Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Aug 13 2024 17:15:53 AWUS01 KWNH 131715 FFGMPD TXZ000-NMZ000-AZZ000-132300- Mesoscale Precipitation Discussion 0876 NWS Weather Prediction Center College Park MD 115 PM EDT Tue Aug 13 2024 Areas affected...Northern & Eastern Arizona...Western & Central New Mexico... Concerning...Heavy rainfall...Flash flooding possible Valid 131715Z - 132300Z SUMMARY...Slow moving mountain/monsoon thunderstorms will be capable of 1-2" totals and widely scattered but localized incidents of flash flooding. Greatest risk of flash flooding will be in proximity to recent burn scars. DISCUSSION...GOES-E WV suite depicts a compact shortwave just east of the central AZ/NM border with anti-cyclonic arched outflow band denoted by transverse banded cirrus across the Four Corners into central CO. This wave resides along the western edge of the synoptic ridge over Texas and with an approaching strong mid-level jet crossing central CA; sub-tropical moisture off the Sea of Cortez and the northeastern Pacific is also being combined and funneled northward through the 700-500mb depth, with a slug of enhanced LPW values at the four-corners of AZ/NM, Sonora and Chihuahua; as well as in an increasingly confluent region over NW NM downstream of the shortwave. Surface to 800mb moisture out of the lower deserts has been decreasing in magnitude but there remains ample values into the .5-.65" range banked up through the Mogollon Rim into the southeast AZ ranges. This moisture is spilling onto the San Francisco Plateau with mid to upper 50s Tds as far north as SE UT/SW CO. As such, deep layer values of 1-1.25" cover much of AZ into the lower valleys of NW NM and the Rio Grande Valley.=20 Full sun has been increasing instability along the edges of the enhanced clouds across NW NM, but even filtered sun onto this increased moisture in the low levels is supporting increasing SBCAPE into the 1000-1500 J/kg through much of the area (minus those cloudy areas...about 500 J/kg, but increasing). Upslope flow out of the low deserts is responding to exiting northern stream shortwave/height-falls further north and increasing low level convergence (particularly along the Rim and into the shorter mountain ranges of NE AZ, so deepening convection is likely to expand in coverage over the next few hours. Given updraft strength and moisture flux into the lower profiles, rates of 1-1.25"/hr are going to be increasingly probable particularly after 20-22z. Slow and confluent steering channels from the southwest will be 10-15kts and decreasing to southerly at 5-10kt across NM, allowing for increased residency for widely scattered spots of 1.5-2" totals. This may induce localized (given likely narrowness to the up/downdrafts) flash flooding conditions.=20 Southwesterly steering, while generally confluent convergence around the Sacramento mountains with likely backing easterly inflow from the southern High Plains in response to development will put increased potential for stronger storms and possible backbuilding/redevelopment on the ridge upstream the recent Salt, Blue2 and South Fork burn scars. This may result in slightly higher risk than normal for flash flooding across these sensitive areas.=20=20=20 Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7kaEJ9PR7TIjZUuo7UuwLl1IzqGtMQ6ReOh-IF_3E0aqepn-lGjBxqdGABJzbg9Gtg2S= gYrANzD90hocxVk80PbmEN0$ for graphic product... ATTN...WFO...ABQ...EPZ...FGZ...PSR...TWC...VEF... ATTN...RFC...ABRFC...CBRFC...WGRFC...NWC... LAT...LON 36940732 36920438 36080398 34700522 32600539=20 31590632 31800717 31620805 31160829 31211033=20 31421150 31971181 32441160 33301110 34441192=20 35721319 36871354 36911241 36910935=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) .