Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue May 06 2025 06:05:09 ACUS01 KWNS 060602 SWODY1 SPC AC 060600 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Tue May 06 2025 Valid 061200Z - 071200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHEAST TEXAS... ....SUMMARY... Severe thunderstorms are likely today across parts of the southern Plains into the Lower Mississippi Valley. Some storms will be capable of producing severe gusts, large to very large hail, and tornadoes. Strong tornadoes will be possible. Isolated strong to severe storms with hail and marginally severe gusts may also occur in the northern Mid-Atlantic. ....Southern Plains/Lower Mississippi Valley... At mid-levels, a low will move into the southern Rockies today, as an associated 60 to 70 knot jet streak translates northeastward across the southern Plains. Within the exit region of the jet, scattered thunderstorms are expected to be ongoing in west Texas at the start of the period, along the western edge of a moist airmass. The moist airmass will be located over much of the eastern half of Texas extending eastward into the lower Mississippi Valley. Scattered to numerous thunderstorms are expected to develop around midday from north-central Texas into southern Oklahoma, in association with warm advection. A severe threat is expected to develop with this convection, and should increase during the afternoon. In areas that heat up, supercells with large hail and severe gusts will be possible. Hailstones of greater than 2 inches in diameter may occur with the more intense supercell updrafts, mainly in northwest and central Texas where mid-level lapse rates are forecast to be steep. Further to the southeast, the airmass is likely to remain undisturbed through midday. A warm front will move slowly northward across central and southeast Texas. From this front southward, surface dewpoints will likely be from the upper 60s to mid 70s F. As surface temperatures warm during the day, strong instability is forecast to develop. The models are in reasonably good agreement that MLCAPE will peak between 3000 and 4000 J/kg during the afternoon. In addition, the mid-level jet will move into the southern Plains, creating strong deep-layer shear favorable for supercells. In response, a 40 to 50 knot low-level jet is forecast to develop across southeast Texas. Forecast soundings to the northwest of the Houston area increase 0-3 km storm-relative helicity into the 350 to 400 m2/s2 range. This shear environment will be favorable for supercells and tornadoes. A few strong tornadoes will be possible within parts of the airmass that heat up the most and remain undisturbed into the early afternoon. MCS development appears likely during the afternoon across east Texas. Rotating storms within the MCS will be capable of large hail and severe gusts. This threat should spread eastward into the lower Mississippi Valley during the late afternoon and early evening. ....Northern Mid-Atlantic... A mid-level low will move northeastward across the Ohio Valley today, as a front advances eastward through the central Appalachians into the Mid-Atlantic. An axis of low-level moisture will be located ahead of the front with surface dewpoints in the 50s F. As surface temperatures heat up during the day, weak instability is forecast to develop along and near this moist axis. Low-level convergence and large-scale ascent associated with the mid-level system will likely support isolated to scattered thunderstorm development. In addition to the weak instability, RAP forecast soundings have moderate deep-layer shear in the Mid-Atlantic with steep low-level lapse rates exceeding 8 C/km. This could support a marginal wind-damage threat during the afternoon, with the threat eventually transitioning eastward into the Hudson River Valley. ...Broyles/Moore.. 05/06/2025 $$ = = = 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) .