River Flood Warning 64, NWS Quad Cities, IA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
330 AM CDT FRI APR 11 2008

.DISCUSSION...
00Z RUN SHORT RANGE MODELS ARE IN GOOD AGREEMENT WITH ROLLING LARGE
SPRING STORM SYSTEM/CUT-OFF UPPER LOW...CURRENTLY SEEN ON W/V
IMAGERY AND PRECIP PATTERNS ON REGIONAL 88D LOOPS SWIRLING OVER
THE NEB/IA BORDER...TO JUST NORTHEAST OF THE DVN CWA OVER SOUTHWEST
WI BY 00Z SAT. THIS FEATURE WILL CONTINUE TO NAG THE LOCAL AREA AS
IT CONTINUES TO GET SLOWED BY CANADIAN BLOCKING PATTERN...WITH THE
CENTER PROGGED NOT TO MAKE IT TO FAR SOUTHWEST LOWER MI UNTIL 00Z
SUNDAY OR SO. TODAY/S HIGH TEMPS WILL OCCUR THIS MORNING UNTIL
OCCLUDED CYCLONE STARTS TO COLD WRAP/ADVECT FROM THE SOUTHWEST AS
THE DAY PROGRESSES. MAY STILL NOT BE WARM ENOUGH IN THE FAR EAST AND
SOUTHEAST AT 12Z-13Z LOOKING AT CURRENT OB TRENDS...AND WILL
CONTINUE TO ADVERTISE A NON-DIURNAL TEMP TREND WITH STEADY TO SLOW
FALL THROUGH MIDDAY AND AFTERNOON. WILL WALK OUT CURRENT SPOKE OF
LIFT AND SCTRD CONVECTION/THUNDER OUT OF THE NORTHEAST THIRD JUST
AFTER 12Z THIS MORNING...WITH NEXT VORT SPOKE AND INSTABILITY SET-
UP AS COLD CORE UPPER LOW ITSELF ROTATES OVERHEAD GENERATING PLENTY
OF NEW SHOWER ACTIVITY FROM WEST TO EAST AS THE DAY PROGRESSES. THE
SHOWERS TO BE MORE NUMEROUS ALONG AND NORTH OF I80 CLOSER TO UPPER
LOW CENTER. WILL BANK ON BOUNDARY LAYER AND SLIGHTLY DEEPER LAYER
TO STAY WARM ENOUGH TO KEEP PRECIP AS RAIN THROUGH AT LEAST LATE
AFTERNOON...BUT AREAS IN THE NORTHWEST MAY EXPERIENCE A RAIN-SNOW
MIX BY 3 PM CDT. EXTENT OF INSTABILITY AND COLD UPPER CORE MAY ALLOW
THE MORE SUBSTANTIAL SHOWERS TO GENERATE SOME SMALL HAIL THIS
AFTERNOON. DIURNAL MIXING SHOULD ALSO DRIVE WIND MACHINE AGAIN...WITH
BRISK SOUTHWEST WINDS POSSIBLY APPROACHING WIND ADVISORY CRITERIA
AT TIMES. GUSTS WILL BE ENHANCED IN PASSING SHOWERS WITH PRECIP-DRAG
MOMENTUM MIX DOWN EFFECT.

WITH NEXT LIFT-WING TONIGHT ROTATING AROUND UPPER LOW AND COOLING
LLVLS...THE STAGE WILL BE SET FOR A PERIOD OF SNOW SHOWERS THAT WILL
LAST INTO SAT MORNING. ADEQUATE DEEP LAYER SATURATION COMBINED WITH
LIFT SUGGESTS UP TO AN INCH OF SNOWFALL POSSIBLE OVER THE NORTHEAST
HALF OF THE DVN CWA BY 12Z SAT MAINLY ON GRASSY AND ELEVATED
SURFACES. SOME LOW TEMPS IN THE NORTHWESTERN CWA COULD DIP INTO THE
UPPER 20S BY EARLY SAT MORNING...BUT MOST OF THE DVN FCST AREA WILL
REMAIN IN THE LOW TO MID 30S. THE CWA WILL STILL BE UNDER THE
INFLUENCE OF THE WESTERN FLANK OF THE UPPER CYCLONE ON SAT WITH
VORT SPOKES AND UNSTABLE CONDITIONS DRIVING SHOWER ACTIVITY. THE
MORNING SHOULD BE MAINLY SNOW CWA-WIDE...BUT BOUNDARY LAYER WARMING
WITH ANY KIND OF BREAKS IN THE PRECIP ACTION MAY MAKE FOR A MIX IN
THE SOUTH HALF/SOUTH OF I80 SAT AFTERNOON. SHOWER ACTIVITY WILL
LINGER INTO SAT EVENING ESPECIALLY EAST OF THE MS RVR...WITH SOME
CLEARING FINALLY EXPECTED LATER ON SUNDAY. NO CHANGES PAST SUNDAY
FOR NOW.      ..12..

