440 
FXUS63 KARX 182008
AFDLSE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
310 PM CDT SUN AUG 18 2002

FORECAST CONCERNS FOR THIS PACKAGE INCLUDE PRECIPITATION CHANCES
TONIGHT AND EARLY MONDAY AND THEN AGAIN TUESDAY NIGHT AND
WEDNESDAY.

18Z SURFACE ANALYSIS SHOWS WEAK HIGH PRESSURE EXTENDING FROM NORTH
DAKOTA...SOUTHEASTWARD THROUGH THE GREAT LAKES. A FRONTAL BOUNDARY
EXTENDS FROM A LOW IN COLORADO...ACROSS CENTRAL KANSAS AND CENTRAL
MISSOURI. VISIBLE SATELLITE IMAGERY SHOWS BAND OF CLOUDS JUST TO
THE NORTH OF THIS BOUNDARY ACROSS NEBRASKA AND IOWA LIFTING
NORTHWARD.

12Z MODELS IN EXCELLENT AGREEMENT WITH ONLY MINOR DIFFERENCES
WITHIN THE QPF FIELDS...ALTHOUGH NOT ENOUGH TO HAVE A SIGNIFICANT
IMPACT ON THE SENSIBLE WEATHER.

TONIGHT...SHORTWAVE TROUGH MOVES OUT OF THE NORTHERN PLAINS
AND ACROSS THE FORECAST AREA. SURFACE BOUNDARY TO THE SOUTH PUSHES
NORTHWARD...WITH LOW LEVEL JET TRANSPORTING MOISTURE NORTHWARD.
ISENTROPIC LIFT...AS SEEN ON THE 305K SURFACE PUSHES NORTHWARD AS
NIGHT WEARS ON. INSTABILITIES RATHER LIMITED AND CONFINED WELL TO OUR
SOUTH...WITH BEST LIS APPROACHING ZERO ACROSS THE FAR SOUTHERN
ZONES. WILL KEEP MENTION OF THUNDER ACROSS THE SOUTH...WITH JUST
SHOWERS FARTHER NORTH. POPS AGAIN WILL TAPER FROM SOUTH TO NORTH.
WILL KEEP LOW POPS IN FOR MONDAY MORNING AS SYSTEM PUSHES SOUTH AND
EAST OF THE AREA. HIGH PRESSURE THEN BUILDS IN CLEARING SKIES FOR
FOR THE AFTERNOON AND OVERNIGHT HOURS.

ON TUESDAY...RETURN FLOW/WARM ADVECTION PATTERN DEVELOPS ACROSS THE
PLAINS AND MINNESOTA. FORCING REMAINS TO OUR WEST DURING THE DAY
AND SPREADS ACROSS THE AREA TUESDAY NIGHT AS FRONT LIFTS NORTHWARD.
AVN MORE ROBUST WITH QPF...MOST LIKELY FROM CONVECTIVE FEEDBACK.
FRONT THEN WAFFLES BACK AND FORTH ACROSS THE AREA THROUGH THE
REMAINDER OF THE WEEK WITH A CONTINUED CHANCE OF TSRA.

TEMPERATURES WILL CONTINUE RATHER PLEASANT NEXT COUPLE OF DAYS.
GUIDANCE NUMBERS SIMILAR THROUGH THE PERIOD...ALTHOUGH TRIMMED
BACK A FEW DEGREES FROM THE FWC NUMBERS ON TUESDAY.


.LSE...NONE.

RABERDING