Area Forecast Discussion
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
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947 FXUS65 KPUB 090416 AFDPUB Area Forecast Discussion National Weather Service Pueblo CO 1016 PM MDT Sat Jun 8 2024 .KEY MESSAGES... - Thunderstorms, a few strong to severe, possible Sunday and Monday across the mountains and adjacent plains with risks transitioning towards hail and heavy rainfall capable of producing localized flash flooding. - Heat build backs into the area by the middle part of next week. && .UPDATE... Issued at 1014 PM MDT Sat Jun 8 2024 Air mass slowly stabilizing late this evening, though a few pockets of CAPE and plentiful outflow boundaries have continued to fire at least weak/moderate convection well past sunset. Still expect most activity to diminish after midnight, though a few sprinkles or light showers may persist on the plains through sunrise. && .SHORT TERM /THROUGH TONIGHT/... Issued at 334 PM MDT Sat Jun 8 2024 Severe risk continues this afternoon across the plains, with latest radar imagery showing more isolated thunderstorm development across the Pikes Peak region along the Raton Mesa. In these areas have seen lee troughing occur while a well defined shortwave moved overhead. Latest RAP analysis showing some CIN remaining in place, which has likely limited any robust updrafts at this. However, guidance now in fair agreement with any remaining CIN eroding here in the near term, with intensity of the current storms likely increasing. While can`t completely rule out a strong to severe storm over the far southern area near the Colorado and New Mexico border this afternoon, think they will be less likely there given some drier air, lower instability, as well as lower shear. From Pueblo up towards the Springs, will see more robust updrafts over the next couple of hours, given a steady southeast wind advecting low 50s dewpoints into this area, resultant CAPE values around 1000 j/kg, and shear upwards of 35 to 45 kt. In these areas this afternoon, expect hail up to around 1.5 inches and wind gusts up to 60 mph. Think this risk will continue through around the 5 pm time frame, with development likely shift to the east. By early this evening, will see the isolated to widely scattered severe storm development to shift east into the plains. Once again, given the above mentioned moisture, instability, and wind shear values, think the highest risk of severe storms will be along and north of the Highway 50 corridor. Will closely monitor the severe threat for Baca county though, as observational data showing some higher dewpoints inching into this area. Along and north of Highway 50 and especially near the Colorado and Kansas border, low to mid 60s dewpoints and steep lapse rates are yielding CAPE just above 3000 j/kg. This much higher instability and moisture along with increasing shear will not only support the continued severe risk, but will support the risk for higher end wind gusts and larger hail. This is especially as CAMS are indicating more upscale development into linear segments. So, will continue to message a high chance for winds up to 80 mph and large hail up to around 2 inches for areas northeast of a Las Animas to Springfield line. The risk for a few tornadoes also remains for these areas even if linear convection develops. Should see the severe risk quickly lower by around the 7 pm time frame but as instability remains in place, can`t rule out additional thunderstorm development into the late evening time frame. While a low confidence scenario at this time, its possible the instability axis swings back into the I-25 corridor and southeast mountains. If this were to occur, could see at least isolated development in these locations. && .LONG TERM /SUNDAY THROUGH SATURDAY/... Issued at 334 PM MDT Sat Jun 8 2024 By Sunday, will see rising heights and weakening flow, but will see moisture and instability remain in place. It does look as if the moisture/instability axis shifts further west, with increased chances for showers and thunderstorms over the mountains and mountain valleys. Guidance is in fair agreement with bringing mid to upper 50s dew points right up to the southeast mountains, and with CAPE values easily in the 1000-1500 j/kg range and quite possibly approaching 2000 j/kg. While there is weakening flow that will support less organized development on this day, I think the risk for hail and damaging winds will remain. Overall setup could support the risk for more wet microbursts/damaging winds on Sunday. The highest risk for severe storms will likely be across the southeast mountains into the I-25 corridor. Additionally, still closely monitoring the potential for heavy rainfall and flash flooding, for these same areas. With higher moisture content air, forcing/focus right into these areas, and with slow storm motions, definitely have concerns for flash flooding. Did debate issuing a Flash Flood Watch for these areas on Sunday, but have opted not to at this time and will let later shifts take a look at additional guidance. The risk for heavy rainfall and flash flooding continues Monday, as upper energy evolves into a closed low on this day. Guidance begins to really diverge with this system, most importantly placement of this system. So, while there might be a slightly higher chance for precip development to shift more across the Continental Divide on Monday, think guidance could easily shift back east. So, at this time, will continue to message more widespread precip development over much of southern Colorado. Severe risk does lower, but will remain possible just given the nature of closed upper level lows. It does appear that by Tuesday, we`ll see coverage of precip chances lower that continues on Wednesday as upper ridging is the trend. This will return building heat to the area though, with well above normal temperatures in the 80s and 90s, and quite possibly 100 degrees, returning to southern Colorado by mid week. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 547 PM MDT Sat Jun 8 2024 VFR conditions are expected to prevail for KALS, and mostly for KPUB KCOS, throughout the forecast period. There will be some MVFR and possibly IFR criteria during the morning hours for KCOS and KPUB due to low CIGs, mainly between 10-16Z at KCOS and 12-16Z at KPUB Winds will be synoptically influenced by a shortwave transitioning over the region. FROPA will occur around 01Z at KCOS and KPUB, but may occur sooner if the boundary is accelerated by outflow from convection to the northeast, this will cause winds to switch to a NE`ly direction at both terminals. Winds at KALS will also switch around to a more NE`ly direction later this evening and then eventually go L&V. Winds will begin to increase out of the SW at KALS and out of the ESE-SE at KCOS and KPUB, by tomorrow afternoon with gusts between 25 to 30 kts expected, increasing more towards the end of the forecast period. There will be developing convection in the vicinity of KALS which may move on station from 20-24Z, SHRA and possible VCTS is also expected in the vicinity of KCOS and KPUB after 20Z as well, although less confident that it will move on station until after the forecast period. If SHRA/TSRA does develop, it could temporarily reduce CIGs and VIS to MVFR/IFR criteria. It could also result in periodic windshifts and increased wind speeds for all terminals. -Stewey && .HYDROLOGY... Issued at 334 PM MDT Sat Jun 8 2024 Rapid snow melt will continue across the mountains leading to elevated flows along the Arkansas River from Leadville to Canon City through Monday as well as on smaller creeks and streams in and near the mountains. Flows are expected to remain within banks for most locations along the Arkansas River but fast flows can still be dangerous. Slightly cooler temperatures may decrease the snow melt Sunday and Monday, however the potential for heavy rainfall will increase both days for the southeast mountains and adjacent plains. This could cause localized flash flooding and push flows above the projected bank full forecast for localized areas depending on where the rain falls. Latest projections place the heaviest rainfall across Teller, western El Paso and Fremont counties on Sunday though the flash flood risk still looks localized. Continue to monitor weather forecasts closely. && .PUB WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...PETERSEN SHORT TERM...RODRIGUEZ LONG TERM...RODRIGUEZ AVIATION...STEWARD HYDROLOGY...KT