Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Oct 19 2024 23:29:30 AWUS01 KWNH 192329 FFGMPD NMZ000-200515- Mesoscale Precipitation Discussion 1106 NWS Weather Prediction Center College Park MD 728 PM EDT Sat Oct 19 2024 Areas affected...eastern NM Concerning...Heavy rainfall...Flash flooding likely Valid 192327Z - 200515Z SUMMARY...A south to north axis of heavy rain is likely to generate widely scattered to scattered flash flooding across eastern NM into the early overnight hours. Training/repeating cells are expected to produce 1 to 1.5+ in/hr rainfall rates leading to additional 2-4 inch totals through 05Z. DISCUSSION...Regional radar and GOES East visible imagery at 23Z showed a broken axis of thunderstorms extending from southwestern Chaves County, north-northeastward into southeastern Colfax County, containing several areas of overshooting tops. These storms were located within an instability axis containing 500 to 1500+ J/kg MLCAPE and anomalous precipitable water values of 0.7 to 1.1 inches via 23Z SPC mesoanalysis data. Accounting for sufficient wind shear aloft, some cells were organized containing mesocyclones and large hail, with trends in MRMS-derived rainfall increasing over the past 1-2 hours, currently showing a few areas with hourly rainfall in excess of 1 inch. Water vapor imagery showed a potent closed upper level low over AZ which has begun to slowly fill and was slowly retrograding toward the west, but individual vorticity maxima have been revolving about the low center with areas of upper level divergence and diffluence east of the low center over much of NM. VAD wind data at KFDX and KMAF showed 850 mb winds have been increasing as well over the past couple of hours, currently near 30 kt from the southeast. An axis of low level convergence near a quasi-stationary front located at the leading edge of an increasing low level jet is expected to maintain a roughly south to north axis of thunderstorms across eastern NM through at least 05Z. RAP forecasts indicate the magnitude of the 850 mb winds increasing over southeastern NM into the 40-50 kt range, with the leading edge possibly serving as a focal point for the highest rainfall rates. While instability is forecast to wane into the overnight with the loss of surface heating, likely contributing to lowering rainfall rates later in the night, RAP forecasts indicate at least 500-1000 J/kg MLCAPE will remain over the east-central to southeastern portion of the state through 06Z. Mean steering flow, roughly parallel to the axis of low level convergence is expected to support repeating rounds and short term training of thunderstorms, allowing for 1 to 1.5+ in/hr rainfall rates in addition to 2-4 inches of rain along a south to north axis over eastern NM. It is thought that the heaviest rain will remain east of the sensitive burn scars located over the southern Sangre de Cristo and Sacramento Mountains through 05Z, however, additional, more isolated cells to the west of the main axis of thunderstorms may support an isolated flash flood threat within weaker pockets of instability, forced by strong dynamic lift east of the AZ closed low. Areas of flash flooding are considered likely over eastern NM, though may remain widely scattered in nature. Storms may propagate more to the east of current HRRR guidance but the flash flood threat will decrease with eastern extent due to higher FFG values toward the TX border. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9qvvrTzyEGHdVp6hoAIxULY2qbMqxx00Djeh1r7RZ3DBWHKMFBy495k6-sQGTkvpkUjc= 56O9wrhA-QGVwRBVO-QlXhI$ for graphic product... ATTN...WFO...ABQ...EPZ...MAF... ATTN...RFC...ABRFC...WGRFC...NWC... LAT...LON 36720430 36450338 35750305 33090349 32160431=20 32120546 32470583 33510612 34530606 35660576=20 36440507=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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .