Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Mar 15 2024 01:54:15 AWUS01 KWNH 150154 FFGMPD TNZ000-MSZ000-LAZ000-MOZ000-ARZ000-TXZ000-OKZ000-150730- Mesoscale Precipitation Discussion 0100 NWS Weather Prediction Center College Park MD 953 PM EDT Thu Mar 14 2024 Areas affected...Northeast TX...Southeast OK...Arkansas...Eastern TN...Northern MS... Concerning...Heavy rainfall...Flash flooding likely Valid 150155Z - 150730Z SUMMARY...Expanding linear convective complex favorably oriented to the deep layer steering flow will allow for areas of intense rainfall rates over 2"/hr and streaks of 3-5" resulting in likely incidents of flash flooding across Northeast TX into Western TN overnight. DISCUSSION...GOES-E 10.3um showing a cooling and expanding convective complex from the Red River of SE OK and NE TX across AR nosing toward W TN at this time. Internally, numerous overshooting tops dotting the center of the complex with -70C indicating maturing/strong updrafts within the favorably unstable environment across the warm sector. To exacerbate the issue, orientation of the overshooting tops denote the growing concern for favorable mergers and training cells; this is related to the exiting of a mid-level shortwave/mature MCV racing across the Mid-Mississippi Valley into S IL. As a result, the associated meso-high blow echo is orienting the outflow boundary toward the strengthening southwesterly LLJ and southerly/nearly orthogonal surface flux across central AR. Ample low level moisture with Tds in the upper 60s to low 70s with modestly steep mid-level lapse rates results in ample unstable air with CAPE values still in the 2000-3000 J/kg range (even in an elevated nature). As such, strong moisture flux/strong updrafts (as noted by the instability and overshooting tops) suggest increasing moisture flux and rainfall efficiency, with hourly rates up to 2"/hr in the cores, though 15-minute rainfall totals of 1-1.3" are likely given 00z HRRR and additive WoFS totals. While a mid-level jet is translating over the top of the complex now, increasing cell motions, but as noted, weak inflection lifting northeast through the flow should allow for some timing (2-4hrs) of favorable training orientation before weak height-falls and right entrance upper level dynamics allows for some forward (southeast) propagation of the line/complex after 07z). As a result, of the efficient rain and training, streaks of training cells mainly out of SE OK across central AR will allow for streaks of 3-5" totals and continue likely flash flooding...given the longer duration potential there. However, other streaks further downstream into W TN/NW MS as well as favorable upstream/back-building near the nose of the EML/Western Gulf LLJ confluence across NE TX, may support similar rates but shorter duration for spots of 2-4" and possible incidents of flash flooding as well. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_2f1HG1wR5FLjzPZ7qqjkcRgKAHp616e_WuwbzabKhacvB7IN_mxD-i2rM_Fh81-ZMkb= ImVjnsmRUjaQSl1H8ci3icI$ for graphic product... ATTN...WFO...FWD...JAN...LZK...MEG...OHX...OUN...SHV...TSA... ATTN...RFC...ABRFC...LMRFC...WGRFC...NWC... LAT...LON 36338831 36068758 35368774 33959029 32469541=20 32719744 33869742 35309502 35949260 36249043=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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .