Apr 6, 2015 UTC Day 2 Convective Outlook
Updated: Mon Apr 6 08:00:00 UTC 2015 (20150406 Z Day 2 shapefile | 20150406 Z Day 2 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20150406  UTC Day 2 Outlook Graphic
Probabilistic Graphic
20150406  UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
   SPC AC 060800

   DAY 2 CONVECTIVE OUTLOOK RESENT 1
   NWS STORM PREDICTION CENTER NORMAN OK
   0300 AM CDT MON APR 06 2015

   VALID 071200Z - 081200Z

   ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS THE CA CENTRAL VALLEY...

   ...SUMMARY...
   SHOWERS AND THUNDERSTORMS ARE FORECAST ACROSS PORTIONS OF THE
   WEST...FROM THE CALIFORNIA AND OREGON VICINITY EAST TO WYOMING.  A
   COUPLE OF STRONGER STORMS OVER THE CALIFORNIA CENTRAL VALLEY COULD
   PRODUCE HAIL -- AND POSSIBLY EVEN A BRIEF TORNADO.  SHOWERS AND
   STORMS WILL ALSO BE POSSIBLE ACROSS A LARGE PORTION OF THE EASTERN
   HALF OF THE COUNTRY.

   ...SYNOPSIS...
   THE UPPER LOW/TROUGH JUST OFF THE W COAST AT THE START OF THE PERIOD
   WILL BEGIN STEADY PROGRESSION ACROSS THE W DAY 2 /TUE/...AND SHOULD
   RESIDE OVER THE GREAT BASIN REGION OVERNIGHT.  DOWNSTREAM INTO THE
   CENTRAL STATES...RIDGING ALOFT IS PROGGED TO INCREASE IN RESPONSE TO
   THE UPSTREAM TROUGHING...AND RESULTING BACKGROUND SUBSIDENCE ACROSS
   A MOIST/DESTABILIZING AFTERNOON AIRMASS E OF THE PLAINS DRYLINE
   SUGGESTS THAT CAPPING WILL PREVAIL -- LARGELY PRECLUDING APPRECIABLE
   SEVERE RISK.

   ALONG WITH WRN U.S. CONVECTION ASSOCIATED WITH THE ADVANCING UPPER
   TROUGH...SHOWERS AND WEAK/GENERALLY SUB-SEVERE STORMS ARE FORECAST
   ACROSS MUCH OF THE ERN HALF OF THE U.S. WITHIN PERSISTENT
   WARM-ADVECTION REGIME.  ONGOING CONVECTION IN THE MID MS/TN VALLEY
   AREA SHOULD SPREAD ACROSS THE APPALACHIANS THROUGH THE DAY...WHILE
   DIURNAL SHOWERS/STORMS DEVELOP SWD INTO FL.  OTHER SHOWERS/STORMS
   ARE EXPECTED NEAR AND N OF THE PERSISTENT POLAR FRONT LYING W-E
   ACROSS THE OH VALLEY THROUGH THE PERIOD.

   ...CA CENTRAL VALLEY...
   AS THE UPPER LOW MOVES ACROSS NRN AND CENTRAL CA DURING THE
   AFTERNOON/EVENING...A POCKET OF VERY COLD ACCOMPANYING AIR AT H5
   /-28 TO -30 C/ ATOP A DIURNALLY HEATING BOUNDARY LAYER WILL RESULT
   IN MODEST CENTRAL VALLEY DESTABILIZATION /LOW-TOPPED SURFACE-BASED
   CAPE ON THE ORDER OF 500 J/KG/.  THIS WILL SUPPORT DEVELOPMENT OF
   SHOWERS AND SCATTERED THUNDERSTORMS BY MID AFTERNOON IN THE WAKE OF
   EARLIER FRONTAL-BAND PRECIPITATION.

   WITH LOW-LEVEL SELYS PROGGED ACROSS THE VALLEY VEERING TO
   MODEST/WSWLY ALOFT...SHEAR WILL BE SUFFICIENT FOR WEAK UPDRAFT
   ROTATION WITHIN LONGER-LIVED CELLS.  THIS -- COMBINED WITH THE
   OVERALL COLD PROFILE ALOFT -- SUGGESTS THAT MARGINALLY SEVERE HAIL
   WILL BE POSSIBLE.  IN ADDITION...0-1 KM SHEAR MAY BE SUFFICIENT TO
   SUPPORT LOW-LEVEL ROTATION -- WHICH COMBINED WITH STRONG UPDRAFT
   ACCELERATION IN THE LOWER LEVELS OF THE STORMS MY YIELD SUFFICIENT
   STRETCHING TO SUPPORT WEAK/BRIEF TORNADO RISK WITH ONE OR TWO
   STORMS.  THUS -- WILL INTRODUCE 5% SEVERE PROBABILITY ACROSS THE
   CENTRAL VALLEY ATTM.  CONVECTION SHOULD DIMINISH FAIRLY RAPIDLY
   AFTER SUNSET AS THE LOW-LEVEL AIRMASS STABILIZES.

   ..GOSS.. 04/06/2015

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