Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jul 30 2025 19:47:24 ACUS01 KWNS 301946 SWODY1 SPC AC 301945 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Wed Jul 30 2025 Valid 302000Z - 311200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHEAST...THE NORTHERN TO CENTRAL HIGH PLAINS...AND KANSAS INTO THE SOUTHERN GREAT LAKES... ....SUMMARY... Widely scattered strong to severe thunderstorms are possible from Kansas into the Mid Mississippi Valley and southern Great Lakes, and over parts of the Mid-Atlantic/Northeast region, and from southern Montana across Wyoming and Colorado. ....20z Update... The previous forecast largely remains on track with only minor adjustments needed. Hail/wind risk probabilities were adjusted across portions of KS into MO and IL to better align with ongoing convection and the progression of a residual outflow boundary in IL/MO and a southward moving cold front in KS. See the previous discussion below and MCDs #1847 and 1848 for additional details. ...Moore.. 07/30/2025 ..PREV DISCUSSION... /ISSUED 1130 AM CDT Wed Jul 30 2025/ ....Mid MS Valley... Radar/visible-satellite mosaic shows a sub-severe squall line from near Saint Louis into northern IL moving slowly east-southeastward across the Corn Belt. Some rejuvenation of storm intensity may occur with storms along the leading edge of the cold pool as it moves into eastern IL/IN/OH/Lower MI. Isolated 50-65 mph gusts capable of wind damage may occur with this activity. Farther west, a weak mid-level shortwave disturbance is implied in satellite imagery near the KS/NE border, and a surface low was analyzed over south-central KS along the trailing frontal zone. These features may aid in focusing scattered storms this afternoon over parts of central and eastern KS. The boundary layer continues to heat/destabilize with surface dewpoints ranging from the upper 60s to mid 70s across central and eastern KS. Isolated severe gusts and possibly large hail may accompany the stronger storms late this afternoon into the evening. ....High Plains... A seasonably moist airmass resides across the central and northern Rockies and adjacent plains late this morning. Water-vapor imagery and earlier radar mosaic data implied a weak disturbance cresting a ridge over the northern WY/southern MT border. Influence from this disturbance and westerly 40-50 kt high-level flow will support some storm organization potential. Forecast soundings across central WY show 1000-1500 J/kg MLCAPE and effective shear 30-40 kt. This may support a couple of supercells capable of threat for large hail. Upscale growth into a linear cluster may evolve in central WY late this afternoon into the early evening, coincident with a risk for severe gusts. Farther south, storm coverage may be locally greater across the Front Range and I-25 corridor from Denver to Pueblo. Isolated to widely scattered wind/hail seem likely with the stronger cores/outflow. Elsewhere, it appears an isolated risk for severe will encompass the larger general area from southern MT into eastern CO. ....Northeast... A weak surface cold front will sag southward into a moist/adequately unstable airmass across New England and parts of NY/PA this afternoon into the evening. Low-level convergence along the front will be weak and will limit overall storm coverage. However, cool temperatures aloft and steep low-level lapse rates will promote a risk of gusty/damaging winds and at least small hail in the storms that form this afternoon. For short-term details regarding the severe risk in portions of northern New England, refer to MCD #1846. $$ = = = 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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .