Area Forecast Discussion
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
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074 FXUS65 KBOU 041935 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 135 PM MDT Tue Jun 4 2024 .KEY MESSAGES... - Breezy, dry, and a little cooler today. - Summer heat through the rest of this week, with a few 90 degree readings over the plains, with Friday the hottest day. - Increasing chances for showers and thunderstorms this weekend into early next week, along with slightly cooler temperatures. && .SHORT TERM /Through Wednesday/... Issued at 145 PM MDT Tue Jun 4 2024 The west to north winds over the CWA at still gusting to 40 mph in the mountains and over the eastern 2/3rds of the plains. Current temperatures are in the mid 70s to lower 80s over the plains and lower foothills, with 50s and 60s in the alpine areas. Models show northwesterly flow aloft tonight to weaken as an upper ridge pushes in from the west on Wednesday. There is little synoptic scale energy for the CWA tonight or Wednesday. the low level winds are mainly downsloping on Wednesday. Cross sections show a bit of a mountain wave set up later tonight into Wednesday morning. Moisture is lacking on Wednesday as is CAPE. Thickness grids show Wednesday highs 4-6 C warmer than today`s, with Denver`s high expected to get above 90 F for the first time this year. Wednesday should be hot dry and sunny. && .LONG TERM /Wednesday night through Tuesday/... Issued at 130 PM MDT Tue Jun 4 2024 A broad upper ridge will remain in place across the Western U.S. through the end of the work week, leading to continued warm and dry conditions across the forecast area. Thursday should be a little cooler than Wednesday, following the passage of a weak cold front Wednesday night. Still, robust daytime heating should warm temperatures back into the upper 80s across most of the lower elevations, with low to mid 80s also possible in the high valleys. The axis of the mid-level thermal ridge should be centered over southern Colorado on Friday, with a shift to modest downslope flow across the region. Mid-level temperatures are expected to be a few degC warmer than Thursday and a return to the 90s looks likely for the plains. How quickly we warm up will likely depend on how much (if any) cloud cover develops as better moisture advects into the region. The increasing moisture will also lead to increasing PoPs, mainly across the higher elevations. Moisture should continue to increase across the region this weekend, with ensemble guidance suggesting PWATs near 125-175% of normal (normalized anomalies near 1-3 sigma). A series of weak shortwaves should traverse the edge of the retreating ridge in this period, and scattered/likely PoPs are in the grids on Saturday and Sunday. Perhaps the most intriguing day of the forecast period is Monday. The GFS and ECMWF both hint at a stronger shortwave/cold front pushing across the region Sunday night or Monday, with deep moisture/upslope flow behind the front. However, these deterministic solutions are well on the cold/wet side of their respective ensembles, and the majority of guidance keeps temperatures in the 70s to low 80s. Beyond that timeframe, guidance generally tries to rebuild the ridge across the region with a gradual trend towards warmer/drier weather. && .AVIATION /18Z TAFS through 18Z Wednesday/... Issued at 1142 AM MDT Tue Jun 4 2024 Models agree well with the west-northwesterly winds at DIA this afternoon. They are expected to decrease by early evening , then go to drainage patterns around 06Z. There will be no ceiling issues through tonight. && .HYDROLOGY... Issued at 130 PM MDT Tue Jun 4 2024 The remaining mountain snowpack will continue to quickly melt off the next several days as temperatures increase across the region. Hydrologic forecasts continue to show elevated flows across the Colorado/Fraser rivers in Grand county, with a few sites forecast to reach action stage by Friday. Meanwhile, the threat of burn area flash flooding will gradually increase this weekend into early next week as a moist airmass advects into the region. Confidence is low for any given day, but something worth watching as we get closer to the weekend. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...RJK LONG TERM....Hiris AVIATION.....RJK HYDROLOGY....Hiris