Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Aug 09 2024 00:25:50 AWUS01 KWNH 090025 FFGMPD AZZ000-UTZ000-NVZ000-CAZ000-090600- Mesoscale Precipitation Discussion 0843 NWS Weather Prediction Center College Park MD 824 PM EDT Thu Aug 08 2024 Areas affected...Much of AZ...Southwest UT... Southeast NV...Adj Southeast CA... Concerning...Heavy rainfall...Flash flooding possible Valid 090030Z - 090600Z SUMMARY...Maturing clusters will continue to seek out remaining unstable air. Increasing cell mergers/outflow collisions will support enhanced short-term rain rates resulting in widely scattered 1-2" totals through early overnight continuing to pose possible localized flash flooding conditions. DISCUSSION...GOES-E Visible and Regional RADAR mosaic depict a few maturing clusters of thunderstorms across the Southwest this evening, including one sinking south out of UT into SE NV/NW AZ, along the Mogollon Rim, as well as across Southeast AZ. GOES-E WV suite depict a pair of shortwaves along the western edge of the decaying ridge over the Four Corners region, although active convection and modest mid-level moisture is supporting MCV upscale development along the axis from NW AZ to the SE AZ wave. Strengthening upper-level jet from Northern California through the Central Rockies has broadened favorable upper-level outflow channels with some anticyclonic arching noted in the debris clouds in E UT, NE AZ, etc; also supporting this strengthening mid-level voriticity axis. The favorable mid-level ascent pattern is resulting in the clusters cooling rapidly (especially across cetnral and southeast AZ) with tops below -65C increasing in coverage. CIRA LPW continues to show elevated moisture in the 700-500mb layer across much of AZ into far S UT, with a ribbon extending eastward across N NM/S CO into the Plains, but animation shows the core of the moisture advection is across the Mongollon Rim where 7H Tds are over 8C per RAP, and given 60s Tds in the upslope out of the low deserts of SW AZ, anomalous values of Total PWat continue to be in the 1.25 to 1.5" range in the inflow region to the aforementioned clusters. This axis of enhanced moisture also aligns with the SE to NW axis of enhanced CAPE that ranges from 2500 J/kg in the SE to 500-1000 J/kg toward the NV/AZ/UT border. Forward propagation of the maturing clusters is providing the ample flux to support increasing 1-1.5"/hr rates and given the 600-400mb steering flow is near zero, updrafts will be fairly vertical to all for localized totals of 1-2" in 1-1.5hrs, potentially inducing scattered incidents of flash flooding into the early overnight period. New development will occur along colliding outflow boundaries and broader updrafts may become a bit more common given slab ascent. All considered scattered incidents of flash flooding will be possible through the early overnight period, with greater potential across S AZ. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9HJ4nzy3nIySTGWZhIWccgaw2qXVPqezHRuyhRmMzm-3CYdddR8kDN6sH3yf8VjAhdXM= SP27kBdyTL8MmDpT69kUPPk$ for graphic product... ATTN...WFO...FGZ...PSR...SLC...TWC...VEF... ATTN...RFC...CBRFC...CNRFC...NWC... LAT...LON 38301464 38191374 37951343 37621269 36991179=20 36581148 35191143 34411120 33600979 33290931=20 32770911 32250913 31560910 31240942 31191057=20 31421180 32011330 33091293 33511391 34401479=20 35031536 35601552 35821480 36541439 37461485=20 37681481 38091486=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) .