Sep 22, 2014 2000 UTC Day 1 Convective Outlook
Updated: Mon Sep 22 19:59:27 UTC 2014 (20140922 2000Z Day 1 shapefile | 20140922 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20140922 2000 UTC Day 1 Outlook Graphic
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 14,550 103,357 Fort Morgan, CO...
Probabilistic Tornado Graphic
20140922 2000 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.
Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 9,538 63,085 Fort Morgan, CO...
2 % 13,860 2,548,023 Denver, CO...Aurora, CO...Lakewood, CO...Thornton, CO...Westminster, CO...
Probabilistic Damaging Wind Graphic
20140922 2000 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.
Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 72,657 6,079,944 Denver, CO...Colorado Springs, CO...Aurora, CO...Lakewood, CO...Savannah, GA...
Probabilistic Large Hail Graphic
20140922 2000 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.
Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 14,345 102,255 Fort Morgan, CO...
5 % 58,211 5,929,019 Denver, CO...Colorado Springs, CO...Aurora, CO...Lakewood, CO...Savannah, GA...
   SPC AC 221959

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0259 PM CDT MON SEP 22 2014

   VALID 222000Z - 231200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS FOR THE CO HIGH PLAINS...

   ...SUMMARY...
   ISOLATED TO SCATTERED THUNDERSTORMS...SOME OF WHICH MAY BE STRONG TO
   SEVERE...ARE FORECAST LATE THIS AFTERNOON INTO THE EVENING OVER THE
   COLORADO HIGH PLAINS.  A FEW MORE INTENSE THUNDERSTORMS MAY APPROACH
   OR BRIEFLY REACH SEVERE LEVELS TODAY OVER PARTS OF THE GEORGIA AND
   SOUTH CAROLINA COASTAL PLAIN.

   UPGRADED PORTIONS OF THE CO HIGH PLAINS TO A SLIGHT RISK FOR THIS
   AFTERNOON AND EARLY EVENING.  THE ONLY OTHER MINOR CHANGE MADE IS TO
   THE GENERAL THUNDERSTORM LINE OVER THE SERN STATES TO REFLECT THE
   SWD PROGRESSION OF CONVECTION ALONG THE FRONT.

   ...CO HIGH PLAINS...
   VISIBLE SATELLITE AND SURFACE OBSERVATION TRENDS DURING THE
   1800-1940Z PERIOD SHOW A CU FIELD DEVELOPING OVER ERN CO AMONGST
   SCATTERED CONVECTIVE DEBRIS CLOUDS OWING THEIR ORIGINS TO A
   DEPARTING MCV OVER WRN NEB AND ASSOCIATED CONVECTION.  A MOIST AXIS
   FROM NERN NM TO NEAR AKO IS DESTABILIZING AS THE RESULT OF SURFACE
   HEATING.  A BELT OF STRONG MID-LEVEL WLY FLOW /30-40 KT/ SAMPLED BY
   THE ERN CO VAD/VWP NETWORK IS MOVING THROUGH THE BASE OF A SHORTWAVE
   TROUGH OVER WY AND WILL BE SUPPORTIVE OF ORGANIZED
   STORMS...INCLUDING THE POSSIBILITY FOR SUPERCELLS.  AN ISOLATED
   LARGE HAIL THREAT APPEARS GREATER THAN EARLIER FORECAST...PROVIDED
   STORMS DEVELOPING OVER THE HIGH TERRAIN AND MOVE EWD INTO THE
   PLAINS.  RELATIVELY MOIST LOW-LEVELS COINCIDING WITH A
   CLOCKWISE-CURVING HODOGRAPH MAY LOCALLY AUGMENT THE THREAT FOR A
   SUPERCELL TORNADO AS WELL.

   ..SMITH.. 09/22/2014

   .PREV DISCUSSION... /ISSUED 1122 AM CDT MON SEP 22 2014/

   ...SYNOPSIS...

