Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Feb 22 2023 21:37:00 AWUS01 KWNH 222136 FFGMPD OHZ000-MIZ000-INZ000-ILZ000-230330- Mesoscale Precipitation Discussion 0072 NWS Weather Prediction Center College Park MD 433 PM EST Wed Feb 22 2023 Areas affected...central/northern IL into northern IN, northwestern OH and southern MI Concerning...Heavy rainfall...Flash flooding possible Valid 222130Z - 230330Z SUMMARY...Heavy rain will continue a threat for flooding from central/northern IL into northern IN and extreme northwestern OH/southern MI. Peak rainfall rates of just over 1 in/hr will allow for an additional 1 to 2 inches of rain through 03Z, but rainfall intensity is expected to decrease with time. DISCUSSION...Regional radar imagery at 21Z showed a broad shield of precipitation extending to the north and northeast of a surface low analyzed over central IL. Localized reports of 1+ in/hr have occurred across portions of central IL over the past few hours where the SPC mesoanalysis indicated MUCAPE near 100 J/kg and precipitable water values of 1.2 to 1.4 inches. MRMS and gauge reports indicated 1 to 3 inches of rain has fallen over the past 12 hours from central IL into north-central IN. Across far northern IN/OH into southern MI, surface temperatures near 32 have supported areas of freezing rain with the freezing line expected to only marginally lift north over the next few hours. As a negatively tilted shortwave over the mid-Mississippi Valley continues to advance northeastward, it is expected to maintain a weakening trend and support the ENE track of the surface low over central IL toward northwestern OH. South-southwesterly 850 mb winds of 50 to 60 kt just ahead of the shortwave and surface low are expected to continue strong ascent over a well-defined warm front extending eastward from the low. Elevated instability is only about 100-200 J/kg according to the 20Z SPC mesoanalysis but is forecast to gradually lower over the next 3-6 hours which should reduce peak rainfall intensity to 0.5 to 0.75 in/hr beyond 00Z. An additional 1-2 inches of rain is expected through 03Z, with rainfall ending from west to east. Expected rainfall should near area 3-hr flash flood guidance of 1 to 1.5 inches, but should primarily lie north of the axis of heavy rain that has fallen over the past 12 hours. Nonetheless, localized areas of flooding will be possible, within a fairly narrow corridor between the warm front and frozen precipitation to the north over southern MI. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5as5StVmTttq9_ugpk6tIhGmT_NrRd3sM1pVodkMzu3_gM1p4U6oC2L8ngmMLySEF3kU= CdQ61tMYOT-tzCn-pwz8U4w$ for graphic product... ATTN...WFO...CLE...DTX...DVN...GRR...ILX...IND...IWX...LOT... ATTN...RFC...NCRFC...OHRFC...NWC... LAT...LON 42298582 42158513 41998453 41968393 42028369=20 42258317 42248313 42208307 42158304 42098305=20 42028310 41978314 41888323 41798332 41758333=20 41718323 41688313 41648303 41618298 41588293=20 41408334 40608683 40238818 40238908 40908949=20 41468881 41828721=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) .