Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Oct 16 2024 08:03:13 FOUS30 KWBC 160802 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 402 AM EDT Wed Oct 16 2024 Day 1 Valid 12Z Wed Oct 16 2024 - 12Z Thu Oct 17 2024 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Kleebauer Day 2 Valid 12Z Thu Oct 17 2024 - 12Z Fri Oct 18 2024 ....2030Z Update... The probability of rainfall exceeding flash flood guidance is less than 5 percent. Kleebauer Day 3 Valid 12Z Fri Oct 18 2024 - 12Z Sat Oct 19 2024 ....THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF NORTHERN NEW MEXICO INTO SOUTHERN COLORADO... Longwave pattern will evolve into a fairly prolific upper trough/closed-low over the Great Basin, slowly migrating eastward with sights on the Four Corners. Large scale ascent will become maximized downstream of the mean trough with a pronounced diffluent pattern in-of the Southern Rockies, including the Sangre de Cristo and San Juan mountain ranges where heavier precip is forecast. A cold front will slowly propagate eastward from the primary disturbance with a return flow setup pressing westward across the Eastern NM plains on the western flank of a sprawling surface high east of the Mississippi. A secondary cold front to the north will plunge southward thanks to a strong ridge of high pressure developing upstream in wake of the primary western low, along with a lee side trough developing over the Front Range. The tandem of boundaries and backed flow will converge over Northern NM with a strong isentropic ascent pattern initiating later Friday evening through Saturday AM and beyond.=20 Convective signals are most pronounced in the initial stages of=20 the pattern evolution mainly due to the return flow setup where=20 more unstable air will advect northwestward into the Eastern NM=20 plains before banking against the lee of the Southern Rockies. Both ensemble and deterministic output for heavy precip are locked in=20 across the area encompassing much of Northern NM, but especially=20 within the confines of places like Raton and points south where=20 topographic enhancement within the convergent axis will generate=20 local precip maxima when the convergence pattern truly solidifies=20 late in the period. Totals of 1-2" of precip are forecast on the=20 southern edge of the San Juans down into portions of the Sangre de=20 Cristos, closing in on some of the prevalent burn scars in the=20 region. A secondary maxima of 1-2" is forecast over that main axis=20 of convergence over Northeastern NM in vicinity of the eastern=20 flank of the Sangre de Cristos, including places like Taos and=20 Angel Fire over into parts of the plains in the lee of the mountain chain. The period before will be more of a primer for the main=20 event this period through the following D4 time frame. The=20 combination of better moisture return and large scale forcing via=20 diffluent mid- level flow and jet coupling provides ample support=20 for a continuation of the previous MRGL risk, as well as an=20 expansion of the risk area further southwest and east to match the=20 ensemble QPF footprint in areas of highest convective potential. Kleebauer Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!5g42U6saYt6fF8s1w3ERsc5Gn_QQxYT_HUCbH9ZqEqmM= P-4qJk74tk1McPAVjSfhMM7lmZFpKFd0X4XQfSw3fSEnHDw$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!5g42U6saYt6fF8s1w3ERsc5Gn_QQxYT_HUCbH9ZqEqmM= P-4qJk74tk1McPAVjSfhMM7lmZFpKFd0X4XQfSw35qA5kYA$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!5g42U6saYt6fF8s1w3ERsc5Gn_QQxYT_HUCbH9ZqEqmM= P-4qJk74tk1McPAVjSfhMM7lmZFpKFd0X4XQfSw3jhIB9sE$=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) .