474 FXUS65 KGJT 162046 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 246 PM MDT Thu May 16 2024 .KEY MESSAGES... - Warmer and breezy conditions expected through the weekend. Temperatures up to 10 degrees over climatology expected. - A frontal boundary straddling the CWA will spark additional showers and thunderstorms Saturday and Sunday. Gusty outflows, lightning, and small hail are possible. - Temperatures cool behind a front at the beginning of next week, then warm back up midweek and beyond. && .SHORT TERM /THROUGH FRIDAY NIGHT/... Issued at 230 PM MDT Thu May 16 2024 A loosely organized low is slowly drifting east across New Mexico this afternoon. Wraparound moisture on its northern periphery is interacting with the northerly orographics on the San Juans and along the southern Continental Divide to produce a persistent batch of thunderstorms and showers on the terrain. This will continue into the early evening as the eastward progression of the low strips away some moisture and sunset takes away some afternoon instability. A few showers will likely get a longer lease on life in the Pagosa Springs area as they remain within reach of forcing into the late evening hours. A few gusty outflows are possible along the southern shoulders of the San Juans as storms degrade. Things will quiet down after midnight and clear skies will prevail overnight. The tap of cooler, drier air gets turned off on Friday, as we shift more westerly ahead of another weak frontal boundary settling southward, thanks to the broad trough working across the Intermountain West to our north. An isolated shower can't be ruled out Friday afternoon along the northern half of the CWA. Winds aloft pick up too, so gusty surface winds(25-35 mph) north of the Colorado River can be expected. Elsewhere, hot and dry conditions quickly take charge, with desert valleys in the upper 80's and the mountain valleys in the 50's and 60's Friday afternoon. A few clouds along the frontal boundary will take some bite out of the warm and sunny conditions. Some of this cloud cover sticks around Friday evening and into the overnight. Weekend warriors will want to take note of the warm and breezy conditions Friday, as this will be a precursor for Saturday and Sunday. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... Issued at 230 PM MDT Thu May 16 2024 On Friday night a system passes over the northern Plains causing a cold front to enter our area from northwest. This system will advect moisture our way, but a midlevel cap looks to prevent convection. On Saturday a weak shortwave makes landfall in southern California, which causes the previous front to switch gears and lift northward. Midlevel warm advection ahead of the wave should improve the lapse rates and with moisture in place there is a chance for afternoon convection. The lifting warm front could act as a focus for lift so showers and storms may develop along that as well as the high terrain. On Sunday a broad trough remains anchored over the western CONUS keeping us is in southwest flow. The moisture from previous days will concentrate across the northern third of the area, which is where showers and storms are possible in the afternoon. The pressure gradient increases on Sunday as well so afternoon wind gusts could approach 45 mph for some locations. Warm advection causes highs to top out at 5-10 degrees above normal. On Monday the western trough comprised of several troughs becomes elongated and pushes eastward through our region later in the day. Strong southwest flow ahead of the system is expected once again and convection returns to the northern half of the area. Those precip chances could expand over the rest of the area since a weak cold front is expected to move through. Conditions dry out Monday night as the trough axis swings east of the Divide. Quasi-zonal flow aloft develops in the wake of the trough. This should keep the weather fairly quiet into midweek. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 1107 AM MDT Thu May 16 2024 VFR conditions under mid to high cloudiness is expected over the next 24 hours. A few showers and storms are possible over SW Colorado this afternoon but coverage will be limited enough to keep VC in the TAF forecast for now. Gusty winds remain the main threat near storms. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...LTB LONG TERM...KJS AVIATION...TGJT