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.


Thursday, March 30, 2023

SPC Mar 30, 2023 0600 UTC Day 2 Convective Outlook

LIVE MAP (ABOVE) ... SPC 0600Z Day 2 Outlook Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1257 AM CDT Thu Mar 30 2023 Valid 311200Z - 011200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN IOWA INTO NORTHWEST ILLINOIS...AND ACROSS NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...EXTREME WESTERN KENTUCKY...WESTERN TENNESSEE...AND FAR NORTHWEST MISSISSIPPI... ...SUMMARY... Intense and widespread severe thunderstorms are expected Friday afternoon into the overnight hours across portions of the Middle Mississippi Valley and Mid-South vicinity, eastward to the Lower Ohio and Tennessee Valleys. Intense, damaging gusts and several tornadoes (some strong and long-track) are expected. ...A bi-modal regional outbreak of severe storms is expected on Friday from the Mid-Mississippi Valley into the Mid-South... ...Synopsis... An amplified large-scale upper trough will be oriented from the northern plains to the southern Rockies early Friday. The trough will continue to deepen as it shifts east toward the MS Valley by 00z, and oriented from the upper Great Lakes to the TN Valley vicinity by Saturday morning. With time, a closed low is expected to develop over eastern SD/NE/IA and a 100+ kt 500 mb jet will overspread the Mid-MS/OH Valley region. Intense southwesterly low-level flow also will overspread the Mid-South through much of the Midwest, with an 850 mb jet around 65-80 kt forecast by late afternoon into the overnight hours. At the surface, a deepening low centered over eastern NE/western IA Friday morning will shift east across IA through the afternoon before lifting toward southern Ontario overnight. A trailing cold front will extend from the low into eastern KS/central OK/west-central TX at 12z, and shift east across much of the Midwest and Mid-South. Ahead of the eastward-advancing front, strong southerly flow will transport 60s F dewpoints northward. Near-60 F dewpoints are expected as far north as eastern IA into northern IL during the afternoon. The warm sector will become more narrow/pinched off with north and east extent toward the Ohio Valley during the evening/overnight hours. However, near 60 F dewpoints are still expected in a narrow corridor ahead of the surging cold front into far southern IN and central KY. Richer boundary-layer moisture will reside from the Mid-South into the Lower-MS/TN Valleys where low to mid 60s F dewpoints are forecast. ...Mid-Mississippi Valley Vicinity... The strongest forcing/DCVA will be located over northern portions of the Mid-MS Valley close to the surface low/triple point. The expectation is that rapid destabilization through the morning (1000-2000 J/kg SBCAPE) and arrival of stronger forcing by early afternoon will result in initial supercell development near the surface low. All severe hazards will be possible with these fast moving storms, including a couple of strong tornadoes, intense damaging gusts and large hail. Cellular activity should spread across eastern IA/northern MO and into northwest IL before tendency toward upscale growth into linear convection ensues with eastward extent as convection develops south and east ahead of the front from east-central MO into northern/central IL. Damaging gusts will become more prominent with linear convection, though QLCS tornadoes will also be possible. Additional storms will likely form near/just north of the warm front and move into parts of far southeast MN and southern WI. This activity should remain elevated, posing a risk for large hail and strong gusts, though any cell rooting on the warm front will pose a tornado risk as well, though the better warm sector is expected to remain south of MN/WI. ...Mid-South Vicinity... A concerning scenario appears to be developing across portions of the MO Bootheel, northeast AR, western TN/KY and far northwest MS vicinity during the afternoon/evening. At least mid-60s F dewpoints are expected beneath modest midlevel lapse rates. This will support 1500-2000 J/kg MLCAPE amid intense vertical shear. Forecast soundings indicate 0-1 km SRH increasing to around 400 m2/s2 by early afternoon. Thunderstorms are expected to develop by early afternoon ahead of the cold front within a pre-frontal trough/low-level confluence zone. Storm motion near 50 kt with supercell wind profiles will support cells capable of significant and long-track tornadoes. With time, upscale growth into a QLCS is expected, and intense wind gusts will be possible in addition to mesovortex tornadoes. ...OH/TN Valley vicinity... Low-level moisture/instability will begin to wane with north and east extent into the nighttime hours. However forecast guidance has consistently shown a few hundred J/kg MLCAPE with little/no inhibition. Forecast guidance generally tends to under-forecast north/east extent of severe potential in strongly forced, intense shear system. As such, the ongoing outlook maintains a broad gradient from Enhanced to Slight risk across this region. Damaging gusts and a few QLCS tornadoes will be possible into the nighttime hours. ..Leitman.. 03/30/2023 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)