358  
ACUS11 KWNS 041808  
SWOMCD  
SPC MCD 041807  
IDZ000-ORZ000-042000-  
 
MESOSCALE DISCUSSION 1559  
NWS STORM PREDICTION CENTER NORMAN OK  
0107 PM CDT FRI JUL 04 2025  
 
AREAS AFFECTED...SOUTHEAST OREGON INTO SOUTHERN IDAHO  
 
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY  
 
VALID 041807Z - 042000Z  
 
PROBABILITY OF WATCH ISSUANCE...20 PERCENT  
 
SUMMARY...THUNDERSTORMS DEVELOPING ACROSS SOUTHEAST OREGON WILL  
GRADUALLY INTENSIFY AS THEY MIGRATE INTO SOUTHERN IDAHO. STORM  
COVERAGE SHOULD REMAIN SUFFICIENTLY ISOLATED TO PRECLUDE WATCH  
ISSUANCE.  
 
DISCUSSION...GOES VISIBLE IMAGERY SHOWS STEADY VERTICAL DEVELOPMENT  
OF CUMULUS AND INCREASINGLY LIGHTNING ACTIVITY ACROSS SOUTHEAST OR  
OVER THE PAST 30 MINUTES AS HEATING OF A SEASONALLY MOIST AIR MASS  
CONTINUES UNDER AND JUST AHEAD OF AN UPPER-LEVEL LOW. ADDITIONAL  
DIURNALLY-DRIVEN DESTABILIZATION SHOULD YIELD MLCAPE VALUES UPWARDS  
OF 500-1000 J/KG AS THIS ACTIVITY SPREADS INTO SOUTHWESTERN ID WHERE  
MID-LEVEL FLOW IS SLIGHTLY STRONGER (30-45 KNOTS). ALTHOUGH BUOYANCY  
WILL REMAIN SOMEWHAT LIMITED, INCREASING DEEP-LAYER SHEAR WILL  
PROMOTE INCREASING STORM ORGANIZATION THROUGH LATE AFTERNOON AS A  
MIX OF THUNDERSTORM CLUSTERS AND A FEW ISOLATED CELLS EMERGES (BASED  
ON RECENT CONVECTIVE TRENDS). STEEPENING LOW-LEVEL LAPSE RATES  
COUPLED WITH 30-40 KNOT FLOW NEAR THE TOP OF THE BOUNDARY LAYER MAY  
SUPPORT A FEW SEVERE GUSTS WITH ANY DEEP CONVECTION, THOUGH THIS  
POTENTIAL WILL BE MAXIMIZED WITH ANY ORGANIZED CLUSTERS THAT CAN  
DEVELOP. ADDITIONALLY, BUOYANCY AND EFFECTIVE SHEAR SHOULD BE  
ADEQUATE FOR LARGE HAIL PRODUCTION (MOST LIKELY BETWEEN 1 TO 1.25  
INCHES IN DIAMETER) WITH MORE DISCRETE CELLS. OVERALL, MODEST  
BUOYANCY AND ISOLATED TO WIDELY SCATTERED STORM COVERAGE SHOULD  
LIMIT THE OVERALL SEVERE THREAT AND PRECLUDE THE NEED FOR WATCH  
ISSUANCE.  
 
..MOORE/MOSIER.. 07/04/2025  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT  
 
ATTN...WFO...PIH...MSO...BOI...  
 
LAT...LON 42091810 42391832 42751837 43231834 43571806 44761525  
44771481 44581426 44251396 43801376 43221362 42831361  
42501366 42171389 42031430 42091810  
 
MOST PROBABLE PEAK WIND GUST...55-70 MPH  
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN  
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