999 
FXUS63 KILX 021844
AFDSPI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
130 PM CDT SUN MAY 2 1999

STRONG OMEGA BLOCK TO BEGIN BREAKING DOWN THIS AFTN/TONIGHT AS IT SHIFTS
E. 12Z MODEL RUNS ARE MORE AGRESSIVE WITH PACIFIC ENERGY BRINGING MORE
CLOUDS AND BETTER CHANCE OF SHOWERS/THUNDERSTORMS MON/TUE. ETA STILL THE
DRIEST SCENERIO BUT AVN/NGM MORE IN SYNC AND WILL LEAN IN THIS
DIRECTION. FAN/FWC TEMPS 1-3 DEGREES WARMER THAN LAST RUN NEXT 48 HRS.

FORECAST CHALLENGE WILL BE WHETHER POPS SHOULD BE INSERTED INTO
MONDAY/S FORECAST...TIMING OF INCREASING CLOUD COVER AND AFFECTS ON
TEMPS.

CLEAR SKIES EARLY TONIGHT TO BECOME MOSTLY CLOUDY OVERNIGHT FROM W-E AND
CONTINUE MON AS SHORT WAVE OVER FAR NE CO SHEARS NE INTO THE EASTERN
DAKOTAS/W MN BY 12Z/MON THEN DEPARTS INTO CANADA LATE MON. STILL DRY SE
IL THRU TUE MORNING BUT WOULD INTRODUCE A 30/40 POP OF A SHOWER NW OF
I-57 MON AND WOULD NOT BE SURPRISED FOR AN ISOLATED THUNDERSTORM W OF
SPI/PIA WHERE BEST DYNAMICS NICK ALONG WITH DEEPER MOISTURE FIELD. 

SMALL POP OF A SHOWER MONDAY NIGHT AS SHORT WAVE DEPARTS WITH LINGERING
LOW LEVEL MOISTURE AND THETA-E RIDGE FROM E TX N TO MN. MUCH STRONGER
UPPER LEVEL TROUGH OVER AK AND THE CANADIAN W COAST TO DIG INTO THE
ROCKIES THRU TUE WITH AVN SHOWING IT EVOLVING INTO A STRONG NEGATIVE
TITLED TROUGH LIFTING INTO IL BY 12Z/WED. AMPLE GULF MOISTURE LIFTING N
AHEAD OF PACIFIC COLD FRONT POISED JUST W OF IL BY 12Z/WED WITH 988 MB
SURFACE LOW OVER UPPER MS VALLEY AND H85 JET INCREASING TO 45-50KTS.
LIKELY CHANCE OF SHOWERS/THUNDERSTORMS W OF SPI/PIA TUE AFTERNOON AND
STATEWIDE TUE NIGHT AND A FEW COULD BE SEVERE. 

FOLLOWED GUIDANCE TEMPS NEXT 48 HRS AS FAN ONLY 0-3 DEGREES MILDER THAN
FWC. 

PRELIMINARY CODED CITY FORECAST FOR COORDINATION...

SPI EW 055/077 058/075 056 14357
PIA EW 055/077 058/075 055 14357