693 FXUS65 KGJT 271149 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 549 AM MDT Sat Apr 27 2024 .KEY MESSAGES... - 6-12 inches of snow expected above 9000 feet through Sunday morning. - Temperatures will remain around 10 degrees below normal today and Sunday thanks to cloud cover and continued shower activity. - Scattered showers and thunderstorms expected Sunday afternoon with small hail and gusty winds possible, along with additional snow in the mountains. && .SHORT TERM /THROUGH SUNDAY/... Issued at 439 AM MDT Sat Apr 27 2024 Low pressure continues to drift eastward this morning as a center of low pressure located just east and north of the Four Corners pushes a series of showers northward through our CWA. Measurable rainfall has been falling most of the morning around the region. Temperatures continue to cool and snow showers have been reported at higher elevations including Telluride, Aspen, and Steamboat Springs. Additional mountain snowfall is expected today and tonight with Winter Weather Advisories in place for mountain zones above 9000 feet. Ample cloud cover and continued precipitation will keep temperatures around 10 degrees or more below climatology today. Afternoon heating will likely get squashed too, as winds shift more northwest this afternoon in the wake of the frontal passage. A few stronger snow showers and isolated thunderstorms will likely develop in the wraparound northwesterly flow this afternoon, when some of our higher peaks will see 3-4 inches of additional snow before sunset. Small hail and gusty outflows will remain a concern this afternoon too. Moisture begins to strip away tonight as the low lifts onto the Plains, this will curb precipitation pretty quickly. A few showers will linger over the Continental Divide heading into daybreak Sunday. Steep lapse rates behind the front Sunday will lead to another round of showers and a thunderstorm or two Sunday afternoon, when a few breaks of sunshine destabilize things once again. Gusty outflows, small hail, and brief downpours will be on the ticket, as well as more snow showers at the higher elevations along the Divide. Desert valleys will warm a bit more thanks to more sunshine Sunday afternoon, but highs will still hang back 5 degrees or more below normal. Shower activity will likely lead to some quick drops in temperatures too, as turbulent mixing delivers more cold air to the surface. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Issued at 439 AM MDT Sat Apr 27 2024 The shortwave pushes east of the Divide Sunday night, with shower activity tapering off gradually through the night. Westerly to northwesterly flow builds in behind this wave, which will promote some isolated mountain showers or storms on Monday afternoon by working on residual moisture. Otherwise, a transient ridge passes overhead on Monday, bringing perhaps the quietest day of the period and kicking off something of a warming trend for the lower elevations along and south of I-70, with highs running 5-10 degrees above normal by Wednesday. Across the northern half of the CWA, look for clouds and winds to be on the increase starting Monday evening as a 90-100 knot jet moves in aloft. Multiple disturbances are progged to ride this jet and clip the northern half of the CWA starting late Monday and continuing through at least Wednesday. Drier air moving in will limit the amount of precipitation that makes it to the ground, with generally less than a tenth of an inch of QPF expected each afternoon. The increased clouds and showers through Thursday will keep temperatures near to a few degrees above normal north of the I-70 corridor. A lobe of low pressure dropping out of the Pacific Northwest late Tuesday has the potential to be the next big system for the Great Basin late in the week. Current guidance tracks this low east through the Pacific Northwest and into the Northern Rockies before beginning to intensify and dropping south into the Great Basin. The details remain fuzzy at this point, as model agreement remains poor. But confidence is growing that widespread precipitation will return for the late week period. && .AVIATION /12Z TAFS THROUGH 12Z SUNDAY/... Issued at 542 AM MDT Sat Apr 27 2024 A spring storm will bring mountain snow and scattered showers and thunderstorms to the region through this TAF period. Intermittent IFR/ILS breakpoint conditions can be expected as gusty winds, small hail, and snow present numerous challenges to aviation today. Thunderstorm activity will taper around sunset, as will shower activity, but lingering clouds and moisture will still produce some opportunity for IFR conditions in the mountains tonight and into Sunday morning. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...Winter Weather Advisory until 6 AM MDT Sunday for COZ004-009- 010-012-013-018-019. UT...Winter Weather Advisory until 6 AM MDT Sunday for UTZ023. && $$ SHORT TERM...LTB LONG TERM...BGB AVIATION...TGJT