MESOSCALE DISCUSSION 0259
   NWS STORM PREDICTION CENTER NORMAN OK
   0604 PM CDT THU APR 09 2015

   AREAS AFFECTED...FAR EASTERN IA AND NORTHERN/CENTRAL IL INTO
   SOUTHEAST WI

   CONCERNING...TORNADO WATCH 39...41...

   VALID 092304Z - 100030Z

   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 39...41...CONTINUES.

   SUMMARY...THE POTENTIAL FOR TORNADOES AND SEVERE HAIL WILL CONTINUE
   FROM FAR EASTERN IA INTO NORTHERN/CENTRAL IL AND SOUTHERN WI...WITH
   THE GREATEST RISK FOR TORNADOES AND POSSIBLY AN INCREASING DAMAGING
   WIND THREAT ACROSS NORTHERN IL THROUGH EARLY/MID EVENING NEAR THE
   WARM FRONT.

   DISCUSSION...AS OF 2230Z...A 996 MB SURFACE LOW CONTINUES TO
   STEADILY DEEPEN NEAR THE QUAD CITIES AREA...WITH A WARM FRONT
   EXTENDING GENERALLY EASTWARD ACROSS FAR NORTHERN IL APPROXIMATELY
   NEAR/JUST NORTH OF I-88/REAGAN TOLLWAY. THE MOST INTENSE STORMS
   /INCLUDING AN APPARENT CYCLIC HP SUPERCELL WITH REPORTED TORNADOES/
   ARE ONGOING NEAR JUST/NORTH OF THE QUAD CITIES IMMEDIATELY AHEAD OF
   THE SURFACE LOW...BUT OTHER ISOLATED DISCRETE STORMS INCLUDING AT
   LEAST TRANSIENT SUPERCELLS ARE ONGOING ACROSS OTHER PARTS OF
   WEST-CENTRAL/NORTHERN IL. 

   WHILE LOW-LEVEL SHEAR/SRH WITHIN THE WARM SECTOR IS STRONG ENOUGH TO
   SUPPORT A TORNADO RISK AMID LOWER 60S F SURFACE DEWPOINTS...ANY
   SEMI-DISCRETE STORMS INTERACTING WITH/CROSSING THE WARM FRONT MAY
   ESPECIALLY POSE A TORNADO THREAT...PARTICULARLY ACROSS NORTHERN IL.
   THIS INCLUDES THE HP SUPERCELL NEAR/JUST NORTH OF THE QUAD CITIES
   AREA...IN ADDITION STORMS OVER LEE/OGLE COUNTIES IL SOUTHWEST OF
   ROCKFORD AS OF 2250Z. SEMI-DISCRETE SUPERCELLS CAPABLE OF SEVERE
   HAIL AND TORNADOES WILL REMAIN THE DOMINANT SCENARIO OVER THE NEXT
   FEW HOURS...WITH A STRONG TORNADO POSSIBLE PARTICULARLY ACROSS
   NORTHERN IL IN VICINITY OF THE WARM FRONT. OVER TIME...AN
   INCREASINGLY MIXED/UPSCALE-GROWING MODE MAY EVOLVE VIA CELL
   MERGERS...WITH A CORRESPONDING DAMAGING WIND RISK ALSO INCREASING
   PARTICULARLY ACROSS NORTHERN IL.

   ..GUYER.. 04/09/2015


   ATTN...WFO...LOT...ILX...MKX...DVN...

   LAT...LON   42149035 42948961 43038829 42468774 40648769 39668986
               40469108 41509102 42149035