FXUS63 KARX 092030
AFDLSE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
230 PM CST SUN NOV 9 2003

.SHORT TERM...THROUGH WEDNESDAY

MAIN FORECAST CONCERN IS THE PCPN CHANCES FOR MON.

ETA/GFS SOLUTIONS FROM THE 12Z SOLUTIONS COMPARABLE AGAIN FOR THIS 
RUN...WITH THE GFS ONLY SLIGHTLY STRONGER WITH SHORTWAVE TO EFFECT 
THE REGION ON MON/TUES. QPF/S AGAIN DIFFERENT...WITH GFS SHOWING 
SOME LIGHT QPF FOR THE SAME TIME FRAME. GFS HAS BEEN THE BETTER 
PERFORMER OVER THE PAST MONTH WITH THESE LIGHTER...THERMODYNAMICALLY 
DRIVEN SYSTEMS. WHILE I DON/T EXPECT MUCH OUT OF THIS MON/TUES 
SYSTEM...WILL CONTINUE TO SIDE TOWARD THE GFS WITH SOME 
SCATTERED...LIGHT PCPN.

500 MB SHORTWAVE MOVES THROUGH THE NORTHERN PLAINS TONIGHT...AND 
ACROSS THE UPPER MISSISSIPPI RIVER VALLEY ON MONDAY NIGHT. AT THE 
SFC...A FRONTAL BOUNDARY WILL REFLECT THE UPPER LEVEL FEATURE...AND 
SLIDE THROUGH THE REGION DURING THE SAME TIME. RH FIELDS CONTINUE TO 
PULL LOW LEVEL SATURATION NORTHWARD...THANKS TO A GOOD SOUTHERLY 
FLOW. EXPECT INCREASING CLOUDS TONIGHT AS A RESULT...WITH MOSTLY 
CLOUDY CONDITIONS ON MONDAY. THERE IS SOME WEAK QG CONVERGENCE 
INDICATED WITH THE SHORTWAVE. 850 MB WARM AIR ADVECTION IS GOOD 
THROUGH 06Z TUE...AS IS THE 925:850 MB THETA-E ADVECTIONS. IN 
ADDITION...GOOD ISENTROPIC UPGLIDE ALONG THE 305:295 K LAYER. 
SIMILAR SCENARIOS HAVE PRODUCED LIGHT RAIN SHOWERS/SPRINKLES OVER 
THE PAST MONTH. HOWEVER...LOOKING CLOSER AT THE 
SATURATION...TIME/HEIGHT X-SECTIONS ALONG WITH FORECAST SOUNDINGS 
INDICATE A DRY NEAR-SFC LAYER...ALONG WITH DRIER AIR AROUND 700 MB. 
ANY PCPN WOULD HAVE TO OVERCOME THIS. FEEL SMALL CHANCES ARE STILL 
WARRANTED...WITH A MON AFTERNOON/EVENING TIME FRAME. WILL MAKE 
ADJUSTMENTS FOR THE TIMING.    

WEAK SFC RIDGING AND AN INFLUX OF DRY AIR POINTS TO CLEARING AND 
SOME SUNSHINE FOR TUESDAY. ANOTHER SHORTWAVE TROUGH...CLIPPER-TYPE 
SYSTEM...WILL SPIN ACROSS THE REGION TUES NIGHT/WED. THE BULK OF THE 
FORCING WITH THIS SYSTEM CURRENTLY LOOKS TO STAY NORTH OF THE 
FORECAST AREA. ALSO...NO SOUTHERLY TAP FOR MOISTURE...SO THIS 
CLIPPER WILL BE BRINGING ITS OWN SATURATION. THIS SCENARIO WOULD 
KEEP THE PCPN CHANCES OVER NORTHERN SECTIONS OF MN AND WI. THIS 
LOOKS REASONABLE AND WILL TAYLOR POPS ACCORDINGLY. PROBABLY THE 
BIGGEST IMPACT THIS NEXT SYSTEM WILL HAVE ON THE FORECAST AREA WILL 
BE IN TERMS OF THE WIND. A STRONG SFC LOW DEVELOPS IN RESPONSE TO 
THIS WAVE...AND BRINGS A TIGHT PRESSURE GRADIENT THROUGH THE REGION 
ON WED. AND WITH THE INFLUX OF COLDER AIR...WED COULD TURN OUT TO BE 
A RATHER BLUSTERY DAY.

.LONG TERM...THURSDAY THROUGH SUNDAY

MRF/ECMWF IN BETTER AGREEMENT THIS GO AROUND...WITH THE MRF BACKING 
OFF ITS PROGRESSIVE SYSTEMS OF THE LAST RUN...COMING MORE IN LINE 
WITH THE SLOWER...MORE CONSISTENT ECMWF MODEL. OF COURSE...THIS 
DOESN/T MEAN THE SOLUTIONS WILL VERIFY...BUT IT LENDS MORE 
CONFIDENCE TO THE POTENTIAL OUTCOMES.

NEARLY ZONAL 500 MB FLOW AFTER THE WED SHORTWAVE KICKS EAST...WITH A 
FEW PERTURBATIONS MOVING ALONG THE FLOW...BUT NOTHING THAT LOOKS 
SIGNIFICANT FOR THIS FORECAST AREA. HIGH PRESSURE BUILDS IN FOR 
THU...AND THEN LOOKS TO BE THE MAIN WEATHER FEATURE FOR NEXT 
WEEKEND.  

&&

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

&&

$$

RIECK