275 FXUS65 KPUB 231009 AFDPUB Area Forecast Discussion National Weather Service Pueblo CO 409 AM MDT Fri Apr 23 2021 .SHORT TERM...(Today and tonight) Issued at 409 AM MDT Fri Apr 23 2021 Early this morning, a persistent area of rain and snow showers was evident through Fremont County back into the upper Arkansas Valley, with an occasional sprinkle/flurry spilling eastward into the Pikes Peak region. Have also noted some occasional lightning strikes over nrn AZ overnight, in the vicinity of the upper vorticity maximum just west of the 4 corners. For today, upper wave/vort max will swing eastward through the area, with strongest upward motion likely from late morning into mid/late afternoon. Model progs show modest instability (CAPE of 200-400 j/kg) developing this afternoon over much of the region, suggesting at least isolated tsra are possible, with last few runs of the HRRR showing a broken line of cells moving across the plains late in the day. Overall, kept a broad brush of scattered pops in place across the area from mid morning into early evening, and increased precip chances for the far sern plains where HRRR shows some moderate convection persisting into early evening. Snow levels stay mainly above 8k feet today, though heavier precip may drag some snow to 7k feet for brief periods this afternoon. Not expecting big accumulations, with 1-3 inches possible over the higher peaks by evening. Max temps today will run cooler than yesterday, especially on the plains as low level flow switches to weak easterly through the day. Overnight, precip ends fairly quickly in the evening, as instability wanes and lift with the upper wave is well east of the area. Skies will clear after midnight, leading to min temps at or slightly below freezing at most locations. .LONG TERM...(Saturday through Thursday) Issued at 409 AM MDT Fri Apr 23 2021 Main Forecast Concerns/Challenges 1)Enhanced fire danger for Saturday through Monday 2)Return of precipitation Tuesday and Wednesday Saturday...A nearly flat ridge of high pressure will be located over the desert southwest on Sat, producing zonal flow across Colorado. Warmer temps and dry conditions are expected, and combined with increasing westerly winds, fire danger will be on the increase once again. Therefore, decided to go with a Fire Weather Watch for the San Luis Valley and the southern foothills area since criteria will be met. However, much will depend on areal coverage and amount of pcpn that may occur today with storms. Plan on high temps in the 60s for the high valleys, and mid 60s to mid 70s for the plains. Sunday and Monday...The next system to affect the state will move onshore as a low pressure trough Sun. The upper jet will carve out across southern CA and the flow aloft will increase and become more southwesterly over the Four Corners region as the pressure gradient tightens. The stronger southwest winds will be very efficient at quickly boosting the temps across the forecast area, with highs expected to be in the 60s to around 70F for the high valleys, and in the lower 70s to mid 80s for the plains. Critical fire weather conditions will be likely both days, for a much larger portion of the forecast area, and additional highlights are probable. As the upper trough pushes into the Great Basin Mon and strengthens, pcpn will return to western CO through Mon morning. This is the time frame when the long range models begin to vary, with the GFS bringing moisture into the state in the morning, while the EC holds off for about 12 hrs longer before the onset of pcpn. However, by Mon evening feel fairly certain that pcpn will spread across all of the higher terrain. Tuesday and Wednesday...The upper low system crosses the state on Tue into Wed, with the GFS showing a more northerly track compared to the EC. However, timing for both days is very similar, with much cooler temps and a good shot for some pcpn across all of the forecast area expected. The best window for some beneficial pcpn will be on Tue, then some lingering showers on Wed as the system gradually exits to the east. Expect high temps both days in the 50s and 60s for most locations. Thursday...Northwest flow aloft will then settle in across the region for Thu, with a few lingering showers possible over the higher terrain. Temps will slowly begin to warm back up, with highs in the 60s to around 70F. Moore && .AVIATION...(For the 12Z TAFS through 12Z Saturday morning) Issued at 409 AM MDT Fri Apr 23 2021 At KCOS, VFR the next 24 hrs, with persistent vcsh for much of the day. Low risk of a tsra this afternoon as instability increases, though confidence is too low to include in the taf at this point. Shower chances will end this evening, with mid level cloud deck scattering out by midnight. General n-ne wind expected through the day, though some gusty and erratic outflow winds will be likely this afternoon and early evening before nly drainage wind develops after sunset. At KPUB, VFR the next 24 hrs, with a period of vcsh this afternoon. A low risk of a tsra here as well, though chance is too low to include in the taf. E winds through the afternoon will turn nly by this evening, though a period of gusty and erratic outflow winds is likely from mid afternoon into early evening. At KALS, VFR the next 24 hrs. Occasional vcsh expected through much of the day, then clearing skies this evening as showers shift east. N-NW winds will be gusty at times, especially this afternoon. && .PUB WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch from Saturday afternoon through Saturday evening for COZ224-229-230-233. && $$ SHORT TERM...PETERSEN LONG TERM...MOORE AVIATION...PETERSEN