MORNING BEFORE MIXING THROUGH THE BOUNDARY LAYER TAKES PLACE BY NOON
AND DISPERSES PARTICULATES...THEREBY SLOWLY IMPROVING CONDITIONS.
THE REST OF TODAY WILL SEE HAZY SUNSHINE AS THE SMOKE LIFTS INTO A
LAYER. OTHERWISE...LOOK FOR COOLER/DRIER CONDITIONS TODAY AS HIGH
PRESSURE BUILDS IN FROM THE NORTHERN PLAINS INTO THE UPPER
MISSISSIPPI RIVER REGION. HIGHS TODAY ARE EXPECTED TO TOP OFF IN THE
UPPER 60S TO THE MIDDLE 70S WITH NORTH WINDS AROUND 10 MPH.

FOR TONIGHT...HIGH PRESSURE WILL SET UP OVERHEAD WITH COOL OVERNIGHT
LOWS RANGING FROM THE MIDDLE/UPPER 40S IN THE SAND COUNTRY OF
CENTRAL WI...TO THE LOWER 50S ELSEWHERE. HAVE INCLUDED PATCHY FOG IN
THE RIVER VALLEYS WITH AREAS OF FOG IN THE SAND COUNTRY OF CENTRAL
WI WITH THIS SETUP. WILL HAVE TO WATCH INCREASING CIRRUS VEIL THAT
MODELS ARE DEPICTING AHEAD OF A WEAK SHORTWAVE TROUGH IN THE CENTRAL
PLAINS. THIS MAY LIMIT RADIATIONAL COOLING/FOG POTENTIAL. HOWEVER...
IF THERE IS LESS CIRRUS...FOG COULD BECOME MORE WIDESPREAD. WILL
HAVE TO KEEP AN EYE ON THIS.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 249 AM CDT TUE JUL 7 2015

LOOKS LIKE DRY/COOLER THAN NORMAL CONDITIONS THROUGH THURSDAY AS
HIGH PRESSURE REMAINS IN CONTROL ACROSS THE REGION. PLAN ON HIGHS IN
THE MIDDLE/UPPER 70S.

SHOWER THUNDERSTORM CHANCES RETURN TO THE AREA AND LINGER THROUGH
THE WEEKEND AS A WARM FRONT LIFTS NORTHWARD INTO THROUGH THE REGION.
GFS PRODUCES 2000-3000J/KG OF MUCAPE ON SATURDAY/SUNDAY AFTERNOONS
AS PRECIPITABLE WATER VALUES INCREASE TO AROUND 2 INCHES. BULK SHEAR
LOOKS MINIMAL IN THE 15-20KT RANGE IN THE HIGHER CAPE AXIS...SO
MAINLY LOOKS LIKE THE POTENTIAL FOR EFFICIENT RAIN-MAKING
THUNDERSTORMS WITH PERHAPS SOME LOCALLY HEAVY RAINFALL. WILL HAVE TO
KEEP A CLOSER EYE ON THIS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 500 AM CDT TUE JUL 7 2015

CIGS...
LOW CLOUDS HAVE CLEARED KLSE AND HIGH PRESSURE WILL BE THE
MAIN WEATHER INFLUENCE INTO THU. SKC/SCT VFR SKIES ARE EXPECTED.

VSBY...
THE SMOKE HAS ALSO CLEARED EAST OF KLSE WITH QUICKLY
IMPROVED VSBY. THE AIR QUALITY FORECAST SUGGESTS THIS SHOULD STAY
THIS WAY...AND WILL KEEP SMOKE OUT OF THE FORECAST. FOG...ON THE
OTHERHAND...COULD BECOME AN ISSUE. WITH THE HIGH MOVING OVERHEAD
TONIGHT...PERFECT DIURNAL SETUP FOR VALLEY FOG AT KLSE - ALBEIT
OUTSIDE OF THE CLIMATOLOGICAL FAVORED TIME PERIOD. DEEP LIGHT WIND
LAYER UP TO 10 KFT PER NAM BUFKIT SOUNDING AND VRB TO LIGHT
SOUTHEAST AT THE SFC. PERFECT FOR 1/4SM FG. HOWEVER...ITS UNCLEAR
WHETHER SOME HIGH CIRRUS COULD PROVIDE A BKN CIG...TEMPERING THE
DIURNAL COOLING. PLUS...NUMERICAL GUIDANCE SUGGESTS T/TD SPREAD WILL
HOLD AT LEAST 3 DEGREES. STILL...NAM BUFKIT DOES INDICATE A NEAR SFC
SATURATION BY 12Z. THIS COULD MANIFEST IN JUST SOME BCFG...OR
SOMETHING MORE. HARD TO SAY RIGHT NOW...BUT WILL ADD BCFG TO HONOR
THE FAVORABLE CONDITIONS. IF DENSE FOG WOULD MANIFEST...SHOULD ONLY
LAST UNDER 1 HOUR.

WINDS...
NORTH WILL BECOME LIGHT AND VRB TONIGHT AS HIGH PRESSURE
MOVES OVERHEAD.

&&

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

$$

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.