Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Columbus, OH...Nashville, TN...Kansas City, MO...Minneapolis, MN...Wichita, KS...
SPC AC 130600
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT MON JUL 13 2015
VALID 131200Z - 141200Z
...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF
IL/INDIANA/KY/SOUTHERN OH/FAR EASTERN IA...
...THERE IS AN ENH RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK
ACROSS THE MIDWEST AND OH VALLEY...
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VALLEY TO THE
CENTRAL/SOUTHERN APPALACHIANS...
...THERE IS A MRGL RISK OF SVR TSTMS FROM THE CENTRAL PLAINS/GREAT
LAKES TO SOUTHEAST STATES...
...THERE IS A MRGL RISK OF SVR TSTMS ACROSS THE NORTHERN
INTERMOUNTAIN REGION...
...SUMMARY...
MULTIPLE ROUNDS OF SEVERE THUNDERSTORMS CAPABLE OF DAMAGING
WINDS...TORNADOES AND LARGE HAIL ARE LIKELY TODAY AND TONIGHT ACROSS
MUCH OF THE MIDWEST...BUT ESPECIALLY ACROSS PORTIONS OF
ILLINOIS...INDIANA...KENTUCKY AND SOUTHWEST OHIO.
...SYNOPSIS...
AMPLIFYING WESTERLIES ARE EXPECTED ACROSS THE NORTHERN HALF OF THE
CONUS...TO THE NORTH OF A PERSISTENT UPPER RIDGE CENTERED OVER THE
SOUTHERN PLAINS. IN PARTICULAR...A STRENGTHENING BELT OF
NORTHWESTERLY WINDS ALOFT IS EXPECTED FROM THE UPPER MIDWEST TO THE
OH/TN RIVER VALLEYS...WHICH WILL GENERALLY COINCIDE WITH A
NORTHWEST-SOUTHEAST-ORIENTED FRONTAL BOUNDARY /SOME OF WHICH MAY BE
MODULATED BY EARLY-DAY OUTFLOW/ ACROSS THE REGION.
...MIDWEST/OH RIVER VALLEY...
MULTIPLE ROUNDS OF POTENTIALLY WIDESPREAD SEVERE THUNDERSTORMS ARE
EXPECTED ACROSS THE REGION TODAY AND TONIGHT. THIS WILL INCLUDE A
FEW TORNADOES...ISOLATED INSTANCES OF LARGE HAIL...AND A
CONSIDERABLE DAMAGING WIND RISK WITH THE POTENTIAL FOR ONE OR MORE
DERECHO-PRODUCING MCS/S ACROSS THE REGION TODAY AND TONIGHT.
AN OVERNIGHT MCS...OVER SOUTHEAST MN AND WESTERN/NORTHERN WI AROUND
MIDNIGHT...MAY BE AROUND PORTIONS OF THE LAKE MI/NORTHERN
IL/NORTHERN INDIANA VICINITIES AT THE BEGINNING OF THE PERIOD /12Z/
THIS MORNING. RESIDUAL OUTFLOW/CLOUD DEBRIS AND POSSIBLY AN MCV WILL
LIKELY BE CONSEQUENTIAL MESOSCALE-RELATED FACTORS INTO THE
AFTERNOON. CURRENT THINKING IS THAT POSSIBLE OUTFLOW/MCV MAY BE
FACTORS FOR RENEWED STORM DEVELOPMENT/INTENSIFICATION DURING THE
AFTERNOON ACROSS THE MIDDLE OH RIVER VALLEY/TN VALLEY TO SOUTHERN
APPALACHIANS...WITH DAMAGING WINDS PROBABLE AND POSSIBLY SOME
TORNADO RISK WITH QUASI-LINEAR/BOW ECHO DEVELOPMENT.
OTHERWISE...ANY PERSISTENT MORNING OUTFLOW/CLOUD DEBRIS SHOULD ALSO
SERVE AS A DELINEATING FACTOR FOR THE MOST CONSEQUENTIAL
DESTABILIZATION INTO THE AFTERNOON...WITH THE STRONGEST
DESTABILIZATION TO BE EFFECTIVELY FOCUSED TO THE WEST/SOUTHWEST OF
EARLY-DAY OUTFLOW ACROSS THE MIDWEST. AN EASTWARD-ADVECTING ELEVATED
MIXED LAYER/PLUME OF VERY STEEP MID-LEVEL LAPSE RATES ATOP A
MOISTURE-RICH BOUNDARY LAYER WITH LOWER/MIDDLE 70S F SURFACE
DEWPOINTS WILL SUPPORT EXTREME INSTABILITY WITH THE LIKELIHOOD OF
4000-6000+ J/KG MLCAPE...PARTICULARLY ACROSS PORTIONS OF IL/WESTERN
INDIANA AND EASTERN IA/MO.
