Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Nov 05 2024 09:32:38 AWUS01 KWNH 050932 FFGMPD ILZ000-LAZ000-MOZ000-ARZ000-TXZ000-051530- Mesoscale Precipitation Discussion 1129 NWS Weather Prediction Center College Park MD 431 AM EST Tue Nov 05 2024 Areas affected...mid-MS Valley into central AR and the Arklatex Concerning...Heavy rainfall...Flash flooding likely Valid 050930Z - 051530Z SUMMARY...Flash flooding is expected to continue from near and south of the St. Louis metro/mid-MS Valley southwestward into the Arklatex through 15Z. While rainfall rates will be lowering overall, occasional pockets of higher rates will maintain areas of flash flooding, especially atop saturated soils. DISCUSSION...Regional radar imagery at 09Z showed an elongated axis of showers and thunderstorms which stretched from the St. Louis metro into south-central MO, west-central AR and the Arklatex. This axis was located along a combined cold/stationary front and outflow boundary which was coincident with the leading edge of heavy rain. Trends in rainfall intensity have shown a decrease in higher rainfall rates over the past few hours as instability has been lowering. 09Z SPC mesoanalysis data showed MLCAPE values were at or less than 500 J/kg just ahead of the combo front/outflow boundary from MO into AR, but increased to 1000+ J/kg over TX. However, the southern portion of the front/outflow was progressing steadily toward the east, to the south of weak wave located ~40 miles southeast of FSM, limiting the flash flood threat for these southern locations. To the north, the front/outflow has been very slow to progress with locations just south of I-44 in eastern MO to the St. Louis metro containing repeating and training echoes for the past 2-3 hours. Water vapor imagery showed the former closed mid-level low over the southern High Plains has begun to open up and elongate from SSW to NNE. Just ahead of the elongating upper vorticity max was a GOES-East DMV sampled 130+ kt jet streak over eastern KS, providing increased lift via strengthening divergence aloft over northern AR into MO within the right-entrance region. As the mid to upper-level trough axis continues to translate east, it is forecast to acquire more of a neutral tilt with the downstream jet streak allowing for an extended period of enhanced lift over MO. Therefore, while instability will continue to gradually lower until sunrise (~12Z), dynamic forcing will support occasional pockets of higher rainfall rates within areas of training that will continue to support pockets of rainfall rates of 1-2 in/hr within an anomalous moisture axis containing PWATs up to 1.8 inches. This potential will exist from near the Arklatex to the central and southern MO/IL border, overlapping portions of the region which have seen heavy rainfall over the past 24 hours. Overlap of additional rainfall with prior rainfall is expected to be greatest across MO into northern AR, but at least an isolated flash flood threat will continue for locations farther south into northwestern LA and northeastern TX. Additional rainfall totals of 2-3 inches are expected through 15Z. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_opc69QMvdrTu-My0ZY0aWZubvA7qylLDKEG21zAWZLR3L4iI5l4BGmrDf_vkk22iL_7= DsEYgJvmZ6xBI6QMY-JS9x0$ for graphic product... ATTN...WFO...LSX...LZK...PAH...SGF...SHV... ATTN...RFC...ABRFC...LMRFC...MBRFC...NCRFC...WGRFC...NWC... LAT...LON 39058971 38568953 37339024 35379164 33599272=20 32389359 31859456 31949496 32439503 33479441=20 35299351 36799266 38379143 39049063=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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .