Temps | Gusts | WU KORD KPWK

CLICK for this month's BIG night sky ...




Cardinal SAT


MOBILE DEVICE? Turn sideways. Weather conditions directly above are near Lakefront. Top tabs refer to O'Hare (official).

Archives for the SPC Convective Outlook are updated daily (approximately) with a live map at the beginning of each article. Follow the link at the end of the article to check for current updates on the NOAA/NWS Storm Prediction Center website. Also, see Archives for Chicago's hourly weather data on CARDINAL NEWS Magazine.


Wednesday, April 20, 2022

SPC Apr 20, 2022 0730 UTC Day 3 Severe Thunderstorm Outlook

SPC 0730Z Day 3 Outlook Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 AM CDT Wed Apr 20 2022 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE FRIDAY AFTERNOON INTO FRIDAY NIGHT ACROSS MUCH OF THE CENTRAL INTO PORTIONS OF THE SOUTHERN GREAT PLAINS... ...SUMMARY... One or two squall lines may evolve across parts of the central Great Plains Friday afternoon into Friday night, posing a risk for hail and strong, damaging wind gusts. Additional thunderstorm activity spreading north of the lower and middle Missouri Valley into parts of the Upper Midwest may pose a risk for severe hail. ...Synopsis... Large-scale mid/upper troughing, with several embedded short waves, appears likely to continue developing inland of the Pacific coast during this period. Models continue to indicate that this will include one significant perturbation accelerating northeast of the lower Colorado Valley into the lee of the Colorado/Wyoming Rockies. This is forecast to be accompanied by strong surface cyclogenesis from the lee of the Front Range north-northeastward through central South Dakota by late Friday night. This will be preceded by a plume of warm elevated mixed-layer air advecting through much of the Great Plains and Upper Midwest. However, models continue to suggest that Gulf moisture return to the deepening lee surface troughing may begin to become disrupted by drying associated with low-level ridging building westward toward the northwestern Gulf coast, beneath a prominent mid-level high centered over the eastern Gulf States. While the mid-level ridge axis initially extending to the north-northwest of this high may gradually pivot across and east of the Mississippi Valley, the western flank of the broad amplified ridging may not shift east of the lower Great Plains until late Friday evening. ...Great Plains into Upper Midwest... Highest boundary-layer moisture, including surface dew points in the mid 60s, may become focused along the warm frontal zone shifting across and north/northeast of the lower and middle Missouri Valley vicinity, and perhaps in a narrow corridor near the dryline across west Texas. It appears that the plume of elevated mixed-layer air will tend to overspread the warm front and provide increasing inhibition, but this may be preceded by convection supported by warm advection, which could pose a risk for severe hail. Stronger/more widespread thunderstorm development seems more likely to focus near the dryline perhaps as it is overtaken by an eastward advancing cold front across the central Great Plains Friday evening. However, to varying degrees, models suggest that this may be preceded by convective initiation to the east of the dryline, perhaps aided by a subtle impulse preceding the main upper trough. This remains unclear, and could considerably impact boundary-layer instability preceding the developing dryline/cold front convection. Even so, modestly deep boundary-layer mixing, with CAPE in excess of 1000 J/kg near the dryline, will contribute to an environment with storms initially posing a severe hail threat, before transitioning to strong, damaging gusts. This should coincide with an upscale growing line of storms aided by increasing forcing downstream of the primary approaching short wave, and southerly 850 mb jet strengthening from 50-70 kt Friday evening. ..Kerr.. 04/20/2022 Read more CHECK UPDATE ZOOM GRAPHIC
SUNRISE AND SUNSET TIMES IN UTC (if you're not logged in to Google)
CHICAGO UTC-6 during CST (Central Standard Time, e.g., winter)
CHICAGO UTC-5 during CDT (Daylight Savings Time, e.g., summer)