Severe Thunderstorm Warning 92, NWS Lincoln, IL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
245 PM CDT TUE JUN 19 2001

FORECAST CONCERNS THIS PD INCLUDES SVR POTENTIAL ACRS SRN HALF OF
CWA INTO THIS EVENING...AND THEN AREAL EXTENT AND DURATION OF PRECIP
OVRNGT INTO WED.

18Z SFC ANALYSIS AND MSAS LI/S INDICATE CDFNT LOCATED FROM JUST SOUTH
OF CHI TO NR PIA TO EAST OF JACKSONVILLE. WEAK WAVE ON BNDRY NR PIA
HAS SLOWED THE EWD PROGRESSION OF BNDRY. HOWEVER...AS WAVE SHIFTS
TO THE NE...FNT SHOULD BEGIN A SLOW CRAWL ACRS THE CWFA LT THIS AFTN
INTO THIS EVENING. BEST INSTABILITY AXIS ALINGED ALONG AND SOUTH OF
FRONT WITH CU DVLPG RAPIDLY OVR THE SE HALF OF FCST AREA. ONCE AGAIN
THE AVN AND ETA WERE SIMILAR IN THE SHORT TERM WITH NOT MUCH TIME TO
LOOK OVR THE AVN BEYOND 72 HRS.

BAND OF ELEVATED INSTABILITY SHOWERS AND TSRA ACRS NRN MO AND SRN IA
SHIFTING EWD THIS AFTN WITH CLOUD TOP TEMPS WARMING AS IT HEADS EAST.
310K ISENTROPIC FCSTS SUGGEST BEST LIFT AND MOISTURE ACRS THE NRN
HALF OF FCST AREA LATE TNT INTO WED MRNG. ETA STILL ADVERTISING
FCST AREA TO BE IN FAVORED RIGHT ENTRANCE REGION OF JET OVRNGT WITH
IMPRESSIVE 250 MB DIFFLUENCE FCST ACRS AREA LATE. LOW LVLS SHOULD
RESPOND TO UPPER LVL FORCING WITH AN INCREASE IN LOW LVL CONVERGENCE
(1000-850 MB THETA-E CONVERGENCE) ALONG SWWD MOVING CDFNT. ELEVATED
CONVECTION SHOULD EXPAND NORTH OF BNDRY OVRNGT WHILE MORE SFC BASED
CONVECTION...WHICH IS DVLPG ACRS THE SRN HALF OF THE CWA THIS AFTN
SHOULD PREVAIL LATE INTO THE EVENING OVR THE SOUTH. PRECIP WL SLOWLY
SHIFT SOUTH WED AS UPPER SUPPORT MOVES AWAY AND SFC HIGH BUILDS SE
COUNTIES NOT SEEING AN END TO THE RAIN THREAT UNTIL LATER WED NIGHT.

UPPER TROF FCST TO MOVE ACRS THE STATE ON THURSDAY WITH ETA PULLING
BACK ON PRECIP CHANCES. BASED ON TIMING OF TROF PASSAGE...WL KEEP
PRECIP CHANCES GOING THU INTO THU NIGHT WITH A DRIER AIR MASS FCST
TO PUSH THROUGH THE CWA FRIDAY. MRF PULLING BACK FROM ITS ORIGINAL
FCST WITH CLOSED LOW ACRS THE TN VALLEY WITH NEW MODEL DATA SUGGESTING
A MORE PROGRESSIVE TRACK (MORE IN LINE WITH THE EURO MODELS) THIS
WEEKEND RATHER THAN FEATURE RETROGRADING INTO THE SERN PTN OF IL.
WL PULL MENTION OF SHOWERS OUT OF THE SE FOR FRIDAY BASED ON CURRENT
MODEL TRENDS.

...PRELIMINARY CCF FOR COORDINATION PURPOSES ONLY.

SPI WB 065/080 057/077 054 44775
PIA WB 063/078 055/075 052 44764
DEC WB 065/080 057/077 054 44775
CMI WB 064/078 055/075 052 44774
MTO TB 067/081 059/078 055 44776
LWV TB 068/084 062/080 057 44776

.ILX...NONE.

SMITH

ILZ027>031-036>038-040>057-061>063-066>068-071>073-191900-

HAZARDOUS WEATHER OUTLOOK FOR CENTRAL ILLINOIS
NATIONAL WEATHER SERVICE LINCOLN IL
1140 AM CDT TUE JUN 19 2001

...THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS THROUGH TONIGHT
AREAS SOUTH OF A QUINCY TO BLOOMINGTON LINE...

A COLD FRONT WILL CONTINUE TO DROP SOUTHEAST ACROSS CENTRAL
ILLINOIS THIS AFTERNOON AND TONIGHT. MOISTURE AND INSTABILITY IN
PLACE ACROSS THE AREA WILL COMBINE WITH THE FRONT TO AID SCATTERED
THUNDERSTORM DEVELOPMENT. SOME OF THESE STORMS MAY BECOME SEVERE.
THE PRIMARY THREAT FROM THESE STORMS ARE DAMAGING WINDS AND LARGE
HAIL.

SPOTTER ACTIVATION MAY BE NEEDED LATER THIS AFTERNOON AND TONIGHT
ACROSS ALL OF CENTRAL AND SOUTHEAST ILLINOIS.

FRIEDERS