Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Oct 24 2023 08:59:47 AWUS01 KWNH 240859 FFGMPD TXZ000-OKZ000-241430- Mesoscale Precipitation Discussion 1149 NWS Weather Prediction Center College Park MD 459 AM EDT Tue Oct 24 2023 Areas affected...Big Country/Northwest TX...Southwest OK... Concerning...Heavy rainfall...Flash flooding possible Valid 240900Z - 241430Z SUMMARY...Prolonged training of moderate rains with scattered embedded intense cores up to 1.5"/hr with spot totals of 3"+ possible. Conditional low-end flooding may become possible through through early morning hours. DISCUSSION...A highly anomolous dynamic and moisture rich environment exists across the Red River Valley into the Edwards plateau as the mid-level remnant moisture from Tropical Cyclone Norma over-rides the surface to mid-level return moisture out the western Gulf of Mexico. Total TPW of 1.7 to near 2" align along the shear axis of the TC from SW TX into OK, which given the digging upper-level trof over SW CA has resulted in very strong/tight gradient to support deep layer strong low-level to support 3.5-4 standard anomaly values of moisture flux across Northwest TX. GOES-E WV along with regional RADAR depict a low-level 850-700mb wave across the Cap Rock lifting north into increasingly favorable diffluent region of the polar/sub-tropical jet across the upper Red River Valley into SW OK. All of these factors are supporting a favorable environment for scattered vertical ascent of this moist slab along a SSW to NNE convergence axis from the Edwards Plateau into SW OK over the next few hours. Regional RAP model sounding denote the deep moist layer, but given the column is fairly saturated, lapse rates are 5.5-6C/km and while higher Theta-E air is available from the western Gulf, it is not providing very unstable profiles for convective development.=20 Still slow vertical ascent with high moisture flux is resulting in a broad shield of .33-.5"/hr rates along the eastern hemisphere of the 850-700mb wave lifting north across the area, though highly focused convective elements embedded within the WAA pattern occassionally are tapping the weak instability for vertical growth. Deep warm cloud layer (10Kft+) support efficient tropical rain showers with capability of 1.5"/hr rates which is expected to increase in coverage (slightly) over the next few hours as the best best low-level convergence starts to align with upper-level divergence in the left exit of the sub-tropical jet exit across NW TX into SW OK through the early morning period. As such, narrow stripes of 1.5-2" are likely, though as the wave lifts north, the trailing confluence zone will allow for longer duration of moderate showers with these embedded efficient cores. As such, a pocket or two of 3"+ is possible over a 2-4hr period which puts the rainfall totals/rates in the range of the high FFG values in the region (enhanced by significant drought conditions). Relative soil moisture is mainly below 30% except for a pocket of 50-60% near Wichita Falls in far NW TX, so more than likely this will be a beneficial rainfall event, but a spot or two of low-end flooding concerns are possible as HREF probablity of 3" reaches 50% by 15-18z across NW TX and SW OK.=20=20=20 Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7EG383Jl5I_M4s62vDgzq3AZUPnyvATSyImyJRZrLC6QQm8kl5m7Zztm9J-KkjISDEpk= v0qLA-Wqi4QT7gGV92VloBg$ for graphic product... ATTN...WFO...LUB...MAF...OUN...SJT... ATTN...RFC...ABRFC...WGRFC...NWC... LAT...LON 35779869 35389784 34519798 33349900 32030023=20 32210088 32750080 33730045 34709997 35419945=20 =20=20=20=20=20=20=20=20=20=20=20=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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .