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.

Sunday, October 10, 2021

SPC Oct 10, 2021 1730 UTC Day 2 Convective Outlook

SPC 1730Z Day 2 Outlook Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1204 PM CDT Sun Oct 10 2021 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDDLE MISSISSIPPI VALLEY AND GREAT LAKES... ...SUMMARY... Strong/isolated severe storms -- including potential for hail, locally damaging winds, and a couple of tornadoes -- are expected to spread from the Mid Mississippi Valley region early, north-northeastward into the Upper Great Lakes through the evening hours Monday. ...Great Lakes to Mid-MS Valley... A potent upper trough will develop a closed low as it lifts northeast across the region on Monday. Strong deep-layer southwesterly flow will become more meridional with time, but increasing winds speeds with height will maintain strong vertical shear. At the surface, a low will track north/northeast from northern MO toward the U.P. of MI while a cold front surges east across the mid-MS Valley into Lower MI and the Ohio Valley by Tuesday morning. Modest boundary-layer moisture will be in place ahead of the front, with surface dewpoints generally in the low 60s, increasing to the mid-60s toward TN/MS. Showers and thunderstorms will be ongoing at the beginning of the period across AR/MO/western IL/eastern IA in the vicinity of the surface low and cold front. Locally gusty winds and hail could accompany this activity. As the downstream airmass warms, weak destabilization will occur and convection will redevelop/intensify across parts of WI/IL into western IN/MI. Deep-layer flow will mostly be unidirectional, but sufficient speed shear is resulting in some enlarged, curved low-level hodographs. As a result, a mixed mode of clusters/lines and semi-discrete cells will be possible with locally damaging gusts, hail and a couple of tornadoes possible across a relatively broad area. As deep-layer flow becomes more meridional, convection may tend to become undercut by the surging cold front. If this occurs, the severe threat will be somewhat diminished as convection becomes elevated. The severe threat should diminish with southward extent as large-scale forcing lessens and midlevel capping/subsidence becomes more of a concern further from the upper trough/low. ..Leitman.. 10/10/2021 Read more LIVE: