Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Feb 22 2023 15:21:31 AWUS01 KWNH 221521 FFGMPD INZ000-ILZ000-MOZ000-222100- Mesoscale Precipitation Discussion 0071 NWS Weather Prediction Center College Park MD 1020 AM EST Wed Feb 22 2023 Areas affected...northeastern MO into central IL and northern IN Concerning...Heavy rainfall...Flash flooding possible Valid 221518Z - 222100Z Summary...Increasing rain with embedded thunderstorms will likely expand across portions of MO into IL and IN over the next few hours. Short term training will have the potential to support rainfall rates over 1 in/hr. Additional rainfall through 21Z should generally be 1 to 2 inches, although localized 2+ inch amounts cannot be ruled out along with localized flooding. Discussion...15Z surface observations placed a warm front extending from a low north of MCI, ESE across northern MO into the OH Valley. Scattered convection has increased in coverage near and north of the warm front across the Mississippi Valley into central IL and western IN over the past 2 hours. The increase appears to be a result of a combination of low level warm air advection, ascent within the right entrance region of a 160-170 kt jet at 200 mb over the Upper Midwest and increasing lift out ahead of a mid-level shortwave trough over the Southern Plains acquiring a negative tilt. 12Z soundings from SGF and ILX showed precipitable water values near 1.2 inches along with nearly 600 J/kg MUCAPE at ILX. While the zonally oriented upper level jet max over the Upper Midwest will be exiting through the day, additional upper jet support should arrive within the left exit region of an existing 130-140 kt speed max located over eastern OK, ahead of the shortwave trough axis. In the low levels, a 50-60 kt 850 mb low level jet will enhance moisture transport to the north with precipitable water values forecast to increase to 1.5 inches locally across the Midwest this afternoon. Mean southwesterly flow will support axes of training heavy rain, combined with RAP forecast MUCAPE values of 250-750 J/kg should allow for hourly rainfall totals in excess of 1 inch, but likely no higher than 1.5 inches in an hour. Additional peak rainfall of 1 to 2 inches is expected through 21Z, but localized totals over 2 inches will be possible as well. Despite fairly dry antecedent conditions, flash flood guidance (FFG) is as low as 1 in/hr in some areas of northern IL/IN and 1 to 2 inches in 3 hours with a focus on central to northern IL. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9bR0Gv5ypgi5BMsG1rP5HgEB7CSXQZKqIcgr10IMzU1xWgk6axUaHHIQXihUi1loyMJN= ovRqdabV2GTpLL0YNd855PM$ for graphic product... ATTN...WFO...DVN...EAX...ILX...IND...IWX...LOT...LSX...SGF... ATTN...RFC...MBRFC...NCRFC...OHRFC...NWC... LAT...LON 41558787 41548541 41108493 40558532 40288623=20 39828770 39308918 38409081 37889216 38059274=20 38579284 39689226 40858998=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) .