Severe Storm Outlook Narrative (AC)
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
ACUS01 KWNS 261654
SWODY1
SPC AC 261653

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



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.