[LeArc] HWODVN@ 5/4/2003 6:24:26 AM

[learc@mailman.qth.net]

The following weather message is provided by McDonough County E.S.D.A.


FLUS43 KDVN 041123
HWODVN
IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-051000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
600 AM CDT SUN MAY 4 2003

...SEVERE WEATHER LIKELY FOR PORTIONS OF THE AREA TODAY AND AGAIN
TONIGHT...A POTENTIAL FOR A FEW TORNADOES BY THIS EVENING...

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

.DAY ONE...TODAY AND TONIGHT

A STRONG STORM SYSTEM WILL MOVE INTO THE WESTERN HIGH PLAINS TODAY.
THIS SYSTEM HAS ALREADY IGNITED THUNDERSTORMS OVER THE EAST CENTRAL
PLAINS AND MISSOURI OVERNIGHT...AND SOME OF THESE STORMS WILL
PUSH INTO SOUTHEAST IOWA...AND NORTHEAST MISSOURI THIS MORNING. THE
STRONGER STORMS COULD PRODUCE HAIL UP TO AN INCH AND A HALF IN
DIAMETER IN THESE AREAS THROUGH 11 AM.  AS THIS ACTIVITY MOVES
EAST AND NORTHEAST INTO MORE STABLE AIR ACROSS THE REST OF THE
AREA BY MIDDAY AND EARLY AFTERNOON...IT SHOULD WEAKEN INTO A MORE OF
A RAIN...MODERATE TO LOCALLY HEAVY...WITH PERHAPS SOME EMBEDDED
THUNDER THREAT. AS A DEVELOPING SURFACE LOW STRENGTHENS OVER THE
CENTRAL PLAINS TODAY AND INCREASES THE PRESSURE GRADIENT OVER THE
AREA...A BRISK SOUTHEAST WIND WILL GUST TO OVER 30 MPH BY THIS
AFTERNOON. A SOUTHERLY FLOW OF AIR AT AROUND 5000 FEET WILL
INCREASE SUBSTANTIALLY TODAY OVER THE AREA TO AROUND 70 MPH
AND FEED MORE UNSTABLE AIR UP OVER THE AREA. THIS WILL CREATE
CONDITIONS OVER THE AREA SUCH THAT MORE THUNDERSTORMS WILL DEVELOP
THIS AFTERNOON. MOST OF THE AREA WILL BE AT RISK FROM MID AFTERNOON
ON FROM THESE STORMS. AGAIN...LARGE HAIL FROM PENNY TO QUARTER SIZE
WILL BE THE PRIMARY THREAT. THE POTENTIAL WILL ALSO EXIST FOR HEAVY
RAINFALL FROM SIGOURNEY...TO SOUTH OF MONMOUTH WITH LOCALIZED AMOUNTS
OF 1 TO 1.5 INCHES.

