Area Forecast Discussion
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
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091 FXUS65 KGJT 271746 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 1146 AM MDT Mon May 27 2024 .KEY MESSAGES... - Isolated showers and thunderstorms are possible over the San Juan Mountains this afternoon with mostly dry and warmer conditions area wide. - Drier and warmer conditions expected this week with temperatures warming to five to ten degrees above normal by mid week. - Precipitation chances remain low through most of the week with any storm activity favoring the high terrain during the afternoon period. && .SHORT TERM /THROUGH TUESDAY/... Issued at 319 AM MDT Mon May 27 2024 A mid-level high pressure ridge develops over the Rockies today ahead of a trough over the eastern Pacific. Modest moisture in the 700 to 500 mb layer combines with jet divergence to generate isolated to low end scattered showers and thunderstorms over the San Juan Mountains with lesser chances over the central Colorado mountains. Driven largely by instability resulting from daytime heating, this activity should diminish by early evening. As the eastern Pacific trough approaches the West Coast on Tuesday the ridge axis is forced east of the Continental Divide by late afternoon. The resultant shift in flow aloft to the southwest carries moisture northward and as a result, afternoon moist convection spreads into the central and northern Colorado mountains and the eastern Uinta Mountains Tuesday afternoon. The warming trend continues early this week with readings near or a couple of degrees warmer than normal today with around 5 degrees of additional warming on Tuesday. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Issued at 319 AM MDT Mon May 27 2024 The upstream trough will continue to push onshore Tuesday night before swinging through the Intermountain West on Wednesday. Southwest flow will deepen across eastern Utah and western Colorado in response with Wednesday`s high temperatures jumping to 5 to 10 degrees above normal. In fact, the first 90 degree day looks possible for some of the lower valleys across southeast and east- central Utah as well as the Grand Valley. Of course, this is subject to change and will be dependent on how far south the approaching trough dives. At the moment, dry weather looks to prevail for most areas through the midweek point with just some passing clouds into Thursday. The higher terrain along the Divide could some isolated to scattered showers and thunderstorms both Wednesday and Thursday afternoons as the trough continues to lift northeast into Saskatchewan. A strong ridge of high pressure amplified over Hudson Bay will keep the low stalled over central Canada on Friday resulting in persistent zonal flow across the Western Slope. A secondary embedded wave looks to push through the flow late in the week, resulting in slightly better shower coverage along the higher terrain. This will also knock temperatures back down closer to the normal for this time of year but overnight lows will continue to trend slightly above normal through the period. Drier weather is projected to return for the weekend. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1146 AM MDT Mon May 27 2024 VFR conditions will prevail with SCT to BKN cumulus over the southern mountains and mostly sunny skies elsewhere. Occasional breezy conditions are possible during the afternoon, but winds should generally remain light and terrain driven. Isolated storms are possible over the San Juans but are not expected to impact TAF sites. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...NL LONG TERM...MMS AVIATION...MDA