Hail in Missouri, May 6, 2002

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
235 AM CDT MON MAY 6 2002

DIFFICULT FORECAST...WITH MANY CONCERNS INCLUDING PRECIPITATION TIMING
IN ACTIVE PATTERN NEXT FEW DAYS...ALONG WITH
POTENTIAL FOR HEAVY RAIN/FLOODING AND STRONG/SEVERE THUNDERSTORMS...AND
LASTLY TEMPS.

NEAR TERM...WATER VAPOR IMAGERY SHOWS WELL DEFINED VORT MAX AND MID LEVEL
TROUGH IN EASTERN NE. EDGE GOES TO ETA ON POSITIONING AND STRENGTH.
THIS SYSTEM WILL LIFT ACROSS MID MISSISSIPPI VALLEY THROUGH EARLY AFTERNOON
WITH 40+ KT LLJ VEERING TOWARD CWA ALONG WITH THETA-E AXIS.
THIS WILL RESULT IN PRETTY GOOD COVERAGE OF SHOWERS/TSTMS ACROSS THE REGION
THIS MORNING...WHICH LATEST RADAR PICS SUPPORT. ACTIVITY MAY LINGER INTO
EARLY AFTERNOON...ESPECIALLY EAST/FAR SOUTH. THEN...LULL IN PRECIPITATION
EXPECTED UNTIL LATE AFTERNOON/EVENING WITH FEW BREAKS...ALLOWING TEMPS TO
JUMP QUICKLY...MAKING FOR WARM AND HUMID CONDITIONS. TEMPS AT 05Z
STILL RUNNING IN MID 60S TO NEAR 70 DEGS...SO WON/T TAKE MUCH SUNSHINE TO
SEND TEMPS INTO 80S. CURRENT TEMP FORECAST TODAY LOOKS PRETTY GOOD.
ADDITIONAL SHOWERS/TSTMS EXPECTED TO DEVELOP ALONG COLD FRONT LATE
AFTERNOON/EVENING AS IT MOVES SOUTH ACROSS CWA. POTENTIAL FOR BUSY EVENING
WITH LARGE HAIL AND DAMAGING WIND THREAT...DEPENDING UPON EXTENT
OF SOLAR INSOLATION THIS AFTERNOON...BOUNDARY LAYER ENERGY POTENTIAL (BLEP)
TECHNIQUE SUPPORTIVE OF STRAIGHT LINE WIND POTENTIAL OF 65 KTS...MAINLY ALONG
AND SOUTH OF I-80 WITH LOCALLY HIGHER TO NEAR 80 KTS POSSIBLE WITH ROTATING
STORMS.

GREAT LAKES ENHANCED FRONT TO STALL TO OUR SOUTH ON TUE...SUPPORTING POTENTIAL
FOR SIGNIFICANT HEAVY RAIN AND SEVERE THREAT LATE TUE-WED.
TEMPS TUE QUIET TRICKY WITH LARGE GRADIENT EXPECTED FROM NORTHEAST TO
SOUTHWEST OF 15 TO 20 DEGS.

MODELS SHOW FRONT LIFTING BACK NORTH AS WARM FRONT TUE NIGHT/EARLY WED.
REAL CONCERNS WITH HOW FAR NORTH FRONT WILL COME...AS IT COULD END
UP BEING FURTHER SOUTH THAN MODELS INDICATE WITH SUBSTATIONAL PRECIPITATION
ON COOL SIDE OF BOUNDARY. THIS WILL HAVE IMPACT ON LOCATION OF HEAVY RAIN
AND SEVERE POTENTIAL TUE NIGHT/WED. AVN/UKMET SOLUTIONS REMAIN
QUITE OMINOUS WITH REGARD TO SEVERE POTENTIAL ON WED. WILL CONTINUE TO
HIGHLIGHT THIS POTENTIAL IN MORNING SIG WX OUTLOOK.

