


Area Forecast Discussion
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
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554 FXUS65 KBOU 031826 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 1226 PM MDT Thu Jul 3 2025 .KEY MESSAGES... - Increased thunderstorm activity over the mountains this afternoon with a slight chance of thunderstorms over the plains tonight. - A chance of thunderstorms and normal temperatures are expected for the Fourth of July and Independence Day weekend. && .UPDATE... Issued at 245 AM MDT Thu Jul 3 2025 Moisture will increase over the higher terrain today ahead of a weak upper level trough. Will see a gradual increase in shower/tstm development, over the higher terrain, by early to mid aftn which will continue thru the early evening hours. Across the plains it will be dry and windy thru the aftn. For late tonight into Fri, the weak upper level trough will move across the area. This feature will be over the mtns by 12z and then move across the far nern plains by 18z. Latest data suggests there could be scattered showers and a few tstms in the morning across the plains with some potential for a few stronger storms over the far nern plains thru 18z. Once this feature exits the area, its not clear how much redevelopment there will be in the aftn into the early evening hours. There will be some mid level cooling in the aftn which could lead to some additional tstms behind the main trough but overall confidence is low at this point. && .DISCUSSION /Through Wednesday/... Issued at 238 PM MDT Wed Jul 2 2025 Few changes to the forecast at this time, as weak convection should be limited to the mountains today. South to southeast steering winds should preclude anything drifting further east. With CAPEs looking to be in the 400-800 J/kg range, threats should be limited to subsevere gusty winds. Mid level moisture will increase from the southwest on Thursday, while low level moisture will increase from the southeast. This will set the stage for a more active day, but the plains airmass will likely remain capped most of the day. The strength of the convection will still be limited by warm air aloft, but the mountains should eventually see pretty good coverage of weak convection, with a threat of gusty winds. On the plains, the storm threat will likely wait until some combination of outflow from the mountains, or more likely the shortwave aloft that will bring some lift in the evening, and possibly lingering overnight in the northeast corner. There could be up to 1000 J/kg of CAPE for the plains in the evening, but with little shear, the threats are mainly subsevere wind gusts, and possibly localized heavy rain if there gets to be some organization to slow moving storms. The timing of the shortwave Thursday night sets up an interesting pattern for the Fourth of July. We`ll likely have convection exiting in the early morning hours, and drying northwest flow aloft by afternoon. There will also be some cooling aloft though, enough to allow for another round of convection in the slightly cooler and drier airmass. We`re hanging on to scattered afternoon/early evening PoPs, but if the drying is enough there may be less activity or a quicker end. In any event, it doesn`t look like a particularly active day in terms of coverage or intensity. For the weekend and beyond, there are just subtle day to day changes as we`ll be under a mean ridge with a couple of shortwaves moving over the top of it. There`s enough variety in the low and mid level moisture in the models to make it hard to pin down details, though there is some tendency towards a little more thunderstorm activity Sunday and Monday and then warming and drying after that as the mean ridge strengthens. Overall, fairly typical early July weather with lower elevation highs mostly in the lower to mid 90s for an extended period and some threat of storms each day. && .AVIATION /18Z TAFS through 18Z Friday/... Issued at 1222 PM MDT Thu Jul 3 2025 VFR through tonight. East to southeast winds will become southerly with gusts to 20 knots at KDEN/KAPA and somewhere between north and west with lighter speeds at KBJC in the 01z-03z time range. Only isolated weak showers or thunderstorms are expected this evening. Late tonight into Friday morning, between 10z and 16z, scattered showers and thunderstorms are expected, with a 20% chance of either variable winds gusting to 25 knots or a brief period of ceilings below 6,000 feet. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...RPK DISCUSSION...Gimmestad AVIATION...Gimmestad