Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
Issued by NWS Kansas City/Pleasant Hill, MO
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763 FXUS63 KEAX 220916 AFDEAX Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 416 AM CDT Wed May 22 2024 .KEY MESSAGES... - Isolated Sprinkles Possible Today - Thunderstorms Thursday Night - More Precipitation Chances Through the Weekend && .DISCUSSION... Issued at 416 AM CDT Wed May 22 2024 H5 trough that brought active weather to the lower Missouri River Valley to Upper Midwest has moved out of the area, and the trailing cold front has pushed well southeast of the forecast area. There is a secondary short-wave trough currently moving across the Central Plains this morning that is producing a line of light showers/sprinkles and moving eastward. Drier air has been filtering in behind the cold front and there is not much forcing at the surface. That has kept the activity over north-central Kansas this morning light. This short-wave will eventually gets here by the mid to late morning hours, and the HRRR along with a few other CAMs have produced light precipitation. Therefore have added slight chance POPs across portions of the area this morning into the early afternoon. Overall QPF amounts are expected to be just a few hundredths of an inch. For a threshold of 0.10 inches, GEFS and other ensemble suite probabilities are under 10 percent. Aside for these light showers, expecting a mild day across the area. Modest height rises behind the exiting weak short-wave should lead to clearer skies, and allow a surface anticyclone to develop across the Central Plains toward the lower Missouri River Valley. Temperatures will be in the mid 70s for most of the afternoon. There is another short-wave trough moving across the lower Mississippi River Valley that may bring some moisture convergence into southwestern and southern Missouri today, but heaviest activity will be concentrated around the Interstate 44 corridor. Have added in some slight chance POPs in our furthest southern counties for a few hours, but QPF amounts should remain light, with very low probabilities for reaching 0.10 inches. Thursday, a closed-low begins to progress into the Northern Rockies with a secondary vort max ejecting toward the Central Plains. During the afternoon on Thursday across our area, this increases H5 heights and allows a thermal ridge axis to move through. The dCVA over the Front Range will result in surface lee cyclogenesis from the Front Range into the High Plains throughout the day Thursday, and will switch low-level flow southerly Thursday afternoon into the lower Missouri River Valley. WAA will allow temperatures to bounce back into mid 80s. The bulk of the afternoon is expected to remain dry, though some isolated showers could develop if stronger isentropic ascent is realized. Current CAMs develop convection in eastern Kansas during the afternoon as the localized vort-max and associated H5 height falls move eastward. For our area, ensemble probabilities for precipitation beginning to increase after 00z and through the overnight hours, as Q-vector convergence steadily increases. Initial storms for our area may struggle a bit, as a strong cap is expected to be in place. If there is enough clearing earlier in the day, perhaps boundary layer destabilization could erode the cap and lead to a more favorable setup for strong to severe storms. 30 kts of 0- 6km bulk shear may be enough to help organize some activity if it can get going. It will not be until later in the overnight hours Thursday into Friday morning when the cold front moves through that there will be enough forcing to push through the cap. 06z CAMs this morning depict a strong QLCS moving eastward from Kansas and Nebraska after 03z. By the time it gets to our area, it will start to outrun a favorable instability axis, and likely begins to weaken. This may hold together long enough to bring a few 60 MPH wind gusts to the western portions of the forecast area. Like with other recent QLCS and MCS events, will need to watch radar trends and determine if cold pool dynamics may help to give the system an extra push. For this event, most of our CWA is highlighted in the SWODY2 marginal risk, with our far southwestern counties clipped by the slight risk. Heading into the rest of the day Friday, the cold front pushes through, and will continue at least rain shower chances with isolated thunderstorms along the remnants of the previous QLCS/MCS. This may bring between 0.25 and 0.50 inches of rainfall through Friday afternoon as the cold front passes through. Amongst NBM members, currently holding onto probabilities between 40 and 50 percent for exceeding 0.25 inches of QPF through Friday afternoon. In the SWODY3, areas east of Interstate 35 are in the marginal risk for a severe storms along the cold front. Ahead of the front in the afternoon, there may be some modest destabilization throughout the warm sector that in the presence of strong convergence could lead to some stronger updrafts. However, the stronger vertical shear will be mainly behind the front, which may make it difficult for robust organization of convection. Most of the low-end severe potential for Friday early afternoon will depend on how the system behaves overnight before arriving in the area. Heading into the weekend, more short-wave perturbations are expected to move through at 500mb that will present additional opportunities for rain showers and thunderstorms. There may be some opportunities for severe weather, though stronger signals currently point to threats being south and east of our area. Should the forcing with with in flow shift northward a bit, may present more active weather for our area. Throughout the region, probabilities for at least 0.10 inches of rainfall over a 24 hour period are generally at least 20 percent, and times approach 50 percent. Temperatures fluctuate between the mid 70s and mid 80s as the series and troughs and ridges move through. Box and whiskers plots of temperatures through next week show a larger amount of spread, indicating uncertainty in the timing of individual waves that will bring precipitation. Amongst deterministic guidance, Sunday appears to be a favorable day for heavier precipitation with stronger vort max moving across the area. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 1125 PM CDT Tue May 21 2024 VFR conds are expected to prevail thru the pd with sct-bkn clouds btn 8-10kft thru 23Z aft which clr skies are expected. Winds will be out of the WNW around 5kts before becmg lgt and vrb aft 23Z. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...None. KS...None. && $$ DISCUSSION...Krull AVIATION...73