Aug 8, 2015 0600 UTC Day 1 Convective Outlook
Updated: Sat Aug 8 05:59:23 UTC 2015 (20150808 1200Z Day 1 shapefile | 20150808 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20150808 1200 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 89,159 3,103,434 Omaha, NE...Lincoln, NE...Des Moines, IA...St. Joseph, MO...Rapid City, SD...
MARGINAL 350,243 20,632,077 Denver, CO...Kansas City, MO...Colorado Springs, CO...Tampa, FL...Aurora, CO...
Probabilistic Tornado Graphic
20150808 1200 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 19,523 1,457,910 Omaha, NE...Lincoln, NE...Council Bluffs, IA...Bellevue, NE...Fremont, NE...
2 % 62,596 2,010,194 Des Moines, IA...St. Joseph, MO...Rapid City, SD...Ames, IA...West Des Moines, IA...
Probabilistic Damaging Wind Graphic
20150808 1200 UTC Day 1 Damaging Wind Probabilities Graphic
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.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 79,799 3,000,116 Omaha, NE...Lincoln, NE...Des Moines, IA...St. Joseph, MO...Rapid City, SD...
5 % 348,027 20,609,373 Denver, CO...Kansas City, MO...Colorado Springs, CO...Tampa, FL...Aurora, CO...
Probabilistic Large Hail Graphic
20150808 1200 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SIG SEVERE 12,176 1,283,926 Omaha, NE...Lincoln, NE...Council Bluffs, IA...Bellevue, NE...Papillion, NE...
15 % 65,744 2,436,010 Omaha, NE...Lincoln, NE...Des Moines, IA...St. Joseph, MO...Rapid City, SD...
5 % 251,861 5,805,990 Kansas City, MO...Colorado Springs, CO...Aurora, CO...Kansas City, KS...Topeka, KS...
   SPC AC 080559

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1259 AM CDT SAT AUG 08 2015

   VALID 081200Z - 091200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS LOWER MO VALLEY...

   ...THERE IS A SLGT RISK OF SVR TSTMS BLACK HILLS AREA...

   ...THERE IS A SLGT RISK OF SVR TSTMS CNTRL HIGH PLAINS...

   ...THERE IS A MRGL RISK OF SVR TSTMS N-CNTRL STATES...

   ...THERE IS A MRGL RISK OF SVR TSTMS ERN GULF COAST STATES...

   ...SUMMARY...
   SEVERE STORMS APPEAR MOST LIKELY OVER PARTS OF THE LOWER MISSOURI
   VALLEY DURING THE LATE AFTERNOON AND EVENING. TORNADOES...VERY LARGE
   HAIL...AND DAMAGING WINDS WILL BE POSSIBLE. LARGE HAIL AND SEVERE
   WINDS SHOULD ACCOMPANY A FEW STORM CLUSTERS OVER THE NORTHERN AND
   CENTRAL HIGH PLAINS IN THE LATE AFTERNOON AND EVENING.

   ...LOWER MO VALLEY AREA...
   PRIMARY FORECAST CONCERN IS OVER THE POTENTIAL FOR A SIGNIFICANT
   TORNADO SETUP ACROSS A LOCALIZED PORTION OF SERN NEB TO SWRN IA
   WHERE A 10 SIG TOR PROBABILITY WAS CONSIDERED FOR THIS OUTLOOK. BUT
   WITH PREDICTABILITY RESIDING PREDOMINATELY ON THE MESO-BETA
   SCALE...WILL DEFER TO LATER OUTLOOKS FOR POSSIBLE DELINEATION OF AN
   ENHANCED RISK PROBABILITY.

   ONGOING MCS CENTERED OVER S-CNTRL NEB/N-CNTRL KS SHOULD BE IN A
   DECAYING STATE AT 12Z THIS MORNING. REMNANT MCV IS PROGGED TO SHIFT
   E THIS MORNING OVER IA AND THEN DAMPEN OVER THE MIDWEST. GUIDANCE IS
   HIGHLY CONSISTENT WITH A LACK OF DIURNALLY DRIVEN CONVECTIVE
   DEVELOPMENT ASSOCIATED WITH THE REMNANT MCV PERHAPS DUE TO THE
   FEATURE OUTPACING THE BUOYANT MOIST SECTOR CURRENTLY ALONG THE MS
   RIVER WWD. THE MORE PROBABLE SCENARIO IS FOR RENEWED TSTM
   DEVELOPMENT LATE AFTERNOON OR EVENING ACROSS PARTS OF THE LOWER MO
   VALLEY WHERE PRONOUNCED DIFFERENTIAL HEATING IS EXPECTED ON THE SRN
   EDGE OF RESIDUAL CLOUD COVERAGE/OUTFLOW BOUNDARY FROM THE DECAYING
   MCS. A RATHER MOISTURE-RICH BOUNDARY LAYER BENEATH A PLUME OF
   MODERATELY STEEP MID-LEVEL LAPSE RATES WILL RESULT IN A CORRIDOR OF
   STRONG DESTABILIZATION WITH MLCAPE AOA 2500 J/KG.

