Area Forecast Discussion
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
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719 FXUS65 KPUB 182037 AFDPUB Area Forecast Discussion National Weather Service Pueblo CO 237 PM MDT Wed Sep 18 2024 .KEY MESSAGES... - Dry and generally quiet Today and Thursday. Frost will be possible in the San Luis Valley Tonight. - Medium to high (50-60%) confidence in a storm system impacting the region during the weekend. - Weekend storm system will bring increased precipitation chances, with chances for severe weather across the plains. && .SHORT TERM /THROUGH THURSDAY/... Issued at 235 PM MDT Wed Sep 18 2024 Dry southwest flow will remain in place across the area today as an upper-low digs down over the west coast. High temperatures this afternoon will be slightly above normal, with high-80s to low-90s over the plains. Otherwise, things will be dry and quiet weather- wise aside from some gusty winds. Tonight, conditions will be quiet, but strong radiational cooling over the San Luis Valley will drop temperatures close to freezing, resulting in some potential frost that could damage vulnerable vegetation. Otherwise, temps over the plains will sit in the 40s-50s tonight. For Thursday, this pattern largely continues. High temperatures will be in the 80s across the plains and in the 70s over the valleys. Surface winds will generally be diurnally-driven and a bit less gusty than today. Skies will remain mostly clear and conditions are expected to be dry. Though humidities will be in the teens across the plains, winds should stay light enough to avoid any major fire weather concerns. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Issued at 235 PM MDT Wed Sep 18 2024 Thursday Night: Thursday evening and night will bring quiet weather to south central and southeastern Colorado. Southwest flow will develop ahead of an approaching system to the west. While orographic forcing will be ongoing, dry air and stable air will limit any precipitation development, with dry conditions expected for the region. Otherwise light winds and mostly clear skies are anticipated. Focusing on temperatures, a mild to cool night is expected. Light, but occasionally downsloping winds will help keep the area around seasonal low temperatures. Friday: For the end of the weekend, active weather starts to make a return. Southwest flow will continue over south central and southeastern Colorado ahead of a closed low to the west of the region. While stronger forcing will remain to the west, synoptic and orographic forcing will increase over the area. Along with that, moisture will start to increase ahead of this system, particularly over the far southeastern plains. With that all said, dry conditions are anticipated for most still, though isolated high based thunderstorms are expected across the far southeastern plains as they develop off of the Raton Mesa and an amorphous dryline. Given the high based nature of the storms, and DCAPE values around 1000 J/kg, strong outflow winds around 40-50 mph will be the primary hazard with any more organized thunderstorms. Outside of that though, breezy conditions with scattered afternoon clouds is expected. As for temperatures, much of the region will remain hot. With downsloping winds and early sun, above seasonal temperatures are anticipated for most. Saturday - Sunday: For the weekend, more widespread active weather is expected for south central and southeastern Colorado. The aforementioned closed low will pass over the region through Saturday and exit the by the end of Sunday. Other than some timing differences, ensemble model guidance are in relatively good agreement about this, leading to medium to high (50-70%) confidence in this pattern evolution. As this feature passes over the area Saturday, precipitation chances will increase area wide, especially along the mountains where forcing will be greatest. Then Sunday as the low treks eastward, wrap around precipitation is anticipated to materialize, though will generally favor areas along and north of Highway 50. With that all said, while most precipitation will remain rain, elevations generally around and above 10,500ft will experience snow. Along with that, severe weather may be a concern across the eastern plains during Saturday afternoon, where the best combination of strong shear, moisture, and instability will reside. With that said though, confidence is low (20-30%) at this time in severe weather development, given uncertainty in how much moisture and instability will be present, which will highly influence the strength of thunderstorms that do develop across the plains. As mentioned though, this system will be exiting the area through Sunday, and as it does so, any showers and storms that are present are expected to lessen in coverage throughout the day, with only isolated mountains showers persisting through the afternoon. Otherwise during this period, breezy conditons and cloudy skies are expected, with clouds increasing through Saturday morning and decreasing through Sunday afternoon. Looking at temperatures, Fall makes a return. Saturday will hover around seasonal values for late September, while Sunday will drop to below seasonal values thanks to a cold front passage during Saturday. Monday - Tuesday: For the start of next week, relatively quieter weather returns. Northwest flow will develop over south central and southeastern Colorado behind the exiting weekend system. While forcing will overall lessen, minor orographics, along with modest support from a broad shortwave, will allow for isolated to widely scattered showers to blossom along the mountains both days. Outside of the mountains though, drier conditions are anticipated to prevail. Beyond all that, light winds and scattered clouds are expected for the area. As for temperatures, Fall stays in place for a bit. Much of the region will hover around seasonal values for late September. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1111 AM MDT Wed Sep 18 2024 VFR conditions are expected at KALS, KCOS, and KPUB through 24 hours. Winds will generally be diurnally driven, though gusty south- southwest winds between 20-25 knots are expected at all 3 TAF sites this afternoon. && .PUB WATCHES/WARNINGS/ADVISORIES... Frost Advisory from 3 AM to 8 AM MDT Thursday for COZ069>071. && $$ SHORT TERM...GARBEROGLIO LONG TERM...SIMCOE AVIATION...GARBEROGLIO