125 FXUS65 KABQ 230543 AAB AFDABQ Area Forecast Discussion...UPDATED National Weather Service Albuquerque NM 1143 PM MDT Thu Oct 22 2020 .AVIATION... 06Z TAF CYCLE Cold front extending along a line from KRTN-KLVLS-KSXU-K4MR-KPVW at 05Z to continue racing s and wwd, reaching the east slopes of the central mt chain and KROW by 09Z. A brief period of n-nely wind gusts to 35 or 40kts possible in vicinity of the frontal passage, then areas of MVFR cigs to fill in behind the front, and especially along the east slopes of the central mt chain, obscuring terrain. MVFR cigs to dissipate by 17Z, as stronger wly flow aloft initiates sfc low pressure developing over srn CO. VFR west of the central mt chain, although sct low clouds may bleed into the KSAF area between 12-15Z. && .PREV DISCUSSION...323 PM MDT Thu Oct 22 2020... .SYNOPSIS... Sharply colder air will overspread much of eastern New Mexico tonight but unfortunately moisture will be limited with mainly low clouds expected in areas east of the central mountain chain. Highs Friday tumble to 15 to as much as 25 degrees below normal across the east while dry and warm conditions persist in the west. Easterly gap winds will signal the arrival of the cooler air into the Rio Grande Valley but the impact will be rather minimal. Beyond Friday, attention turns to a cold and deepening upper level storm system that will bring increasing windiness on Saturday followed by significantly colder air and widespread precipitation for much of the area later Sunday through Tuesday. Mountain snow and mixed rain and snow, heavy at times, will be common in western and northern New Mexico while a mixture of sleet, freezing rain and snow is expected in the east. This will be the first significant storm event since early September and could bring over a foot snow to the northern and western high country. Anyone planning outdoor activities or travel Sunday through Tuesday should closely monitor the latest weather forecasts and be prepared to make alternative plans. && .DISCUSSION... SHORT TERM...(TONIGHT THROUGH SATURDAY)... A backdoor cold front is poised to enter far northeast NM shortly with the front rushing south and west through the night. Strong winds will be possible behind the front, close to wind advisory speeds near the TX border. Blowing dust will be likely for a few hours behind the front. Will hold off on any highlights. Low clouds will form along the east slopes of the central mountain chain. If the front spills into the RGV the east and southeast winds should be weak. Friday will be much colder in the east and a little cooler in the central areas. Mostly clear and cool to chilly Friday night. Saturday will be much warmer in the east with highs returning to above normal. But that will be the last day the east gets above normal well into next week, if then. See below for details. CHJ LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)... ...MAJOR WINTER-LIKE STORM SYSTEM EXPECTED TO IMPACT MUCH OF THE AREA SUNDAY NIGH THROUGH TUESDAY... This forecast period promises to deliver a memorable collection of extremes as we quickly transition from dry, breezy/windy and warm wx on Saturday to full-on winter storm beast mode Sunday night through at least Tuesday. In a nutshell... daytime temperatures in the 20s and 30s forecast in the northern high country and across much of the east on Monday with 40s and 50s elsewhere. Potential for a FOOT or more of snow across the northern mountains, mix of rain/snow in the western valleys, periods of freezing rain/sleet on the eastern plains before becoming snow for all but the lowest elevations across southern parts of the area Monday night- Tuesday morning. Major league changes. Leading edge of a modified cP air mass expected to reach far northeast New Mexico before daybreak Sunday quickly advancing south and west as the day progresses. The very shallow nature of this colder air mass will naturally result in a more rapid southward progression on the eastern plains than toward the west, but in time gradual air mass deepening will send the colder air spilling westward into the central valley corridor Sunday evening with widespread, solid upslope conditions expected in the east. Backdoor front should trend a bit faster with each forecast cycle and this would fit with local studies/previous experience when dealing with shallow, modified arctic intrusions. Unfortunately, not a lot of precip potential initially outside the northern high terrain near the NM/CO line and in the deeper upslope zone along the east slopes of the Sangres. Temperature forecast across the northeast will be challenging to say the least, but have trended toward the colder side of guidance and that is probably not cold enough. NBM showing 39F on the low end at Clayton for Sunday. This cold air mass will gradually deepen beneath a strengthening and increasingly moist southwest flow aloft that develops Sunday ahead of a potent shortwave diving south from the Inland NW. Latest deterministic runs of the ECMWF and Canadian models are in very good agreement developing a deep, closed upper low over southern CA by 00Z Tuesday - a trend supported by their respective ensemble mean solutions. Similarly, the 12Z GFS develops a closed 552dam low over northern AZ but its placement is actually farther north/east of the 12Z GEFS - a trend that is not supported for now. Weak low offshore of southern CA will eject eastward ahead of the deepening low Sunday night and may become an important player in our forecast-- particularly in drawing mid-level moisture northeastward as it opens up. The EC and Canadian are more defined with this wave versus the GFS, which may partially explain differences in 500mb placement to the west by 00Z Tue. The relative warm air stream above the surface cold air will result in a mixture of wintry precipitation types and this was by far the biggest challenge. The most critical period for any freezing precipitation will be Sunday PM through Monday before the cold pool aloft shifts far enough east and surface temperatures moderate going into Tuesday. Meanwhile, impressive surface to 700-mb frontogenesis will result in strong forcing for lift with widespread rain/snow developing over western NM Sunday night and Monday not to mention excellent orographic forcing. 700-mb temperatures don't look as impressively cold as a few days ago but still plenty cold for snow and plenty cold for late October. The northern and western high terrain could hit the October snow lottery if trend continue. The upper low lumbers eastward Tuesday and may linger through Tuesday night-Wednesday per the EC trend. Much to be determined on the exit strategy for mid-week. KJ && .FIRE WEATHER... ...RED FLAG WARNING REMAINS IN EFFECT FOR THE NORTH CENTRAL MOUNTAINS AND ALONG AND EAST OF THE CENTRAL MOUNTAIN CHAIN TODAY... Near record high temperatures expected again today from the Middle RGV and across the East Central Plains. Stronger southwest to west winds will lead to more widespread critical fire weather conditions over the North Central Mountains as well as from the central mountain chain over the Northeast and East Central Plains. The strongest wind gusts could reach around 40 mph along the I-40 corridor from Clines Corners to the Texas border. A strong cold front will plunge through the eastern plains tonight and Friday morning with gusty north to northeast winds. The front may leak through canyons into the RGV Friday morning, but isn't expected to get any farther to the west. High temperatures on Friday will be 5-20 degrees cooler than normal over the east, while west of the RGV highs will remain 5-10 degrees warmer than average. Increasing westerly winds aloft combined with a rapid recovery in temperatures may produce locally critical fire weather conditions over portions of eastern and central New Mexico Saturday. Considered adding a Fire Weather Watch due to the forecast mountain top wind speeds, but at this time, the minimum humidity forecast ranges from 15-25 percent for a large portion of the forecast area. Much colder than normal air will begin to pour into the state Sunday and will continue Monday and Tuesday, while an upper level storm system slowly moves over the region. Monday and Tuesday could see daytime highs 15 to 35 degrees colder than normal as well as widespread hard freezes. While the details remain uncertain to some extent, this storm system could bring wetting precipitation in the form of mountain snow and lower elevation rain and snow Sunday night through Wednesday. CHJ && .ABQ WATCHES/WARNINGS/ADVISORIES... None. && $$