National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KARX 240729
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
230 AM CDT FRI MAY 24 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 230 AM CDT FRI MAY 24 2013

850 MB MOISTURE TRANSPORT/JET WILL KICK OFF/ENHANCE SHOWERS/ISOLD
STORMS OVER MN/NORTHERN IA TONIGHT...ALONG AND NORTH OF A SFC WARM
FRONT. CORFIDI VECTORS WOULD TAKE THE COMPLEX SOUTHEAST. MODELS AT
ODDS WITH EACH OTHER ON WHERE THE MORE LIKELY PCPN WILL
LIE...GENERATING THE MAIN MASS OF PCPN IN SLIGHTLY DIFFERENT
LOCATIONS. THIS LOWERS FORECAST CONFIDENCE IN WHERE TO PLACE THE
HIGHER PCPN CHANCES. TRENDS SEEM TO FAVOR THE SOUTHWEST 1/2 OF THE
FORECAST AREA THOUGH...AND WILL SIDE WITH THAT.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 230 AM CDT FRI MAY 24 2013

AN UPPER LEVEL RIDGE HOLDS ACROSS THE UPPER MISSISSIPPI RIVER VALLEY
INTO THE EARLY PART OF THE NEW WORK WEEK...SLOWLY SHIFTING EAST FOR
THE FOLLOWING WEEKEND. TROUGH HOLDS WEST OF THE RIDGE...SPITTING OUT
PIECES OF UPPER LEVEL ENERGY FROM TIME TO TIME. WHILE NOT AN OVERTLY
STRONG...BLOCKING TYPE PATTERN...ITS NOT MOVING VERY FAST AT
ALL...WITH LITTLE IN THE WAY OF 250-300 MB JETS TO MOVE IT ALONG.
AND DESPITE HAVING THE RIDGE OVER THE REGION FOR THE NEXT FEW
DAYS...THIS DOES NOT MEAN ITS GOING TO BE DRY.

NAM/GFS/ECMWF ALL HAVE A WARM FRONT HANGING ACROSS THE CENTRAL
PLAINS/MID MISSISSIPPI RIVER VALLEY THROUGH THE WEEKEND...FINALLY
GETTING A PUSH NORTHWARD THROUGH THE FORECAST AREA ON TUESDAY. 850
MB MOISTURE TRANSPORT IS FAIRLY PERSISTENT INTO AND THROUGH THE
BOUNDARY INTO THE MIDDLE OF NEXT WEEK. THIS TRANSPORT WILL BE A MAIN
FOCUS FOR SHOWER/STORM DEVELOPMENT...AND WHERE THIS NOSES INTO WILL
HOUSE THE BETTER INITIATION REGIONS. MODELS FOCUS THEIR QPF ON THE
MOISTURE TRANSPORT - VICINITY OF THE WARM FRONT...AND CAN/T FAULT
THIS PLACEMENT. ANY MCV FROM OVERNIGHT CONVECTION WILL BE ANOTHER
CONSIDERATION...ALTHOUGH FERRETING OUT WHERE THESE MAY MOVE IS MORE
PROBLEMATIC FARTHER OUT IN THE FORECAST PERIOD.

WITH THE PUSH NORTHWARD ON TUE OF THE WARM FRONT...WARMER/SEASONABLE
AIR SHOULD RETURN...ALONG WITH INSTABILITY AND THUS BETTER CHANCES
FOR THUNDERSTORMS IF CONVECTION CAN DEVELOP.

OVERALL...RAIN WILL BE ON THE RADAR NEARLY EVERY DAY THROUGH THE
WEEKEND AND INTO THE MIDDLE PART OF NEXT WEEK. THAT DOES NOT MEAN
EVERYDAY WILL BE A WASH OUT THOUGH...OR THAT EVERYONE WILL SEE RAIN
EVERYDAY. RAIN CHANCES WILL BE HIGHER TO THE SOUTHWEST THROUGH THE
WEEKEND...GRADUALLY MOVING NORTHWARD FOR THE START OF THE NEW WORK
WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1128 PM CDT THU MAY 23 2013

CLEAR SKIES AND LIGHT WINDS WILL PREVAIL OVERNIGHT INTO FRIDAY
MORNING AS A RIDGE OF HIGH PRESSURE MOVES THROUGH THE REGION.
WINDS WILL PICK UP OUT OF THE SOUTHEAST ON FRIDAY WITH SOME GUSTS
IN THE 15-20KT RANGE POSSIBLE...PARTICULARLY AT RST. UPPER LEVEL
CLOUD COVER WILL BE ON THE INCREASE FRIDAY NIGHT AS THE NEXT
SYSTEM MOVES INTO THE PLAINS WITH A BAND OF RAIN SHOWERS LIKELY
DEVELOPING OUT AHEAD OF IT. THE BETTER CHANCES FOR SEEING THE RAIN
APPEARS TO BE AFTER 6Z...BUT RST COULD HAVE A FEW SHOWERS DEVELOP
A TAD EARLIER. EVEN AS THE RAIN MOVES IN...DRY AIR IN THE LOW
LEVELS SHOULD KEEP CONDITIONS VFR AT THE ONSET. THIS WILL LIKELY
CHANGE GOING INTO SATURDAY AS THE LAYER SATURATES OUT.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY TIL 7 AM CDT FOR
     WIZ017-029-032>034-041>044.

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

$$

SHORT TERM.....RIECK
LONG TERM......RIECK
AVIATION.......HALBACH