&&

.AVIATION...
A STRONG STACKED LOW PRESSURE SYSTEM WILL MOVE ACROSS NORTHEAST IA
AND SOUTHERN WI TODAY AND TONIGHT...BRINGING GUSTY WINDS...LOW
CLOUDS...AND PERIODIC RAIN/SNOW SHOWERS.  CEILINGS WILL LOWER TO
1K-3K FT BY 15Z.  SOUTHERLY WINDS AT 15-20KTS WILL GRADUALLY BECOME
WEST AND NORTHWESTERLY THROUGH THE PERIOD...OCCASIONALLY GUSTING UP
TO 30KTS.  VISIBILITIES OVER 6SM WILL PREVAIL THROUGH THE PERIOD...
BUT MAY BE REDUCED TO 3-5 SM DUE TO RAIN/SNOW SHOWERS BETWEEN 16 AND
00Z AND AGAIN AFTER 06Z.    ..14..

&&

.HYDROLOGY...
HAVE ADDED MARENGO TO THE MIX OF RIVER FLOOD WARNINGS...BUT WILL
HOLD OFF FOR NOW ON ADDING THE SKUNK RIVER AT SIGOURNEY WITH THE
CREST LOOKING TO REACH JUST BELOW FLOOD STAGE. WILL HAVE TO WATCH
STAGES/LEVELS INTENTLY THROUGH THE EARLY MORNING. THE FCST POINTS ON
THE DES MOINES RIVER ALSO LOOKING TO STAY JUST BELOW FS...BUT ARE
GETTING CLOSE.

&&

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

&&

12/14

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
505 AM CDT FRI APR 11 2008

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-121000-
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-
505 AM CDT FRI APR 11 2008

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

A VERY LARGE LOW PRESSURE STORM SYSTEM WILL ROTATE ITS WAY OVER AND
JUST NORTH OF THE AREA TODAY. THIS SYSTEM WILL CONTINUE TO GENERATE
OCCASIONAL RAIN SHOWERS TODAY INTO THIS EVENING. BRISK SOUTHWEST
WINDS FLOWING AROUND THE LOW PRESSURE CENTER WILL BUFFET THE AREA
TODAY...GUSTING TO OVER 35 MPH AT TIMES. AN UNSTABLE ENVIRONMENT MAY
ALLOW SOME OF THE STRONGER SHOWERS TO PRODUCE SMALL HAIL...AS WELL
AS ENHANCED WIND GUSTS OVER 40 MPH.

COLDER AIR WILL SPILL INTO THE AREA THIS AFTERNOON AND ESPECIALLY
TONIGHT...WITH THE PRECIPITATION CHANGING FROM RAIN SHOWERS TO SNOW
SHOWERS. THERE IS THE POTENTIAL FOR LIGHT SNOW ACCUMULATIONS...
ESPECIALLY NORTHEAST OF A LINE FROM CEDAR RAPIDS TO PRINCETON
ILLINOIS TONIGHT AND INTO SATURDAY MORNING. UP TO AN INCH OF
ACCUMULATION MAY OCCUR IN THESE AREAS...MAINLY ON GRASSY AND
ELEVATED SURFACES. SOME LOCALIZED SLICK SPOTS MAY DEVELOP ON BRIDGES
AND OVERPASSES TONIGHT AND EARLY SATURDAY MORNING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

SCATTERED SNOW SHOWERS WITH MINOR AND LOCALIZED ACCUMULATIONS WILL
AFFECT MUCH OF THE AREA ON SATURDAY.

MANY AREA RIVERS...INCLUDING THE MISSISSIPPI RIVER AND ITS
TRIBUTARIES...ARE EXPECTED TO CONTINUE TO EXPERIENCE SIGNIFICANT
RISES TODAY AND OVER THE WEEKEND. FLOODING IS LIKELY IN MANY
LOCATIONS. PLEASE SEE OUR LATEST FLOOD WARNINGS AND STATEMENTS FOR
THE LATEST INFORMATION.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED FOR TODAY AND TONIGHT.

12

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
656 AM CDT FRI APR 11 2008

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

0655 AM     HEAVY RAIN       5 E CEDAR RAPIDS        41.97N 91.58W
04/11/2008  M1.10 INCH       LINN               IA   TRAINED SPOTTER

            24 HOUR RAINFALL.

&&

14

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
813 AM CDT FRI APR 11 2008

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

0754 AM     HEAVY RAIN       W NORWAY                41.90N 91.93W
04/11/2008  M1.86 INCH       BENTON             IA   TRAINED SPOTTER

            TOTAL RAINFALL FROM YESTERDAY. 1.50 INCHES FROM ONE
            THUNDERSTORM. REPORTED THAT PRAIRE CREEK IS OUT OF ITS
            BANKS.

&&

MIKEZ

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
822 AM CDT FRI APR 11 2008

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

0815 AM     HEAVY RAIN       FULTON                  41.87N 90.16W
04/11/2008  M1.45 INCH       WHITESIDE          IL   TRAINED SPOTTER

&&

DLF