Severe Thunderstorm Warning 30, NWS Lincoln, IL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
237 PM CDT WED APR 19 2000

AS OF 18Z...SFC ANALYSIS SHOWS LOW PRESSURE CENTERED OVER SOUTH
CENTRAL SD. WRMFNT FROM THE LOW THROUGH CNTRL IA INTO NORTHERN IL.
DRYLINE EXTENDS FROM THE LOW THROUGH WESTERN IA AND NW MISSOURI.

LOW LVL MSTR RAPIDLY MOVING NE ALONG THE BOUNDARY WILL BE JUST ONE
OF MANY INGREDIENTS TO SET THE STAGE FOR WIDESPREAD THUNDERSTORM
ACTIVITY ACROSS THE CWA. MAIN CONCERNS ARE TIMING OF PCPN INTO AREA
TNGT AND TOMORROW AS WELL AS ANY EFFECTS FRM CLOUD CVR AHEAD OF
DRYLINE.

MID TO UPPER 50 SFC DEWPTS ALREADY IN PLACE ACROSS MOST OF CWA...
WITH LOW TO MID 60S ACROSS CNTRL MISSOURI...MOVING IN AHEAD OF THE
DRYLINE WITH DEWPOINTS IN THE 30S IMMEDIATELY BEHIND. ALL MODELS
INITIALIZED WELL WITH UPR LVL FEATURES...PLACING VORT MAX UNDERNEATH
SFC LOW IN SD. BUT MODELS DO DIFFER ON SFC FEATURES...ESPECIALLY PAST
18 HOURS. LIKE THE POSITIONING OF THE AVN WITH SFC LOW AT PRESENT
TIME AS WELL AS PLACEMENT OF DRYLINE. WILL FOLLOW AVN FOR THIS
FORECAST...WHICH WILL BRING IN A STRENGTHENING LOW AS IT MOVES INTO
IL. EXPECT CONVECTION TO BEGIN TO DEVELOP AHEAD IN/NEAR THE TRIPLE
POINT IN S/SE IOWA AND ALONG THE DRYLINE IN CNTRL MISSOURI BY LATE
AFTERNOON AND EVENING. THIS ACTIVITY WILL MOVE RAPIDLY EAST TOWARDS
THE AREA AND ARRIVE AFTER 02Z IN THE AREA. SEVERE WEATHER LOOKS
FAVORABLE AS EXCELLENT DIRECTIONAL SHEAR IN PLACE...LOW LVL MSTR AND
SERIES OF UPR LVL JET MAXES TO ENTER THE AREA. EXPECT WIDESPREAD
SHOWERS AND THUNDERSTORMS TONIGHT WITH MSTR AHEAD OF FRONT AND
INCREASING LIFT. LOCALLY HEAVY RAIN POSSIBLE IN SOME AREAS AS WELL
ECHOS START TO TRAIN OVERNIGHT ACROSS CNTRL IL.

THURSDAY...THE DRYLINE WILL MOVE THROUGH THE CWA. TIMING WOULD PUT
THE DRYLINE ENTERING THE WESTERN CWA BY 15Z WITH IT EXITING THE AREA
BY 22Z. LOW TO MID 60 DEWPTS SHOULD BE IN PLACE AHEAD OF THE DRYLINE
AT THE SFC WITH UPR LVLS SHOWING JET MAXES COUPLING AROUND 18Z OVER
CNTRL IL. THE ONLY CONCERN WOULD BE AMOUNT OF DEBRIS LEFT OVER FROM
OVERNIGHT CONVECTION. AGREE WITH SPC THAT SE IL IN BEST LOCATION FOR
SVR WX DURING THE LT AFTN/EVENING HOURS. NOT RULING OUT PROBLEMS
WITH SEVERE ACROSS ECNTRL IL THOUGH BASED ON TIMING OF DRYLINE AND
UPPER LEVEL STRUCTURE.

THURSDAY NIGHT...LOW WILL MOVE RAPIDLY AWAY FROM THE AREA. BEHIND IT
STG GRADIENT WILL BRING IN GUSTY NWSTRLY WINDS AND SOME LEFT OVER
SHOWERS IN THE WRAPAROUND.

EXPECT CLR SKIES AND MORE NORMAL TEMPERATURES RETURNING TO
THE AREA AS STG RIDGE BEGINS TO BUILD IN FRI AND THROUGH THE
WEEKEND.

...PRELIMINARY CCF FOR COORDINATION ONLY...

SPI TB 059/064 042/055 039 26783
PIA TB 058/062 040/054 038 26783
DEC TB 057/064 042/054 038 26783
CMI TB 056/065 042/053 037 26674
MTO TB 056/070 042/055 040 26597
LWV TB 057/073 044/057 040 26597

.ILX...
IL...NONE.

FISHER/KETCHAM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN, IL
937 PM CDT WED APR 19 2000

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0920 PM    RUSHVILLE                 IL   .75 INCH HAIL
04/19/00   SCHUYLER                       (ESDA)

BYRD

ILZ036-040-041-047>051-200400-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LINCOLN IL
1010 PM CDT WED APR 19 2000

...NEW TORNADO WATCH ISSUED FOR WEST CENTRAL ILLINOIS...

THE FOLLOWING COUNTIES ARE INCLUDED IN A NEW TORNADO WATCH THAT IS
IN EFFECT UNTIL 4 AM CDT...

FULTON...SCHUYLER...MASON...CASS...SCOTT AND MORGAN.

THE FOLLOWING COUNTIES WERE PREVIOUSLY IN A TORNADO WATCH THAT
EXPIRED AT 10 PM CDT...

SANGAMON AND MENARD.

MILLER

ILZ048-051-200345-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LINCOLN IL
1021 PM CDT WED APR 19 2000

...THE TORNADO WATCH FOR SANGAMON AND MENARD COUNTIES EXPIRED AT 10
PM...

ALTHOUGH THIS WATCH WAS ALLOWED TO EXPIRE...SEVERE WEATHER IS STILL
POSSIBLE...ESPECIALLY LATER IN THE NIGHT...AS STRONG TO SEVERE STORMS
MOVE OUT OF MISSOURI.

ANOTHER TORNADO WATCH HAS BEEN ISSUED JUST TO THE WEST OF SANGAMON
AND MENARD COUNTIES...VALID UNTIL 4 AM.

IF YOU ARE IN MENARD OR SANGAMON COUNTIES...YOU SHOULD STILL BE
ALERT FOR THE POSSIBILITY OF SEVERE WEATHER OVERNIGHT.

GEELHART