Area Forecast Discussion
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
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476 FXUS65 KGJT 270455 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 1055 PM MDT Thu Sep 26 2024 .KEY MESSAGES... - Dry and unseasonably warm conditions are expected for the remainder of the week through at least the first few days of next week. 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 tomorrow afternoon. Outside of Friday, dry conditions prevail. && .SHORT TERM /THROUGH FRIDAY/... Issued at 236 PM MDT Thu Sep 26 2024 The blocky pattern across the CONUS continues with a low...ridge low pattern extending from the EPac through the Southeast. The northern extend of the ridge over us is getting deformed a bit by a more robust wave moving through the northern stream near the Canadian/US border. The interface between this wave and the ridge has tightened the thermal profile aloft...hence a core of stronger Southwesterlies. A bit of mositure has been caught up in this flow and evident on the 12Z KGJT RAOB which has led to the uptick in cloud cover today. The subsidence inversion over this moisture should prevent much upscale and not expecting any shower activity...but late day heating and strong terrain circulations may have another say. The chance of storms continues to be hinted at tomorrow along the central and divide mountains...and farther back into the central San Juans. Large scale ascent is not very evident but rather isentropic levels show easterly upslope flow as early as tonight pushing moisture into this area. A weak low level boundary connected to the northerly wave looks to dive down the High Plains of CO tomorrow morning and this added upslope looks to help form these mainly terrain based storms tomorrow. Coverage looks widely scattered at best and there could be a few gusty winds in the afternoon associated with these high based storms which should be ending through the evening...possibly lingering over the eastern San Juans toward midnight. Well above normal/near record temperatures continue. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... Issued at 236 PM MDT Thu Sep 26 2024 There remains no big changes to the pattern through the weekend and really into early next week. The downstream low which will have absorbed Helene will slowly be filling as we head into Monday. The upper ridge remains firmly anchored over the 4 Corners region and a more compact cyclone will be heading lingering near the SoCal Coast. This keeps the hot airmass in place along with the dry conditions. There is some lingering moisture over the San Juans going into Saturday which will likely pops some more convective clouds but confidence extremely low this will turn into anything of significance. Temperatures will continue to run some 10 to 15 degrees above normal with 90 degrees expected over many of the lower desert valleys. The latest 90 degree temperature recorded at GJT is Sept 27th so this may be pushed back by a few days with records possible each day through Monday. The early to mid part of next week will only be slightly cooler. The northern stream looks to be dipping a bit farther south through the latitudes and finally being to break down blockier pattern over the southern CONUS. There may a better chance of perception showing in the forecast...but not until late in the week. Confidence in models figuring this out by then is not high. && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 1053 PM MDT Thu Sep 26 2024 VFR conditions will prevail for the next 24 hours. Aside from some passing high clouds, skies will be generally clear, and winds will follow typical terrain driven patterns. Some mid level clouds may move in for higher elevation terminals tomorrow afternoon. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...15 LONG TERM...15 AVIATION...TGJT