Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Aug 14 2023 05:21:32 AWUS01 KWNH 140521 FFGMPD TNZ000-KYZ000-ILZ000-MOZ000-ARZ000-141100- Mesoscale Precipitation Discussion 0922 NWS Weather Prediction Center College Park MD 120 AM EDT Mon Aug 14 2023 Areas affected...Southern MO...Northern AR...Southern IL...Western KY...Far Northwest TN... Concerning...Heavy rainfall...Flash flooding likely Valid 140520Z - 141100Z SUMMARY...Training thunderstorms likely to continue flash flooding through late overnight period. Additional 2-4" totals w/isolated 5" possible.=20 DISCUSSION...GOES-E 10.3um and Regional RADAR mosaic depict an intense line of thunderstorms remaining in a favorable training pattern across the Southern Plains into the Ozark Plateau with ongoing flash flooding. At this time, the environment is becoming increasingly favorable for the risk for flash flooding to expand eastward in the downwind portion of MO into the Tri-Rivers area of S IL/W KY over the next few hours. 05z Surface map denotes the northern stream cold front has intersected and under-cut the southern stream frontal zone from SW MO and upstream. However, the southern stream warm front extends ESE across NE AR into the lower MS Valley, with upper 70s to low 80s Tds across the region starting to feel LLJ acceleration toward the north and northeast providing increased isentropic ascent and moisture convergence across SE MO ahead of the stronger supercell in Ozark county and bowing segment ahead of the northern stream cold front.=20 The WAA has strong convergence as the 850-700mb streamlines angle eastward. With total PWATs up to 2.25" and 15-20kts, cells may be a bit less efficient than their upstream counterparts, likely with scattered 1.5-2"/hr rates, slowly filling in with time.=20=20 Additionally, strong divergence aloft entering right entrance region of 3H jet (and general diffluence) should help to maintain updraft strength. Steering flow may not be also as ideal as upstream, but should allow for training/repeating segments over the next few hours should support streaks of 2-4" across south-central to southeast MO into IL/W KY resulting in localized flash flooding. OK into SW MO/NW AR... Southern stream shortwave/MCV is tracking quickly across northwest to north-central OK sweeping the back edge of stronger updrafts across central OK into northeast OK (see MPD 921 for more information). At current pace, interpolation would bring it toward the OK/AR border around 09z. Southerly low-level flow will transport some weak low to mid-level dry air from the broader dry pocket across TX/SW AR, but flow is expected to veer toward more westerly and remain transporting enhanced mid-level moisture (noted by 2-2.5" TPW axis or within 850-500mb layers on CIRA LPW). This wave is likely to continue eastward acceleration but provide strong moisture flux convergence to support a second wave of intense rain-fall rates of 2-2.5"/hr, after the initial wave has passed through. Additional 2-3" with this wave, are likely to reaggravate flash flooding across S MO/N AR and bring totals of 3-4" across this area, with scattered spots of 5"+ possible by 12z. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9NfiXhTXx-bxDpxI0-GD55YA8Tsskmz_jVrks3MMaC39bf2FGM75QuBwBOPu_QzoxPSh= F2wUJPybFMzSOoLLMroYbKc$ for graphic product... ATTN...WFO...LSX...LZK...MEG...PAH...SGF...TSA... ATTN...RFC...ABRFC...LMRFC...MBRFC...NCRFC...OHRFC...NWC... LAT...LON 38268898 37808808 36298830 35848937 35519166=20 35449411 36319451 37399433 37689395 38139218=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) .