Saturday Midday SPC DAY 1 Outlook:
DAY 1 CONVECTIVE OUTLOOK CORR 2 NWS STORM PREDICTION CENTER NORMAN OK
1153 AM CDT SAT JUL 26 2014
VALID 261630Z - 271200Z
...THERE IS A MDT RISK OF SVR TSTMS FROM SOUTHERN IA/NORTHERN MO...ACROSS CENTRAL IL...INTO CENTRAL/SOUTHERN IND... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE MID MS AND OH VALLEYS... CORRECTED FOR WEB GRAPHICS #2
...SUMMARY...
SEVERE STORMS...SOME ACCOMPANIED BY VERY LARGE HAIL...DAMAGING GUSTS AND A COUPLE OF TORNADOES ARE EXPECTED LATER THIS AFTERNOON INTO TONIGHT FROM EASTERN NEBRASKA TO PARTS OF THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS. THE MOST CONCENTRATED RISK AREA SHOULD BE THIS EVENING INTO TONIGHT FROM SOUTHERN IOWA AND NORTHERN MISSOURI...ACROSS CENTRAL ILLINOIS...AND INTO CENTRAL/SOUTHERN INDIANA...WHERE ONE OR MORE ORGANIZED THUNDERSTORM CLUSTERS COULD PRODUCE SWATHS OF DAMAGING WINDS. THE DAMAGING WIND RISK COULD REACH AS FAR AS SOUTHERN OHIO AND NORTHERN KENTUCKY OVERNIGHT. ...POTENTIAL FOR MULTIPLE SEVERE THUNDERSTORM COMPLEXES TO AFFECT PARTS OF MID/UPPER MS VALLEY INTO OH VALLEY TODAY AND TONIGHT... MORNING WATER VAPOR LOOPS SHOW THE PRIMARY BAND OF WESTERLIES EXTENDING ACROSS THE NORTHERN PLAINS INTO THE GREAT LAKES REGION. A STRONG UPPER LOW OVER SASK/MANITOBA WILL DEVELOP SOUTHEASTWARD...WHILE SEVERAL SMALLER SHORTWAVE TROUGHS TRAVEL ACROSS THE MID/UPPER MS VALLEY INTO THE GREAT LAKES. THE RESULT WILL BE SEVERAL POTENTIAL AREAS OF CONCERN FOR SEVERE STORMS TODAY...AND HIGHER-THAN-USUAL UNCERTAINTY REGARDING WHICH CLUSTER WILL BE OF GREATEST RISK. ...SD/NEB/WESTERN IA THIS AFTERNOON... AN INTENSE THUNDERSTORM CLUSTER HAS FORMED THIS MORNING OVER SOUTHEAST SD. THESE STORMS ARE EXPECTED TO TRACK SOUTHEASTWARD THROUGH THE LATE MORNING AND AFTERNOON ACROSS EASTERN NEB AND WESTERN IA. THE STORMS HAVE NOT SHOWN ANY SIGNS OF WEAKENING...BUT IT REMAINS UNCERTAIN IF THIS CLUSTER IS THE START OF A LARGER LONG-LIVED BOW ECHO EVENT...OR IF THE OUTFLOW FROM THESE STORMS WILL EVENTUALLY LEAD TO UPSCALE GROWTH LATER TODAY. REGARDLESS...VERY LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE THROUGH THE AFTERNOON. ...MO/IL THIS AFTERNOON... A WEAK REMNANT MCV IS NOTED IN VISIBLE SATELLITE IMAGERY OVER NORTHEAST KS. SCATTERED SHOWERS AND THUNDERSTORMS HAVE BEGUN TO FORM AHEAD OF THIS FEATURE OVER WESTERN MO. 12Z MODEL SOLUTIONS LEND LESSENED CONFIDENCE THAT THIS GROUP OF CONVECTION WILL BECOME AN ORGANIZED SEVERE-PRODUCING SYSTEM. HOWEVER...AMPLE MOISTURE/CAPE AND INCREASING WINDS ALOFT INDICATE THE RISK OF UPSCALE-GROWTH DOES EXIST. IF THESE STORMS MATURED...THEY WOULD LIKELY POSE A RISK OF SEVERE WIND AND HAIL ACROSS MO INTO IL. ...NORTHERN IL INTO OH THIS AFTERNOON... A SMALL-SCALE VORTICITY MAX IS SHOWN IN MOST 12Z INITIALIZATIONS OVER SOUTHERN MN. THIS FEATURE IS EXPECTED TO TRACK SOUTHEASTWARD ACROSS NORTHERN IL THIS AFTERNOON AND EVENTUALLY INTO THE OH VALLEY THIS EVENING. STRONG INSTABILITY IS DEVELOPING AHEAD OF THIS SYSTEM...AND IT APPEARS LIKELY THAT SCATTERED THUNDERSTORMS WILL DEVELOP BY MID AFTERNOON. IF THIS SCENARIO OCCURS...ISOLATED SEVERE STORMS INCLUDING DAMAGING WINDS AND HAIL COULD OCCUR IN THIS REGION THROUGH THE EVENING. ...MO/IL/IND THIS EVENING... MODELS SOLUTIONS ARE QUITE DIVERSE REGARDING THE LOCATION AND TIMING OF STRONG CONVECTION BY THIS EVENING. HOWEVER...GIVEN THE MESOSCALE ORGANIZATION OF THE SYSTEM OVER NEB...IT APPEARS PROBABLE THAT THIS CLUSTER OR A REMNANT OUTFLOW WILL CONTINUE TO BE A RISK OF SEVERE WIND AND HAIL THROUGH THE EVENING. ITS UNCLEAR WHICH OF THE AFOREMENTIONED CONVECTIVE CLUSTERS WILL BECOME A DOMINANT RISK TODAY...BUT THIS SCENARIO WOULD LIKELY POSE THE GREATEST RISK OF WIDESPREAD DAMAGING WINDS THIS EVENING AND TONIGHT ACROSS THE MODERATE RISK AREA
. ..HART/ROGERS.. 07/26/2014