National Weather Service Forecast Discussion |
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590 FXUS65 KBOU 141139 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 539 AM MDT Tue Apr 14 2026 .KEY MESSAGES... - Snow expected Tuesday for the high mountains, with a good chance of light rain showers over the rest of the CWA into Tuesday evening. - Critical fire weather conditions for southern lincoln county this afternoon. - Widespread critical fire weather conditions over the plains Thursday afternoon. - Next system moves in Thursday night into Saturday morning with the promise of measurable precipitation for all the forecast area. Perhaps cold enough for snow on the plains. && .DISCUSSION /Through Monday/... Issued at 1159 PM MDT Mon Apr 13 2026 Current satellite pictures show the upper closed low centered over the northwestern corner of Arizona at this hour. Currently, there is decent convection over western Colorado, with even a few lightning strikes over the Four Corners. A cold front has pushed westward across all the plains this evening and is currently moving up into the foothills with north and northeasterly winds behind it. However, temperatures across the plains are still in the 50s this late evening. The upper trough is progged to move northeastward slowly across Colorado Tuesday into Wednesday morning. The best synoptic scale energy moves across our CWA from 18Z to about 03Z late Tuesday. The instability is weak according to the soundings. The best QPF with the system starts late Tuesday morning in the mountains and goes into early evening. Snowfall amounts above 9,500 feet could get close to 10 inches total in a couple spots from now through Tuesday evening, but the majority of the higher mountains would only see 3-6 inches. It doesn`t warrant any highlights. Over the plains, the system should bring 40-60% chances of rain showers from 18Z to 06Z. The northern border plains could see 0.25 of rain from it at best, with less over the rest of the low lands. Will end the pops over the plains before sunrise Wednesday morning. However, a few alpine showers may linger into Wednesday morning. Temperatures should only reach the 60s for highs over the plains today, warmest over the far eastern border. There is weak upper ridging over the CWA Wednesday with a dry airmass in place and temperatures still in the 60s over most of the plains. Increasing southwesterly flow is expected Thursday with a dry airmass and temperatures warming well into the 70s over the plains. This will increase fire weather conditions significantly by afternoon. The southwesterly flow aloft continues Thursday night well into Friday, with the next upper trough pushing across Colorado Friday afternoon through Friday night. Models still show this system to be stronger with colder air available as well as more moisture and measurable precipitation for all of the CWA Friday and Friday night. Temperatures are warming a tad from previous models, but snow is not out of the question for most areas. We can only hope for some much needed measurable precipitation. For the later days, Saturday through Tuesday, models show west- northwesterly flow aloft behind the exiting trough on Saturday, then upper ridging moves in from Saturday night and continues in place through Monday. Southwesterly flow aloft moves in later Monday through Tuesday as the next upper trough approaches from the west. There may be lingering light showers over the mountains on Saturday, but overall the 4 day period looks pretty dry with temperatures warming up to above seasonal normals, once again, Sunday through Tuesday. && .AVIATION /12Z TAFS through 12Z Wednesday/... Issued at 539 AM MDT Tue Apr 14 2026 Winds had become light and VRB this morning, with a weak pressure northerly pressure gradient and mid level clouds offsetting normal drainage winds. We do think there should be a transition to NE-E 15Z-18Z, with possibility (30% chance) of going SE. But speeds should be 10 kts or less. Models have slowed somewhat with the upper level disturbance, but are still fairly consistent showing more organized showers developing over the Front Range Foothills by 18Z (scattered lighter showers before that) and then pushing E-NE across the plains through at least 00Z. Given the dry sub-cloud layer, we expect a gusty W-NW outflow to originate in the foothills and push east ahead of the more organized period of showers. That shift could reach the airports as early as 19Z or as late as 22Z and is reflected in the TAF. We`ll eventually see a shower or two likely at the airports but again these will be relatively high based so only light rain for the most part. We have opted to take out the gusty VRB winds however, since DCAPE is