Skip Navigation Links weather.gov 
NOAA logo-Select to go to the NOAA homepage NOAA's National Weather Service   Select to go to the NWS homepage
Storm Prediction Center
navigation bar left  
  navigation bar end cap


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

Jul 16, 2008 0800 UTC Day 2 Convective Outlook
Updated: Wed Jul 16 05:57:40 UTC 2008  (Print Version)
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
SPC Day 2 0800Z Outlook Categorical
  
  
 Forecast Discussion

   SPC AC 160556
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1256 AM CDT WED JUL 16 2008
   
   VALID 171200Z - 181200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE UPR MS VLY
   SWWD INTO THE CNTRL HIGH PLAINS...
   
   ...SYNOPSIS...
   SRN BRANCH OF THE POLAR WLYS WILL REMAIN ALONG THE CANADIAN BORDER
   ON THURSDAY WITH A WEAKER SUB-TROPICAL BRANCH EXISTING FROM THE GRT
   BASIN INTO THE CNTRL PLAINS.  NUMEROUS MID-LVL SHORTWAVE TROUGHS
   WILL TRANSLATE EWD WITHIN BOTH STREAMS AND BE IMPETUS FOR PERIODIC
   TSTM CLUSTERS.  THESE STORMS WILL FAVOR THE BAROCLINIC ZONE THAT
   WILL VACILLATE IN AN E-W CORRIDOR EXTENDING FROM CNTRL/NRN NEW
   ENGLAND WWD THROUGH THE CNTRL/UPR GRTLKS...UPR MS VLY...CORN
   BELT...CNTRL PLAINS AND FINALLY INTO THE CNTRL/NRN HIGH PLAINS.
   
   ...UPR MS VLY SWWD TO THE CNTRL HIGH PLAINS...
   A CLUSTER OR TWO OF TSTMS WILL LIKELY BE ONGOING AT 12Z THURSDAY
   OVER PARTS OF THE UPR MS VLY AND CNTRL GRTLKS REGION AS A MODEST
   MID-LVL WAVE WITHIN THE PRIMARY BELT OF WLYS EJECTS INTO ONTARIO. 
   AS THIS DISTURBANCE MOVES EWD...PRIMARY BELT OF LOW-MID/LVL FLOW
   WILL FOLLOW IN TANDEM.
   
   UPSTREAM...WEAKENING LOW-LEVEL FLOW WILL GRADUALLY BACK AND FOCUS
   ACROSS PARTS OF THE CORN BELT AND CNTRL PLAINS DURING THE AFTN.  AIR
   MASS ALONG/S OF THE FRONT...PROBABLY SITUATED FROM CNTRL WI SWWD
   INTO NEB AND NE CO DURING THURSDAY AFTN...WILL BECOME VERY UNSTABLE
   GIVEN MID 60S-LWR 70F DEW POINTS BENEATH MODESTLY STEEP H7-H5 LAPSE
   RATES.
   
   MODELS HAVE BEEN SUGGESTING FOR QUITE SOMETIME NOW THAT A PIECE OF
   THE UPR TROUGH COMPLEX OVER THE SRN GRT BASIN/BAJA CA REGION WILL
   ROTATE ABOUT THE RIDGE AND INTO THE CNTRL HIGH PLAINS BY THURSDAY
   AFTN.  CONVECTION WILL LIKELY INITIATE BOTH OVER THE HIGH PLAINS AND
   EWD ALONG THE FRONT INTO NEB AND IA BY MID-AFTN IN ADVANCE OF THIS
   DISTURBANCE.  VERTICAL SHEAR IS FCST TO BE WEAK...BUT MAY ULTIMATELY
   BE STRONGER ALONG SRN PERIPHERY OF THE WAVE...ESPECIALLY OVER THE
   PLAINS.  THIS IN COMBINATION WITH INCREASING DEEP LAYER
   MOISTURE/INSTABILITY WILL LEAD TO ORGANIZED TSTMS WITH LARGE HAIL
   AND DMGG WINDS.
   
   EVENING EVOLUTION INTO AN MCS IS LIKELY OVER PARTS OF THE CNTRL
   PLAINS AS THE SLY LLJ DIURNALLY INCREASES...MAXIMIZING MOISTURE
   TRANSPORT INTO WRN KS AND SRN NEB.  OTHER STORMS WILL LIKELY
   REGENERATE ALONG THE FRONT RANGE WELL INTO THE EVENING AS OUTFLOW
   BOUNDARIES TRAVEL UPSLOPE AMIDST MODEST INSTABILITY.  SOME STORMS
   WILL CONTINUE TO PRODUCE DMGG WIND GUSTS/HAIL.
   
   ...NRN HIGH PLAINS...
   BOUNDARY LAYER WILL BE COMPARATIVELY DRIER ACROSS NE WY AND SCNTRL
   MT THAN FARTHER S AND E THURSDAY AFTN.  BUT...LWR-MID 50S SFC DEW
   POINTS COINCIDENT WITH STEEP LAPSE RATES WILL CONTRIBUTE TO 500-1000
   J/KG MLCAPE.  WEAK UPSLOPE COMPONENT AND THE APPROACH OF THE NEXT
   SRN POLAR STREAM DISTURBANCE WILL AID IN ISOLD HIGH-BASED TSTM
   INITIATION BY LATE AFTN.  EFFECTIVE SHEAR AOA 45 KTS WILL BE
   FAVORABLE FOR SUPERCELLS WITH PRIMARILY LARGE HAIL.  ACTIVITY WILL
   TRY TO DEVELOP EWD ON THE LWR PLAINS TOWARD SW SD OVERNIGHT WITH
   PERHAPS ISOLD DMGG WIND GUSTS/HAIL.
   
   ...NRN/ERN FL INTO CSTL GA/SC...
   SHORT TERM MODELS ARE IN BETTER AGREEMENT ON THE EVENTUAL TRACK OF
   THE SFC LOW...THOUGH 00Z NAM IS FARTHER W WITH THE SYSTEM.  NUMEROUS
   TSTMS WILL DEVELOP OVER NRN/ERN FL AND SPREAD INTO CSTL GA/SC
   THROUGH THURSDAY AFTN.  ALONG WITH THE HEAVY RAINFALL THREAT...ISOLD
   STORMS MAY ALSO PRODUCE DMGG WIND GUSTS.  ANY TORNADO THREAT WILL
   HINGE ON STRENGTH OF THE LOW-LVL WIND FIELDS...WHICH ARE FCST TO BE
   STRONGER IN THE 00Z NAM THAN ANY OTHER MODEL.  WITH THIS
   UNCERTAINTY...ONLY LOW SVR PROBABILITIES ARE JUSTIFIED ATTM.
   
   ..RACY.. 07/16/2008
   
   CLICK TO GET WUUS02 PTSDY2 PRODUCT

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z

        
Top/Latest Day 1 Outlook/Today's Outlooks/Forecast Products/Home
Weather Topics:
Watches, Mesoscale Discussions, Outlooks, Fire Weather, All Products, Contact Us

NOAA / National Weather Service
National Centers for Environmental Prediction
Storm Prediction Center
120 David L. Boren Blvd.
Norman, OK 73072 U.S.A.
spc.feedback@noaa.gov
Page last modified: July 16, 2008
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities