Area Forecast Discussion
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
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737 FXUS65 KGJT 240553 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 1153 PM MDT Sun Aug 23 2026 .KEY MESSAGES... - This week will see daily afternoon thunderstorm chances, particularly along the higher terrain of western Colorado and eastern Utah. - Localized heavy rainfall continues to pose a threat to flash flooding over burn scars and susceptible terrain. - Daytime highs will run ~5 degrees above normal to start the week. && .DISCUSSION... Issued at 1014 PM MDT Sun Aug 23 2026 THIS WEEK: The current synoptic level setup continues to be dominated by high pressure over the west. Beginning on Monday, moisture and PWAT anomalies begin to take a downturn compared to previous days. This will mean less widespread precipitation chances for the area. However, there remains enough moisture to cause daily afternoon thunderstorm chances over the higher terrain. Orographic lift will also be a contributing factor to help enhance these mountain storm chances. Additionally, morning cloud cover has the ability to dictate where storm activity materializes as daytime heating can affect the evolution of storms. As a result of all of this, localized heavy rainfall is possible from these storms which inherently poses a threat of flash flooding, especially around burn scars and susceptible terrain. By midweek, the high gradually shifts back towards the Desert Southwest. Because of the continuous presence of moisture, each afternoon`s storm chances may look similar to each other. That is, isolated to scattered and mostly confined to the higher terrain. Synoptic forcing will be somewhat weak for this period, with the occasional shortwave interrupting the flow around the high, which will provide some additional lift. So long as the surface levels remain saturated in certain places, flash flooding will remain a concern, particularly for burn scars and susceptible terrain. Primary threats with these storms continue to be localized heavy rainfall, lightning, and gusty outflows. Daytime highs will start off ~5 degrees above normal to start the week, with a slight uptick to ~5-10 degrees above normal by late week. By the weekend, temperatures begin to gradually decrease each day. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1123 PM MDT Sun Aug 23 2026 Isolated showers with an occasional thunderstorm are tracking east across the region generally north of I-70. Look for these to continue overnight and into the morning. Isolated to scattered showers and thunderstorms will redevelop over the higher terrain with some impact to the mountain TAF sites between 18Z and 00Z. Lightning, gusts to 45 kts and some hail are the threats from these storms generally along and north of the I-70 corridor. These storms will diminish after about 02Z. Otherwise expect VFR conditions with generally light terrain driven winds. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ DISCUSSION...BS AVIATION...DB