Area Forecast Discussion
Issued by NWS Goodland, KS
Issued by NWS Goodland, KS
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252 FXUS63 KGLD 012002 AFDGLD Area Forecast Discussion National Weather Service Goodland KS 202 PM MDT Wed May 1 2024 .KEY MESSAGES... - A few thunderstorms may develop in northwest Kansas late this afternoon, south of Interstate 70 and east of Highway 25. An isolated supercell is possible, mainly between 4-8 PM MDT, capable of producing large hail, damaging winds and perhaps a tornado. - More widespread thunderstorms will develop north of I-70 in northwest KS and southwest NE this evening. A few severe storms capable of producing large to very large hail are possible, mainly between 8pm-3am MDT. Storms will rapidly exit the region (into south-central and southeast NE), thereafter. - Scattered thunderstorms are anticipated to develop over portions of northeast CO and northwest KS Friday afternoon. Severe storms capable of producing damaging winds are possible, mainly late Fri aft/eve, when storms may increase in coverage and track SE toward southwestern and south-central KS. && .SHORT TERM /THROUGH SATURDAY NIGHT/... Issued at 200 PM MDT Wed May 1 2024 Most of the area remains cloudy and cool this afternoon, with some clearing noted on satellite across southern and western portions. A warm front was surging northward across southwest Kansas, and at 19z was roughly along a Garden City to Jetmore line. Meanwhile, a cold front was moving out of the Colorado Front Range in response to an upper level shortwave trough. Not much has changed from previous thinking. The warm front to the south has a chance of reaching southern Logan and Gove counties by later this afternoon, which would potentially put them in the warm sector which is very unstable. Latest RAP analysis shows up to 3000 j/kg in that area with bulk shear values of up to 60 kts. In fact, latest runs of the HRRR and RAP show initiation occurring by 21-23z around the Lake Scott area. Any discrete supercell in that location would be capable of producing large hail, damaging winds and perhaps a tornado. Those storms seem to fade by 02-03z, and attention turns to the northwest where more widespread convection will be getting underway in response to the upper dynamics and surface cold front. While storms may initially be surface based, expecting mostly elevated storms this evening across much of northwest Kansas and southwest Nebraska. MUCAPE values will be around 1500-2500 j/kg and shear values around 60 kts. So elevated supercells will certainly be possible, capable of producing large to very large hail and perhaps a few isolated damaging wind gusts. This risk will move east through the late evening hours and spill into the overnight hours in far eastern areas like Norton and Graham counties, finally exiting to the east by 07-09z. There will also be a risk of excessive rainfall in the northeast part of the area, particularly from McCook to Oberlin and Norton, where mean rainfall amounts are around 1 inch and 90th-95th percentile rainfall amounts are in the 1 to 2 inch range. Low temperatures will range from the upper 30s in Colorado to the middle 40s in north central Kansas. Thursday will be breezy in the morning, then diminishing winds, mostly sunny and mild in the afternoon with highs in the 60s. A weak shortwave trough comes out of Colorado in the afternoon and evening hours bringing a chance for scattered showers and perhaps an isolated thunderstorm through the evening and overnight, with best chances in northeast Colorado. Low temperatures will range from the upper 30s to lower 40s. The pattern does not change much on Friday. Another shortwave trough moves out of the Rockies in the afternoon, a bit stronger than the one on Thursday, with increasing chances for showers and thunderstorms with the associated surface cold front. Showers and storms will be likely by Friday night as the front moves through the area. Surface based instability will be rather limited, generally under 1000 j/kg is forecast ahead of the front, but deep layer shear values will be 40-50 kts. Those parameters may be sufficient for a few severe storms capable of producing hail up to quarter size and gust winds. Instability rapidly decreases after about 03z as the front races southeast, probably ending the severe threat. High temperatures will be in the upper 60s to lower 70s and lows Friday night ranging from the lower 30s in northeast Colorado to the middle 40s in north central Kansas. && .LONG TERM /SUNDAY THROUGH TUESDAY/... Issued at 149 AM MDT Wed May 1 2024 The area is under southwesterly flow aloft at the start of the long term period with low pressure centered over Saskatchewan/Manitoba on into Ontario, upper level ridging building across the western CONUS, and our next low pressure system coming into view off the coast of the Pacific Northwest. At the surface, a front is forecast to push through during the Friday afternoon-Friday evening timeframe. With this, expecting gusty southerly winds shifting northerly and shower/storm chances up to ~50-70% working in from the west with QPF ranging generally from a quarter to three-quarters of an inch, locally higher amounts possible. Heading into the weekend, upper level ridging will build back in with flow becoming briefly zonal before approach of the next system has flow returning southwesterly. A disturbance skirts south of the area, then east on Sunday, and with the low level southeasterly flow allowing for increased moisture into the area, at least expect to see some increased cloud cover but also some shower/thunderstorm chances (up to around 20-30%). Guidance is coming into somewhat better agreement with regards to timing/placement of the early week system. Latest deterministic guidance shows the upper low centered in vicinity of the Great Basin Sunday evening before crossing the Rockies throughout the day Monday within an upper level trough becoming negatively tilted. Still monitoring potential for multiple hazards with this system, including gusty southerly to southwesterly winds ahead of it and associated increased fire weather concerns/possible blowing dust concerns. Additionally will be looking at the potential for strong to severe thunderstorms across eastern portions Monday afternoon- evening where the dryline is forecast to set up with instability reaching around 1000-2000 J/kg and 0-6 km shear values in the 50-70 knot range. A frontal passage will then sweep through the area, with gusty post-frontal winds into Tuesday. Again will be looking at potential for fire weather concerns. For temperatures, highs are forecast generally in the low-mid 70s Friday, mid 60s to lower 70s Saturday before warming into the 70 to low 80s thereafter. For low temperatures, the forecast calls for low- mid 30s to middle 40s Saturday morning, low-mid 40s Sunday morning, middle 40s to middle 50s Monday morning, and 40s Tuesday, Wednesday mornings. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1118 AM MDT Wed May 1 2024 MVFR ceilings likely to prevail at both KGLD and KMCK through the afternoon, though a brief improvement to VFR possible at KGLD in mid afternoon. Tonight, scattered to numerous showers and thunderstorms will develop with an upper level disturbance. Both terminals likely to be impacted by lower ceilings and rain. There is also a slight risk for hail with any stronger thunderstorm. Convection expected to end around 06-07z, but low ceilings persisting through the overnight. A return to VFR expected at both terminals early Thursday morning. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...None. CO...None. NE...None. && $$ SHORT TERM...024 LONG TERM...CC AVIATION...024