Area Forecast Discussion
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
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796 FXUS65 KBOU 050630 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 1230 AM MDT Fri Jul 5 2024 .KEY MESSAGES... - Chance of showers and a few storms over the northeast plains after midnight - Somewhat cool and mainly dry conditions will persist Friday through early next week. - Best chance for showers and storms in the extended will be Sunday. && .UPDATE... Issued at 813 PM MDT Thu Jul 4 2024 NW flow aloft is over the area with nrn CO on the srn end of an upper level jet. This feature was allowing for a few high based showers mainly near the WY-NE border. Overnight, there appears to be a disturbance embedded in the flow which will move across late tonight into Fri morning. This feature may enhance shower development along with a few storms over the nern plains after midnight. && .SHORT TERM /Through Friday/... Issued at 228 PM MDT Thu Jul 4 2024 Current satellite imagery shows cumulus development mainly across Jackson, Larimer, Weld, and Logan Counties this afternoon. SPC mesoanalysis shows low instability (SBCAPE < 250 J/kg) across the northern sector of northeast CO. A few weak showers are visible on radar along the WY border in Weld County. As the afternoon continues, expected more cumulus and shower development along the northern tier and foothills. A stray storm is possible. Early evening, the Palmer Divide may see a few showers as well. They will likely be low in coverage and high-based. Brief gusty winds up to 30- 40 mph are possible if a more developed shower or a weak storm is nearby. Overall, chances are less than < 15%. Cooler night expected again tonight with lows in the 50s across the lower elevations and 30s for high country. Can`t rule out a few showers across the plains. Friday`s weather will be similar to Thursday with fair weather with highs in the upper 70s to low 80s for the plains and 50s and 60s for a good portion of the high country. Most of the region will remain dry with the exception of a low chance for the Palmer divide and southern foothills where there is marginal instability. && .LONG TERM /Friday night through Thursday/... Issued at 228 PM MDT Thu Jul 4 2024 Upper level high over California and Nevada will continue to bring a heat wave to the western states while northwest flow ushers in "coolish" air over Colorado. For Friday night and Saturday, an upper level trough passing northeast of Colorado may bring showers and storms to the eastern plains late Friday night and Saturday. Lower elevation may see a surge of northeast winds from showers and storms over the Central Plains. If this pushes through, this may keep highs from reaching the lower 90s over northeast Colorado. If not, a westerly downslope flow is expected to push highs into the lower 90s over northeast Colorado. Elevated fire weather conditions will be possible over the higher terrain where westerly winds will be a little stronger. Cold front pushes south through the area Saturday night. Behind it, we could see showers/storms, mainly over the eastern plains where the better and deeper moisture will reside. This will lead to a cool day Sunday with temperatures expected only to be in the mid to upper 70s over northeast Colorado. Models are in pretty good agreement showing an upper level trough will produce at least scattered showers and thunderstorms Sunday afternoon/evening. Soundings show the airmass is well capped to begin the day, so something watch as this system nears. Cooling aloft and lift as the trough nears should be enough to overcome the cap. For Monday, subsidence behind the trough should result in a mostly dry day. Temperatures start to warm, but highs are expected to stay below normal with readings in the lower to mid 80s. For Tuesday through Thursday, the upper level high creeps closer to Colorado. Even though the high is still west of the state (over Utah) and flow aloft is northerly, warmer air will be filtering into the area. The GFS model remains quicker with the eastward progression of the ridge and thus a day early with 90 degree heat returning to the area. Expect highs to be near 90F Wednesday over northeast Colorado. If we don`t hit 90F Wednesday, we will very likely hit it Thursday as the ridge crawls eastward. Chances for showers and thunderstorms will be low with no well defined system or plume of moisture headed for Colorado. Could see a weak trough in the northerly flow aloft bring a round or two of isolated/scattered convection, so will have low PoPs (10-30) in for the afternoon/evening hours. && .AVIATION /06Z TAFS through 06Z Saturday/... Issued at 1228 AM MDT Fri Jul 5 2024 VFR through Friday. Light northeast winds will prevail, becoming southerly at KDEN/KAPA Friday evening. Some uncertainty about KBJC wind direction in the evening, likely either south or west. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...RPK SHORT TERM...Mensch LONG TERM...Meier AVIATION...Gimmestad