Area Forecast Discussion
Issued by NWS Goodland, KS
Issued by NWS Goodland, KS
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581 FXUS63 KGLD 040841 AFDGLD Area Forecast Discussion National Weather Service Goodland KS 241 AM MDT Sat May 4 2024 .KEY MESSAGES... - Fire weather concerns return Monday through Thursday for most of the Tri-State area, but favor along and south of I-70. - Thunderstorms, a few of which may become strong to possibly severe, will be possible Monday afternoon/evening. && .UPDATE... Issued at 1012 PM MDT Fri May 3 2024 The entire CWA has been cleared from earlier Severe Thunderstorm Watches. Most of the area is not seeing any precip at this time, and the remaining eastern zones seeing activity is seeing sub severe returns on radar. Still could see gusts 40-50 mph in the remnants as they exit, but severe wx is done for this night. Have added in Fog for all areas, along with patchy frost in the NW. && .SHORT TERM /THROUGH SUNDAY NIGHT/... Issued at 130 PM MDT Fri May 3 2024 Not much has changed from previous thinking with two areas of concern for the remainder of the afternoon and this evening. Convective initiation has occurred in eastern Colorado near Las Animas. HRRR shows this activity expanding into northeast Colorado south of I-70 and northwest Kansas over the next few hours. Latest analysis and forecast of SBCAPE shows 1500-2000 j/kg available along with effective bulk shear values of 40-50 kts. Those parameters should be sufficient for a few severe thunderstorms capable of producing large hail, damaging winds and perhaps a tornado with any discrete supercell. Further north, initiation has also occurred along the cold front in the Nebraska panhandle. As the cold front surges south this evening, convection will increase rapidly into a line capable of producing damaging wind gusts. Given the same parameters above, a few embedded cells in the line will also be capable of producing large hail and a brief tornado. The front will exit the area by around 06z ending the severe threat, though a few showers and storms may linger past 06z in southern and eastern areas. Mean precipitation amounts for the event range from around a tenth to a quarter of an inch in Colorado, a quarter to a half inch west of Highway 83, and around a half inch east of Highway 83. The higher percentiles show locally up to 1 inch possible in just about the entire area, with up to about 1.5 inches in northeast corner (McCook, Oberlin, Norton) and southern areas (Tribune, Leoti). Winds will gradually diminish overnight with low temperatures ranging from the lower 30s in Colorado to the lower 40s in north central Kansas. Saturday will be mostly sunny and breezy with just a hint of shortwave ridging aloft ahead of weak shortwave in southeast Colorado. High temperatures will be in the lower 60s. Saturday night now looks dry with the shortwave staying south of the area. There will be some increase in clouds with low temperatures in the lower 40s. Models do hint at fog developing in western portions of the area late Saturday night into Sunday morning (along the Kansas and Colorado border area and westward). Southwest flow aloft continues on Sunday with embedded weak waves which may result in a few isolated showers and thunderstorms by Sunday afternoon. There is a very narrow corridor of weak instability forecast along the Kansas and Colorado border area with a 100-200 j/kg currently indicated. So, not expecting any severe storms should any develop. High temperatures will be in the upper 60s to lower 70s. Shower and thunderstorm chances increase going into Sunday night with height falls ahead of the approaching trough and nocturnal low level jet. MUCAPE increases overnight to 1500-2000 j/kg with shear values of 40-50kts. So may see elevated thunderstorms late with a risk for hail, but confidence is low at this time range. Low temperatures will be in the 50s. Main trough axis ejects out of the Rockies and across the plains with a negative tilt on Monday. Surface low will deepen in the Nebraska panhandle with the dry line trailing south into the forecast area. The dry line will be the focus for convective initiation in the afternoon and the models indicating the dry line will likely be in eastern areas at least for a few hours before moving east. Timing of initiation will be critical, but if it happens before the dry line moves out may see a short window for severe storms along/east of Highway 83. Instability and shear will be more than adequate for a risk of large hail, damaging winds and tornadoes. West of the dry line may see few wraparound high based showers, but no severe threat. However, afternoon relative humidity values will be dropping to near critical or critical values and wind speeds also appear to meet critical thresholds for fire weather concerns. Precipitation should be east of the area Monday night. High temperatures will range from the upper 60s in Colorado to the upper 70s in north central Kansas and lows Monday night in the upper 30s to lower 40s. && .LONG TERM /MONDAY THROUGH FRIDAY/... Issued at 238 AM MDT Sat May 4 2024 For Monday, there are still a lot of potential hazards that are unclear if they`ll happen as there is still a sizable spread in 500mb low track and surface low setups. Compared to prior forecasts, there is more consensus on the upper trough swinging more into the Northern Rockies and Plains. In this scenario, the deeper part of the low pressure would be well north into the Dakotas, Montana, or even Southern Canada. With it, the rest of the lower pressure and potential front would swing through the area during the day Monday and bring dry air across most of the area. With this, the severe weather threat would be limited to Highway 83 and east or maybe even completely out of the area. The main hazard would be the potential for high winds (namely gusts to 60mph+) as long as the upper low swings near the area. Blowing dust across the area and critical fire weather conditions south of I-70 would also be possible with the strong winds and dry conditions (though the dust could be hampered by recent moisture). There are still some scenarios that keep the low closer to the area with dryline closer to the Colorado border (instead of Central KS/NE). While scenarios like this now have a 25% chance, it is worth mentioning that this scenario would bring the same threat for high winds, but the severe threat would be much greater with all hazards possible. Critical fire weather would be more limited to parts of Eastern Colorado and the dust threat would likely decrease as we would have stratus which would weaken low level lapse rates. Tuesday, the upper trough is forecasted to spin over the Northern Rockies and Plains which will keep the area in roughly westerly flow aloft and relatively low pressure at the surface. The main thing to watch will be for a potential smaller wave to move around the larger low and generate lower pressure near the area. That could strengthen the winds a bit and maybe wrap some more precipitation into the area, though severe weather looks to be unlikely at this time. A small disturbance could also weaken/disrupt the height gradients which would lower the chance for strong/high winds. Temperatures would likely be similar to Monday in the 70`s. Critical fire weather conditions would be possible again along and south of I-70 depending on how dry the air gets during the afternoon. The rest of the week looks to have troughing or laminar flow above the area as a cut-off low is forecast to try and split off from the main flow and shift off to the west coast. This would likely give us average temperatures in the 60`s and 70`s with daily chances for precipitation if smaller disturbances move through the flow and across the area. Hazardous weather looks to be unlikely for this time period except for the possibility of lows dropping into the mid to low 30`s if enough cold air advects into the area and little to no moisture returns. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1045 PM MDT Fri May 3 2024 Both terminals will see MVFR fog/ceilings that are expected to impact the terminals through at least through 14z-16z, before going VFR. Winds northerly around 20-30kts, diminishing to around 10-15kts by 10z, then eventually veering southeast from 21z onward. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...None. CO...None. NE...None. && $$ UPDATE...JN SHORT TERM...024 LONG TERM...KAK AVIATION...JN