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Weather conditions on bar directly above are near Lakefront. Tabs under Moon Phases refer to O'Hare (official).

Archives for SPC Convective outlook are updated daily with a live map a the beginning of the article. Touch or click map to get possible update, and follow link at end of article for referral to NOAA/NWS Storm Prediction Center. Archives for Chicago's hourly weather data were updated 24-48 hours after end of each day prior to Dec. 2020.

Friday, April 15, 2022

SPC Apr 15, 2022 0600 UTC Day 1 Convective Outlook

SPC 1200Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1232 AM CDT Fri Apr 15 2022 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST OKLAHOMA...ACROSS PORTIONS OF THE LOWER MS VALLEY INTO THE MID-SOUTH... ...SUMMARY... Isolated strong to severe thunderstorms are expected Friday evening and night from central/eastern Oklahoma into the lower Mississippi Valley and Mid-South. Large hail and damaging winds should be the main threats where thunderstorms develop. A brief tornado can not be ruled out across eastern Oklahoma into western Arkansas during the evening. ...Northeast OK to Lower MS Valley/Mid-South... Seasonally strong zonal flow is forecast to continue across much of the CONUS Friday. Though several weak disturbances will traverse lower latitudes, general height rises are expected through the period. Latest satellite imagery and surface observations suggest higher-PW air mass is surging north across the Edwards Plateau toward the TX South Plains as LLJ is strengthening across this region. This moisture increase will prove instrumental, along with the remainder of strong daytime heating, for convective development across northeast OK by early evening. Latest model guidance suggests intense boundary-layer heating will be noted west of the dryline from west TX into western OK. Forecast soundings reflect this with dry-adiabatic lapse rates in the lowest 3km near/west of the dryline by 22z. As the low-level flow veers across this region, deeper convergence should contribute to robust convective initiation downstream over northeast OK shortly thereafter. SBCAPE should be on the order of 1500 J/kg with this early development, and wind profiles certainly favor organized long-lived updrafts with surface-6km bulk shear values in excess of 50kt. Steep lapse rates, strong shear, and long hodographs all favor large hail with this activity. Have introduced Sig Hail to this portion of the outlook where surface-based supercells should develop, then track/propagate southeast toward western AR. While large hail will be the primary concern, locally damaging winds and perhaps a brief tornado can not be ruled out. Additionally, have expanded low severe probabilities across the Ozark Plateau toward the MS Delta region of southeast MO/extreme western KY. Current thinking is decidedly westerly component will encourage elevated warm-advection supercells to spread a bit farther downstream than earlier anticipated. Surface cold front will also surge south across this region during the overnight period which will aid thunderstorm activity along/north of the wind shift. Larger complex of storms should sag south through sunrise. ..Darrow/Weinman.. 04/15/2022 Read more CHECK UPDATE ZOOM GRAPHIC