456 FXUS65 KPUB 190552 AFDPUB Area Forecast Discussion National Weather Service Pueblo CO 1152 PM MDT Mon Oct 18 2021 .UPDATE... Issued at 934 PM MDT Mon Oct 18 2021 Given recent trends, have decided to issue a High Wind Warning for the southern Sangres for late tonight through midday Tuesday. Previously mentioned mountain wave setting up tonight should yield southerly gusts up to around 75mph later tonight, with HRRR continuing to show this possibility at this time. Would not be surprised to see a few higher gusts to 80-85mph Tuesday morning, before winds diminish by late morning into midday. UPDATE Issued at 715 PM MDT Mon Oct 18 2021 Update this evening was to expire the Red Flag Warning which was in effect for eastern Huerfano, Las Animas and Baca Counties. Gusts may continue this evening, though RH values will continue to improve. A Red Flag Warning remains in effect from Noon until 7 PM MDT Tuesday for strong winds, low relative humidity and dry fuels, that includes Fremont, southern El Paso, Pueblo, Huerfano, Las Animas, Crowley, Otero, Bent, Prowers, Kiowa and Baca Counties. && .SHORT TERM...(This evening through Tuesday) Issued at 306 PM MDT Mon Oct 18 2021 ...Critical Fire Weather Conditions on the Plains Tuesday... Upper level low moving through the Great Basin this afternoon, while lee surface trough deepens on the plains. Tightening pressure gradient and deeper mixing ahead of the low have led to gusty winds across much of the area, with patchy Red Flag Conditions along the Raton Mesa eastward into Baca County. Upper low moves quickly eastward into nwrn CO overnight, then pushes eastward along the CO/WY border through the day Tue. Models suggest brief band of snow showers spreading across the Continental Divide toward 12z as main lift with the low/trough comes across, then mainly scattered snow showers through the day Tue, especially in nw flow enhanced locations in Lake County around Leadville/Fremont Pass. Not expecting much more than a dusting to an inch of snowfall across most of the Divide, though higher peaks of the Sawatch could see an inch or two if they're lucky. Surface winds over much of the area will remain breezy overnight, with perhaps some strong gusty winds in the lee of the eastern mountains, especially the srn Sangres, where HRRR shows some gusts over 50 kts, as brief mt wave sets up 09z-15z before forward shear increases by late morning. For Tue, upgraded the Fire Weather Watch to a Red Flag Warning, as deep mixing and increasing downward vertical motion should enhance winds along and east of the mountains through the day, while dewpoints drop off into the teens, which should more than offset any cooling in surface temps. Maxes should end up about 8-10 degf cooler at most locations as mid level temps fall behind the departing upper trough. .LONG TERM...(Tuesday night through Monday) Issued at 306 PM MDT Mon Oct 18 2021 Tuesday night...The upper low pressure system will be exiting the region Tue night, producing some lingering snow showers over the central mts through around midnight, as well as push a weak cold front south across the state during the overnight hours. Additional snow accumulations of up to an inch are expected as the shower activity wanes. Expect minimum temps overnight to drop into the 20s to around 30F for the high valleys, teens for the heart of the San Luis Valley, and 30s across the plains. Wednesday through Saturday...The story for the rest of the week and into the weekend is a ridge of high pressure, producing dry conditions, lighter winds and warming temps. Overnight low temps are forecast to be in the 20s to around 30F for the high valleys, and 30s to around 40F for the plains. Highs will be slightly cooler for Wed due to the cold front, in the upper 50s and 60s for most areas, then 60s for the high valleys and 70s for the plains for Thu through Sat. Sunday and Monday...Long range models are still indicating a Pacific longwave trough will move onshore over the weekend, approaching the region and introducing some isolated pcpn chances along the Continental Divide starting Sunday. There are some timing and strength differences between models, so confidence is low at this time on what this next pattern shift will actually mean for south central and southeast Colorado. Stay tuned. Moore && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 1146 PM MDT Mon Oct 18 2021 VFR conditions with dry weather are expected across the TAF sites this period. Mid/high clouds are possible later this morning, as an upper level system passes to the north. Increasing flow aloft will provide some LLWS this morning, especially across ALS, and have added that in the forecast. This should end later this morning, as gusts increase across the sites. These gusty winds will be observed well into the afternoon and evening, with some veering to more of a northwest direction late in the period. && .PUB WATCHES/WARNINGS/ADVISORIES... Red Flag Warning from noon to 7 PM MDT Tuesday for COZ222- 227>237. High Wind Warning from 3 AM to noon MDT Tuesday for COZ074-075. && $$ UPDATE...RODRIGUEZ SHORT TERM...PETERSEN LONG TERM...MOORE AVIATION...RODRIGUEZ