259 FXUS65 KGJT 050609 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 1209 AM MDT Thu Jun 5 2025 .KEY MESSAGES... - Light showers will continue overnight but remain isolated to scattered. Another round of showers and storms is expected Thursday afternoon. Moderate to heavy rain and localized flash flooding will be the main threats. Stronger storms have potential for gusty winds and small hail as well. - Uncertainty lies in morning cloud cover which could delay the start of afternoon convection or impact storm intensity and resultant storm coverage later in the day. - Unsettled weather remains in place for the remainder of the week resulting in below-normal temperatures and a daily afternoon thunderstorm threat. Drier and warmer conditions potentially by the weekend. && .UPDATE... Issued at 1200 AM MDT Thu Jun 5 2025 Showers have ended across southeast Utah with some light showers lingering across southwest Colorado. Let the Flood Watch expire at midnight since the threat for excessive rainfall and flash flooding has lessened. && .SHORT TERM /THROUGH FRIDAY/... Issued at 349 PM MDT Wed Jun 4 2025 Complex and dynamic scenario this afternoon where there is a heavy rainfall and flooding threat across the southern CWA where anomalous moisture remains in place. Across the central and northern CWA under a slightly drier regime there is more a gusty wind threat. Upstream storms moving off the Wasatch toward a northward lifting outflow boundary look to spread this wind threat near and north of I-70 through the afternoon and early evening. Subsidence behind an early wave has quieted the far southern CWA and confidence is decreasing that it can recover for a heavy rainfall threat the remainder of the evening. However there is a trailing upstream wave and upper jet support moving through the 4 Corners this evening to support redevelopment. Soundings still show the deep skinny CAPE profile and a robust warm cloud depth in the south which would support moderate to heavy rainfall rates even with weaker updrafts. The northern and southern stream will be merged over our CWA with the confluent flow continuing to pull anomalous upstream moisture through the central CWA while drier air drops in up North. This is likely to keep at least some degree of convection going into the early morning hours. This residual moisture and clouds should again play a role in the strength of convection on Thursday. Energy from an upstream shearing low will again be pulled through the flow tomorrow giving a boost to the shear profile. Enough cloud cover will inhibit the release of instability but where pockets of sunshine can break out on the edge of the drier air in the North...stronger organized storms would result. So another complex scenario with heavy rainfall...hail and stronger winds all potential threats. The back edge of the this shearing wave moves through tomorrow evening which again keep a threat of late night storms going. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Issued at 349 PM MDT Wed Jun 4 2025 Very little changes to end out the week with confluent flow staying in place overhead and due to persistent upstream split flow and low pressure hovering over the central Pacific Coast. Moisture slowly wanes but not enough to prevent daily afternoon shower and thunderstorm activity well into the weekend. An arriving Rex High later in the weekend...over-topping the anchored Cali-Low will drop into the Great Basin and help dry and warm things up into early next week. Though warmer the afternoon thunderstorm threat will continue into early next week through the threat of heavy rainfall will most likely be replaced by gusty outflow winds. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1200 AM MDT Thu Jun 5 2025 Showers will continue overnight across northern and southern parts of western Colorado with light to pockets of moderate rain at times, reducing vis and cigs briefly to MVFR. Lightning potential remains isolated as this cannot be ruled out. Skies remain sct to bkn with VFR conditions outside of showers. After some clearing after 12Z through late morning, expect storms to develop over the high terrain after 17 or 18Z and some drift into the valleys by late afternoon into the evening. Confidence was higher to include prevailing rain or VCTS at KTEX but lower elsewhere as far as timing, so introduced PROB30 groups for thunderstorms after 20Z across most TAF sites. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ UPDATE...MDA SHORT TERM...15 LONG TERM...15 AVIATION...TGJT