367 
FXUS63 KILX 280903
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
403 AM CDT SUN JUN 28 2015

.SHORT TERM...(TODAY)
ISSUED AT 357 AM CDT SUN JUN 28 2015

ONGOING CONVECTION ACROSS NORTH IOWA WILL SLOWLY MOVE INTO WESTERN 
AND NORTHWESTERN IL THIS MORNING, BUT WILL BE DIMINISHING AS IT 
MOVES INTO THE AREA. SCATTERED CONVECTION WILL REMAIN POSSIBLE THIS 
MORNING SO WILL KEEP CHC POPS IN THE FORECAST, MAINLY WEST OF I-55. 
MODERATELY STRONG WEATHER SYSTEM WILL THEN DROP INTO EASTERN IA BY 
AFTERNOON WITH A TRAILING COLD FRONT EXTENDING INTO NORTHERN AND 
WESTERN MO. HIRES/SHORT RANGE MODELS DEVELOP CONVECTION ALONG AND 
AHEAD OF THE SYSTEM IN WESTERN HALF OF IL AND EASTERN MO. MODERATE 
INSTABILITY WILL BE AHEAD OF THIS SYSTEM WITH SUFFICIENT BULK SHEAR 
AND 0-3KM HELICITY TO PRODUCE SUPERCELLS IN NORTHWESTERN/WESTERN IL 
AND NORTHEASTERN MO. STORMS ARE EXPECTED TO MOVE SOUTHEAST EFFECTING 
THE CWA DURING THE AFTERNOON. AGREE WITH SPC OUTLOOK OF SLIGHT RISK 
OVER WESTERN PART OF THE CWA WHERE THERE WILL BE A SLIGHT OVERLAP OF 
BEST INSTABILITY AND BEST SHEAR/HELICITY EXISTS. HOWEVER...WOULD NOT 
BE SUPRISED IF SLIGHT AREA GETS EXPANDED EASTWARD SOME LATER THIS 
MORNING OR AFTERNOON. SO WILL HAVE LIKELY POPS IN THE WEST FOR THE 
CONVECTION. WINDS WILL BE LIGHT AHEAD OF THE SYSTEM OUT OF THE 
SOUTHWEST. AFTER HIGHS SHOULD BE SLIGHTLY WARMER THAN YESTERDAY AS 
850MB TEMPS WILL BE AROUND 14C.

&&

.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 357 AM CDT SUN JUN 28 2015

A LITTLE WARMER THIS EVENING AS WINDS GET A SOUTHERLY COMPONENT IN 
ADDITION TO PERSISTENT CLOUD COVER WITH THE PRECIP TRAPPING THE 
TEMPS OVERNIGHT. VIGOROUS SHORT WAVE MOVING INTO THE MIDWEST WITH A 
DEVELOPING SFC LOW COLLIDING WITH LIMITED BUT SLIGHTLY INCREASING 
MOISTURE IN THE BOUNDARY LAYER AS SOUTHERLY WINDS PUSH RICHER 
INSTABILITY INTO THE MIDWEST. BETTER SHEAR IS TO THE WEST/SW WITH 
THE DEVELOPMENT OF ROTATING STORMS, AND TIMING OF MAX HEATING WILL 
DEF PLAY A ROLE IN THE EVOLUTION FOR THE EVENING.  AS IT STANDS, 
WEST CENTRAL IL AND SOUTHWEST INTO MO IN A SLIGHT RISK FOR THE 
OVERNIGHT HOURS WITH THE REMAINDER OF CENTRAL IL IN A MARGINAL RISK 
TO SEE THE REMAINS OF THE MORE ORGANIZED STORMS THROUGH THE 
REMAINDER OF THE NIGHT BRINGING THE THREAT FOR WIND AND HAIL.

NORTHWESTERLY FLOW INTO THE REGION FROM THE PAC NW MAINTAINING A 
STEADY STREAM OF SHORT WAVES FOR THE FORECAST. SOME TIMING ISSUES 
REMAIN FROM RUN TO RUN, BUT IN GENERAL, AGREEMENT FOR PRECIP TONIGHT 
AND INTO TOMORROW...AGAIN ON TUESDAY...AND WED AFTERNOON.  AT THAT 
POINT IN THE FORECAST, THE SERIES OF WAVES STARTS TO HAVE A LITTLE 
MORE DISSONANCE FROM MODEL TO MODEL.  OVERALL THE FORECAST REMAINS 
WET AND STORMY WITH TEMPS SLIGHTLY BELOW NORMAL WITH NORTHWESTERLY 
FLOW.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1136 PM CDT SAT JUN 27 2015

VFR CONDITIONS ACROSS CENTRAL IL TERMINALS THIS EVENING AS A WEAK
HIGH PRESSURE RIDGE APPROACHES FOR THE REMAINDER OF THE NIGHT. SOME
VISIBILITY REDUCTIONS POSSIBLE LATE IN THE NIGHT DUE TO
FOG...PRIMARILY WEST OF KSPI-KPIA WHERE SURFACE DEWPOINTS HIGHEST
AND MOISTURE PROFILE IS SOMEWHAT DEEPER. HAVE NOT INCLUDED IN TAFS
YET AS IT APPEARS LOW LIKELIHOOD AT THIS POINT. SCATTERED CUMULUS
CLOUDS TO APPEAR AGAIN BY 15Z AS A LOW PRESSURE SYSTEM APPROACHES
FROM THE NORTHWEST. SHOWERS AND THUNDERSTORMS WILL SPREAD INTO THE
REGION 17-20Z WITH THIS SYSTEM. AT THIS TIME...TIMING AND
LOCATION UNCERTAINTIES WITH THUNDERSTORMS THAT DEVELOP INITIALLY
PRECLUDE MENTION OF IFR/MVFR CIGS/VSBYS ALTHOUGH STRONGER STORMS
WILL CONTAIN IFR CONDITIONS AS WELL AS GUSTY AND VARIABLE WINDS.
AFTER 00Z...INCORPORATED MVFR CIGS/VSBYS IN TAFS AS SHOWER
ACTIVITY SHOULD BECOME MORE WIDESPREAD...AND THUNDERSTORM
POTENTIAL WILL CONTINUE.

WINDS LIGHT AND VARIABLE OVERNIGHT...INCREASING TO S-SW 8-12 KTS
STARTING AROUND 15Z AND CONTINUING THROUGH THE END OF THE TAF
PERIOD.


&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...AUTEN
LONG TERM...HJS
AVIATION...ONTON