Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Dec 06 2022 20:19:58 FOUS30 KWBC 062019 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 319 PM EST Tue Dec 06 2022 Day 1 Valid 16Z Tue Dec 06 2022 - 12Z Wed Dec 07 2022 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Bann Day 2 Valid 12Z Wed Dec 07 2022 - 12Z Thu Dec 08 2022 ....THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FROM PORTIONS OF EASTERN OKLAHOMA INTO NORTHERN ARKANSAS AND SOUTHERN MISSOURI... ....North Texas and Eastern Oklahoma eastward into the western Tennessee Valley... Models still suggest the potential for locally heavy to excessive rainfall from eastern Oklahoma into northern Arkansas and southern Missouri on Wednesday as a southern stream trough pivots across the Southwest U.S. on Wednesday and across the High Plains Wednesday night. As this occurs, the downstream upper level ridging underneath the broad/deep low centered over north-central Canada will result in upper level confluence and an eventual jet streak across the Central Plains and Upper Midwest on Day 2. Increasing southern-stream forcing coupled with the frontogenetic, entrance-region upper jet forcing from the northern stream will make for a favorable environment for deep layer lift across the outlook areas. Both the GEFS and SREF showed a relatively quick bout of robust low-mid layer moisture transport, with 8500-700 mb moisture flux anomalies topping out between +3-3.5. PW values and a stripe of 1.5-1.7" PWs traversing the outlook areas Wednesday and Wednesday night. The progressive nature of the favorable forcing (forward-propagating Corfidi or MBE vectors), along with the relative lack of deep-layer instability (MUCAPEs generally less than 750 J/Kg) will be the primary inhibitors to the flash flood risk. In addition, per the latest NASA SPoRT analysis, 0-100cm soil moisture percentiles are running between 10-30% of normal across much of the outlook area. Nevertheless, per earlier collaboration with WFOs in the Plains and given the anomalous degree of deep-layer forcing and moisture, consistent with the 00Z and 12Z GEFS-based first-guess fields, maintained the targeted Slight Risk area and surrounding Marginal Risk areas with few changes. Hurley/Bann 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!58IZzKQ0OX1tITddbPYFG2g_6SbWnQ4SzH5DG2Lju8wU= dFJJmhp6CiyqzQbIBHl2xOpS3kCrorVOumtoIKtUP_PnA5Y$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!58IZzKQ0OX1tITddbPYFG2g_6SbWnQ4SzH5DG2Lju8wU= dFJJmhp6CiyqzQbIBHl2xOpS3kCrorVOumtoIKtUOfz2_h0$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!58IZzKQ0OX1tITddbPYFG2g_6SbWnQ4SzH5DG2Lju8wU= dFJJmhp6CiyqzQbIBHl2xOpS3kCrorVOumtoIKtUrE7lX-8$=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) .