WITHIN THIS UNSTABLE ENVIRONMENT...IT SEEMS LIKELY THAT A SECONDARY
ROUND OF STORMS ARE EXPECTED TO FORM WITHIN A CORRIDOR THAT MAY
INCLUDE FAR SOUTHERN WI/SOUTHEAST MN...AND MORE LIKELY...IL/NEARBY
INDIANA AND FAR EASTERN PORTIONS OF IA/MO. GIVEN THE HIGH MOISTURE
CONTENT/EXTREME INSTABILITY IN THE PRESENCE OF CONSIDERABLY
STRENGTHENING MID-LEVEL WINDS...SEMI-DISCRETE INTENSE SUPERCELLS CAN
BE EXPECTED BY MID/LATE AFTERNOON INTO EARLY EVENING. LARGE HAIL AND
A COUPLE OF TORNADOES WILL BE POSSIBLE. EVEN WHILE LOW-LEVEL
SHEAR/SRH WILL GENERALLY BE MODEST...A STRONG TORNADO CANNOT BE
RULED OUT WITHIN A HIGH CAPE ENVIRONMENT...PARTICULARLY WITH
OUTFLOW-BOUNDARY-RELATED AFTERNOON/EARLY EVENING DEVELOPMENT WHERE
LOW-LEVEL SRH/VORTICITY WILL BE ENHANCED. BY EVENING...THESE STORMS
SHOULD TEND TO MERGE/GROW UPSCALE INTO A SOUTHEASTWARD-MOVING MCS
WITH THE POSSIBILITY OF A RENEWED ROUND OF WIDESPREAD/POTENTIALLY
INTENSE DAMAGING WIND GUSTS.
...CENTRAL PLAINS...
A HOT/WELL-MIXED BOUNDARY LAYER WILL EXIST ACROSS THE REGION DURING
THE AFTERNOON...WITH THE POTENTIAL FOR ISOLATED/WIDELY SCATTERED
THUNDERSTORM DEVELOPMENT BY LATE AFTERNOON/EARLY EVENING ACROSS
EASTERN CO INTO KS/MO...ESPECIALLY IN AREAS NEAR/JUST NORTH OF A
WEAK SURFACE LOW/TROUGH. AS MUCH AS 25-35 KT OF EFFECTIVE SHEAR
COULD SUPPORT SOME SEMI-SUSTAINED MULTICELLS CAPABLE OF LOCALLY
DAMAGING WINDS AND POSSIBLY SEVERE HAIL.
...SOUTHEAST STATES/CAROLINAS...
ALTHOUGH CLOUD COVER/SOME PRECIPITATION EARLY IN THE DAY MAY BE
FACTORS...WIDELY SCATTERED STRONG THUNDERSTORMS SHOULD
REDEVELOP/INTENSIFY ACROSS THE REGION DURING THE AFTERNOON IN
VICINITY OF A WEAK SURFACE LOW AND NEARBY SURFACE TROUGH. SOME OF
THESE STRONGER STORMS WILL BE CAPABLE OF ISOLATED DAMAGING WIND
GUSTS. ADDITIONALLY...SOME OF THE UPSTREAM STORMS /POSSIBLY AS AN
ORGANIZED MCS/ COULD SPREAD SOUTH-SOUTHEASTWARD INTO PARTS OF THE
REGION LATE TONIGHT INCLUDING THE SOUTHERN APPALACHIANS
VICINITY/SOUTHEAST STATES.
...NORTHERN INTERMOUNTAIN REGION...
ONE OR MORE SUBTLE MID-LEVEL IMPULSES MAY INFLUENCE THE REGION AS
SEMI-COOL/MODERATELY STRONG CYCLONIC UPPER-LEVEL FLOW OTHERWISE
OVERSPREADS THE REGION. WHILE THE AIR MASS WILL NOT BE OVERLY
MOIST...DIURNALLY STEEPENING LAPSE RATES IN CONJUNCTION WITH
MODERATELY STRONG MID/HIGH-LEVEL SOUTHWESTERLY WINDS MAY SUPPORT
SOME STRONG/POTENTIALLY SEVERE STORMS CAPABLE OF HAIL/GUSTY WINDS
THIS AFTERNOON/EARLY EVENING.
..GUYER/PICCA.. 07/13/2015
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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