   MORNING WATER VAPOR IMAGERY AND 12Z UPPER-AIR DATA INDICATE A
   SHORT-WAVE TROUGH OVER THE TN VALLEY WHICH WILL PROGRESS SEWD AND
   EVENTUALLY EVOLVE INTO A CLOSED MID-LEVEL CIRCULATION OVER THE
   CAROLINAS TOWARD 23/12Z. UPSTREAM FROM THESE DEVELOPMENTS...A
   SHORT-WAVE TROUGH OVER THE CNTRL ROCKIES WILL TRANSLATE ENEWD INTO
   THE NRN/CNTRL PLAINS...EFFECTIVELY UNDERCUTTING THE MEAN LONG-WAVE
   RIDGE IN PLACE WEST OF THE MS VALLEY.

   AT THE SURFACE...A COLD FRONT WILL CONTINUE SLOWLY SWD THROUGH THE
   SERN U.S...WITH THE POTENTIAL FOR WEAK FRONTAL WAVE DEVELOPMENT AS
   LARGE-SCALE FORCING FOR ASCENT IS ENHANCED BY THE SHORT-WAVE TROUGH
   MENTIONED ABOVE. ELSEWHERE...A LEE TROUGH WILL STRENGTHEN WHILE
   SHIFTING EWD THROUGH THE NRN AND CNTRL HIGH PLAINS.

   ...SERN STATES THIS AFTERNOON...

   A NE-SW-ORIENTED BAND OF SHOWERS AND TSTMS IS ONGOING AS OF MID
   MORNING ALONG OR IN THE IMMEDIATE WAKE OF THE COLD FRONT FROM CNTRL
   SC TO SERN AL. ABUNDANT SUNSHINE TO THE SOUTH OF THIS ACTIVITY ALONG
   WITH BOUNDARY-LAYER DEWPOINTS IN THE 60S WILL SUPPORT AIR MASS
   DESTABILIZATION WITH AFTERNOON MLCAPE APPROACHING 1000-1500 J/KG.
   THIS INSTABILITY IN CONJUNCTION WITH INCREASING HEIGHT FALLS/DCVA
   ASSOCIATED WITH THE MIGRATORY SHORT-WAVE TROUGH SHOULD PROMOTE AN
   UPTICK IN CONVECTIVE COVERAGE AND INTENSITY BY AFTERNOON AMIDST A
   KINEMATIC ENVIRONMENT FEATURING GRADUALLY STRENGTHENING VERTICAL
   SHEAR. AS SUCH...SOME POTENTIAL WILL EXIST FOR MULTICELLS OR LINE
   SEGMENTS CAPABLE OF LOCALLY DAMAGING WIND GUSTS AND/OR MARGINALLY
   SEVERE HAIL.

   ...CNTRL HIGH PLAINS THIS AFTERNOON/EVENING...

   THE MASS RESPONSE TO THE APPROACHING SHORT-WAVE TROUGH WILL MAINTAIN
   A 30-35 KT SLY LLJ ACROSS THE REGION TODAY...WHICH IN TURN WILL
   ENHANCE THE POLEWARD FLUX OF LOW-LEVEL MOISTURE E OF THE LEE TROUGH.
   CONSIDERABLE EARLY-DAY CLOUDINESS WILL SLOW THE DESTABILIZATION
   PROCESS...BUT WHERE CLOUD BREAKS CAN OCCUR...THE INCREASING MOISTURE
   MAY YIELD AFTERNOON MLCAPE APPROACHING 500-1000 J/KG. INCREASED
   FORCING FOR ASCENT ATTENDANT TO THE MID-LEVEL IMPULSE SHOULD BOLSTER
   TERRAIN-INDUCED CIRCULATIONS AND CONVERGENCE IN THE LEE OF THE FRONT
   RANGE TO FOSTER WIDELY SCATTERED TSTMS LATER TODAY. 

   MARGINAL SUPERCELL STRUCTURES ARE POSSIBLE OWING TO A VERTICALLY
   VEERING WIND PROFILE WITH DEEP-LAYER SHEAR STRENGTHENING TO 35-45
   KT. ISOLATED OCCURRENCES OF LARGE HAIL AND STRONG WIND GUSTS WILL BE
   THE PRIMARY HAZARDS...THOUGH A BRIEF TORNADO IS ALSO POSSIBLE.

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z