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.


Monday, February 20, 2023

SPC Feb 20, 2023 0600 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 PM CST Sun Feb 19 2023 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears likely to remain generally low across much of the U.S. today through tonight. ...Synopsis... As the center of a broad, deep mid-level low emerging from the Arctic turns southward through Hudson Bay, models indicate that the leading edge of broad mid-level troughing (within the mid-latitude westerlies to the south) will begin to shift offshore of the north Atlantic Seaboard during this period, while the trailing edge shifts east of the Rockies. This regime will include a couple of smaller-scale perturbations accompanied by deepening surface cyclones: one across the lower St. Lawrence Valley/Canadian Maritimes vicinity and another across the Upper Midwest/Great Lakes. Cold fronts trailing the cyclones are forecast to overspread much of the Northeast and the Upper Midwest/Northern Great Plains through much of the Ohio, middle Mississippi and lower Missouri Valleys by 12Z Tuesday. At the same time, upstream, models indicate that the westerlies will begin to undergo considerable amplification, including mid-level ridging building from the mid-latitude Pacific (near 150-160 W) north-northwestward through western Alaska. As this proceeds, a vigorous downstream short wave impulse is forecast to dig near the British Columbia coast, into the Pacific Northwest by the end of the period, around the northeastern periphery of a blocking mid-level high. Initially centered over the southern mid-latitude eastern Pacific, the high may begin to reform to the west-northwest, while an initially positively tilted trough to its southeast slowly begins to accelerate inland across the Baja California vicinity. This may lead to some suppression of ridging on the western flank of a persistent subtropical high, gradually becoming centered over the Caribbean. ...Southwest... Within the mid-level troughing across the subtropical eastern Pacific, the most significant embedded perturbation and mid-level cold core are forecast to initially pivot southwestward, then southward, away from the coastal areas, before accelerating eastward toward northern Baja California Sur by early Tuesday. As this occurs, any appreciable risk for thunderstorm activity is expected to generally become focused well to the south of the international border vicinity. ...Gulf States into southern Appalachians... An initial influx of low-level moisture off the Gulf of Mexico, as far northeast as the southern Appalachians vicinity by late this afternoon, may contribute to weak destabilization supportive of scattered showers. Aided by forcing for ascent associated with weak perturbations on the southern fringe of the westerlies, thermodynamic profiles may become marginally conducive for a few lightning flashes with some of this activity. The somewhat better/deeper low-level moisture appears likely to remain capped by warm layers aloft as it initially spreads northeast and east of Texas/Louisiana coastal areas. However, as the more prominent short wave trough digs southeast of the Upper Midwest late this evening into the overnight hours, suppression of the mid-level inhibition in a corridor across southeastern Arkansas through the northern Mississippi/Alabama vicinity may allow for weak thunderstorm development. ..Kerr/Wendt.. 02/20/2023 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)