Area Forecast Discussion
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
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373 FXUS65 KGJT 291759 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 1159 AM MDT Mon Apr 29 2024 .KEY MESSAGES... - A disturbance passing to our north will bring rain showers and mountain snow to the northern half of the CWA tonight. Snow accumulations of 1-3 inches expected. - Afternoon winds will remain gusty this week, as a series of disturbances along the jet stream impact the region. - A brief cool spell on Thursday in the wake of a cold front will drop temperatures, before things warm back up heading into the weekend. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 332 AM MDT Mon Apr 29 2024 Skies have begun to clear out across the CWA this morning with some drier air arriving under a weak ridge traversing the region. Remnant moisture is still hung up on the west side of the Divide, with a few low/mid cloud ceilings being reported in Craig, Eagle, Aspen, and Gunnison. Unfortunately, much of this cloud cover will remain hung up on the terrain until reinforcements arrive later today. Desert valleys along the state line will see generous sunshine today though. The respite from the clouds will be brief today, as another trough of low pressure approaches from the northwest this evening and pushes additional cloud cover across the region, primarily north of I-70. Winds will pick up ahead of this disturbance across northeast Utah and northwest Colorado this afternoon. Southwesterly winds will gust on the order of 20-30 mph until about sunset. Warm air advection will push temperatures back into the range of late April climatology too. A few early showers from this disturbance are possible late afternoon on the eastern Uintas, but most precipitation will hold off into the overnight hours after midnight. Showers will struggle to reach the I-70 corridor, but northward we will see light rain early Tuesday morning for most locales below 8000 feet. Snow accumulations on the eastern Uintas, Elk Heads, Flat Tops and the Park Range will hover around 1-3 inches, with a few higher totals up on the upper peaks. Precipitation tapers quickly around lunch Tuesday and we get back to our regularly scheduled spring programming of breezy conditions under cloud free skies. Winds will, once again, pick up to around 20-30 mph around the region Tuesday afternoon, thanks to a generous jet streak draped over northern Colorado all day. Afternoon highs will have no problem getting back into the 70`s for most of our lower elevations. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Issued at 332 AM MDT Mon Apr 29 2024 Zonal flow sets up across the region at the start of the long term period. A messy area of low pressure will be situated over Idaho and Montana bringing some widespread precip to those areas all the way back to the Pacific Coast. During the day Wednesday, the system becomes a bit more organized as one center of low pressure forms along the US/Canadian border and upper level support causes a midlevel trough to form which will be reflected at the surface as a cold front. A jet streak will ride above these features and as it rounds the base of the upper level trough, will bring the cold front into our CWA while also providing some lift. The front itself will also cause some lift so with all these ingredients in place, there`s no wonder the models are bringing some valley rain and mountain snow to the the northern half of the CWA along with some isolated thunderstorms. Some differences kept popping up between models and with the latest runs there are some minor timing differences but the general gist of said precip forming ahead of, and along, the cold front is in reasonable agreement. With that, look for precip chances to increase during the Wednesday and continuing through Thursday morning/early afternoon. After that, model agreement is awful. Both the EC and GFS pick up on small wave moving across the northern Intermountain West as an area of low pressure moves into the PacNW. The GFS brings this low ashore into Washington State Friday night and has it filling (weakening) while the EC brings the low down the West Coast and does NOT have it filling. All that being said, we may see a few showers for the rest of the long term period as small disturbances brush our northern and southern neighbors but nothing significant noted. Will be interceding to see how the models resolve themselves with regards to that area of low pressure. As far as temperatures are concerned, Thursday will be the coolest day as the cold front moves through. Won`t be short lived though as temps increase 5 to 10 degrees Friday and continue the upward trend into the weekend. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1159 AM MDT Mon Apr 29 2024 A weak disturbance moving over northwest Colorado will bring lowered ceilings for KHDN. There`s a slight chance for showers at KHDN through 21Z, but odds didn`t favor mentioning in the TAF. Meanwhile, ceilings below ILS breakpoints at times at KASE and KEGE may slow traffic into those airports this afternoon. Breezy west and southwest winds will be common for most sites into the evening. A more energetic disturbance moves over the area tonight with showers almost certain at KHDN in the early morning hours. This activity is likely to bring ceilings to ILS breakpoint levels, but impact on visibility less certain. Elsewhere, winds will drop off and VFR conditions continue during the remainder of the period. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...LTB LONG TERM...TGR AVIATION...NL