Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Sep 18 2025 01:57:16 AWUS01 KWNH 180157 FFGMPD TXZ000-OKZ000-KSZ000-COZ000-NMZ000-180745- Mesoscale Precipitation Discussion 1100 NWS Weather Prediction Center College Park MD 956 PM EDT Wed Sep 17 2025 Areas affected...Southeast CO...Far Northeast NM...Southwest KS...OK Panhandle...Northern TX Panhandle... Concerning...Heavy rainfall...Flash flooding possible Valid 180155Z - 180745Z SUMMARY...WAA band with some short-term training across TX Panhandle to given way to upscale convective clusters out of SE CO/NE NM. Scattered repeating through the overnight period may present hourly rates/totals to 1.5" and localized 2-3 3-6 hour totals downstream. Isolated incident or two of flash flooding is considered possible. DISCUSSION...GEOS-E WV suite shows a broad closed low over the central High Plains though the inner core short wave/vorticity features are fairly consolidated but showing a generally flat elongated orientation across central CO toward the Sand Hills of Nebraska. The upstream shortwave is sliding eastward with an associated upper level speed max into a weakly diffluent region across SW KS attm. As speed max rounds the base, this will expand and overall divergence aloft will be favorable for upscale convective growth toward the later portion of the period.=20 However, in the short-term term, scattered more severe-type convection with solid hail generation exists across much of SE CO, though organization suggests some random collision/mergers are possible over the next few hours. More concerning is VWP and RAP analysis suggests strengthening southerly to south-southwesterly low level jet across the Texas Panhandle is responding to the overall height-falls/ejection of the wave. A weak thermal boundary from NNW to SSE is acting as the isentropic ascent fact across far NE NM into the northern TX Panhandle. Here, WAA is solid and MUCAPEs are near 2000 J/kg to support the elevated convection. CIRA LPW also notes backed up moisture gradient from afternoon upslope, combined with an axis of enhanced 850-700 to ..5" near this ascent plane, allowing for increasing moisture flux into the currently severe/hail producing cells. Given total moisture to 1.25" and increasing speed to 35kts, convergence should support 1.5"+/hr rates.=20=20 Deep layer flow at the southern edge of the jet is support some weak south-easterly motions for some scattered potential for training/repeating elements. This may result in localized 2-3" totals and possible flash flooding conditions over the next few hours. With time, the strength and veering of the LLJ will expand ascent across SE CO into SW KS into the aforementioned expanding divergence field toward 06-07z. Forward propagation is likely to limit overall coverage, but repeat tracks and expanding clusters may also support localized 2-3" totals and isolated flash flooding conditions through middle of overnight period. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9MXfjDXLe0g4EuNA_kspVcIBGmDFRnIA_hjcQzRmgqAhNjIiRQD-utosqBglXLfDCAsS= a9FJQ3jEiP6VKvF01Emqufk$ for graphic product... ATTN...WFO...ABQ...AMA...DDC...GLD...OUN...PUB... ATTN...RFC...KRF...TUA...NWC... LAT...LON 38580228 38510076 38069976 36809946 35410016=20 35220225 35830347 37200421 38270358=20 =3D =3D =3D 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) .