National Weather Service Forecast Discussion |
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000 FXUS65 KBOU 190537 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 1137 PM MDT Mon Mar 18 2024 .KEY MESSAGES... - Warmer weather, with occasional light mountain snow showers this upcoming week. && .UPDATE... Issued at 802 PM MDT Mon Mar 18 2024 Another clear and quiet night with no adjustments needed to current fcst. && .SHORT TERM...(This evening through Tuesday) Issued at 257 PM MDT Mon Mar 18 2024 Quiet weather prevails this afternoon across northeast Colorado. Surface observations show temperatures in the mid to upper 50s across the lower elevations. Some of the deeper snowpack areas are running a bit cooler a the lower 50s. Tonight, expect mainly clear skies with lows in the upper 20s and 30s for the lower elevations and teens/20s for the high country. Tomorrow will trend a bit warmer with some warming in temperatures aloft and decreasing snowpack. Highs rise into the 60s for the most lower elevation spots with mid 60s across the east plains. The upper level low (that once helped bring last weeks snow) will slowly shift eastward across AZ. It will be well south and weaker, but will support lower coverage light snow showers across the central and southern Colorado mountains in the afternoon. .LONG TERM...(Tuesday night through Monday) Issued at 257 PM MDT Mon Mar 18 2024 Wednesday, the stubborn closed low accelerates eastward through New Mexico, but the bulk of the remnant moisture stays to our south. Aloft, weak northwest flow will prevail, and mild conditions with low elevation highs in the low 60`s along with dry weather can be expected. The best opportunity for a stray shower will be for our southern mountains in the afternoon. Moving into Thursday, a glancing shortwave will produce a shot of reinforced northwesterly flow and Pacific moisture. As a result, a few light mountain snow showers should materialize, and westerly surface winds will strengthen across the northern tier of our mountains and foothills, when gusts may approach 50 mph for wind- prone locations. The lower elevations will be warmer under the effects of the downslope winds, with highs climbing into the mid to upper 60`s. Highs on Friday will drop just a few degrees behind the weak surface front associated with Thursday`s shortwave, but even then temperatures look likely to remain in the 60`s. Looking ahead at Saturday, the west coast will begin to be impacted by a developing trough. Over Colorado, flow aloft turns increasingly westerly with a rise in moisture advection and increased potential for mountain snow showers, especially later in the day. Subsidence should keep the plains and urban corridor dry, and sustain the mild temperatures for another day. Solutions begin to diverge more considerably for the latter half of the weekend and particularly into early next week. There is overall consensus among ensemble means depicting a longwave trough pushing across the Rocky Mountain region during this period, and good agreement on the return to unsettled weather, with ~70-90% of ensemble members (depending on the suite in question) pointing to some precipitation for the wider Front Range region as early as Sunday afternoon/Sunday night. Ensemble mean tracks still aren`t overly favorable for a higher-impact upslope event (too far north), but the system does look to carry better potential for colder air and some deterministic solutions such as the GFS do depict some bifurcation in the flow, with one low dipping farther south. In any case, the bulk of this event is just beyond our long term forecast period, so there`s plenty of time to iron out more details and for things to change. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1137 PM MDT Mon Mar 18 2024 VFR to prevail through Tuesday. Skies will be clear through Tuesday morning and then mid clouds will increase Tuesday afternoon, mainly over the higher terrain at first. The clouds then spread eastward through Tuesday evening, with ceilings above 6000 feet. Southerly drainage winds will prevail through about 15-16Z at DEN and APA, then become variable to east for Tuesday afternoon. Winds return to a drainage direction after 00Z Wednesday. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...RPK SHORT TERM...Mensch LONG TERM...Rodriguez AVIATION...Meier