Area Forecast Discussion
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
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174 FXUS65 KBOU 160314 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 914 PM MDT Mon Jul 15 2024 .KEY MESSAGES... - Still hot today, but a few degrees cooler than this weekend. - Scattered afternoon showers and thunderstorms today with a couple severe storms possible over the plains. - Higher chance of showers and thunderstorms both Tuesday and Wednesday, with an uptick in storm intensity and severe threat. Temperatures cooling to below normal levels for Wednesday. - More typical summer weather for the latter half of this week with scattered afternoon showers and storms most days. && .UPDATE... Issued at 901 PM MDT Mon Jul 15 2024 Scattered showers are still ongoing across a few different spots of the CWA, with gusty outflow winds noted from a few of these showers. This activity has been slowly weakening over the past couple of hours, and this trend should continue through the rest of the evening. Main adjustment this evening was to update the PoPs and winds in the next few hours to better match current observations. Otherwise, the previous forecast was largely in good shape. && .SHORT TERM /Through Tuesday/... Issued at 255 PM MDT Mon Jul 15 2024 Storms continue to develop in the foothills spreading to the plains until late evening. A few outflows have recently reported 25-30 mph gusts along coop sensors along the I-25 corridor. Storms will likely produce little rainfall and gusty winds up to 45 mph through this evening. There is potential for severe storms mainly near the northeast corner this evening where storms could produce wind gusts up to 60 mph. Tonight, clouds should clear. Tuesday, 700mb temperatures range between 12-13C which should lead to cooler surface temperatures. Expect areas above 8 thousand feet to range between 63-78F. There is a chance that Denver could break 90F but mid-level clouds arrive quickly by early afternoon thus will keep a forecast high of 89F. Low elevations will range between 82- 92F. A shortwave trough sweeps across northeast Colorado bringing scattered showers and storms by Tuesday afternoon. PWATs hover near normal between 0.65-0.80 inches and storm motion should move rather quickly thus the flood threat should remain limited for both the East Troublesome and Cameron Peak burn scars. Additionally, favorable MLCAPE values near 1000 J/kg, bulk shear values near 40- 45kts and mid-level rates between 7-8 C/km could lead to potential severe storms mainly for the Palmer Divide and plains. && .LONG TERM /Tuesday night through Monday/... Issued at 255 PM MDT Mon Jul 15 2024 Similar conditions are expected Wednesday with cooler temperatures and increased moisture. Northeast Colorado remains on the eastern periphery of an upper level ridge with a trough settling across the Great Lakes and Midwest. Although we won`t completely tap into the cooler airmass, we will benefit from another frontal push of cooler, upslope flow from the northeast early Weds morning. Can`t rule out some stratus development across the plains behind the front through the morning hours. With that being said, there will be sufficient advection of moisture in the lower levels from east to west, bringing higher dewpoints further westward than Tuesday. Higher values will exist over the far east plains in the low 60s with 50s pushing toward the I-25 corridor. Upper level support will be minimal, but a jet max positioned to the northeast will provide weak ascent and sufficient deep layer shear. The higher instability will co-locate with the best moisture and daytime heating with MLCAPE values in the 1000-2000 J/kg range across the I-25 corridor. The northeast corner may remain stable due to the AM stratus. All in all, this will support scattered showers and thunderstorms in the afternoon with a couple strong to severe storms. Highs range in the mid to upper 80s across the plains. A welcome cooling from previous days. Thursday and Friday, ensemble guidance shows a consensus on the upper level ridge centering over the Great Basin/Desert Southwest. Northeast CO sits within the northerly flow aloft on the east of the ridge. Ensemble means show slight warming closer to normal temperatures with scattered showers and thunderstorms both days with the highest chances over the mountains and foothills. Ensemble guidance show a few embedded waves that move through the northerly flow over the course of the weekend. This generally will keep temperatures below normal. Moisture remains in place to support scattered afternoon showers and thunderstorms each day. && .AVIATION /00Z TAFS through 00Z Wednesday/... Issued at 537 PM MDT Mon Jul 15 2024 Weak showers around the terminals are likely to continue for the next couple of hours. Radar shows quite a few showers/storms upstream across the I-70 mountain corridor, with this activity generally drifting east. With temperatures in the low to mid 70s, the chances for organized convection is low but a few TS can`t be completely ruled out. The main concern over the next few hours is how the winds play out with showers continuously spitting out outflow with varied directions. The weather should quiet down by later this evening, with VFR conditions expected overnight. Tomorrow`s weather looks fairly similar today, with enough moisture/instability for widely scattered TS by the mid-afternoon. Main threat tomorrow will again be gusty outflow winds. && .HYDROLOGY... Issued at 255 PM MDT Mon Jul 15 2024 Above normal moisture moves into the region starting Tuesday with scattered afternoon showers and thunderstorms. Some stormy will be capable of localized heavy rainfall. Storm motions won`t be concerningly slow; however, the marginal winds aloft will warrant a low risk for flash flooding over the burn areas for at least Weds and Thurs. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Hiris SHORT TERM...AD LONG TERM...Mensch AVIATION...Hiris HYDROLOGY...Mensch