Severe Thunderstorm Warning 105, NWS Quad Cities, IA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
320 AM CDT THU SEP 8 2005

.SYNOPSIS...
WEAK COOL ADVECTION CONTINUES OVER THE CWA EARLY THIS MORNING...AS
HIGH PRESSURE HAS SETTLED SOUTH INTO THE WESTERN GREAT LAKES.  ON
THE HEELS OF THE HIGH...VIGOROUS WARM ADVECTION THUNDERSTORMS HAVE
DEVELOPED OVER SOUTHEAST SOUTH DAKOTA...WITH OTHER STORMS ARCHING
NORTHWEST INTO CENTRAL NORTH DAKOTA.  AT THIS TIME...THE LEAD MCS IS
BOWING SOUTHEAST TOWARDS AN INSTABILITY GRADIENT THAT EXTENDS INTO
WEST CENTRAL IOWA.  WE HAVE BEEN WATCHING THIS GRADIENT FOR MOVEMENT
IN THE LAST SEVERAL HOURS AND FIND NONE. STILL WITH THE CURRENT MCS
GAINING SIZE AND STRENGTH...WE MAY HAVE TO CARRY POPS FOR THE
STRATIFORM RAIN REGION IN THE WEST EVEN THOUGH UPDRAFTS MAY NOT BE
SUPPORTED IN THIS CWA.

&&

.SHORT TERM (TODAY AND TONIGHT)...
MCS EVOLUTION WILL DOMINATE THIS MORNINGS FORECAST...AS INCREASING
CLOUDS AND POTENTIAL RAIN/EMBEDDED THUNDER AFFECT THE WEST.  THE
WARM FRONT APPEARS NOW TO REMAIN SOUTH OF THE AREA THROUGH THE
DAY...WHICH IS BEST SHOWN IN THE NAM SOLUTION.  IN ADDITION...THE
NAM BRINGS A SECOND WAVE DOWN ALONG THE FRONT LATER TODAY (THIS IS
LIKELY THE CAUSE FOR THE BAND OF STORMS INTO NORTH DAKOTA).  WILL
HAVE THE HIGHEST AND MOST WIDESPREAD POPS THIS AFTERNOON AND EVENING
AS THE MAIN SHORT WAVE PASSES THROUGH THE AREA.  TEMPERATURES WILL
BE HELD LOWER DUE TO LIGHT NORTHEAST FLOW AND CLOUDS NORTH WHERE
TEMPS MAY HOLD IN THE 70S...FARTHER SOUTH...LOWER TO MID 80S APPEAR
TO BE THE RULE UNDER PARTLY CLOUDY SKIES THIS MORNING AND LIGHT
SOUTHEAST FLOW.

SEVERE WEATHER POTENTIAL WILL DEPEND ON MESOSCALE FEATURES AND THE
AMOUNT OF HEATING WE CAN GET AHEAD OF THE DEBRIS CLOUDS FROM THE
SOUTH DAKOTA STORMS. WILL NOT GEAR UP TOO MUCH FOR THIS...BUT IF WE
CAN DEVELOP CAPES OVER 1500...THERE SEEMS TO BE ENOUGH SUPPORT FOR
LOWER END WINDS GUSTS AND POSSIBLY SOME LARGE HAIL.

AFTER STORMS ROLL EAST OF THE AREA MID EVENING WEST AND AROUND
MIDNIGHT EAST...WINDS WILL BECOME MORE SOUTHERLY BY SUNRISE.  FOG
POTENTIAL MAY NEED TO BE WATCHED SHOULD THE SCATTERED SHOWERS AND
STORMS ORGANIZE AND PRODUCE MORE WIDESPREAD PCPN.  06Z NAM IS GOING
ALONG THOSE LINES...AND IF OBSERVATIONAL DATA SUPPORTS IT...WE MAY
UPDATE TO RAISE POPS AFTER THE INITIAL ISSUANCE.

..ERVIN..

&&

.LONG TERM (FRIDAY THROUGH WEDNESDAY)...
MODEL AGREEMENT IS GOOD FOR BENIGN WEATHER TO DOMINATE THROUGH EARLY
NEXT WEEK... WITH A TROUGH DIGGING IN TO THE WEST AND A FRONT
APPROACHING THE AREA MIDWEEK.  WILL LEAN ON A MODEL BLEND FOR THE
PERIOD.

ANY LINGERING PRECIP AND CLOUDS SHOULD EXIT THE AREA ON FRIDAY...
LEAVING A WARM AND CLEARING DAY OVER THE CWA.  PRESSURE GRADIENT
TIGHTENS ON SATURDAY AND SHOULD FORCE STRONG WINDS AND GOOD
MIXING... AND WITH 850MB TEMPS 20-22C... EXPECT SATURDAY TO BE
BREEZY AND QUITE WARM.  UPPED MAX TEMPS AGAIN INTO THE UPPER 80S TO
LOW 90S ACROSS THE AREA.  SUNDAY WILL BE LESS WINDY BUT WARM AGAIN
WITH 850MB TEMPS REMAINING NEAR 20C AND ADEQUATE MIXING.  UPPED MAX
TEMPS FOR SUNDAY AS WELL.

NEXT SYSTEM TO AFFECT THE AREA WILL APPROACH ON TUES/WED AS STRONG
UPPER-LEVEL TROUGH DIGS INTO THE ROCKIES.  SURFACE LOW LIFTING
NORTHEASTWARD AHEAD OF TROUGH IS PROGGED TO PUSH A COLD FRONT
THROUGH THE AREA ON WED.  TREND ON THESE SYSTEMS HAS BEEN FOR THEM
TO MOVE MORE SLOWLY WITH WEAKER FRONTS THAN MODEL PROGS AT THIS
RANGE... BUT BAROCLINICITY WITH THIS SYSTEM LOOKS STRONGER THAN
OTHERS (AS IT SHOULD GIVEN SEASONAL CHANGES).  HAVE INCREASED POPS
IN NORTHWEST TO CHANCES ON WED WITH SOME CONFIDENCE IN SEEING PRECIP
AHEAD OF THE TROUGH TO THE WEST.

