Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Nov 05 2022 08:14:20 FOUS30 KWBC 050814 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 413 AM EDT Sat Nov 05 2022 Day 1 Valid 01Z Sat Nov 05 2022 - 12Z Sat Nov 05 2022 ....THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL ACROSS PORTIONS OF THE LOWER MISSISSIPPI/TENNESSEE VALLEY... Convection associated with a cold front is moving east across the Mississippi River this morning. Embedded thunderstorm cells will continue to develop along the southern end of the front over the Marginal Risk area, as shown by all of the HiRes guidance. These storms are continuing to take advantage of plentiful Gulf moisture, which will allow the storms to continue to produce up to 2"/hr rainfall rates as the weakening line moves through the lower MS & TN Valleys this morning. Separate cells continue to develop ahead of the line, especially along the Gulf Coast. These cells dropping up to an inch of rain in areas ahead of the main line which may itself produce up to 2" of rain will be enough to produce isolated flash flooding. These cells are propagating north along the line, which due to training may result in isolated flash flooding in areas further north into MS and western AL. On the large scale, a potent wave moving northeast across IA at the start of the period is supporting a 130 kt southerly jet streak that stretches from AR through the U.P. of MI. This puts the Marginal Risk area in the right entrance region of that jet streak, which will help support the convection into the afternoon hours. PWATs of over 2 inches, which is over +3 standard deviations above the normal, are also present in the Marginal Risk region. These supportive ingredients will counter the weakening line and departing upper level support to keep the isolated flood threat ongoing into this afternoon. A small expansion of the inherited Marginal Risk area was made towards the west approaching the MS River to account for diminishing rain on the back side of the departing line contributing to any isolated flash flooding right just after 12Z this morning. Wegman Day 2 The Day 2 outlook will be updated by 0830Z. Day 3 The Day 3 outlook will be updated by 0830Z. Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!-9E9oVMkKv9rv48OZrPOCnx37nmfHtecHzXDyDSruglM= 3OaW0nOTMFFb2BezRlFznhuh1-CfYZUN7KJ1YicCGm6sFTo$=20=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!-9E9oVMkKv9rv48OZrPOCnx37nmfHtecHzXDyDSruglM= 3OaW0nOTMFFb2BezRlFznhuh1-CfYZUN7KJ1YicCA5zMjVY$=20=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!-9E9oVMkKv9rv48OZrPOCnx37nmfHtecHzXDyDSruglM= 3OaW0nOTMFFb2BezRlFznhuh1-CfYZUN7KJ1YicCUEwK4Rg$=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) .