   UNCERTAINTY DOES EXIST OVER THE TIMING OF TSTM INITIATION GIVEN 
   CAPPING CONCERNS WITH LARGELY 700-MB SWLYS MAINTAINING WAA. SOME
   CAMS SUGGEST TSTMS WILL BE DELAYED UNTIL JUST AFTER SUNSET AS THE
   LLJ INTENSIFIES AND PROVIDES NECESSARY FORCED ASCENT. OTHER GUIDANCE
   INDICATES LATE AFTERNOON INITIATION PERHAPS AIDED BY A SUBTLE
   MID-LEVEL IMPULSE EJECTING FROM THE FOUR CORNERS AREA. SHOULD THIS
   OCCUR...RELATIVELY STRONG LOW-LEVEL SRH ALONG THE EARLY-DAY OUTFLOW
   BOUNDARY/RESULTANT EFFECTIVE FRONT COULD FAVOR A COUPLE INTENSE
   SUPERCELLS /PARTICULARLY GIVEN THAT OVERALL FORCING SHOULD BE
   MODEST/. A CONDITIONAL RISK FOR VERY LARGE HAIL AND A STRONG TORNADO
   IS APPARENT. WILL MAINTAIN INHERITED SIGNIFICANT SEVERE
   PROBABILITIES /DRIVEN BY HAIL/...BUT MESOSCALE PREDICTABILITY IS TOO
   LOW FOR A LOCALIZED UPGRADE TO ENHANCED RISK PROBABILITIES THIS
   OUTLOOK. REGARDLESS OF WHEN TSTM INITIATION OCCURS...UPSCALE GROWTH
   INTO A LATE EVENING MCS SEEMS PROBABLE WITH A DAMAGING WIND RISK
   MOST LIKELY DURING THE EARLY STAGES OF STORM-SCALE MERGERS UNTIL
   CONVECTION TENDS TO WEAKEN OVERNIGHT.

   ...BLACK HILLS AREA...
   LOW-AMPLITUDE SHORTWAVE TROUGH OVER THE ERN GREAT BASIN SHOULD REACH
   THE NRN HIGH PLAINS BY EARLY SUN. WITH A LEE CYCLONE BECOMING
   ESTABLISHED OVER ERN WY...A MODEST INCREASE IN LOW-LEVEL MOISTURE IS
   EXPECTED FROM THE LOWER PLAINS. OVERALL BUOYANCY WILL BE
   LIMITED...BUT STEEP LAPSE RATES AND ELONGATED STRAIGHT-LINE
   HODOGRAPHS SHOULD FAVOR A COUPLE SPLITTING SUPERCELLS AND/OR AN
   ORGANIZED CLUSTER WITH LARGE HAIL/SEVERE WINDS AS THE PRIMARY
   HAZARDS.

   ...CNTRL HIGH PLAINS...
   WHILE FORCING FOR ASCENT AND VERTICAL SHEAR SHOULD NOT BE AS STRONG
   AS FARTHER N...COMPARATIVELY RICHER LOW-LEVEL MOISTURE SHOULD STILL
   FAVOR ISOLATED TO WIDELY SCATTERED TSTMS FORMING ALONG A LEE TROUGH.
   A COUPLE OF SEMI-ORGANIZED CLUSTERS WITH A SEVERE WIND/HAIL THREAT
   SHOULD DEVELOP WITH THE MOST PROBABLE CORRIDOR ACROSS PARTS OF
   E-CNTRL CO/W-CNTRL KS TO THE NW OF A BAROCLINIC ZONE PROGGED FROM
   CNTRL KS TO THE OK/TX PANHANDLES.

   ..GRAMS/MOSIER.. 08/08/2015

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