..MAYES..

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.

&&

ERVIN/MAYES

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1200 PM CDT THU SEP 8 2005

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-091000-
BENTON IA-BUCHANAN IA-BUREAU IL-CARROLL IL-CEDAR IA-CLARK MO-CLINTON
IA-DELAWARE IA-DES MOINES IA-DUBUQUE IA-HANCOCK IL-HENDERSON IL-HENRY
IA-HENRY IL-IOWA IA-JACKSON IA-JEFFERSON IA-JO DAVIESS IL-JOHNSON IA-
JONES IA-KEOKUK IA-LEE IA-LINN IA-LOUISA IA-MCDONOUGH IL-MERCER IL-
MUSCATINE IA-PUTNAM IL-ROCK ISLAND IL-SCOTLAND MO-SCOTT IA-
STEPHENSON IL-VAN BUREN IA-WARREN IL-WASHINGTON IA-WHITESIDE IL-
1200 PM CDT THU SEP 8 2005

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

A THUNDERSTORM COMPLEX OVER NORTHWEST IOWA WILL MOVE ACROSS THE AREA
THIS AFTERNOON AND EVENING.  AFTERNOON HEATING WILL ALLOW FOR SOME OF
THE STORMS TO REACH SEVERE LEVELS INTO THE MID EVENING HOURS.  THE
GREATEST RISK WILL BE LARGE HAIL...POSSIBLY UP TO THE SIZE OF
GOLFBALLS AND DAMAGING WINDS OF 60 TO POSSIBLY 70 MPH. AN ISOLATED
BRIEF TORNADO IS ALSO POSSIBLE.

THE LOCATIONS MOST AT RISK FOR SEVERE WEATHER WILL BE ALONG AND
ESPECIALLY SOUTH OF A VINTON IOWA TO CEDAR RAPIDS TO GREATER QUAD
CITIES TO HENNEPIN ILLINOIS LINE BETWEEN 2 PM AND 10 PM THIS
AFTERNOON AND EVENING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

NO HAZARDOUS WEATHER AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE SOUTH OF A VINTON IOWA TO QUAD CITIES
TO HENNEPIN ILLINOIS AXIS...MAINLY BETWEEN 2 AND 10 PM.   PLEASE
RELAY ANY NEAR SEVERE TO SEVERE REPORTS TO THE NOAA NWS OFFICE IN THE
QUAD CITIES.

NICHOLS

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
114 PM CDT THU SEP 8 2005

IAZ051>053-063>068-076>078-087>089-098>099-
ILZ009-015>018-024>026-034>035-
MOZ009>010-090000-
BENTON IA-CEDAR IA-CLINTON IA-DES MOINES IA-HENRY IA-
IOWA IA-JEFFERSON IA-JOHNSON IA-JONES IA-KEOKUK IA-
LEE IA-LINN IA-LOUISA IA-MUSCATINE IA-SCOTT IA-
VAN BUREN IA-WASHINGTON IA-BUREAU IL-HANCOCK IL-
HENDERSON IL-HENRY IL-MCDONOUGH IL-MERCER IL-PUTNAM IL-
ROCK ISLAND IL-WARREN IL-WHITESIDE IL-CLARK MO-
SCOTLAND MO-

THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH
775 IN EFFECT UNTIL 7 PM CDT FOR THE FOLLOWING AREAS

IN ILLINOIS THIS WATCH INCLUDES 10 COUNTIES

IN NORTH CENTRAL ILLINOIS

BUREAU                PUTNAM

IN NORTHWEST ILLINOIS

HENRY                 MERCER                ROCK ISLAND
WHITESIDE

IN WEST CENTRAL ILLINOIS

HANCOCK               HENDERSON             MCDONOUGH
WARREN

IN IOWA THIS WATCH INCLUDES 17 COUNTIES

IN EAST CENTRAL IOWA

BENTON                CEDAR                 CLINTON
IOWA                  JOHNSON               JONES
LINN                  MUSCATINE             SCOTT

IN SOUTHEAST IOWA

DES MOINES            HENRY                 JEFFERSON
KEOKUK                LEE                   LOUISA
VAN BUREN             WASHINGTON

IN MISSOURI THIS WATCH INCLUDES 2 COUNTIES

IN NORTHEAST MISSOURI

CLARK                 SCOTLAND

THIS INCLUDES THE CITIES OF...ALEDO...ANAMOSA...BETTENDORF...
BURLINGTON...CARTHAGE...CEDAR RAPIDS...CLINTON...DAVENPORT...
FAIRFIELD...FORT MADISON...HENNEPIN...IOWA CITY...KAHOKA...
KEOSAUQUA...KEWANEE...MACOMB...MARENGO...MEMPHIS...MOLINE...
MONMOUTH...MOUNT PLEASANT...MUSCATINE...OQUAWKA...PRINCETON...
ROCK FALLS...ROCK ISLAND...SIGOURNEY...STERLING...TIPTON...
VINTON...WAPELLO AND WASHINGTON.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
214 PM CDT THU SEP 08 2005

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0205 PM     HAIL             2 WNW PACKWOOD          41.14N 92.12W
09/08/2005  1.00 INCH        JEFFERSON          IA   LAW ENFORCEMENT

            QUARTER SIZE HAIL AND HEAVY RAIN.

&&

MDB