Flash Flood Warning 11, NWS Quad Cities, IA

000 
WGUS73 KDVN 111144
FFSDVN

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
644 AM CDT THU JUN 11 2009

IAC111-ILC067-MOC045-111152-
/O.CAN.KDVN.FF.W.0011.000000T0000Z-090611T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LEE IA-HANCOCK IL-CLARK MO-
644 AM CDT THU JUN 11 2009

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CLARK...NORTHERN
HANCOCK AND LEE COUNTIES...

THE RAIN HAS LESSENED OVER THE AREA AND LOCAL LAW ENFORCEMENT 
OFFICIALS REPORT THAT THE STREET FLOODING HAS ENDED. THEREFORE...THE 
FLASH FLOOD WARNING HAS BEEN CANCELLED.

LAT...LON 4023 9150 4025 9151 4028 9193 4056 9192
      4061 9187 4060 9172 4077 9172 4081 9167
      4067 9115 4064 9121 4064 9107 4060 9093
      4023 9145

$$

33

AREA FORECAST DISCUSSION...CORRECTED HEADER
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
302 PM CDT WED JUN 10 2009

.SYNOPSIS...
WEAK INVERTED TROUGH EXTENDING NORTH FROM LOW PRESSURE IN SE KS
REMAINS OVER EASTERN IA THIS AFTERNOON...KEEPING PLENTY OF LOW LEVEL
MOISTURE AND CLOUD COVER IN PLACE. THE SE KS LOW WAS LOCATED ALONG
THE STALLED SURFACE FRONT...STRETCHED FROM CENTRAL OK NORTHEAST
ACROSS CENTRAL MO INTO SRN IL EARLY THIS AFTERNOON. SATELLITE AND
RADAR TRENDS INDICATED ANOTHER LARGE MCS ALONG THIS BOUNDARY THIS
AFTERNOON IN THE SOUTHERN PLAINS...THIS TIME FURTHER SOUTH THAN
YESTERDAY/S FROM TX PANHANDLE INTO S CENTRAL KS. THIS WAS OCCURRING
IN AREA OF FORCING AHEAD OF STRONG UPPER SHORTWAVE EVIDENT ON WV
IMAGERY LIFTING OUT OF NM. AS THE SHORTWAVE LIFTS NORTHEAST...THEN
EAST...ADDITIONAL MCS ACTIVITY WILL RIPPLE ALONG AND NORTH OF THE
SYNOPTIC BOUNDARY...LIKELY AFFECTING AT LEAST THE FAR SOUTH LATE
TONIGHT.

&&

.SHORT TERM...TONIGHT AND THURSDAY...
NORTHWARD EXTENT OF NEXT ROUND OF THUNDERSTORMS AS WAVE RIPPLES
ALONG THE BOUNDARY TO THE SOUTH IS THE PRIMARY CHALLENGE. QPF FIELDS
IN SHORT TERM OF BOTH DOMESTIC AND EURO MODELS REMAINS OF LITTLE
ASSISTANCE THIS AFTERNOON. FOLLOWING BLEND OF SREF AND ECMWF
FOR SYNOPTIC FEATURES...STRONG NM SHORTWAVE IS SHOWN TO RIPPLE A
SURFACE LOW ALONG THE BOUNDARY NEAR STL 12Z THU WITH H8 WAVE FURTHER
NORTH ACROSS FAR SE IA DURING THIS TIME. CHALLENGE IS AGAIN THE
EXTENT OF CONVECTION OCCURRING WITH THIS FEATURE IN THE WEAKLY
CAPPED ENVIRONMENT ALONG AND EXTENDING WELL SOUTH OF THE BOUNDARY
AND ITS IMPACT ON DEVELOPMENT FURTHER NORTH. ALTHOUGH HEAVY RAIN NOT
LIKELY...FORCING AND AVAILABLE INSTABILITY AND FORCING SUPPORTS AT
LEAST LIKELY POPS ACROSS THE FAR SOUTH AFTER MIDNIGHT INTO EARLY THU
MORNING. HAVE EXTENDED CHANCE POPS AS FAR NORTH AS I-80 WITH ONLY
SLIGHT CHANCES FURTHER NORTH. ABSENCE OF CAPE AND MARGINAL MID LEVEL
LAPSE RATES WILL LIMIT MENTION OF THUNDER TO ISOLATED AND CONFINED
TO THE FAR SOUTH. LOW LEVEL MOISTURE CONVERGENCE HAS BOOSTED SURFACE
DEWPOINTS INTO THE UPPER 50S TO LOWER 60S OVER MOST OF THE FORECAST
AREA AND WITH AN ABUNDANCE OF HIGH CLOUDS STREAMING INTO THE
REGION... HAVE GONE WITH MINS IN MID 50S TO LOWER 60S. EXCEPTION IS
FAR NORTHEAST...WHERE NE WINDS HAVE BROUGHT IN DRIER AIR OUT OF THE
GREAT LAKES HIGH.

