Severe Thunderstorm Warning 172, NWS Quad Cities, IA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
250 PM CDT SUN AUG 3 2003

NEAR TERM...
AS THE VORT...SEEN SPIRALING DOWN ACRS THE AREA ON W/V IMAGERY...
GETS MORE DIRECTLY OVERHEAD...CVA PUNCH INTO UNSTABLE AIRMASS WILL
END..AS WILL THE SCTRD CONVECTION DOTTING THE AREA. WILL STILL
HAVE TO ACCOUNT FOR SOME LINGERING EVENING ACTIVITY IN ZONES...BUT
WILL THEN CLEAR OUT THINGS AS SFC RIDGE NOSES DOWN THE UPPER MS RVR
VALLEY. FEEL TEMPS TO GENERALLY DIP INTO THE UPPER 50S AGAIN OVER
MUCH OF THE CWA...WITH SOME LOCATIONS IN THE NORTH POSSIBLY REACHING
DOWN INTO THE MID 50S. PREFER THE MET LOWS...BUT FWC VALUES CLOSE
AND ALSO LOOK REASONABLE. ALTHOUGH CLEAR SKIES...LIGHT WINDS AND
TEMPS COOLING TOWARD DPTS TO OCCUR LATER TONIGHT...FEEL DENSE FOG
THREAT NOT TO BE WIDESPREAD ENOUGH FOR ZONE MENTION.

UPPER LOW CENTER TO SLOWLY GYRATE ACRS LOWER MI ON MONDAY...AND
UNLIKE TODAY...NOT MUCH IN THE WAY OF A INCOMING VORT TO GENERATE
WIDESPREAD SCTRD CONVECTION. BUT...AGAIN AN UNSTABLE SET UP IN THE
LOW TO MID LEVELS(ALTHOUGH BEST LLVL INSTABILITY TO SET UP JUST TO
THE SOUTH OF THE CWA)JUST TO THE WEST OF COOL CORE UPPER LOW...
WOULD THINK AN ISOLATED TO WIDELY SCATTERED AFTERNOON SHOWER/
THUNDERSTORM SCENARIO TO UNFOLD. WILL TREND TOWARD THE NGM SOLUTION
WHICH DEPICTS THIS...WHILE GFS AND ETA/META ARE DRY. ANOTHER WEAK
MIXING DAY AND AFTERNOON CU SUGGEST COOLER MET HIGHS MAY BE THE WAY
TO GO...GENERALLY UPPER 70S TO AROUND 80.   ..12..

TUESDAY THROUGH SUNDAY...
PESKY UPR LOW FINALLY LIFTS AND MOVES INTO ONTARIO.  MEANWHILE OUR
RGN REMAINS UNDER NW FLO WITH A STG RDG OVR THE SWRN US.  MODELS ARE
CONSISTENT WITH DROPPING A WK SHRTWV THRU OUR RGN ON TUES.  THIS
SHRTWV GOES THRU APPARENT DEEPENING AS IT HITS THE BASE OF THE
LONGWAVE TROF ACRS OHIO VLY ON WED.  BELIEVE THE PCPN SHOULD END BY
LATE TUESDAY/EARLY WEDNESDAY SO HAVE KEEP WEDNESDAY DRY.  SFC HI
PRES BUILDS INTO THE RGN THRU DAY 6 AS WRN UPR RDG GRADUALLY BUILDS
INTO THE CENTRAL US.

LATE DAY 6/DAY 7 HOLDS THE POTENTIAL FOR TSTMS.  AS UPR RDG BUILDS
INTO AK...STG TROF TRIES TO SQUASH THE EMERGING CENTRAL US RDG.  THE
RESULT IS POTENTIAL CDFNT MOVG SLOWLY INTO IOWA...POSSIBLY STALLING
OUT ACRS OUR RGN.

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

BELLES

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-040915-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
457 AM CDT SUN AUG 3 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN IOWA...
NORTHWEST AND WEST CENTRAL ILLINOIS...AND NORTHEAST MISSOURI.

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS WILL BE LIKELY AGAIN TODAY INTO THIS EVENING
ACROSS THE OUTLOOK AREA. CONDITIONS DO NOT LOOK IDEAL FOR WIDESPREAD
SEVERE WEATHER. HOWEVER...A FEW THUNDERSTORMS MAY PRODUCE HAIL UP TO
DIME SIZE AND POSSIBLY SOME BRIEF FUNNEL CLOUDS...MAINLY DURING THE
PERIOD FROM MID AFTERNOON INTO EARLY EVENING.

AN UPPER LEVEL LOW WILL MOVE FROM LAKE SUPERIOR TO SOUTHERN LAKE
MICHIGAN BY LATE TONIGHT. A COUPLE LOBES OF ENERGY ROTATING AROUND
THE WEST SIDE OF THE LOW WILL MOVE THROUGH THE AREA...WITH THE FIRST
ARRIVING AROUND MID MORNING...AND THE SECOND TOWARD LATE AFTERNOON.
THE FIRST FEATURE WILL PRODUCE WIDELY SCATTERED THUNDERSTORMS MAINLY
FROM EAST CENTRAL IOWA INTO NORTHWEST ILLINOIS FROM LATE MORNING
INTO AFTERNOON. THUNDERSTORMS WILL BECOME MORE WIDESPREAD BY LATE
AFTERNOON WITH THE ARRIVAL OF THE SECOND FEATURE. THE BEST CHANCE
FOR THUNDERSTORMS WILL BE ALONG A BOUNDARY LINGERING FROM ABOUT
FREEPORT TO MACOMB ILLINOIS.

MODERATE INSTABILITY...ALONG WITH WEAK WIND SHEAR...WILL PREVENT
THUNDERSTORMS FROM BECOMING SEVERE. HOWEVER...SOME STORMS MAY
BRIEFLY BE CAPABLE OF PRODUCING DIME SIZE HAIL AND HEAVY DOWNPOURS.
CONDITIONS WILL ALSO BE FAVORABLE FOR BRIEF FUNNEL CLOUDS TO DEVELOP
ALONG SHOWERS OR THUNDERSTORMS...ESPECIALLY THOSE THAT FORM ALONG
BOUNDARIES. THESE WILL BE MOST LIKELY DURING THE LATE AFTERNOON AND
EARLY EVENING HOURS. THIS TYPE OF FUNNEL CLOUD IS USUALLY SHORT
LIVED AND RARELY TOUCHES THE GROUND.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED FOR TODAY OR TONIGHT.

SHEETS