Area Forecast Discussion
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
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167 FXUS65 KGJT 100956 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 356 AM MDT Fri May 10 2024 .KEY MESSAGES... - Snowfall will favor the eastern Uinta mountains in northeast Utah and the higher elevations of the San Juans and central Colorado mountains through Saturday. - Snow amounts in excess of 6 inches have a 40 percent probability of occurring over the highest peaks of the San Juans mountains over the next 36 hours...with lesser probability of at least 20 percent along the Elk and West Elk mountains. Main travel corridors are expected to mostly remain wet during the day. - Unsettled conditions will persist through the weekend along with a slow warming trend...however temperatures will remain below normal. Above normal temperatures return next week. && .SHORT TERM /THROUGH SATURDAY/... Issued at 356 AM MDT Fri May 10 2024 Satellite imagery indicates clouds and showers wrapping around the center of the low pressure system that appears to be centered somewhere over southeast/east-central Utah. Webcams indicate the best snowfall rates falling over Monarch Pass and the central spine on the eastern fringe of our CWA as expected. Further west, scattered convective showers are developing over the San Juans and moving into the central mountains, tracking over lower elevations as they do but precipitation rates appear light at this time with roads at the higher passes remaining wet at this time, most likely due to the mild antecedent conditions. These showers are brief and expect more of the same as we head into the day today. Snow accumulations thus far have been around 2 to 4 inches at best across the eastern Uintas and portions of the West Elks and Sawatch, really closer to the eastern side of our zones bordering PUB. This is as expected with limited impact on our side with wet roads during the day. There appears to be two circulation centers with this retrograding low under the Rex Block, one over east central Utah currently as of this morning and another that will develop over southern Nevada as the low retrogrades and the east-central Utah circulation sort of fizzles out by this afternoon. This along with steepening lapse rates especially across the Four Corners should allow for more convection this afternoon to develop over southwest Colorado and track into the central mountains and around the low to the north across northwest Colorado and northeast Utah by this evening. Expect scattered to widespread showers with embedded thunderstorms. Milder temperatures should keep snow levels above 9000 feet but any convection could lower snow levels and increase rates at times, although with the convective nature of showers and quicker motions, these conditions should be brief. Another 2 to 4 inches of snow remains possible in the higher elevations with passes remaining wet. A brief pause in shower activity looks to be seen this evening across the south but redevelops as the low center shifts closer across southern Utah by Saturday morning prior to daybreak. Some hi res CAMs are picking up on increasing convective showers Saturday morning across southeast to east- central Utah and spreading into southwest and west-central Colorado by Saturday afternoon as the low moves northeast across southeast Utah to west-central Colorado with the trough axis moving overhead. More widespread shower and thunderstorm activity is expected on Saturday as this happens. Temperatures will continue to warm though with another 2 to 4 inches of snow possible at the highest elevations of the San Juans and central mountains, mostly above 10,000 feet with limited impacts at pass level and some wetting rain among some of the lower elevations. Despite the slowly warming temperatures each day today through the weekend, temperatures will still remain below normal. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... Issued at 356 AM MDT Fri May 10 2024 The back edge of the trough will be moving eastward, crossing the Divide Saturday evening before subsidence takes hold by Sunday morning with northerly flow on the backside of the exiting trough. A ridge of high pressure tries to build across the Great Basin into the Intermountain West Sunday, but additional shortwaves will move through the unsettled northerly flow, allowing for continued development of afternoon convective showers, favoring the higher elevations of western Colorado mostly along the Continental Divide. Conditions should be mostly dry though across eastern Utah and far western Colorado, especially lower elevations. An additional couple of inches of snow will be possible at the higher peaks but, again, little to no impact is expected. Unsettled northerly flow will keep showers in the forecast for Monday morning but a weak transitory ridge will build in from the west for the afternoon. This advection of drier air will see showers taper off in coverage, though scattered activity will continue over the mountains. For Tuesday and Wednesday, moisture will once again be on the rise as a trough of low pressure begins to dig into the Intermountain West. This will kick the ridge east and see flow aloft shift to the west/southwest. Winds don`t look to increase too much ahead of this system but, by the midweek point, scattered to potentially numerous showers and some storms can be expected. The trough is projected to drop through the area from the north Wednesday night into Thursday, potentially trying to close off another low over the Desert Southwest with a Rex Block trying to form once again over the west by the end of next week. This is still a ways out and a lot can change but it does look to remain unsettled through next week as well. Temperatures through the period will start off below normal on Sunday given the unsettled pattern. A gradual rebound will occur with a slow warming trend as we head into the new work week and the flow begins to shift to a more mild component. High temperatures should rise to around 5 degrees above normal next week with slightly cooler than normal highs for the mountain areas. A similar trend is expected for low temperatures through the period. A brief cooldown is possible Wednesday into Thursday if that trough moves through the area from the north. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 926 PM MDT Thu May 9 2024 Isolated showers are possible tonight especially around KGUC and KASE. Another round of showers develops towards sunrise and spreads across the region through the afternoon and early evening. A few storms could occur along with 30 mph wind gusts. VFR conditions are most likely although brief MVFR periods are possible. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...MDA LONG TERM...MDA/MMS AVIATION...TGJT