Area Forecast Discussion
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
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649 FXUS65 KGJT 291750 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 1150 AM MDT Wed May 29 2024 .KEY MESSAGES... - Conditions mainly dry and breezy, with chances for isolated to scattered showers and thunderstorms over the higher terrain each afternoon/evening throughout the week and into early next week. - Aside from a brief dip to near normal temperatures Thursday, expect above normal warmth this week. && .SHORT TERM /THROUGH THURSDAY/... Issued at 347 AM MDT Wed May 29 2024 With the ridge pushed out onto the Plains and the trough moving ashore in the Pacific Northwest, the southwesterly flow aloft over eastern Utah and Western Colorado is advecting a drier airmass above 550 mb into the region spelling a down turn in convective activity this afternoon. Will still have isolated to scattered showers and thunderstorms favoring the terrain through peak diurnal heating with the warmest high temperatures for the week at five to ten degrees above normal for the end of May, a little warmer than yesterday. Look for increased winds at 20 mph gusting 30 mph this afternoon with the tightening pressure gradient ahead of a cool front pushing in from the northwest. Shower activity will continue into the evening in the northern mountains as a cool front moves through. There isn`t much moisture entrained with this front, limiting convection in spite of the frontal dynamics. The primary threats will be gusty outflow winds and occasional lightning. The front will move to the southeast through the region overnight possibly kicking off an isolated shower and dropping temperatures Thursday by about five degrees. With the drier air in place, Thursday will see yet a further down-tick in convective activity across the region with only isolated showers and thunderstorms mostly along the Continental Divide. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Issued at 347 AM MDT Wed May 29 2024 As noted in previous discussions, there`s been a noticeable poleward shift in the polar jet according to latest models. As a result, flow aloft has weakened, and the influence of long wave energy appeared markedly diminished over the forecast area in the long term. As little moisture was indicated to move into the area with flow largely zonal, moist convection will be the product of diurnal warming and the resultant instability it brings. Aside from Saturday, afternoon and early evening thunderstorms are expected to be isolated in coverage and confined mainly to the mountains of the Continental Divide. The main threat from this activity will be strong outflow winds as the subcloud layer appeared very dry in forecast soundings. The uptick in shower activity Saturday appeared to be the result of easterly flow over the eastern Plains of Colorado which drives moisture to the forecast area`s eastern boundary. Aside from the aforementioned mountains, the remainder of the forecast area will be dry with temperatures hovering near 5 degrees above normal on average. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1150 AM MDT Wed May 29 2024 VFR conditions should prevail over the next 24 hours. Isolated to scattered showers and thunderstorms have developed late this morning over the northern and central mountains and are expected to favor the high terrain, although some drift into adjacent valleys to the east-northeast cannot be ruled out. Gusty outflow winds to 40 mph or greater are possible near any storms. Confidence was high enough to include VCTS at KHDN, KASE, KEGE and KGUC where convection is expected to continue. Otherwise, breezy afternoon winds of 20 to 35 mph are possible at times with partly to mostly sunny skies elsewhere. Gusty winds and VCSH expected to accompany the frontal passage, especially across the north this evening. Skies should clear and showers dissipating overnight. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...DB LONG TERM...NL AVIATION...MDA