407 FXUS65 KABQ 231132 AAA AFDABQ Area Forecast Discussion...UPDATED National Weather Service Albuquerque NM 532 AM MDT Fri Oct 23 2020 .AVIATION... 12Z TAF CYCLE Cold front has reached the east slopes of the central mt chain, with terrain obscured in areas MVFR to IFR cigs/vsybs in br/fg/fzfg from Raton Pass towards KCAO and swd through KLVS and KCQC. Improving conditions aft 16Z as stronger wly flow aloft initiates sfc low pressure development over srn CO. VFR west of the central mt chain, although sct low clouds may bleed into the KSAF area between 12-16Z on sely sfc winds. && .PREV DISCUSSION...308 AM MDT Fri Oct 23 2020... .SYNOPSIS... A backdoor cold front will bring notably colder temperatures to the eastern plains of New Mexico today. In fact, readings will likely be 15 to 25 degrees below average. Warmer readings, gusty winds and low relative humidity will support high fire danger Saturday afternoon, especially over northeast New Mexico. A major change in the weather pattern will develop for Sunday through the middle of next week. An arctic air mass will invade the Land of Enchantment Saturday night into Sunday. An approaching storm system will bring higher moisture and good chances for precipitation. With cold air in place, a wintry mix of snow, freezing rain and sleet is forecast across the region and significant travel impacts may develop, especially Sunday night into Tuesday. Persons with travel plans should monitor the situation and consider making adjustments to limit their risk to these winter hazards. && .DISCUSSION... SHORT TERM...(FRIDAY THROUGH SATURDAY)... The cold front has reached Roswell and Clines Corners, with spotty low clouds over the northeast and east central so far. Still expecting some low clouds to develop along the east slopes of the central mountain chain, but only a relatively weak easterly wind into the RGV this morning. It will be much colder in the east, and a little cooler central and west today. Saturday will be much warmer in the east with highs returning to above normal. Ridgetop winds over the central mountain chain and San Juan/Tusas may be quite gusty, and a wind advisory may be required Saturday afternoon. LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)... It's beginning to look a lot like...winter weather! Confidence has moved into the high category that a complex winter storm will impact the Land of Enchantment; however, there are several finer details in the extended periods that need to be ironed out that will determine the location, duration and severity of potential impacts. 700mb speed max of 35-50 kts will be centered squarely over NM for Saturday night, and this will continue to support breezy to locally windy conditions over the higher terrain, with the Sangre de Cristo mountain peaks favored for the strongest winds. Meanwhile, a 1047mb surface high pressure originating from northwest Canada will drive a potent cold front through the Great Plains. Models bring this front into northeast NM between 09-12Z Sun, then it will likely gobble up more real estate of the eastern plains throughout the day. This will result in a very tricky high temperature forecast for Sun. Strangely enough, the NBM mean increased readings, but will continue to knock these values down considerably into the lower end of the spread. A very sharp gradient will setup across the plains, and predicting its exact location this far out is too difficult. But knowing models are notorious for being way too slow, especially with shallow fronts, it seems to be a good target of opportunity to push the colder air mass closer to the northeast/central highlands. This front is likely to push its way through the central mts and below canyon/gap winds are possible compliments of a strong surface pressure gradient. Southwest flow aloft will increase substantially as a trough takes aim for the Desert SW Sun night. A weakening upr low/open wave will race through the CWFA during this time, setting up an over-running situation over the ern plains as warmer air/moisture aloft migrates over the shallow but cold boundary layer. Sounding profiles support sleet and/or freezing rain, but the biggest forecast challenge is where the snow vs. mixed-phased precipitation boundary will develop. This will ultimately impact snow and any ice accumulations, and it is important to note that any graphics depicting projected amounts should be used with caution during this period given the previously mentioned uncertainties. Regardless, the key message will be a cold air mass/hard freeze and hazardous winter travel conditions. By Monday, the GFS/ECMWF deterministic and ensemble guidance have come into rather decent agreement that a closed low will form over southern UT/northern AZ and drift south. The Canadian remains as a significant outlier with the placement of the upr low (southern CA) and have opted to discount this solution for now. Models still show strong frontogenetical forcing over the Four Corners into northern NM/southeast CO. Add orographic lift to the equation and models are painting very impressive precipitation amounts that approach/exceed one inch. With cold air in place, this storm system could turn into a significant snow machine, with the northern mts primed to receive more than one foot of snow, especially on the west slopes and peaks. If this situation materializes as progged, nearly two feet of snow could fall along the San Juans/Tusas peaks. But let's not jinx it just yet. By Mon night, the precip band should slide southeast and this may bring a decent shot for light snow in the ABQ and Santa Fe metro areas. With that said, forecast confidence begins to diminish substantially. Models start to diverge by Tuesday on how quickly the upr low will traverse central/southern NM, and this will have an impact on how long winter-related impacts will be felt. GFS, GEFS and EPS remain fairly progressive with precipitation ending Wednesday. Meanwhile, the ECMWF is intriguing with the closed low ejecting northeast much sooner, bringing wrap-around precipitation to northeast NM for Wed night into Thursday. Lots can change between now and then...so stay tuned. DPorter && .FIRE WEATHER... ...FIRE WEATHER WATCH IN EFFECT FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FROM NORTH CENTRAL INTO EAST CENTRAL NEW MEXICO DUE TO STRONG WINDS...LOW HUMIDITY...AND AN UNSTABLE AIRMASS... A strong cold front has pushed through much of the eastern plains and was approaching the east slopes of the central mountain chain. Humidities will increase and temperatures will be considerably cooler, by 15-40 degrees. West of the RGV, dry and warmer than normal conditions continue today. Westerly winds aloft strengthen Saturday as surface low pressure in the lee of the central mountain chain deepens. Ridgetop winds over the San Juan/Tusas and Sangre de Cristo to the Sandia mts could gust to around 50-55 mph. Minimum humidities are somewhat marginal for critical fire weather conditions, especially east of the Pecos Valley and into the Northeast Plains, but suspect the stronger winds may allow for lower humidities than what's currently forecast. Temperatures will also recover to 5-10 degrees warmer than normal, so have decided to go with a Fire Weather watch. A dramatic change to colder and wetter is still forecast starting Sunday. There may be some locally critical fire weather conditions Sunday over western New Mexico, but critical conditions are not expected for the rest of the week. An unseasonably cold front will plow into the east Sunday then spread westward Sunday night. Precipitation will develop late Sunday and continue into the middle of next week in the form of rain, sleet, freezing rain and/or snow over the east, and rain and snow west. Accumulating snow in the northern mountains could be substantial. The coldest days could be Monday and Tuesday before a warning trend commences. Expect a widespread hard freeze Sunday, Monday and Tuesday nights. && .ABQ WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch from Saturday afternoon through Saturday evening for the following zones... NMZ102-103-107-108. && $$