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130 FXUS65 KBOU 022017 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 217 PM MDT Sat May 2 2026 .KEY MESSAGES... - Above average temperatures and dry conditions expected for the weekend. - Unsettled weather returns Monday night through Wednesday with increasing chances for rain showers and some snow for the plains as well as mountain snow. -Significant snowfall accumulations are possible (60% chance) in the mountains Monday night through Wednesday. Chances are increasing for snow along the I-25 corridor Tuesday evening into Wednesday. && .DISCUSSION /Through Saturday/... Issued at 217 PM MDT Sat May 2 2026 It is a nice sunny day across Colorado today with an upper-level ridge bringing quiet weather and warm temperatures into the region through tomorrow. Afternoon temperatures today and tomorrow will climb into the 60s and 70s at low elevations. Relative humidities will be dry both days, with values dropping into the low teens and perhaps the single digits. Despite the low RH values, we are not overly concerned about fire weather due to the very light winds in place. We have some 30-40% PoPs over the Denver metro area and I-25 corridor on Monday afternoon as Pacific moisture ahead of an approaching trough continues to be advected over the area and daytime destabilization occurs. However, most of these convective showers will be high-based or virga. Model soundings suggest DCAPE values ~600 J/kg due to the dry air at the low levels, indicating that these high-based showers will also be able to produce some gusty winds. A strong cold frontal passage is expected to arrive Monday evening, bringing an initial surge of moist, cool air, and enough lift for additional rain showers to develop over the plains, as well as snow showers over the northern Front Range and Cheyenne Ridge. Snow levels should remain above 8,000 ft along and behind the front. A deep Pacific low will continue to track east inland over Southern California and Arizona, becoming a shortwave trough before possibly phasing with the strong upper-level trough sliding south over the northern plains on Tuesday. While there is still some uncertainty regarding how these synoptic features will evolve, ensemble guidance has been trending towards a phased solution, which would put our CWA in a decent position for measurable rain and snow Monday night through Wednesday. The main surge of cold air will arrive late Tuesday morning, which is when the snowfall will begin to ramp up over the Front Range. Snow levels look to fall from around 8,000 feet Tuesday midday, to 6,000 ft by late afternoon. The eastern Colorado plains and Denver metro area will likely remain too warm for snow during the day, but we lowered daytime temperatures down to the upper 30s/low 40s given that we expect stratiform-like rain coverage most of the afternoon. Temperatures will continue to gradually cool down through the day on Tuesday, with a transition to snow over the Denver metro area early Tuesday evening. While it is too early to tell with high certainty, the current model guidance and ingredient-based assessment of this system suggests at least light snow (T-2") accumulations on grassy/elevated surfaces over the Denver metro area, with higher amounts (2-4") over the Palmer Divide due to upslope enhancement. The mountains will likely see more significant accumulations (8-13"), with the highest amounts occurring over the Front Range, especially above 8,000 feet. The left exit region of an upper-level jet streak will be positioned over the eastern plains Wednesday morning, continuing to favor upward motion through at least Wednesday morning. However, snow should gradually diminish Wednesday afternoon as northerly flow begins to bring drier air into the region. For now, enough cloud cover Wednesday night into Thursday morning should keep low temperatures from plummeting into the 20s across the I-25 corridor, but if it dries out sooner than currently in model guidance, most of the area could be in for a deep freeze Thursday morning. && .AVIATION /18Z TAFS through 18Z Sunday/... Issued at 1144 AM MDT Sat May 2 2026 Variable, weak winds are expected again at DIA this afternoon. Pretty normal drainage winds are expected by 04Z this evening continuing overnight. There will be no ceiling issues. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...AA AVIATION...66