Storm Prediction Center Mesoscale Discussion 1673

   Mesoscale Discussion 1673
   NWS Storm Prediction Center Norman OK
   0504 PM CDT Wed Jul 17 2024

   Areas affected...northeast OR and eastern WA

   Concerning...Severe potential...Watch unlikely 

   Valid 172204Z - 180000Z

   Probability of Watch Issuance...5 percent

   SUMMARY...Isolated to widely scattered dry thunderstorms will be
   capable of localized strong to severe gusts across parts of
   northeast Oregon into eastern Washington through mid-evening. The
   disorganized and localized nature of the threat will preclude a
   severe thunderstorm watch.

   DISCUSSION...Isolated high-based, low-topped thunderstorms are
   ongoing across parts of the Blue Mountains in northeast OR to the
   east side of the Cascades in southern WA. This activity is being
   aided by a minor mid-level impulse that will drift northeast across
   the region through this evening. Surface temperature-dew point
   spreads across the Columbia and Snake River Valleys are quite large
   from 60-65 F, with 50s spreads farther north in eastern WA across
   the Columbia Plateau. This is yielding a very deeply mixed
   thermodynamic profile which will be conducive to dry microbursts as
   thunderstorms gradually expand northeastward into early evening. The
   meager buoyancy and modest large-scale forcing for ascent should
   yield isolated to widely scattered convective coverage. The belt of
   enhanced mid/upper flow attendant to the minor impulse is
   consistently progged to remain on the backside of the convection to
   its south in eastern OR. This should inhibit appreciable
   organization, suggesting a spotty strong to severe gust threat.

   ..Grams/Gleason.. 07/17/2024

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...OTX...PDT...

   LAT...LON   44981891 45282025 45872075 47082076 47781970 47881897
               47901846 47771745 46531718 44921827 44981891