UPDATED...
MONITORING CLOSELY CONVECTIVE TRENDS IN EASTERN NE. LINEAR CONVECTION
CONTINUES DEVELOPING ON NOSE OF 50 KT LLJ AT 0730Z. MODELS SUGGEST
LLJ TO VEER THIS MORNING...SO EXPECT LINEAR CONVECTION TO SLIDE SLOWLY E/SE
TOWARDS SOUTHERN CWA. AT PRESENT TIME...HEAVY RAINS WITH CONVECTIVE
COMPLEXES STAYING SOUTH OF CWA ACROSS MO. SOME MODERATE RAIN IN FAR SOUTH IN
STRATIFORM REGION WITH UP TO 1/4 INCH OR SO POSSIBLE. KIRKSVILLE REPORTING .30
SO FAR. FFG VALUES IN SOUTH AS LOW AS 1.2 INCHES IN 1 HOUR AND 1.5 INCHES IN
3 HOURS...WHICH IS CONCERNING. ATTIM...STILL GOING TO HOLD OFF ON FLOOD WATCH...
GIVEN LITTLE QPF SO FAR. BUT...THIS WILL NEED TO BE MONITORED FOR ANY POSSIBLE
CHANGES TO THINKING.

.EXTENDED...WILL LIKELY LET RIDE...DUE TO TIME CONSTRAINTS.

.DVN...
IA...NONE.
IL...NONE.
MO...NONE.

MCCLURE

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-009-
015>018-024>026-034-035-MOZ009-010-071100-

SIGNIFICANT WEATHER OUTLOOK
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
611 AM CDT MON MAY 6 2002

...POTENTIAL FOR HEAVY RAIN AND SEVERE WEATHER NEXT FEW DAYS...

SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS PORTIONS OF SOUTHEAST IOWA...
WEST CENTRAL ILLINOIS AND NORTHEAST MISSOURI THROUGH MIDDAY.
MOST OF THE ACTIVITY WILL BE FOUND SOUTH OF HIGHWAY 34. NO SEVERE
WEATHER IS EXPECTED HOWEVER...HEAVY RAIN...GUSTY WINDS TO NEAR 40 MPH
AND SMALL HAIL WILL BE POSSIBLE WITH THE STRONGEST STORMS.
RAINFALL AMOUNTS WILL BE HIGHEST SOUTH OF A LINE FROM KEOSAUQUA...TO
FORT MADISON...AND MACOMB...WHERE ONE QUARTER TO ONE HALF INCH IS
LIKELY...WITH LOCALLY HIGHER AMOUNTS OF NEAR 3/4 INCH POSSIBLE. FURTHER
NORTH EXPECT SCATTERED SHOWERS...WITH A FEW THUNDERSTORMS POSSIBLE.
RAINFALL AMOUNTS WILL GENERALLY AVERAGE A FEW HUNDREDTHS TO LESS THAN
TWO TENTHS OF AN INCH.

THE PRECIPITATION WILL DIMINISH BY EARLY AFTERNOON...HOWEVER
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO REDEVELOP LATE
THIS AFTERNOON AND EVENING...AS A COLD FRONT APPROACHES FROM THE
NORTHWEST. THERE IS THE POTENTIAL FOR A FEW OF THESE STORMS TO BECOME
SEVERE...PRODUCING LARGE HAIL UP TO GOLFBALL SIZE...DAMAGING STRAIGHT
LINE WINDS OF 60 TO 80 MPH...AND HEAVY RAINFALL.

ANOTHER ROUND OF RAIN AND THUNDERSTORMS IS EXPECTED LATE TUESDAY AND
TUESDAY NIGHT...WITH THE CONTINUED THREAT OF LARGE HAIL AND
HEAVY RAINFALL.

A MORE SIGNIFICANT OUTBREAK OF SEVERE WEATHER IS ANTICIPATED ON
WEDNESDAY...AS SURFACE LOW PRESSURE AND A STRONG COLD FRONT SWEEP ACROSS
THE REGION DURING THE AFTERNOON AND EVENING.

THIS EXTENDED PERIOD OF RAIN WILL GRADUALLY SATURATE SOILS ACROSS THE
REGION...AND MAY LEAD TO LOCALIZED FLOODING AND GRADUAL SIGNIFICANT
RISES ON AREA RIVERS.

STORM SPOTTER ACTIVATION MAY BE REQUIRED LATE THIS AFTERNOON AND
EVENING. STAY TUNED TO NOAA WEATHER RADIO...OR YOUR FAVORITE RADIO OR
TELEVISION STATION FOR LATER FORECASTS AND UPDATES ON THIS DEVELOPING
SITUATION.