Mesoscale Discussion 1519
Issued: · Valid: –
Summary
High-based storms across central and northeast Montana may increase in intensity through early morning, bringing the potential for severe wind gusts and hail.
Product Text
000 ACUS11 KWNS 060110 SWOMCD SPC MCD 060110 MTZ000-060315- Mesoscale Discussion 1519 NWS Storm Prediction Center Norman OK 0810 PM CDT Sun Jul 05 2026 Areas affected...Central to northeast Montana Concerning...Severe potential...Watch unlikely Valid 060110Z - 060315Z Probability of Watch Issuance...20 percent SUMMARY...High-based storms ongoing across central Montana may see some uptick in intensity over the next few hours as they approach a regional buoyancy maximum. However, the onset of nocturnal cooling and antecedent inhibition downstream cast uncertainty on this scenario. DISCUSSION...Over the past 30 minutes, high-based convection across central/south-central MT has experienced an uptick in lightning counts indicative of a slight strengthening trend. This may be attributable to storms moving into the western periphery of a more buoyant air mass where dewpoints are in the low 50s, increasing into the low 60s into northeast MT on the western side of a weak cold front. Based on mesoanalysis estimates and 00 UTC GGW and BIS RAOBs, this moisture is supporting MLCAPE values on the order of 1000-2000 J/kg within a relatively narrow corridor. It appears possible that further intensification could occur as convection migrates further into this air mass. Effective bulk shear values should increase to around 40-45 knots as buoyancy profiles and convection deepen, resulting in increased organization and an uptick in severe wind potential. However, analyses also depict increasing MLCIN immediately downstream of the ongoing convection, which should increase further with the coming onset of nocturnal cooling. Recent HRRR/RRFS time-lagged ensemble guidance hints at this potential, but has been too aggressive with wind forecasts so far across this region and only gives a 30-50% chance for severe gusts through early morning. This limits confidence in this scenario; watch issuance seems improbable at this time. ..Moore/Gleason.. 07/06/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BYZ...GGW...TFX... LAT...LON 45840729 45720762 45750777 46000792 46530814 46720837 46830880 46910918 47090961 47340992 47620974 47820922 47900815 48160667 48740516 48710475 48550441 48250412 47900409 47450407 46670411 46160442 45840729 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN