Severe Thunderstorm Warning 110, NWS La Crosse, WI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
341 AM CDT TUE AUG 1 2000

FORECAST CONCERNS THIS PACKAGE...SHRA/TSRA CHANCES TODAY/TONIGHT...
THEN CLOUDS AND TEMPS.

SURFACE ANALYSIS AT 07Z SHOWED AN AREA OF WEAKENING CONVECTION IN
CENTRAL TO NORTHEAST WI...IN AN AREA OF WEAKENING 850MB MOISTURE
TRANSPORT/CONVERGENCE. ANOTHER GENERALLY INCREASING AREA OF SHRA/TSRA
WAS LOCATED FROM AROUND KDLH TO KMSP TO KFRM. THIS AREA WAS LOCATED
IN AN AREA OF FAVORABLE DYNAMICS AHEAD OF A SHORTWAVE AND COLD FRONT
PUSHING INTO WESTERN MN...AND FAVORABLE LOW LEVEL Q-G CONVERGENCE...
MOISTURE AND WARM ADVECTION. MORE CONVECTION DEVELOPING RAPIDLY IN
NORTHWEST AND WEST CENTRAL WI AHEAD OF THIS BAND. LAPS SOUNDINGS IN
THIS AREA INDICATING CAPES OF 3000-3500 J/KG WHEN LIFTING THE 850-
800MB LAYER.

00Z MODELS SIMILAR AND LOOK TO HAVE REASONABLE GRASP ON REALITY AT
06Z. 00Z MODELS COMPARED TO THEIR 12Z RUNS A BIT STRONGER WITH THE
WESTERN MN WAVE TODAY AND A BIT SLOWER WITH THE WAVE DROPPING THROUGH
SASKAT AND MANITOBA TODAY INTO NORTHEAST MN TONIGHT. MAIN IMPACT
WILL BE TO SLOW THE COLD FRONT/TROUGH PASSAGE ACROSS THE FORECAST
AREA BY ABOUT 6 HRS. FAVORED ETA/AVN SOLUTIONS FOR TIMING/DETAILS.

FAVORABLE LOW LEVEL FORCING...MOISTURE TRANSPORT...WARM ADVECTION/
ISENTROPIC LIFT...Q-G CONVERGENCE MOVES ACROSS THE AREA TODAY
AHEAD OF THE FRONT/TROUGH...AND EXITS TO THE EAST AND SOUTH THIS
EVENING. SPC DAY 1 SLIGHT RISK LOOKS REASONABLE WITH DECENT CAPES/
INSTABILITY ACROSS THE AREA TODAY/THIS EVENING...BUT WIND SHEAR
MARGINAL.

GENERALLY UPPED POPS ACROSS THE FORECAST AREA TODAY WITH PRECIP ON
OUR DOORSTEP EARLY THIS MORNING. CONTINUED SHRA/TSRA CHANCES LONGER
INTO THIS EVENING/TONIGHT WITH THE SLOWER PASSAGE OF THE FRONT. WED
LOOKS TO BE A PLEASANT DAY WITH LOWER HUMIDITIES BEHIND THE FRONT
AND THE CANADIAN HIGH BUILDING IN.

NUMERICAL TEMP GUIDANCE QUITE SIMILAR FROM THE1 SECOND PERIOD ON...AND
LOOKS REASONABLE. FAVORED COOLER AVN-FAN NUMBERS FOR HIGHS TODAY WITH
MORE CLOUDS AND SHRA/TSRA AROUND MUCH OF THE DAY...ESPECIALLY THE
NORTH HALF OF THE FORECAST AREA.

.LSE...NONE.

RRS

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-032>034-
041>044-053>055-061-020200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LA CROSSE WI
1207 PM CDT TUE AUG 1 2000

...SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE AREA THIS
AFTERNOON AND EVENING...

THERE IS A SLIGHT CHANCE OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST
MINNESOTA...NORTHEAST IOWA...AND SECTIONS OF SOUTHWEST INTO CENTRAL
WISCONSIN THIS AFTERNOON AND EVENING.

A LOW PRESSURE SYSTEM WAS LOCATED NEAR MANKATO MINNESOTA LATE THIS
MORNING...WITH A COLD FRONT EXTENDING SOUTHWEST THROUGH EXTREME
NORTHWEST IOWA AND INTO NEBRASKA. WARM...MOIST...AND UNSTABLE AIR
AHEAD OF THIS FRONT WILL SET THE STAGE FOR THUNDERSTORM DEVELOPMENT
THIS AFTERNOON AND EVENING...AS THE FRONT ADVANCES EASTWARD. SOME OF
THESE THUNDERSTORMS MAY BE SEVERE...WITH THE MAIN SEVERE WEATHER
THREATS BEING LARGE HAIL AND STRONG WINDS.

SPOTTER ACTIVATION MAY BE NECESSARY LATER THIS AFTERNOON. STAY TUNED
FOR LATER STATEMENTS.

CONSIDINE