AWUS01 KWNH 012107 FFGMPD COZ000-NMZ000-AZZ000-UTZ000-020300- Mesoscale Precipitation Discussion 1545 NWS Weather Prediction Center College Park MD 406 PM EST Sun Nov 01 2026 Areas affected...Four Corners region into southeastern AZ and southwestern NM Concerning...Heavy rainfall...Flash flooding likely Valid 012105Z - 020300Z SUMMARY...Flash flooding is likely to continue over the Southwest from the Four Corners region into southeastern AZ and southwestern NM over the next 6 hours. Peak hourly rainfall of 0.5 to 1.0+ inches and additional totals of 1 to 3 inches are expected. Another round of storms will be possible for central AZ later this afternoon. DISCUSSION...Water vapor imagery through 2030Z showed the eastward push of deeper moisture advancing toward the east across UT/AZ into western CO/NM, out ahead of an upper trough axis over central UT/AZ. This was also seen in layered PW imagery with drier air moving eastward into western UT/AZ. IVT values within the main moisture axis ranged from 700 kg/m/s over southern CO to over 1000 kg/m/s in southern AZ, with the axis oriented from southwest to northeast. Numerous flash flood warnings and reports have occurred across central AZ into southeastern AZ near the Tucson metro over the past 6 hours. As the upper shortwave trough axis over UT/AZ continues to advance east and northeast over the next 6 hours, the ongoing axis of heavy rain over eastern AZ/western NM into the Four Corners region will translate east, forecast to orient from the southern AZ/NM border into northeastern NM by 02Z. Despite a lack of higher instability, hourly rainfall of 0.5 to 1.0+ inches will remain possible within this axis as strong forcing aloft combines with orographic enhancement, especially into the San Juan Mountains. An additional 1 to 3 inches will be possible into the evening hours. Back to the west, in the wake of clearing skies over the southwestern to central portion of AZ, surface heating has been allowing for growing instability with the 20Z SPC mesoanalysis showing 500-1000 J/kg extending from Yuma into western Maricopa County. While the magnitude of instability is likely near its peak, some northeastward expansion of instability into central AZ appears likely through 00Z. A few showers/thunderstorms are expected to form within this instability axis where moisture should remain sufficient to support hourly rainfall in the 0.5 to 1.0 inch range within areas of short term training. These additional rains could result in exacerbating flooding conditions ongoing across the region with an additional 1 to 2 inches prior to the loss of daytime heating. Otto ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...ABQ...EPZ...FGZ...GJT...PSR...PUB...SLC...TWC... ATTN...RFC...FWR...STR...TUA...NWC... LAT...LON 39100740 38500581 36970492 35450481 33520556 31890753 31220862 31100981 31071099 31191163 31671302 31811336 32031351 32411339 35241254 37401084 38680935