Area Forecast Discussion
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
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329 FXUS65 KBOU 150849 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 249 AM MDT Sat Jun 15 2024 .KEY MESSAGES... - A return to hot and mainly dry weather this weekend into early next week. - Snowmelt producing minor impacts from high streams. Gradually diminishing flows next week. - Cooler for Tuesday and Wednesday && .SHORT TERM /Through tonight/... Issued at 248 AM MDT Sat Jun 15 2024 An upper level ridge pattern begins over northeastern Colorado. Westerly flow and weak mid-level moisture will result in isolated showers mainly west of the Divide. Dry air aloft and low PWATs hint that these showers could produce little to no rainfall. Model soundings display decent DCAPE values between 600-800 J/kg meaning showers could produce wind gusts up to 40 mph. CAMs suggests a shower or two crossing into the lower elevations mainly along the Palmer Divide by late afternoon until early evening. Additionally, warm temperatures return this afternoon. Areas west of the Divide could reach the upper 60s to upper 70s this afternoon. Temperatures across the urban corridor and plains increase above normal reaching the 90s. Tonight, above normal low temperatures are expected. && .LONG TERM /Sunday through Friday/... Issued at 248 AM MDT Sat Jun 15 2024 The overall pattern Sunday through Monday will have SW flow aloft over the area. At the sfc, it appears nern CO will have to contend with a boundary associated with convection to the north both days. Exactly how far south this boundary will be is a big question mark at this time. It could stay along the CO-NE border area both days or end up further south near a Denver to Akron line. North of this boundary temps will likely be in the 85-90 degree range while south of it readings will be in the mid to upper 90s. In addition, higher dewpoints will be in place north of the boundary with decent MLCAPE both days. However, with that being said, there is a decent capping inversion in place both days which will likely prevent convective development along and north of the boundary. As a result, have kept pops in the isolated category both days near the CO-NE border. By Tue, little change is expected to the overall pattern aloft as SW flow aloft will continue. A cold front is still expected to move across nern CO late Mon night thru Tue morning. This will lead to a more stable airmass across the plains thru the aftn. Over the higher terrain, there could be some isold high based tstms in the aftn. As far as highs, readings will drop into the upper 70s to mid 80s across the plains. For Tue night into early Wed, there are considerable differences in the handling of low level moisture across the area. The GFS has a stronger sfc high pres building into the area with deeper low level moisture remaining to the south and east. Meanwhile, the ECMWF has deeper moisture returning by Tue night. As a result, it has nocturnal convection developing over portions of the plains overnight into early Wed. At this point, confidence is low in either solution so have just left a slight chc of storms across portions of the plains. As for the rest of Wed, SW flow aloft will remain over the area. Both the ECMWF and GFS indicate a return of better low moisture across the higher terrain by Wed aftn with increasing MLCAPE. As a result this may lead to sct tstms. Across the plains, it looks more stable by aftn so will only keep in a slight chc of storms. Highs on Wed will still be slightly below seasonal normals across nern CO. Looking ahead to Thu and Fri, the flow aloft will remain SW. Meanwhile, the low level flow across the plains will become southeast allowing for deeper low level moisture to return. As a result, will see increasing MLCAPE with at least a slight chc of aftn and evening tstms. Finally, highs will rise back above seasonal levels across nern CO. && .AVIATION /06Z TAFS through 06Z Saturday/... Issued at 248 AM MDT Sat Jun 15 2024 VFR conditions continue through the TAF period. A few low clouds at KDEN should burn off by 11Z this morning. Winds remain light then shift northerly by late morning. Expect showers to develop in the foothills this afternoon and there is potential for one or two to reach the terminals between 21-00Z. With high DCAPE values, showers could produce gust winds up to 14-20kts. Winds should shift southeast by early evening. && .HYDROLOGY... Issued at 248 AM MDT Sat Jun 15 2024 Elevated flows continue in the mountain streams, with Flood Advisories remaining in effect for the streams above Granby and Grand Lake. Remain alert of the dangers of water that is running high and cold. Flows are expected to gradually decrease next week as the peak snowmelt is passing by. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...AD LONG TERM...RPK AVIATION...AD HYDROLOGY...AD/RPK