ACUS01 KWNS 061938 SWODY1 SPC AC 061937 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0137 PM CST Thu Mar 06 2025 Valid 062000Z - 071200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...20z Update... The previous forecast remains on track with no forecast changes required. Sporadic lightning flashes have been noted across parts of the Great Basin and northern AZ over the past few hours. Recent LightningCast data suggests overall lightning potential remains low for the near-term with the relatively greatest chance for lightning across central/northern UT. This trend of isolated/infrequent lightning is expected to continue through late evening from CA into the central Rockies. See the previous discussion below for additional details. ..Moore.. 03/06/2025 .PREV DISCUSSION... /ISSUED 1026 AM CST Thu Mar 06 2025/ ...Synopsis and Discussion... Upper pattern is expected to remain fairly progressive today as the trough currently extended from the Great Lakes off the NC Coast continues eastward/northeastward and the upper low currently over central CA/NV shifts southeastward towards the Lower CO Valley. Shortwave ridging that extends between these two trough from the southern Plains into the northern Rockies is forecast to dampen as it shifts eastward into the MS Valley. Most prominent surface feature is the expansive ridging that currently extends from the Lower MS Valley into southern Alberta/Saskatchewan. The dry and stable airmass associated with this ridge will promote stable conditions across much of the central and eastern CONUS throughout the day. Some modest moisture return is anticipated this evening through tonight across the southern Plains as lee cyclogenesis over the central High Plains increases the pressure gradient and southerly flow strengthens. Warm low- to mid-level temperatures will keep the southern Plains stable. Isolated lightning flashes are possible across the Great Basin and into the central Rockies. Here, a shortwave trough rotating around the parent upper low will progress through the region, with the associated large-scale ascent interacting with modest buoyancy fostered by relatively moist low/mid-levels and cold temperatures aloft. Some small (i.e. sub-severe) hail is possible within a few of the deeper cores. Additional isolated lightning flashes are anticipated farther west across central CA where another shortwave trough rotating around the upper low will contribute to strong ascent amid cold mid-level temperatures. $$