THU...KEPT CHANCE POPS IN THE SOUTHEAST FOR POTENTIAL WRAP AROUND
SHOWERS IN THE MORNING. OTHERWISE...WILL AGAIN SEE LINGERING LOW
CLOUDS IN THE MORNING THEN DRYING BY AFTERNOON. SIMILAR AIRMASS TO
TODAY WILL AGAIN ALLOW MAXES IN THE LOWER TO MID 70S.

.LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY...
THERMODYNAMICS AND MOISTURE FLUXES ARE THE MAIN FORCING MECHANISMS
DRIVING THE SENSIBLE WX. MODELS DO NOT HANDLE THESE FEATURES WELL
AND IT IS REFLECTED IN A LACK OF RUN TO RUN CONTINUITY. THEREFORE
...A LOWER THAN NORMAL CONFIDENCE EXISTS.

THURSDAY NIGHT/FRIDAY SHOULD BE DRY AS NO APPARENT TRIGGER IS
EVIDENT TO GET ANYTHING GOING. HOWEVER...THE 12Z MODELS HAVE DONE
ANOTHER REVERSAL. UKMET HAS HAS AN MCS MOVING ACROSS THE AREA ON
FRIDAY WHILE THE ECMWF AND GFS SUGGEST A DECAYING MCS ARRIVING
FRIDAY AFTERNOON. FRIDAY NIGHT/SATURDAY...THE MODELS SHOW PLENTY OF
H7 MOISTURE WITH LIFT ALOFT. HOWEVER...AT LOW LEVELS NO WAA IS
APPARENT AND THERE IS NO LLJ EITHER. SO...WILL KEEP THE CURRENT IDEA
OF A DRY FCST FOR FRIDAY NIGHT/SATURDAY.

MODELS SHOW A RESPECTABLE MCS DEVELOPING IN THE PLAINS SATURDAY
NIGHT/SUNDAY. SAID MCS IS THEN ADVECTED BY SOME MODELS INTO THE AREA
ON SUNDAY. SO...ASSUMING THE ABOVE SCENARIO IS CORRECT....SATURDAY
NIGHT SHOULD BE DRY AND SOMETHING MAY AFFECT THE AREA SUNDAY. IF THE
MCS WOULD REACH THE AREA...THE SOUTH THIRD OR SO OF THE CWFA WOULD
HAVE THE BEST CHANCES OF SEEING ANYTHING. THEREFORE...WILL GO WITH
SCHC POPS FOR SUNDAY.

SUNDAY NIGHT ON IS MORE DIFFICULT AS ALL MODELS GO OFF ON DIFFERENT
SCENARIOS. MODEL SOLUTIONS ARE HIGHLY SMOOTHED AS WELL WHICH MAKES
IT MORE DIFFICULT TO SEE ANY SIGNALS. SO...THE ENTIRE PERIOD HAS
BEEN BROAD BRUSHED WITH SCHC POPS WITH SOME CHC POPS ADDED FOR
MONDAY/MONDAY NIGHT AS THE SFC BOUNDARY NUDGES CLOSER TO THE CWFA.
OVERALL PATTERN IS SET UP FOR MULTIPLE MCS EVENTS RIDING ALONG THE
BOUNDARY AS THE H5 RIDGE BUILDS IN THE CENTRAL PART OF THE CONUS.
...08...

&&

.AVIATION...
LINGERING LOW LEVEL MOISTURE WILL CONTINUE VFR CONDITIONS WITH CIGS
REMAINING IN 4KFT TO 6 KFT RANGE OVER MUCH OF THE AREA INTO THE
EVENING. ANOTHER DISTURBANCE IN THE CENTRAL PLAINS MOVING ALONG A
STALLED BOUNDARY WELL TO THE SOUTH WILL SEND ANOTHER ROUND OF
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE REGION LATE
TONIGHT. BRL WILL BE MOST LIKELY TO SEE TSRA AND HAVE PROB 30
THUNDER GROUP LIMITED TO THIS SITE. LINGERING MOISTURE WILL LIKELY
RESULT IN ANOTHER ROUND OF MVFR CIGS DUE TO BOTH LOW CIGS AND BR/HZ
THU MORNING AT ALL SITES.

&&

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

&&

SHEETS/08

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
434 AM CDT WED JUN 10 2009

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-110945-
BUCHANAN-DELAWARE-DUBUQUE-BENTON-LINN-JONES-JACKSON-IOWA-JOHNSON-
CEDAR-CLINTON-MUSCATINE-SCOTT-KEOKUK-WASHINGTON-LOUISA-JEFFERSON-
HENRY IA-DES MOINES-VAN BUREN-LEE-JO DAVIESS-STEPHENSON-CARROLL-
WHITESIDE-ROCK ISLAND-HENRY IL-BUREAU-PUTNAM-MERCER-HENDERSON-
WARREN-HANCOCK-MCDONOUGH-SCOTLAND-CLARK-
434 AM CDT WED JUN 10 2009

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

.DAY ONE...TODAY AND TONIGHT

THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS GENERALLY ALONG AND
SOUTH OF HIGHWAY 34 TODAY AND TONIGHT. SEVERE WEATHER IS NOT
EXPECTED WITH ANY THUNDERSTORMS...THOUGH THEY MAY PRODUCE A BRIEF
PERIOD OF HEAVY RAINFALL.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.

LE