THIS EVENING IS SHAPING UP TO BE QUITE STORMY...WITH AN OUTBREAK OF
SEVERE THUNDERSTORMS LOOKING LIKELY AS A STRONG AND WRAPPED UP WARM
FRONT PUSHES UP OUT OF MISSOURI AND ACROSS SOUTHEAST IOWA AND WEST
CENTRAL ILLINOIS. SUFFICIENT SHEAR AND INSTABILITY ALONG THE WARM
FRONT WILL RESULT IN THE POTENTIAL FOR SUPERCELLS...CONTAINING
LARGE HAIL...DAMAGING WINDS AND POSSIBLY A FEW TORNADOES. HAIL
UP TO GOLFBALL SIZE...DAMAGING WINDS TO 75 MPH...AND A FEW TORNADOES
WITH A STRENGTH RATING UP TO F3 STATUS WILL BE POSSIBLE THIS
EVENING...MAINLY ALONG AND SOUTH OF HIGHWAY 34 (FAIRFIELD IOWA TO
SOUTH OF MONMOUTH ILLINOIS). NORTH OF HIGHWAY 34 THE MAIN THREAT WILL
BE LARGE HAIL FROM PENNY TO QUARTER SIZE. HOWEVER...THE WARM FRONT AT
THE SURFACE IS EXPECTED TO LIFT SLOWLY NORTH TO NEAR THE INTERSTATE
80 CORRIDOR OVERNIGHT...BRINGING THE RISK FOR SUPERCELLS WITH IT.
LATEST INDICATIONS SUGGEST THIS LATE NIGHT SUPERCELL THREAT MIGHT
REACH A LINE FROM WILLIAMSBURG...TO JUST SOUTH OF THE QUAD CITIES
BY 1 AM. AT THIS TIME OF NIGHT...THERE WILL BE A DIMINISHED THREAT
FOR TORNADIC ACTIVITY...BUT THE RISK FOR LARGE HAIL AND DAMAGING WIND
GUSTS WILL STILL EXIST. BY MIDNIGHT...SOME OF THE EARLIER SUPERCELLS
AROUND THE ROUTE 34 CORRIDOR MAY BE CONSOLIDATED INTO A SQUALL LINE
AND PRODUCING A STRAIGHT LINE WIND THREAT ACROSS WEST CENTRAL
ILLINOIS.

ANOTHER FACTOR TO CONSIDER IS THE RISK FOR SOME FLASH FLOODING.
RECENT HEAVY RAINS HAVE MOISTENED SOILS CONSIDERABLY...THEREFORE ANY
ADDITIONAL HEAVY RAIN COULD RESULT IN RAPID RUNOFF...QUICKLY FILLING
SMALL STREAMS AND CREEKS. MANY CREEKS AND STREAMS IN LOUISA...
MERCER...HENRY...BUREAU AND PUTNAM COUNTIES ARE RUNNING AT OR JUST
BELOW BANKFULL...THEREFORE THESE COUNTIES ARE MOST AT RISK FOR SEEING
FLOODING PROBLEMS. IN ADDITION...HEAVY RAINS WILL LIKELY CAUSE RISES
ON AREA RIVERS EARLY NEXT WEEK.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THE LARGE AND SLOW MOVING STORM SYSTEM WILL THEN SHIFT ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY ON MONDAY. THIS SYSTEM WILL BE CLOSE
ENOUGH TO THE AREA TO POSSIBLY PRODUCE SCATTERED SHOWERS AND
THUNDERSTORMS IN UNSTABLE CONDITIONS THAT WILL DEVELOP BY MONDAY
AFTERNOON. THERE IS THE POTENTIAL FOR SOME OF THESE STORMS TO PRODUCE
HAIL LARGE ENOUGH TO BE CONSIDERED SEVERE...AND SOME LOCALIZED
DOWNBURSTS TO 60 MPH.

EMERGENCY MANAGERS AND SPOTTERS SHOULD STAY TUNED TO NOAA WEATHER
RADIO...COMMERCIAL TELEVISION OR RADIO STATIONS...OR YOUR CABLE
TELEVISION PROVIDER FOR LATER STATEMENTS CONCERNING THIS POTENTIALLY
DANGEROUS SEVERE WEATHER THREAT.

.SPOTTER INFORMATION STATEMENT...

STORM SPOTTER ACTIVATION WILL LIKELY BE NEEDED TODAY AND AGAIN
TONIGHT...ESPECIALLY ALONG AND SOUTH OF THE INTERSTATE 80 CORRIDOR.

&&

UPCOMING SPOTTER TRAINING CLASSES:

May 6, 2003:  Training - Chadwick, IL -  7 pm

Severe weather and tornado spotter training will be conducted in
Chadwick, Illinois (Carroll County) at the fire department at 7 pm.
This will be a free 2 hour class.  For additional information,
contact county ESDA coordinator Greg Miller.

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING URL:
http://www.crh.noaa.gov/dvn

$$

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