Area Forecast Discussion
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
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080 FXUS65 KGJT 282130 CCA AFDGJT Area Forecast Discussion...CORRECTED National Weather Service Grand Junction CO 330 PM MDT Sun Apr 28 2024 .KEY MESSAGES... - Showers diminish this evening as the atmosphere stabilizes in the wake of today`s disturbance. - Above normal temperatures return during the first half of the week. - A fast moving system in northwest flow will bring another round of showers and localized thunderstorms to the eastern Uinta Mountains and northwest Colorado Monday night through Tuesday morning. && .SHORT TERM /THROUGH MONDAY NIGHT/... Issued at 330 PM MDT Sun Apr 28 2024 Expect showers to diminish this evening in the wake of the weak short wave passing over the forecast area now, along with cooling surface temperatures helping stabilize the atmosphere. Skies clear from west to east during the night, though clouds are likely to hang on over the northern and central Colorado mountains through sunrise Monday. Flow becomes zonal on Monday as a trough sweeps from the West Coast to the Great Basin during the day. An increased pressure gradient across the north should lead to breezy afternoon winds. Warm air advection combined with morning sunshine will lead to warmer temperatures Monday afternoon with readings expected climb to near 5 degrees above seasonal norms for most locations. A modest push of moisture ahead of the trough combined the destabilizing effect of surface warming may lead to isolated showers/thunderstorms over the eastern Uinta Mountains as well as the Elkhead, Park and Flat Top Mountains during the afternoon. Shower chances ramp up Monday evening and become likely across the northwest Colorado plateau and the northern Colorado mountains overnight. This fast moving system is expected to deliver up to 6 inches of new snow across portions of the Park Range, mainly above 9,000 feet. More scattered activity is expected along the I-70 corridor east of the Debeque Canyon and portions of the Grand Mesa and central Colorado mountains. Areas to the south will see little chance for precipitation from this quick hitting storm. Despite pushing a cold front to near the I-70 corridor, overnight lows are expected to show little change as gradient driven winds keep the lower levels mixed. && .LONG TERM /TUESDAY THROUGH SATURDAY/... Issued at 330 PM MDT Sun Apr 28 2024 The quick moving shortwave and cold front that tracked along the Wyoming and Colorado border and brought showers to the northern tier of the CWA Monday night will be long gone by the mid morning hours on Tuesday. In its wake, mainly dry weather is in store for the remainder of the day with temperatures near to above normal across the south and near to below normal across the north. There may be an isolated returning pop-up shower along the Continental Divide Tuesday afternoon, but that would be about it. Wednesday into Thursday, another trough is progged to dig south and eastward out of the Pacific Northwest and across the northern Four Corners states, towing a cold front along with it. Ahead of this system, the pressure gradient tightens and kicks up the winds a good bit Wednesday afternoon with gusts upwards of 35 to 45 mph. Near critical fire weather conditions may be a concern across the lower elevations of southeast Utah and southwest Colorado where relative humidities dip into the teens. Up north and along the Continental Divide mountains, precipitation is likely to break out along the front with rain in the valleys and snow in the highest elevations...mainly above 9000 to 10000 feet. Farther south, dry air in the lowest levels may keep much precipitation from reaching the ground, at least initially. Any virga would only enhance the winds in those areas. The evolution of this system beyond Wednesday remains somewhat uncertain, primarily as a result of how fast the trough ejects eastward. Most guidance is fairly quick with conditions improving by Thursday afternoon. The GFS on the other hand is much slower and doesn`t clear precipitation out until Thursday night. For now, will lean towards the faster solutions while keeping the GFS in mind as a less favored potential outcome. Either way, Thursday will end up much cooler in the wake of the front with highs several degrees below normal. For Friday and Saturday, the pattern looks mainly dry aside from a couple weak waves brushing the far northern tier of the CWA. Perhaps these waves can squeeze out a shower or two in the northern mountains, but otherwise it`s more likely to stay dry with limited moisture and ridging trying to build in from the west. This will also allow temperatures to quickly warm back up with highs returning to well above seasonal norms by the start of the weekend. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 1145 AM MDT Sun Apr 28 2024 Just as this morning`s low clouds and fog started clearing out, daytime heating and a weak wave moving overhead have allowed clouds to start filling back in. Ceilings will hover between VFR/MVFR across most mountain terminals this afternoon with ILS breakpoints being reached at times as well. Scattered showers and a few storms will be around but will start to diminish after the sun sets. Any shower or storm can produce erratic and gusty winds. More widespread VFR returns late this evening with skies becoming partly cloudy overnight. Quiet weather then prevails through the day on Monday with light, terrain driven winds. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...NL LONG TERM...MDM AVIATION...TGJT