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.

Mesoscale Discussion 60
< Previous MD         Next MD >
MD 60 graphic

   MESOSCALE DISCUSSION 0060
   NWS STORM PREDICTION CENTER NORMAN OK
   0330 PM CST SUN FEB 08 2015

   AREAS AFFECTED...NRN SAN JOAQUIN AND SACRAMENTO VALLEY

   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

   VALID 082130Z - 082300Z

   PROBABILITY OF WATCH ISSUANCE...40 PERCENT

   SUMMARY...IT REMAINS UNCLEAR WHETHER THE SEVERE WEATHER POTENTIAL
   LATE THIS AFTERNOON WILL RISE TO A LEVEL THAT REQUIRES A WATCH...BUT
   AT LEAST SOME INCREASE IN SEVERE WEATHER PROBABILITIES APPEAR
   POSSIBLE BY THE 22-23Z TIME FRAME.

   DISCUSSION...GIVEN SUFFICIENT BOUNDARY LAYER INSTABILITY...VERTICAL
   SHEAR PROFILES ARE ALREADY SUPPORTIVE OF ORGANIZED SEVERE STORM
   DEVELOPMENT...INCLUDING SUPERCELLS...ACROSS MUCH OF THE REGION.  AND
   DEEP LAYER MEAN WIND FIELDS SHOULD CONTINUE TO STRENGTHEN THROUGH
   THE REMAINDER OF THE AFTERNOON...AS A 90-100+ KT 500 MB JET STREAK
   NOSES TOWARD THE SAN FRANCISCO BAY AREA.

   HOWEVER...AS OF 2130Z...THE POTENTIAL FOR APPRECIABLE BOUNDARY LAYER
   DESTABILIZATION REMAINS UNCLEAR.  AN EVOLVING PRE-FRONTAL
   PRECIPITATION BAND...WITH EMBEDDED CONVECTION...CONTINUES TO
   RESTRICT SURFACE HEATING.  AT THE SAME TIME...TEMPERATURES
   ALOFT...EVEN NEAR THE UPSTREAM MID-LEVEL COLD CORE...WHICH MAY NOT
   IMPACT THE INTERIOR VALLEYS UNTIL LATER THIS EVENING...DO NOT APPEAR
   ESPECIALLY COLD /MODELS SUGGEST -20 TO -22C AT 500 MB/.  ON THE
   OTHER HAND...IT DOES APPEAR THAT BREAKS IN THE OVERCAST COULD ALLOW
   FOR AT LEAST SOME ADDITIONAL BOUNDARY LAYER WARMING THROUGH MID TO
   LATE AFTERNOON...COINCIDENT WITH AT LEAST WEAK MID-LEVEL COOLING.

   THE LEADING EDGE OF THE MID-LEVEL CLEAR SLOT IS IN THE PROCESS OF
   PROGRESSING INLAND ACROSS NORTHERN AND CENTRAL CALIFORNIA COASTAL
   AREAS.  AS THIS FEATURE ADVANCES EASTWARD INTO THE SACRAMENTO AND
   NORTHERN SAN JOAQUIN VALLEYS THROUGH THE 22-00Z TIME
   FRAME...ASSOCIATED DRYING WILL CONTRIBUTE TO INCREASING CONVECTIVE
   INSTABILITY...PROVIDING AT LEAST SOME POTENTIAL FOR INTENSIFYING
   STORM DEVELOPMENT.  

   IT CURRENTLY APPEARS THAT STRONGEST STORM DEVELOPMENT COULD BECOME
   FOCUSED NEAR THE SACRAMENTO AND STOCKTON AREAS...PERHAPS INCLUDING
   THE POSSIBILITY OF A TORNADO OR TWO...IN ADDITION TO THE RISK FOR
   LOCALLY STRONG SURFACE GUSTS AND SMALL TO MARGINALLY SEVERE HAIL.

   ..KERR/HART.. 02/08/2015


   ATTN...WFO...HNX...STO...MTR...

   LAT...LON   38222229 38842225 39772227 40082163 38622088 37842033
               37232026 36732088 36952126 37642194 38222229 

Top/All Mesoscale Discussions/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: February 08, 2015
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities