Area Forecast Discussion
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
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091 FXUS65 KBOU 190005 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 605 PM MDT Tue Jun 18 2024 .KEY MESSAGES... - Cooler through Wednesday with scattered showers and a few storms. - Scattered thunderstorms Thursday into Friday - Turning hot and drier this weekend through early next week && .SHORT TERM /Through Wednesday/... Issued at 141 PM MDT Tue Jun 18 2024 Cooler temperatures have settled in across the forecast area today after a cold front swept through the region earlier this morning. As the troughing pattern continues over the western CONUS, there is a slight chance we get some weak rain showers or an isolated storm to develop over the higher terrain this afternoon. Current water vapor imagery indicates low level moisture is lacking at this time, but looking upstream, low and mid level moisture looks to be heading our way. The better chances for precipitation will be overnight tonight and tomorrow as the trough shifts eastward and a 90 kt jet will be in place to provide upper level support to northern CO. CAMs indicate banded precipitation spreading across the plains and continuing into tomorrow. Forecast soundings also show a dry to start moisture profile becoming increasingly saturated as low level flow will be from the southeast, allowing for moisture support from the Gulf. With the increasing moisture in place, some lower level stratus are expected to help keep Wednesday`s high temperatures on the cooler side. Temperatures are forecast to be 10-20 degrees below the norm and will likely struggle to reach the 70s across forecast area. && .LONG TERM /Wednesday night through Tuesday/... Issued at 230 PM MDT Tue Jun 18 2024 Models are in very good agreement overall with regard to the weather pattern. With more moisture and higher precipitable water values, scattered showers and a few storms will work their way eastward across the plains through tomorrow evening. Most of these should be ending by late evening in/near the mountains with some drying aloft noted, but linger over the eastern plains with low level 850-700 mb theta-e advection. For Thursday, the airmass should moisten a bit further across the area with deepening southerly flow. There are indications a little of this starts to peel off the easterly wave (broad circulation around Potential Tropical Cyclone One) in the western Gulf of Mexico. We`ll also be returning to warmer temperatures, which gives us more instability and probably an area of 1000-1500 J/kg MLCAPE over the northeast plains. Thus, a couple stronger storms would be possible, and perhaps an isolated pulse severe storm. By Friday, there`s a better chance some of this tropical moisture spreads northward across the forecast area and onto the western slope of Colorado. This would keep at least scattered shower and storm coverage in the forecast in/near the mountains, along with adding a threat of locally heavy rainfall. It appears an embedded shortwave could be arriving a little late for higher storm coverage, but something to keep an eye on for Friday afternoon and evening. For Saturday, the above shortwave will be passing to the east of Colorado, resulting in drying and subsidence through the weekend. Ensembles are in good agreement with that timing, and the subsequent mid level ridging over the Central Rockies and Great Basin into early next week. The combination of the ridge, drier airmass, and westerly flow aloft all supports a return of hot temperatures for the lower elevations, with mid and upper 90s expected for the plains and I-25 Corridor for Sunday, Monday, and Tuesday. There could still be enough moisture under the ridge for scattered mountain convection, and isolated storms on the plains each afternoon/early evening. But overall these would be high based with gusty winds and mainly light rainfall. Finally, depending on the fire intensity near Ruidoso, New Mexico (it is flaring up again this afternoon), the HRRR Smoke shows some smoke spreading across Colorado Thursday. && .AVIATION /00Z TAFS through 00Z Wednesday/... Issued at 541 PM MDT Tue Jun 18 2024 There will be a few showers in the vicinity of the terminals this evening but they are not expected to impact operations. Any ceilings that would form will be elevated and not significant. Winds will not be the typical drainage but will be ESE at DEN and APA. Late tonight and into tomorrow morning, there will be better moisture advected in from the east which may lead to status development. The limiting factor that could keep stratus away from the terminals would be the very dry air that is in place in this post-frontal airmass. But given pattern recognition, there is usually stratus that develops shortly after sunrise on setups like this and the stratus can last for the entire morning. The stratus will breakup around midday leading to some sunshine and gusty SE winds at DEN and APA. There will be showers and perhaps a couple thunderstorms tomorrow afternoon and evening. It is unlikely these would produce much of an impact as they will be elevated and likely won`t produce strong winds at the surface. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Bonner LONG TERM...Barjenbruch AVIATION...Danielson