


Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
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761 ACUS11 KWNS 091949 SWOMCD SPC MCD 091948 MTZ000-WYZ000-IDZ000-092115- Mesoscale Discussion 1618 NWS Storm Prediction Center Norman OK 0248 PM CDT Wed Jul 09 2025 Areas affected...portions of eastern Idaho into southern Montana Concerning...Severe potential...Watch possible Valid 091948Z - 092115Z Probability of Watch Issuance...60 percent SUMMARY...Severe gusts will become an increasing concern as at least scattered thunderstorms develop and mature through the afternoon. A Severe Thunderstorm Watch issuance may be needed. DISCUSSION...Deepening CU over eastern ID/southern MT are indicating attempts at thunderstorm initiation atop a destabilizing boundary layer with eroding convective inhibition. 19Z mesoanalysis shows boundary-layer lapse rates already reaching 9 C/km in some spots, with 500+ J/kg MLCAPE. RAP forecast soundings indicate a dry boundary layer extending to 500 mb, which is being overspread by stronger mid-upper level flow and 30 kts of effective bulk shear (i.e. straight hodographs indicating speed shear). Organized, high-based multicells should traverse portions of the the northern Rockies, accompanied by mainly a severe gust threat. If confidence increases in greater coverage of severe gusts, a Severe Thunderstorm Watch may be needed. ..Squitieri/Mosier.. 07/09/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BYZ...GGW...RIW...TFX...PIH...MSO...BOI... LAT...LON 45111508 46501254 47021071 47090875 46540812 45790811 45150871 44900926 44541039 44241175 44011271 43841336 43811402 43871457 45111508 MOST PROBABLE PEAK WIND GUST...65-80 MPH