Area Forecast Discussion
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
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968 FXUS65 KBOU 292040 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 240 PM MDT Wed May 29 2024 .KEY MESSAGES... - Scattered thunderstorms this afternoon and evening. A few severe storms are likely with large hail and strong winds in areas east of I-25 the main threat. - Scattered afternoon showers and thunderstorms Thursday-Friday. A few could be severe across the eastern plains. - Warmer and drier beginning Saturday. Hottest temperatures so far this year likely Sunday into Monday. && .SHORT TERM /Through Thursday/... Issued at 239 PM MDT Wed May 29 2024 Ongoing scattered storms and showers should continue through this evening. Weaker shear, instability, and lower dew points should keep showers non-severe. Areas across the eastern plains to right of the dryline align with SPC slight risk through this evening. Far east, MLCAPE increases near 800-1000 J/kg and lapse rates between 7- 8C/km. There still a lack of favorable shear for thunderstorm development but the threat of hail is high. Up to 2 inch hail could occur from these severe storms along the eastern plains. With cyclone development near DIA and robust outflow boundaries, the threat of landspouts will occur through this evening mainly for Morgan, Washington, Logan, eastern Adams, and eastern Arapahoe counties. Thursday, a cold front will arrive which will lead to lower temperatures in the afternoon. Although conditions should become stable after the front, daytime heating may lead to scattered storms and showers along the Palmer Divide and adjacent plains. There is low confidence in a severe threat of tornadoes but wind gusts up to 60 mph and up to 1 inch hail will likely become the main threat. && .LONG TERM /Thursday night through Wednesday/... Issued at 239 PM MDT Wed May 29 2024 Scattered thunderstorms are expected to continue into the evening Thursday, mainly along and south of I-70. However, the NAM has joined the GFS in showing isolated/scattered storms are able to break the cap across northeast Colorado. Some of these storms are expected to be strong to severe with ML CAPE to around 1000 J/kg. For Friday, westerly flow aloft will increase as a trough passes north of Colorado. Meanwhile at the surface, easterly winds will transport moisture westward with dew points in the upper 40s to lower 50s as far west as I-25. With dew points this high, ML CAPE reaches 1000-1500 J/kg. Seems to be a good setup for strong to severe storms due to good shear, moisture, and instability. One limiting factor to severe storms will be low clouds Friday morning and how long they persist. They could limit warming and result in a capped airmass. Southwest flow aloft will bring warmer and drier conditions to much of the area Saturday. A dry line sets up over the eastern plains Saturday. To the west of it, weak isolated high based showers and storms are expected. To the east of the dry line, strong to severe thunderstorms will again be possible. For Sunday through Wednesday, models continue to advertise a warmer and drier period even though upper level details are somewhat uncertain. For Sunday, a lee side surface trough is expected to develop under a westerly flow aloft. This will bring gusty westerly downslope winds. Temperatures heat up along the Front Range with the first 90 degree day possible. The eastern plains may end up east of the lee side trough. Areas east of the trough will see a chance for afternoon/evening thunderstorms. Monday and Tuesday will remain mild and dry. Downslope flow weakens, which should result in slightly cooler temperatures, though highs are still expected to reach the mid to upper 80s over northeast Colorado. Surprisingly good agreement among the models for Wednesday. They show an upper level trough passing well north of cold. A cold front associated with this system dives south across Colorado Tuesday night bringing cooler and continued dry air for Wednesday. && .AVIATION /18Z TAFS through 18Z Thursday/... Issued at 1209 PM MDT Wed May 29 2024 Expect VFR conditions through the TAF period. With scattered showers developing earlier, VCTS could begin as early as 19Z-20Z. These storms should remain weaker as favorable conditions for severe storms remain east of all terminals. Wind direction will likely become difficult as showers pass nearby but generally wind speeds between 12-20 mph producing gusts up to 25-35 mph. Winds shift southwest tonight then shifting northerly into Thursday morning. Wind speeds increase between 10-13kts through late Thursday morning. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...AD LONG TERM...Meier AVIATION...AD