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 1418
< Previous MD         Next MD >
MD 1418 graphic

   MESOSCALE DISCUSSION 1418
   NWS STORM PREDICTION CENTER NORMAN OK
   0200 PM CDT MON JUL 21 2014

   AREAS AFFECTED...MUCH OF CNTRL/NRN NV...PORTIONS OF FAR SRN ID/FAR
   SERN ORE/FAR ERN CA...NWRN UT

   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

   VALID 211900Z - 212130Z

   PROBABILITY OF WATCH ISSUANCE...5 PERCENT

   SUMMARY...THUNDERSTORMS WILL CONTINUE TO INCREASE IN COVERAGE AND
   INTENSITY THROUGH THE AFTERNOON...AND ISOLATED SEVERE STORMS WILL BE
   POSSIBLE. HOWEVER...THE ISSUANCE OF A WW IS NOT ANTICIPATED.

   DISCUSSION...VISIBLE SATELLITE IMAGERY HIGHLIGHTS THE ONSET OF
   DIURNAL CONVECTIVE DEVELOPMENT ACROSS THE CNTRL GREAT BASIN AND
   VICINITY. THUNDERSTORMS ARE LIKELY TO BLOSSOM FROM TOWERING CU
   CURRENTLY ALONG THE CREST OF THE SIERRA IN FAR E-CNTRL CA...AND
   ALONG TERRAIN-DRIVEN CIRCULATIONS FOCUSED ON MOUNTAIN RANGES OF
   CNTRL NV...WHERE WIDESPREAD STRONG INSOLATION IS ONGOING. FARTHER TO
   THE NW...A MID-LEVEL CLOUD BAND DRAPED FROM NRN CA TO NWRN NV
   APPEARS TO BE THINNING IN SOME AREAS...BUT IS STILL OFFERING
   DIFFERENTIAL HEATING ALONG ITS PERIPHERY TO ENHANCE LOW-LEVEL
   CONVERGENCE RELATED TO ATTENDANT BAROCLINIC CIRCULATIONS...ALONG
   WITH EVENTUAL THUNDERSTORM DEVELOPMENT. FURTHERMORE...
   MESO-BETA-SCALE CIRCULATIONS -- PERHAPS DRIVEN BY ANTECEDENT
   CONVECTION -- ARE STREAMING NEWD IN THIS CLOUD BAND FROM PERSHING
   COUNTY TO HUMBOLDT COUNTY...AND MAY ALSO ENCOURAGE ASCENT AND STORM
   FORMATION ALONG THEIR PERIPHERIES. MORE CLOUD-FREE AREAS NW OF THIS
   BAND ARE ENHANCING SFC HEATING/DESTABILIZATION AND OPPORTUNITIES FOR
   STORM DEVELOPMENT INTO FAR SERN ORE AND ADJACENT NWRN NV. STORMS
   EVOLVING FROM THESE VARIOUS REGIMES ARE EXPECTED TO ADVANCE
   NEWD/ENEWD THROUGH THE AFTERNOON.

   WITH ENHANCED TROPOSPHERIC MOISTURE IN PLACE -- E.G. PW VALUES
   AROUND 1 INCH PER GPS DATA -- SFC DEWPOINTS ARE HOLDING IN THE
   MIDDLE 40S TO LOWER 50S -- TO FOSTER 500-1500 J/KG OF SBCAPE PER
   MODIFICATIONS TO THE 12Z ELKO RAOB. A FEW STRONG UPDRAFTS/DOWNDRAFTS
   MAY ENSUE...WITH STEEP TROPOSPHERIC LAPSE RATES IN PLACE.
   ALSO...WITH MODERATE SWLYS OVERLYING THE REGION...25-40 KT OF
   EFFECTIVE BULK SHEAR WILL BE SUFFICIENT FOR LOCALLY
   ORGANIZED/SUSTAINED CONVECTIVE STRUCTURES -- INCLUDING MULTICELL
   CLUSTERS AND PERHAPS ONE OR TWO TRANSIENT/MARGINAL SUPERCELLS.
   ISOLATED INSTANCES OF SVR WIND GUSTS MAY ENSUE. HOWEVER...WITH A
   DEARTH OF LARGE-SCALE FORCING FOR ASCENT ACROSS THE REGION...AND
   WITHOUT STRONGER BUOYANCY...SVR-TSTM COVERAGE IS EXPECTED TO BE
   SUFFICIENTLY LIMITED SUCH THAT WW ISSUANCE IS NOT WARRANTED.

   ..COHEN/HART.. 07/21/2014


   ATTN...WFO...SLC...PIH...VEF...BOI...LKN...REV...

   LAT...LON   38441614 37751829 38381949 39992038 41651947 42301788
               42111516 41901191 40871262 38441614 

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: July 21, 2014
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities