National Weather Service Forecast Discussion |
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379 FXUS65 KBOU 272001 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 201 PM MDT Fri Mar 27 2026 .KEY MESSAGES... - Well above normal temperatures again for the weekend into early next week. - Areas of elevated to locally critical fire weather conditions possible over the weekend and Monday. - Pattern change by the mid to latter portions of next week, but highest chances of meaningful precipitation focused on the mountains. && .DISCUSSION /Through Friday/... Issued at 155 PM MDT Fri Mar 27 2026 Cooler temperatures behind the cold front finally makes it seem more like spring than summer today. ACARS soundings still show mid-level moisture sticking around across the plains. However, current visible satellite imagery does show some erosion this past hour. At this point, don`t think the low clouds will fully clear out before sunset, so have slightly lowered max temperatures accordingly. A surface high pressure will travel from the north to the central Great Plains this afternoon and overnight tonight. Tightening of pressure gradients will lead to gusty southerly winds today for the Palmer Divide & eastern plains and into Saturday morning for the eastern plains. Gusts up to 40-50 mph are possible at times before gradually weakening by late Saturday morning. Elevated-to-critical fire weather conditions are possible Saturday afternoon as guidance is in good agreement relative humidity values taking below 20% for the majority of the plains and foothills. However, there is some uncertainty with strength and duration of the winds. For the eastern plains, (particularly Lincoln and Washington counties) the gusty southerly winds are progged to exit the area before relative humidities dip below 15%. However, if the winds last longer, fire weather highlights will be needed. For areas near South Park and northern Front Range foothills, lee-troughing on Saturday will result in breezy downslope winds. However, they should stay below 25 mph, aside from brief 30-45 mph wind gusts. For these reasons, have opted out of any fire weather highlights. With the lee-troughing, some mid-level moisture will be advected onto the plains. Isolated virga showers are possible (about 30% chance) Saturday afternoon/evening as modeled Skew-T soundings show elevated instability with high-based LCL`s. With any virga, gusty outflows may occur as DCAPE values range between 600-1200 J/Kg. Persistent upper level ridging will continue through Monday, once again allowing warm air advection to bring above normal temperatures (and possibly record-breaking temperatures, particularly Sunday). The thermal ridge is progged to bring 700-mb temperatures between +10 to +12 C, resulting in surface temperatures in the high 70s to possibly even low 80s. The current record for high temperature on Sunday, March 29 is 79 degrees (current forecast is 80 degrees). With mostly dry conditions and flat ridging leading to breezy downslope winds, elevated-to- critical fire weather conditions are possible each day, with highest concern being Monday due to breezier southwest winds aloft. Ensemble guidance continues to be in good agreement of a pattern change mid-week next week. A shortwave trough will trek across the northern U.S., with increasing southwest flow aloft advecting moisture into Colorado. In this pattern regime, usually southwestern Colorado will receive the best precipitation. However, the majority of the GEFS and ECMWF ensemble solutions show measurable QPF for the mountains. For the plains, it is more uncertain, with the GEFS being slightly drier due to the track of the low. With a cold front associated with the low expected, temperatures will likely be low enough to support snow for the mountains, and possibly even rain/snow mix for the plains. Stay tuned for more details!&& && .AVIATION /18Z TAFS through 18Z Saturday/... Issued at 200 PM MDT Fri Mar 27 2026 Model`s wind forecasts show brisk southeasterly winds at DIA this afternoon, eventually getting due southerly early this evening. Will keep the gusts to 30 knots going for late this afternoon through all the evening. More normal, weaker drainage winds are expected by 08Z. Concerning the Stratus deck, the latest VAD Wind Profile data is showing that the cloud deck thinning but still around 3,000 thick. Not certain when it will go to SCT. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...MAI AVIATION...66