314 FXUS65 KBOU 062157 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 257 PM MST Sun Feb 6 2022 .SHORT TERM...(This evening through Monday) Issued at 124 PM MST Sun Feb 6 2022 The trough responsible for a few snow showers in the JeffCo foothills this morning, and a cooler day today, will be well south of Colorado by tonight. In it's wake, pretty strong subsidence will overspread our area all the way through Monday. Skies clear out even more after sunset with the loss of convective-induced cumulus. Light winds across most areas other than the east slope foothills will mean excellent radiative cooling conditions should exist. North and Middle Parks will drop well below zero tonight given a nice snow pack, subsidence aloft and clear skies. Expect lows in the river valleys of Middle Park to drop to around -15, maybe -20. North Park should be 0 to -10, and South Park around 0. Across the plains lows should be in the teens to low 20s, with the warmest temps in the urban heat islands and nearest the foothills. On Monday flow aloft will be dry out of the northwest, and a significant warming trend will get going. 700 mb temps warm 7-9 degC over the course of the day, warming all the way to 0 degC, and with full sun temperatures across the plains should reach the low 50s other than areas that have deeper snowpack like Weld County southeastward through Morgan, eastern Arapahoe/Adams, and Washington Counties. Highs in those areas will remain in the 40s, but a good deal of melting is expected across the entire area. The mountain valleys will warm up nicely into the 30s other than Middle and North Parks, where highs should only reach the 20s under stout inversions. .LONG TERM...(Monday night through Sunday) Issued at 255 PM MST Sun Feb 6 2022 Upper ridging will be in control the weather over northeast and north central Colorado Monday night. A weak upper trough is progged to push across in the northwesterly flow aloft on Tuesday. The northwesterly flow aloft continues through Wednesday with another weak upper trough to move across the CWA Wednesday night. The models have not been consistent with this feature, as it now looks weaker than it did yesterday. The QG Omega fields show a brief period of weak upward vertical velocity for the CWA Tuesday early. There is downward motion progged Tuesday afternoon and night. On Wednesday and Wednesday evening, weak upward motion is again progged. This is followed by weak subsidence late Wednesday night. The low level winds should mainly be normal diurnal tends most of the five periods. There could be some downsloping mixed in here and there. Cross sections indicate a mountain wave set-up late Monday night into tuesday morning. It is not real strong. Highlights wouldn't be necessary if models remain consistent with this feature. Moisture is lacking Monday night into Wednesday afternoon. There is some in the mid and upper levels. The QPF fields show a tad of measurable snowfall for some of the CWA Wednesday afternoon and night, but it is minor. It looked better yesterday, but still minimal. Will go with some 10-20% pops late Wednesday afternoon and evening. For temperatures, Tuesday's highs are 0-1.5 C cooler than Monday's highs. Wednesday's readings are are 0-1 C warmer than Tuesday's. For the later days, Thursday through Sunday, models have north- northeasterly flow aloft on Thursday, then northwesterly flow aloft on Friday. Another weak upper trough is progged to move across the CWA Friday night into early Saturday. Strong northerly flow aloft is expected for the rest of Saturday. This weakens Sunday as upper ridging pushing eastwards towards Colorado. The chances for precipitation are not very significant at this time with the through. The weekend looks dry with little moisture available. Temperatures are night near seasonal normals, with Sunday's readings to warm a bit. && .AVIATION...(For the 18Z TAFS through 18Z Monday afternoon) Issued at 1031 AM MST Sun Feb 6 2022 VFR through Monday. North winds 8-13 kt should be the norm across the terminals the rest of today though BJC may just remain light and variable. Tonight, wind should shift to drainage though the surface pressure gradient favors more of a SW direction drainage at APA and DEN than normal, but speeds should be 10 kts or less all night. They should be west all night at BJC at 5-10 kts. Winds will be light and variable Monday morning, eventually becoming NW at APA and DEN at 10 kts or less. BJC may experience mountain wave activity Monday evening where west winds may gust over 20-25 kts, but until then winds will be light and probably out of the southwest. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Schlatter LONG TERM....RJK AVIATION.....Schlatter