Severe Thunderstorm Warning 95, NWS Quad Cities, IA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
305 PM CDT FRI JUL 26 2002

OVERNIGHT CONVECTION DYING SLOWLY ACROSS SRN IA...WITH THE RESULTING
DEBRIS CLOUDS KEEPING TEMPS DOWN ACROSS CWA.  MAIN AREA TO WATCH FOR
NEW CONVECTION WILL BE IN THE WESTERN IOWA/EASTERN NEBRASKA AREA.
WHILE THERE IS LOTS OF SUNSHINE TO THE SOUTH OF THE DEBRIS CLOUD
REGION...THAT AREA IS PRETTY HEAVILY CAPPED.  TEMPS RISING REAL
NICELY IN NW IA WHERE SUNSHINE IS GETTING THROUGH.  LATEST SURFACE
ANALYSIS INDICATING SURFACE FRONT EXTENDING FROM SE NEBRASKA...EAST
TO SRN PORTIONS OF CWA...AND INTO CENTRAL IL.  TOUNGE OF GOOD
MOISTURE ACROSS WESTERN IA WITH SOME MID 70S DEWPOINTS. REMAINDER OF
12Z ANALYSIS INDICATING 850 MB MOISTURE PLUME OVER EASTERN/CENTRAL
IA...WITH 850 LLJ DECREASED IN STRENGTH TO LESS THAN 20 KTS.  THE
DDC SOUNDING SHOWING THAT THE LLJ SHOULD SET BACK UP IN THAT
AREA...AS THEY ARE ALREADY BACK UP AT 30 KTS.  CURRENT SHORT WAVES
HARD TO PICK OUT ON ANALYSIS...BUT ON WV THE ONE ROLLING ACROSS
NEBRASKA IS MUCH CLEARER.  THIS SHORT WAVE SHOULD BE THE KEY TO
TONIGHTS MCS.

MAINFORECAST PROBLEM TODAY INCLUDES WHERE AND WHEN OF PRECIPITATION
NEXT FEW DAYS.

12Z MODELS APPEAR TO HAVE INITIALIZED FAIRLY WELL...THOUGH SURFACE
LOW CENTER BY 18Z IS A LITTLE TOO FAR EAST ON ALL MODELS. IN
GENERAL...PREFER AVN THIS FORECAST AS IT SEEMS TO BE HANDLING THE
STRENGTH AND MOVEMENT OF THE CURRENT SHORTWAVE OVER NEBRASKA BETTER
THAN ETA.  HOWEVER...ETA HAS SLIGHTLY BETTER HANDLE ON SURFACE
FEATURES...SO WILL BE GOING WITH A BLEND OF THE TWO.

LITTLE QUESTION ABOUT MCS TONIGHT...WILL RUN AXIS OF STRONGEST
STORMS AND HIGHEST QPF FROM SOUTHEAST IA TO NORTH CENTRAL IL... AS
THIS IS THE TRACK THE SHORTWAVE SHOULD TAKE. THE PRECIPITATION FROM
THIS MCS SHOULD LINGER THROUGH THE MORNING...KEEPING TEMPS DOWN
UNTIL SUNSHINE BREAKS OUT IN LATE AFTERNOON.

SATURDAY NIGHT THERE IS MORE QUESTION ABOUT MCS POTENTIAL...AS THE
FEATURES DO NOT COME TOGETHER AS WELL AS TONIGHT.  BEST LIFT AND
MOISTURE IS FURTHER NORTH...WITH MAIN SURFACE WAVE.  WARM MID LEVEL
TEMPS THAT MOVE IN AS THE SURFACE FEATURE MOVES NORTH MAY KEEP
PRECIPITATION FROM DEVELOPING.  THIS WILL ALSO HELP TO MAKE SUNDAY A
REAL SCORCHER...WITH FEWER DEBRIS CLOUDS LINGERING ABOUT TO KEEP
SUNSHINE OUT.  WILL GO SLIGHTLY WARMER THAN GUIDANCE...ESPECIALLY AS
GUIDANCE HAS WARMED UP TO MATCH THIS MORNINGS CCF DATA.

SUNDAY NIGHT LITTLE QUESTION ON ANOTHER MCS AS A STRONGER WAVE MOVES
THROUGH THE AREA.  WILL LEAVE HIGH CHANCE POPS IN FOR NOW...BUT FEEL
LATER SHIFTS WILL LIKELY BE RAISING THIS AS LONG AS THE MODELS
CONTINUE TO SHOW THE SAME OR SIMILAR SOLUTION.  BY MONDAY MORNING
THERE OUGHT TO BE ENOUGH DEBRIS CLOUD TO KEEP TEMPS ON THE COOL
SIDE...AND WILL HANG ON TO MORNING POPS.

EXTENDED...TUE-FRI
HAVE REMOVED TUESDAY POPS AS THE MODELS APPEAR TO BE MOVING THIS
FEATURE ALONG A LITTLE FASTER THAN PREVIOUSLY.  WILL BE LEAVING WED
AND THURS DRY ALSO...AS NO SIGNIFICANT WAVES MOVE THROUGH AREA THAT
TIME FRAME.  HAVE THROWN POPS INTO FRIDAY...MAINLY TO ACCOUNT FOR A
WARM FRONT THAT DEVELOPS TO THE NORTH OF THE CWA.

.DVN...
IA...NONE.
IL...NONE.
MO...NONE.

LRE