Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Nov 22 2022 20:23:43 FOUS30 KWBC 222023 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 322 PM EST Tue Nov 22 2022 Day 1 Valid 16Z Tue Nov 22 2022 - 12Z Wed Nov 23 2022 ....THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ALONG THE EAST CENTRAL COAST OF FLORIDA... ....16Z Update... Very few changes made to the previous forecast. A small westward expansion was made to coordinate better with the CAMs in this area. The convection is very slow moving into the coast so far, but individual cells so far have not been very strong. Daytime heating should help to intensify the convection this afternoon. Several of the CAMs are suggesting convection developing along a line from the Marco Island, FL area to the southern end of Lake Okeechobee, but with this area being fairly rural, FFG values are not expected to be met by any convection that does form. The latest HREF guidances suggests a 60 percent chance of achieving 2 year ARI values in the Fort Pierce and Vero Beach areas, and even a 25 percent chance of reaching 10 year ARI values in the same area. The EC and GFS both agree on PWAT values remaining 2.5 standard deviations above normal with values approaching 2". Wegman ....Previous Discussion... The axis of above average PW values..2+ standard deviations above the mean...will persist across central Florida day 1. Onshore easterly to east southeasterly low level flow expected to persist in this high PW...supporting an area of defined boundary layer convergence along the east central Florida coast day 1, with continued potential for showers and isolated heavy totals. The 0000 UTC hi res guidance has trended mostly offshore for day 1 with any heavy precip potential. However, several of the global models (GFS, EC, CMC) along with a few of the latest hrrr runs show continued potential for locally heavy rainfall amounts.=20 Confidence is not great with respect to where heaviest totals will occur, but there is potential for slow moving or nearly stationary cells along the east central coastal sections of Florida that may produce isolated runoff issues, especially over more urbanized regions. With respect to changes to the previous outlook for this period, the north side was trimmed south out of JAX WFO to the northern border of WFO MLB. The southern portion was extended slightly farther to the south to the southern border of WFO MLB. Oravec Day 2 Valid 12Z Wed Nov 23 2022 - 12Z Thu Nov 24 2022 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Wegman Day 3 The Day 3 outlook will be updated by 2030Z. Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!8VBnWGP-mo1pIBv43xoyGBCyKb5nuCJh378aNcbzbPHU= ExLk6R-WkVhHeX5wjn7EMFNS4mpRms9aLvnLkPsN-v8e1wI$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!8VBnWGP-mo1pIBv43xoyGBCyKb5nuCJh378aNcbzbPHU= ExLk6R-WkVhHeX5wjn7EMFNS4mpRms9aLvnLkPsNYn-bTRQ$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!8VBnWGP-mo1pIBv43xoyGBCyKb5nuCJh378aNcbzbPHU= ExLk6R-WkVhHeX5wjn7EMFNS4mpRms9aLvnLkPsNiDnEGfI$=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) .