Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Sep 20 2023 07:45:13 FOUS30 KWBC 200745 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 344 AM EDT Wed Sep 20 2023 Day 1 Valid 12Z Wed Sep 20 2023 - 12Z Thu Sep 21 2023 ....THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS EASTERN OKLAHOMA INTO WESTERN ARKANSAS, AND CENTRAL TO SOUTHEAST FLORIDA PENINSULA... ....Eastern Oklahoma into western Arkansas... An upper vort expected to move slowly east northeastward from central Missouri into central Illinois during Wednesday. While convection has been active in the vicinity of this vort during Tuesday, the latest hi res runs are not showing much in the way of convection along the track of this vort across south central Missouri into southwest Illinois during the day 1 period. At the moment, this lessening trend looks reasonable given very little in the way of instability along and ahead of the track of the vort across Missouri into Illinois. With precip below average across these regions over the past few weeks and soil moisture low, the previous marginal risk area was removed from this region. Better instability is expected to persist on the southwest side of this vort across the Southern Plains . Latest hi res guidance is showing potential for additional convection to fire in the vicinity of eastern Oklahoma/western Arkansas along the position of a stationary frontal boundary. 850-700 mb moisture flux continues to be anomalous, 1 to 2 standard deviations above the mean, into this front day 1. This will support potential for additional convection to push east southeast from eastern Oklahoma into western Arkansas/far northeast Texas. HREF neighborhood probabilities are high for 1"+ amounts across this area, 40-70%, decreasing to 20-50% along the Oklahoma/Arkansas border area.=20 ....Central to Southeast Florida... No changes made to the previous broad marginal risk area across central to southeast Florida. PW values will remain high, 2"+ in the vicinity of the stationary front currently across the central portion of the peninsula. An upper trof will begin to amplify day 1, supporting another round of organized convection across the central to southern Florida Peninsula Wednesday afternoon. Low confidence in any qpf details, but localized runoff issues possible, especially in urbanized regions. HREF neighborhood probabilities are high for 1, 2 and 3"+ amounts in the upcoming day 1 period in the marginal risk area. Oravec 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!4927NaFurQMva88zbIPdMxGWgHbgp5MjNTLts1jw035f= PwW4yMJQiNEnL-Lp1XcxxZDAYUcKd-d9O9LFHELKQzp5T0A$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!4927NaFurQMva88zbIPdMxGWgHbgp5MjNTLts1jw035f= PwW4yMJQiNEnL-Lp1XcxxZDAYUcKd-d9O9LFHELKvejSmQ4$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!4927NaFurQMva88zbIPdMxGWgHbgp5MjNTLts1jw035f= PwW4yMJQiNEnL-Lp1XcxxZDAYUcKd-d9O9LFHELK1HykKVg$=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) .