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, August 28, 2023

SPC Aug 28, 2023 2000 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 2000Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Mon Aug 28 2023 Valid 282000Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS PORTIONS OF THE SOUTHEAST... ...SUMMARY... Isolated storms capable of strong and gusty winds are possible across the Southeast this afternoon. ...20Z Update... ...Southeast... 18Z soundings sampled a moist, moderately buoyant, and weakly sheared environment across the region. This matches the overall expectation outlined in the previous outlook (appended below), with a predominantly disorganized multicellular storm mode anticipated. Isolated water-loaded downbursts remain possible, particularly from southern MS and across much of AL where the highest storm coverage is anticipated. ...Central/Southern High Plains... Convective initiation has already occurred across the high terrain, with southeastward motion still expected to take these storms into the High Plains. Mesoanalysis estimated effective bulk shear is already 20 to 25 kt across the region, with some additional increase anticipated throughout the afternoon. As such, some organization is possible, with an attendant threat for a strong gust or two. Overall coverage is still expected to remain too low for an outlook area. ..Mosier.. 08/28/2023 .PREV DISCUSSION... /ISSUED 1126 AM CDT Mon Aug 28 2023/ ...Southeast this afternoon... A weak midlevel trough persists from the northern Gulf of Mexico to the southern Appalachians with multiple embedded vorticity maxima. Vertical shear is very weak across the Southeast, and thermodynamic profiles are less favorable for strong downdrafts compared to previous days. Thus, scattered pulse-type storms are expected this afternoon along a combination of a stalled synoptic front, weak differential heating zones and local sea breeze circulations. The wind-damage threat appears to be on the lower margins for an outlook area, but will maintain the 5% area for the possibility of isolated downbursts. ...Central/southern High Plains this afternoon/evening... Similar to yesterday, a few storm clusters will form this afternoon and move south-southeastward from southeast WY across eastern CO into eastern NM through this evening. Effective bulk shear of 25-30 kt will support semi-organized storms, a few of which could produce gusty outflow winds and small hail. However, the storms will be relatively low topped for late summer and the severe threat appears too marginal to add an outlook area. ...Tropical cyclone Idalia and FL... Tropical storm Idalia is expected to become a hurricane later today into tonight while moving northward toward the southeast Gulf of Mexico (please refer to latest NHC advisories for additional information). The stronger wind profiles and associated supercell threat will likely be delayed in FL until Tuesday during the day, so will not add any tornado probabilities in this update. 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)