Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Aug 26 2025 18:39:22 AWUS01 KWNH 261839 FFGMPD WYZ000-UTZ000-IDZ000-NVZ000-270030- Mesoscale Precipitation Discussion 1008 NWS Weather Prediction Center College Park MD 238 PM EDT Tue Aug 26 2025 Areas affected...Southern ID...Northeast NV...Northern UT...Western WY...- Concerning...Heavy rainfall...Flash flooding possible Valid 261840Z - 270030Z SUMMARY...Highly anomalous moisture and strong dynamic forcing should allow for scattered to numerous thunderstorms capable of 1" rates & 1-2" localized totals. Favorable environment for redevelopment may allow for some repeating cells/tracks which will further enhance scattered incidents of flash flooding through evening. DISCUSSION...GOES WV mosaic suite depicts a very broad upper-level trough with some subtle WNW to SE negative tilting lifting northward across central NV with the core near central Nye county with broad downstream highly diffluent environment expanding across N NV, S ID into W WY/N UT providing areas of enhanced mid to upper-level cloudiness. This is greater near the core of the DPVA; allowing for better filtrated insolation further downstream across the ID/NV border, increasing heating. The bigger concern is seasonally near record moisture and flux streaming through the Great Basin, providing higher low level theta-E air with Tds in the mid to upper 50s in higher plateaus of NV and UT and even some low 60s near the southern portions of the Snake River Plain.=20 While the filtered sunlight has some limitations for surface temperatures, the areas that have best clearing are already seeing convective development given limiting capping environments and strong DPVA and divergence aloft with large scale broad ascent pattern. MUCAPEs of 750-1250 J/kg have been increasing as the deep layer moisture reaches 1-1.25" total moisture (with a few 12z RAOBs breaking, or nearing daily record values). Surface to boundary layer moisture convergence is further enhanced near the clear skies of NE NV into SE ID and so convection is stronger there and downstream into S-central ID. Cores are likely to be narrow but increase in overall coverage allowing for some localized 1-1.5" totals in 30-90 minutes, as deep layer flow is generally weak support 5-10 kt cell motions and increased duration of moderate to heavy rainfall locally. As such scattered incidents of flash flooding are possible, particularly near burn scars. Through this evening, upper-level divergence further increases across NE NV into S ID, but along the eastern side of the circulation has increased convergence through depth with a smaller scale shortwave/vorticity center lifting northward along the central UT mountains. This shortwaves and interaction with outflow boundaries from initial cells will allow for secondary and perhaps tertiary development that may repeat. As such, the risk for heavy rainfall is likely to persist through much of the evening. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6NQydPb5XCTg83a4hfFgTuifh8rS1gvX42k7NT31o62I-SzZa5Me5zB78hdcQ5ZU-_B0= F1k--t3Mbad3rxec-6Kwcpo$ for graphic product... ATTN...WFO...BOI...LKN...PIH...RIW...SLC... ATTN...RFC...PTR...RSA...STR...NWC... LAT...LON 43931096 43581037 42781010 42071002 41241009=20 40351032 38891133 38931209 39531217 40041231=20 40811274 40961393 39961518 39871592 40361643=20 42041699 43041689 43151684 43581620 43721511=20 43591390 43541281 43701192=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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .