101 FXUS65 KABQ 211755 AAB AFDABQ Area Forecast Discussion...UPDATED National Weather Service Albuquerque NM 1155 AM MDT Sat Aug 21 2021 .AVIATION... 18Z TAF CYCLE Fields of cumulus are expanding and beginning to gain vertical development over the higher terrain areas of northern and central New Mexico early this afternoon, a sign of thunderstorm development that will continue this afternoon. By late afternoon another area of instability and increased moisture in the east central plains is expected to yield scattered thunderstorms as well. Storms will drift to the north northeast at 10 to 20 kt and will be capable of brief downpours, gusty downburst winds and small hail through the evening. Storms will then diminish and should come to an end before midnight in most areas. Another, potentially more robust, round of storms is expected over the southwestern mountains and central mountain chain of New Mexico on Sunday as moisture continues to seep into the area. 52 && .PREV DISCUSSION...246 AM MDT Sat Aug 21 2021... .SYNOPSIS... A relatively quiet Saturday is in store for most with near normal temperatures. The exception today will be across south central and eastern New Mexico where isolated thunderstorms are expected to develop this afternoon. Storm coverage increases briefly Sunday and into Monday as moisture increases across western and central New Mexico, but another reduction in precipitation chances arrives Tuesday and Wednesday as temperatures warm. Precipitation chances potentially increase again though towards the latter half of the week and into next weekend. && .DISCUSSION... SHORT TERM...(TODAY THROUGH SUNDAY)... Showers and thunderstorms will return to the forecast today especially for areas east of I-25 and south of I-40 as well as the Sangre de Cristo mountains. Low level moisture has diminished somewhat in the last 24 hours over northern and western NM, so some of the cells may be drier with gusty erratic winds but little to no rain. Showers and storms become more widespread on Sunday but will be focused from southwest to northeast over the region. Temperatures will be within a few degrees of normal, but will be slightly cooler over the southwest and south central on Sunday, where the greater rain chances and cloud cover are expected. LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)... The H5 high remains over eastern OK/western AR Sunday night, but will begin its journey westward as we head into Monday. A modest moisture tap still looks to develop although models are backing off on PWATs slightly. Enough moisture and instability will still be in place for afternoon convection along and west of the RGV, but better storm coverage will likely be across the southwest where the deeper moisture will reside. By Tuesday and Wednesday, however, the high builds farther westward which cuts off the moisture tap. PWATs fall areawide with values around to less than 0.5" across north central and northwest NM and around 0.75" elsewhere. Again, the exception may be across the southwest where PWATs are forecast to hang on to values near an inch. So while another significant reduction in storm coverage is expected, isolated afternoon storms may still be possible in the Gila area. Models are still not in agreement beyond Wednesday, but there still remains hope that moisture values and storm chances will increase. During the latter half of the week, a trough will move inland into the PacNW and cross the northern Rockies. As it does so, the high builds back over the Great Basin area, and the trough sends a backdoor cold front southward through the Great Plains. The GFS and Canadian have been pretty consistent in depicting a deeper trough that sends this backdoor front into NM, bringing an increase in moisture and storm chances. Meanwhile, the ECMWF has been pretty stubborn in keeping conditions dry across the area. The hopeful news is that the ECMWF seems to be trending towards the GFS's wetter solution although it is about 24 hours slower in getting there. So while the first half of the week isn't necessarily the news rain- loving New Mexicans were hoping for, there is perhaps something to look forward to for the second half of the week. 15 && .FIRE WEATHER... The upper high over Texas will be building westward today and moreso Sunday with a plume of moisture spreading into southern and eastern NM today and from southwest to northeast over the state on Sunday. This will bring an uptick in showers and storms today for areas south of I-40 and east of I-25 and on Sunday especially between the Continental Divide to the Pecos Valley. Cell motion today and tonight will be from southwest to northeast and will trend a bit more from south to north on Sunday, especially south of I-40. Some of the activity may be drier with gusty and erratic outflow winds this afternoon and evening especially from the Rio Grande Valley westward where dew points have trended drier in the last 24 hours. As the upper ridge axis continues to nose westward early to mid next week, will have to watch what happens with Hurricane Grace which is moving west over Old Mexico. The flow of moisture into New Mexico may be disrupted by the westward extending ridge axis but there is potential that some moisture from Grace could be drawn northward as that system weakens. For now though, there will be enough moisture for isolated to scattered generic showers and storms over the western and northern high terrain. Ventilation rates will be mostly good to excellent for a majority of locales today and Sunday, then rates diminish early next week. && .ABQ WATCHES/WARNINGS/ADVISORIES... None. && $$