Flash Flood Guidance
Issued by NWS
Issued by NWS
019 AWUS01 KWNH 212257 FFGMPD COZ000-NMZ000-220400- Mesoscale Precipitation Discussion 1038 NWS Weather Prediction Center College Park MD 656 PM EDT Sat Sep 21 2024 Areas affected...southern CO into northern NM Concerning...Heavy rainfall...Flash flooding possible Valid 212253Z - 220400Z Summary...Localized flash flooding will be possible across portions of northern NM into southern CO through 04Z due to the potential for multiple rounds of thunderstorms with brief training. Rainfall rates of 0.5 to 1 inch in 30-60 minutes will be possible along with localized totals of 1-2 inches. Discussion...GOES East water vapor imagery showed a closed low over northeastern AZ at 2230Z, tracking toward the ENE. Several rounds of showers and thunderstorms have developed out ahead of the closed low within a diffluent and divergent flow pattern aloft. SPC mesoanalysis data from 22Z showed MLCAPE ranged between 500-1000 J/kg across northern NM but was less than 500 J/kg over southern CO. At the surface, an easterly/upslope component to the flow was present to the north of a cold front and outflow boundary where anomalous precipitable water values remained but were beginning to be pushed east ahead of the closed low. While instability values are likely near their max given the time of day, multiple rounds of thunderstorms will remain possible from northeastern NM into southern CO as the closed low continues east, each round carrying the potential for short term training with possible rainfall rates as high as 0.5 to 1 inch in 30-60 minutes. The multiple rounds could contribute to an additional 1-2 inches of rain by 04Z, though these higher totals are likely to remain highly localized. These storms will pose a localized flash flood threat to the region, mainly in/near the Sangre De Cristo Mountains and westward into adjacent terrain of north-central NM and mainly across sensitive burn scar locations. Otto ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...ABQ...GJT...PUB... ATTN...RFC...ABRFC...WGRFC...NWC... LAT...LON 38590488 38460454 37300452 36820409 36310360 35520376 35140487 35120532 35290573 35540591 35790606 35900638 36050671 36320683 36600683 36950663 37170628 37410576 37650552 37840541 38120542 38500520