Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jul 09 2025 07:30:35 ACUS03 KWNS 090730 SWODY3 SPC AC 090729 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Wed Jul 09 2025 Valid 111200Z - 121200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE HIGH PLAINS OF THE SOUTHERN AND CENTRAL ROCKIES NORTHEAST TO THE UPPER GREAT LAKES AND FROM THE CAROLINAS TO CENTRAL PENNSYLVANIA... ....SUMMARY... A few strong to severe thunderstorms capable of producing large hail and damaging winds will be possible across portions of the central Great Plains. Additional strong storms capable of producing sporadic wind damage will be possible from the Carolinas to central Pennsylvania. .... Central Plains ... A low-amplitude short-wave trough across the central Great Plains will begin to phase with / be absorbed by a larger scale trough moving across the northern Great Plains. At the surface, a cold front will slowly push southeast through much of Iowa during the day. At the start of the forecast period, convection from the previous day should still be ongoing across portions of the area. The overall pattern would suggest that one or more mesoscale convective vortices (MCVs) may accompany this ongoing convection. Guidance consensus and the overall pattern would support this convection persisting through much of the day. To the south of this convection, diurnal heating of a moist airmass below steep mid-level lapse rates will result in a strongly unstable atmosphere by mid afternoon. Additional thunderstorms should develop within this strongly unstable atmosphere and be capable of producing large hail and damaging winds. At present, the combination of a weakening mid-level wind field and uncertainty associated with the location of any ongoing/persistent convection prevents the inclusion of higher probabilities with this forecast. However, locally enhanced effective-layer shear associated with any remnant MCVs should support some organization of a severe threat such that an upgrade to Level 2/Slight Risk may be warranted as the details of such features become clear. .... Carolinas to central Pennsylvania ... Diurnal heating of a moist and weakly capped boundary layer will result in afternoon thunderstorms. Precipitable water values look to be less on Friday than previous days, but still should be sufficient for widely scattered to scattered wet downbursts. Wind damage will be possible with the stronger downbursts. .... Eastern Colorado into the southern Great Plains ... Thunderstorms are expected to develop across northeast Colorado during the afternoon. Large-scale flow should result in these storms moving southeast through the evening and overnight hours as they grow upscale into a large MCS. The overall pattern would suggest the potential for at least a couple of severe wind reports associated with this southeastward moving MCS. ...Marsh.. 07/09/2025 $$ = = = To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .