Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jan 10 2024 08:10:46 FOUS30 KWBC 100810 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 309 AM EST Wed Jan 10 2024 Day 1 Valid 12Z Wed Jan 10 2024 - 12Z Thu Jan 11 2024 ....THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF COASTAL AND DOWNEAST MAINE... Steady progression of heavy precip will move northeast through ME this morning, exiting by the afternoon time frame with only some remnant light precip prevailing after 18z. Heaviest rainfall potential will exist in-of coastal ME up through Downeast locations before exiting. A very consistent 0.75-1.5" is forecast from south to north within the 12-18z time frame before conditions improve, much of it falling in a 2-4 hr time. The current setup is a compounding issue of heavy rain just before 12z and just after within the beginning of this D1 forecast. Heavy rains and snowmelt will contribute to local flooding concerns until the system moves out of the area. The previous forecast SLGT/MRGL risks over ME were mostly kept with only some minor adjustments within Downeast ME. This will conclude a very active flood pattern over the past 60 hrs with copious amounts of heavy rainfall and flooding reports extending from the central Gulf Coast up to New England. Kleebauer Day 2 Valid 12Z Thu Jan 11 2024 - 12Z Fri Jan 12 2024 ....THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE MID-MISSISSIPPI VALLEY THROUGH ARKANSAS TO THE ARKLATEX... Much of the D3 period will be fairly quiet on the rainfall front as the synoptic pattern resets ahead of the next disturbance to impact much of the CONUS. The process begins Thursday evening as a digging upper trough exits the southwestern US and ejects into the southern plains. By the time it reaches the longitude of west TX, shortwave trough will begin tilting more neutral with a negative orientation transpiring by the end of the period. The area downstream of the mean trough will enter an area of difluence with flow increasing out of the south, advecting rich Gulf air back through the Lower Mississippi Valley and Arklatex. Surface low will spawn in-of central OK and begin intensifying as the upper pattern allows with instability fields gaining momentum on the eastern flank of the low. Showers and isolated storms will begin firing in east TX, LA, and AR by 00z Friday, continuing to expand in coverage and magnitude by the end of the period. Deterministic guidance remains steadfast with the coverage and totals within the time frame of 00-12z Friday with all guidance keen on 1 to locally as high as 2" within a short time after cell initiation with some indications of locally higher over northern AR where cell mergers take place. This is only the beginning process of a large scale rainfall footprint that will occur after this period, but the prospects of convective development in a maturing instability field with PWAT anomalies blossoming to 1-2 deviations above normal allows for some low-end potential for flash flood concerns, especially within any urban corridors or terrain (Ozarks). The MRGL risk was maintained across much of Arkansas up into the Mid-Mississippi areas of southeast MO and far western KY, as well as bisecting the Arklatex. Kleebauer 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!6LjpBnu-6scch8HCKmg665zSDkO3LMEofZGeNqZo9B8L= 6i3Z6cc63Issw4EmnG_YsNs2QOTQjQa0WK7rtaLCSn0sSBo$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!6LjpBnu-6scch8HCKmg665zSDkO3LMEofZGeNqZo9B8L= 6i3Z6cc63Issw4EmnG_YsNs2QOTQjQa0WK7rtaLCqrOsNxk$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!6LjpBnu-6scch8HCKmg665zSDkO3LMEofZGeNqZo9B8L= 6i3Z6cc63Issw4EmnG_YsNs2QOTQjQa0WK7rtaLCmqeXcQs$=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) .