[LeArc] HWODVN@ 5/9/2003 1:47:58 PM

Fri, 09 May 2003 13:47:58 -0500

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

FLUS43 KDVN 091847
HWODVN
IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-101000-

HAZARDOUS WEATHER OUTLOOK...CORRECTED TYPO
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
145 PM CDT FRI MAY 9 2003

...POTENTIALLY DANGEROUS WEATHER SITUATION SATURDAY AND SATURDAY
EVENING...A SIGNIFICANT OUTBREAK OF SEVERE WEATHER EXPECTED WITH
THREATS OF LARGE HAIL...DAMAGING WINDS AND TORNADOES...

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

.DAY ONE...TONIGHT
A WEAK FRONTAL ZONE WILL HOVER ACROSS EXTREME SOUTHEAST IOWA...
NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS LATE TODAY. A LINE OF
THUNDERSTORMS WILL DEVELOP ALONG THIS BOUNDARY LATE THIS AFTERNOON
AND CONTINUE THROUGH THE EVENING HOURS.  THESE STORMS WILL PRODUCE
HEAVY RAINS...LOCALLY HEAVY UP TO 2 INCHES.   A FEW STORMS WILL
BECOME SEVERE AND PRODUCE LARGE HAIL UP TO THE SIZE OF GOLF-BALLS...
AND STRONG AND DAMAGING WINDS OF 60 TO 70 MPH. THESE STORMS SHOULD
STAY SOUTH OF A PRINCETON TO MONMOUTH TO MEMPHIS LINE.  THE RISK OF
TORNADOES TONIGHT WILL BE MINIMAL.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

A SIGNIFICANT OUTBREAK OF SEVERE WEATHER IS EXPECTED SATURDAY AND
SATURDAY NIGHT.  A NEAR RECORD STRENGTH LOW PRESSURE SYSTEM WILL
DEEPEN AS IT LIFTS FROM THE SOUTHERN PLAINS THROUGH THE MISSISSIPPI
VALLEY LATE SATURDAY.  LATEST TRENDS CONTINUE TO SUGGEST THE MAIN LOW
WILL MOVE FROM NORTHWEST MISSOURI THROUGH SOUTHEAST IOWA INTO
NORTHWEST ILLINOIS BY SATURDAY EVENING...ROUGHLY ALONG OR NEAR A LINE
FROM LAMONI IOWA...TO NEAR THE QUAD CITIES...TO FREEPORT ILLINOIS.
THE AIRMASS ALONG AND AHEAD OF THE LOW WILL BECOME VERY UNSTABLE...
AND SUPPORTIVE OF EXTREMELY LARGE HAIL UP TO THE SIZE OF BASEBALLS...
VERY DAMAGING WINDS IN EXCESS OF 70 MPH AND POTENTIALLY TORNADOES.

AT THIS TIME...IT APPEARS THE GREATEST RISK FOR TORNADOES WILL BE
ROUGHLY SOUTH OF A LINE FROM FAIRFIELD TO THE QUAD CITIES TO
PRINCETON ILLINOIS.  THE MOST REASONABLE SCENARIO IS FOR ROTATING
THUNDERSTORMS...CALLED SUPERCELLS TO DEVELOP BY MID AFTERNOON IN
NORTHERN MISSOURI AND MOVE INTO SOUTHEASTERN IOWA AND WEST CENTRAL
ILLINOIS BY LATE AFTERNOON.  THE STRENGTH AND CHANGE IN DIRECTION OF
THE EXPECTED LOW LEVEL WINDS...COUPLED WITH VERY MOIST AND UNSTABLE
AIR NEAR THE GROUND WILL CREATE AN ENVIRONMENT CONDUCIVE FOR
TORNADOES TO DEVELOP.

IF SURFACE TEMPERATURES REACH WELL INTO THE 80S AHEAD OF THE STORMS
AS IS EXPECTED...THE POTENTIAL WILL EXIST FOR SEVERAL TORNADOES...
WITH POSSIBLY ONE OR TWO STRONG TORNADOES OF F3 ON THE FUJITA
SCALE...OR WINDS IN EXCESS OF 150 MPH.  THE STRENGTH OF THIS SYSTEM
ALSO WILL CREATE AN ENVIRONMENT WHERE A MODEST INCREASE IN LOW LEVEL
WINDS INTO THE STORMS...ABOVE WHAT IS CURRENTLY PROJECTED...WOULD
PRODUCE A VIOLENT TORNADO OF F4 ON THE FUJITA SCALE...OR WINDS UP
TO 220 MPH.

LOCATIONS NORTH OF THE PRINCETON TO FAIRFIELD AXIS WILL BE AT RISK
FOR LARGE HAIL UP TO THE SIZE OF GOLF-BALLS WITH AN ISOLATED TORNADO
OR TWO.

THIS FRONTAL SYSTEM IS THE SAME ONE RESPONSIBLE FOR MUCH OF THE
SEVERE WEATHER IN RECENT DAYS FROM THE SOUTHERN PLAINS INTO THE
SOUTHEASTERN STATES.

RESIDENTS OF EASTERN IOWA...NORTHWEST AND WEST CENTRAL ILLINOIS AND
NORTHEAST MISSOURI SHOULD STAY TUNED TO NOAA WEATHER RADIO
FOR LATER STATEMENTS CONCERNING THE POTENTIALLY DANGEROUS WEATHER
SITUATION FOR SATURDAY AND SATURDAY EVENING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE THIS EVENING AND OVERNIGHT...MAINLY
SOUTH OF A LINE FROM STERLING ROCK FALLS...TO THE QUAD CITIES...TO
WASHINGTON.

SPOTTER ACTIVATION WILL BE NEEDED OVER MUCH OF THE AREA SATURDAY
AFTERNOON AND EARLY EVENING.  LOCATIONS SOUTH OF A PRINCETON TO QUAD
CITIES TO FAIRFIELD LINE SHOULD PREPARE FOR ONE OF THE STRONGEST AND
MOST WIDESPREAD SEVERE WEATHER EVENTS THAT HAS OCCURRED OVER THE PAST
10 YEARS.

&&

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

$$

NICHOLS