Area Forecast Discussion
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
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310 FXUS65 KGJT 022351 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 551 PM MDT Sun Jun 2 2024 .KEY MESSAGES... - Showers and thunderstorms will fire over northern portions of the CWA today. Gusty winds and small hail expected from the stronger cells. - Another round of convection expected Monday with the Flat Tops and northern mountains favored during the evening hours. - Temperatures will remain above normal and into the coming week. The warmest temperatures of the season thus far will be Thursday and Friday at 10 to 15 degrees above normal. - Major stem rivers will continue to show rises over the coming days thanks to warm surface temperatures. && .SHORT TERM /THROUGH MONDAY NIGHT/... Issued at 1217 PM MDT Sun Jun 2 2024 Convection has already started firing over the northern valleys as expected. This convection is in response to an approaching shortwave trough that is just to our west. As it moves through, convection will increase though models have consistently placed the convection over northern portions of the CWA. Limited moisture will preclude most, if any, convection for areas south though a quick popup can`t be completely ruled out. Forecast soundings highlight dry lower levels across the area which is also borne out with local obs reporting humidities in the teens. This type of environment favors gusty surface winds and don`t see that changing this afternoon. Some outflow winds from the stronger cells will likely reach 40 to 50 mph, if not a bit higher. Forecast DCAPE values range from 500 to over 1000 J/kg in some spots so chances are increased for stronger downdrafts associated with this convection. Along with the winds, some hail will also be possible. Outside of the convection, the usual Cu buildup over the higher terrain will occur along with some high clouds moving overhead. Convection will die down later this evening giving way to calm conditions. The next shortwave trough to move in will move in from the northwest. The base of the trough won`t move through until the late evening hours on Monday so while northern portions of the CWA might see a few showers/storms coverage will be minimal at best. One thing many areas will see will be some gusty surface winds ahead of the wave. Areas north of the San Juans will see gusts of 25 to 35 mph with lower gusts south. Heading into the evening hours, the northern mountains and Flat Tops are favored to see some showers and a few storms. Like today, outside of the showers/storms, look for some mid to high level clouds from mid afternoon onwards. Warm temperatures remain. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Issued at 1217 PM MDT Sun Jun 2 2024 A weak but dry embedded wave may kick off a few more thunderstorms across the northwest Colorado mountains on Tuesday afternoon but, elsewhere, look for drier and warmer weather. A strong ridge of high pressure will build across the Desert Southwest while a potent upper level low dominates the eastern CONUS. Benign weather prevails for Wednesday before the axis of the ridge begins to shift east of the Divide as troughing elongates off the Aleutian Islands. Aiding in the shift will be the presence of a cut off low centered off the coast of Baja, helping to deflect that ridge axis by Thursday. Guidance remains inconsistent regarding the weak advection of subtropical moisture into the area underneath the ridge with the latest NBM knocking back shower potential late in the week. For now, the arrival of at least high-based moisture would bring some passing clouds. This weekend will see the cut off low swing northeast into the southwest CONUS but confidence on what impacts we will see remains low. Overall, the long term will be quiet but by the time we hit the weekend a shift towards more unsettled conditions is possible. As noted in prior discussions, the strong warming trend will be the main highlight of the long term period. Under the building ridge highs will climb to 10 to 15 degrees above normal and even approach the lower triple digits in our desert valleys. Even with the ridge axis shifting farther east later in the period highs will remain 5 to 10 degrees above normal through the weekend. Low temperatures each night will also be unseasonably warm. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 541 PM MDT Sun Jun 2 2024 A few scattered showers and thunderstorms will continue over the next couple of hours across northwest Colorado. The primary concern with these will be gusty outflows, a few of which will near 40 mph. Elsewhere across the region, scattered mid and upper level clouds continue through the period as waves of Pacific moisture work across the Great Basin. Winds will settle down at sunset, remaining light and terrain driven through the overnight hours. Monday afternoon, winds pick back up mostly westerly again, with gusts 25-35 mph and higher near showers and thunderstorms. Monday`s shower activity is expected mostly north of I-70. Gusty outflow winds and brief downpours will impact terminals near these showers. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...TGR LONG TERM...MMS AVIATION...TGJT