Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Nov 26 2023 08:01:17 FOUS30 KWBC 260801 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 300 AM EST Sun Nov 26 2023 Day 1 Valid 12Z Sun Nov 26 2023 - 12Z Mon Nov 27 2023 The probability of rainfall exceeding flash flood guidance is less than 5 percent. As a shortwave trough swings through the base of a longwave trough becoming established along the East Coast today, it will become negatively tilted with a 150 kt jet streak at the trough base near 250 mb moving across the Mid-Atlantic states. A surface low is expected to deepen as it tracks through southeastern New England Sunday night at the same time that the left exit region of the Mid-Atlanitc upper jet max sets up over coastal New England, supporting increased divergence aloft. While strong low level convergence following the surface low track will likely allow for a stripe of heavy rain from southeastern New England to the southern coast of Maine Sunday night, instability is expected to be negligible for inland locations which should limit peak rainfall rates to near 1 in/hr. While the more aggressive members of the 00Z HREF and the 06Z HRRR begin to approach the 2 inches in 3 hour FFG for southeastern New England, the heaviest rain should be only of a 2-3 hour duration for any given location with localized totals of 2+ inches possible for the event, limiting the threat for flash flooding. Given the recent lack of rain for this portion of the Northeast and coordinating with the affected WFOs, no risk area was introduced for southeastern New England. Otto 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!89OLqG8oyDJgnJw85rszexiOL-d_4QZygb6IHWPnCJ1T= g7O3s6jB-lSXQf-5iWCeHWP7uVeoYkslf_jww-HMntwyqpc$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!89OLqG8oyDJgnJw85rszexiOL-d_4QZygb6IHWPnCJ1T= g7O3s6jB-lSXQf-5iWCeHWP7uVeoYkslf_jww-HM6wV3QzM$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!89OLqG8oyDJgnJw85rszexiOL-d_4QZygb6IHWPnCJ1T= g7O3s6jB-lSXQf-5iWCeHWP7uVeoYkslf_jww-HMPYEyk7M$=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) .