Area Forecast Discussion
Issued by NWS Goodland, KS
Issued by NWS Goodland, KS
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391 FXUS63 KGLD 021141 AFDGLD Area Forecast Discussion National Weather Service Goodland KS 541 AM MDT Thu May 2 2024 .KEY MESSAGES... - 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 organize into a squall line that tracks SE toward southwestern and south-central KS. Dangerous travel conditions associated with widespread strong to severe wind and significant reductions in visibility associated with blowing dust are possible along the I-70 corridor in eastern CO and western KS Friday afternoon and evening. && .SHORT TERM /THROUGH FRIDAY NIGHT/... Issued at 415 AM MDT Thu May 2 2024 Overview: An upper level low centered invof the US/Canada border (southern Saskatchewan, northern MT/ND) this morning will slowly progress eastward into Manitoba (tonight).. then northeastward into Ontario (Fri-Fri night). Today-Tonight: Potent shortwave energy (rounding the base of the aforementioned upper low) in WY at 08Z this morning will lift ENE-NE into South Dakota (this afternoon) and Minnesota (tonight). Modest synoptic subsidence and surface pressure rises in the wake of the upper wave (manifesting as a ~1010-1015 mb surface high building southward from Nebraska into northwest and north-central KS) will yield a clearing trend and decreasing wind.. with near average highs in the 60s. Fri-Fri night: Shortwave energy presently moving ashore the PAC NW will dig southeastward into southern Idaho (tonight) and track eastward across southern Wyoming (Fri).. rounding the base of the aforementioned upper low and broad upper trough over the northern Rockies.. then lift northeastward across South Dakota and Minnesota (Fri night). A low-level southerly return flow regime will be re-established in the lee of the Colorado Front Range during the day on Fri.. as the MSLP-H85 height gradient re-orients and tightens in response to the development and intensification of a lee cyclone in Colorado (aided by the aforesaid shortwave energy /DPVA/ approaching from the west). Guidance indicates that strengthening southerly flow will advect seasonably rich moisture (4-9C 850 mb dewpoints) into northwest Kansas -- beneath a pronounced/pristine elevated mixed layer (8-9 C/km 700-500 mb lapse rates) -- yielding ~1500 J/kg mlcape/mucape at peak heating. Guidance suggests that an evaporatively-cooled airmass.. emanating from fairly widespread precipitation assoc/w the upper wave in Wyoming and the NE Panhandle.. will surge southeastward into northeast Colorado (manifesting as an abruptly northerly wind shift and effective cold frontal passage) during the mid-afternoon (~21Z). Simulated reflectivity forecasts via recent runs of the HRRR and NAM NEST indicate that convection will [1] rapidly develop along the effective cold front in northeast CO and [2] evolve into a forward propagating MCS that progresses E-SE through northwest KS during the late afternoon and early evening. With the above in mind, expect a potential for widespread damaging winds and, quite possibly.. a progressive dust storm. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... Issued at 217 AM MDT Thu May 2 2024 Saturday morning the area is under west-southwesterly flow aloft with upper level ridging now centered over the Intermountain West and the next low pressure system off the coast of the Pacific Northwest. After a mostly dry day Saturday with high pressure moving across, weak waves will then move through the flow in the Saturday evening-Sunday timeframe and may trigger a few showers and thunderstorms (~20-30% chance). Sunday afternoon-evening the upper low progresses across the Great Basin. Breezy to windy conditions are expected Sunday into Monday due to the tightening gradient between high pressure moving off to the east and a developing low in the lee of the Rockies. Current forecast calls for gusts to around 30-40 mph. Into the first part of the work week, winds of this magnitude may create critical fire weather conditions, mainly focused across west and southwest portions of the area where relative humidity is forecast to drop into the 10-20% range. Also expecting showers and thunderstorms for parts of the area on Monday. Some uncertainty remains in position of the surface low which would influence severe potential. If any part of the CWA would be favored to see strong to severe storm potential, expecting it`d be across the eastern 1/3 to 1/2 of the area where CAPE values to around 1000-2000 J/kg coincide with better moisture and ample shear. Current confidence is low as the latest guidance has trended the surface low farther east, and the severe potential for our CWA hinges on its timing/ placement. Will continue to monitor as guidance comes in better alignment. SPC`s current Day 6 (Monday) 15% risk is east of the area, from southwest NE/eastern half of KS/central OK. Tuesday-Wednesday may again have potential for portions of the area (mainly west and southwest) reaching near-critical to critical fire weather conditions with RH forecast in the teens and winds gusting 25-35 Tuesday and to around 25 mph Wednesday. For temperatures, highs are forecast generally in the 60s for Saturday before undergoing a warming trend into the 70s to low 80s by the start of the work week, ever so slightly cooler Wednesday- Thursday. For low temperatures, expecting low-mid 40s Sunday morning, into the upper 40s to middle 50s Monday morning, and upper 30s to mid-upper 40s Tuesday, Wednesday, Thursday mornings. && .AVIATION /12Z TAFS THROUGH 12Z FRIDAY/... Issued at 530 AM MDT Thu May 2 2024 GLD: VFR conditions will rule through the TAF period. Scattered to broken mid-level ceilings (~12,000 ft AGL) will give way to clear skies by mid to late morning. NW winds at 12-17 knots will increase to 20-30 knots within a few hours after sunrise.. at the onset of diurnal heating/mixing.. decreasing to 15-20 knots during the early afternoon. Winds will become light and variable at/around sunset this evening and persist overnight.. shifting to the S at 12-17 knots around sunrise Fri morning, at the end of the TAF period. MCK: Lingering MVFR ceilings (~1,000 ft AGL) at 11Z are anticipated to rapidly lift/scatter within an hour or two after sunrise, by ~14Z. VFR conditions will rule through the remainder of the TAF period. NW winds at 10-15 knots will increase to 20-30 knots within a few hours after sunrise.. at the onset of diurnal heating/mixing.. and persist through early afternoon, decreasing to 15-20 knots during the mid-late afternoon. Winds will become light and variable at/around sunset this evening (as high pressure in Nebraska builds southward over Kansas) and persist overnight, shifting to the S at 10-15 knots at the end of the TAF period.. around or shortly after sunrise Fri morning. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...None. CO...None. NE...None. && $$ SHORT TERM...Vincent LONG TERM...CC AVIATION...Vincent