Area Forecast Discussion
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
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072 FXUS65 KGJT 260910 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 310 AM MDT Thu Sep 26 2024 .KEY MESSAGES... - Dry and unseasonably warm conditions are expected for the remainder of the week through next. Near-record highs are expected to continue today through the weekend. - A weak disturbance brings potential for isolated afternoon storms over the eastern portions of the southern and central Divide mountains on Friday. Outside of Friday, dry conditions prevail. && .SHORT TERM /THROUGH FRIDAY/... Issued at 310 AM MDT Thu Sep 26 2024 High pressure will remain in control today with dry, southwest flow as the ridge axis remains to our east. This will also lead to another day of very warm, near record high temperatures, which will be between 10 and 15 degrees above normal. Overnight lows will continue to be cool with efficient radiational cooling under clear skies, but for this time of year, lows will still be around 5 to 10 degrees above normal. A shortwave trough will move across the Intermountain West and Northern Rockies late this afternoon and evening, resulting in occasionally breezy winds across the north with some localized critical fire weather conditions but overall, winds should remain light and terrain driven for most areas. This disturbance disrupts the flow and breaks down the ridge only temporarily, pushing the high back westward as the shortwave pushes south down the Plains and Front Range on Friday. We may see a little moisture sneak westward over the Divide, allowing for isolated afternoon storms over the far eastern Divide and eastern San Juans, but at the very least, expect some cumulus buildups over the ridges during the afternoons with mostly clear conditions in the lower valleys. Given the hi-res CAMs are picking up on this activity with the NBM still showing fairly dry conditions and minimal chances, decided to blend in some of the HRRR and hi res WRF models to better reflect these afternoon storm chances. The resilient high pressure ridge builds back in over the area by Friday evening, with a quick end to any convection by sunset. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Issued at 310 AM MDT Thu Sep 26 2024 Upper-level ridging remains the dominant synoptic forcing through the weekend resulting in continued warm and dry conditions. Predictability decreases heading into the new work week with an upper-level trough tracking along the US/Canada border, squishing the northern portion of the ridge. To the southwest along the southern California coast there could also be a low pressure disturbance, although the evolution of this feature varies drastically between global models. We will have to wait and see how these two storm systems evolve and potentially interact with one another, but current trends locally support additional warm, dry days through the first half of the week. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1030 PM MDT Wed Sep 25 2024 VFR conditions under high pressure will continue through the TAF period. A few clouds might develop Thursday afternoon. Winds will respond slightly with more afternoon gusts, maintaining their terrain dominated influence. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...MDA LONG TERM...KAA AVIATION...TGJT