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.


Friday, July 16, 2021

SPC Jul 16, 2021 1730 UTC Day 2 Convective Outlook

SPC 1730Z Day 2 Outlook Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Fri Jul 16 2021 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHEAST/MID-ATLANTIC AND THE NORTHERN/CENTRAL PLAINS... ...SUMMARY... Isolated strong to severe storms will be possible across portions of the Northeast/Mid-Atlantic and northern/central Plains on Saturday. ...Northeast/Mid-Atlantic... A belt of modestly enhanced mid-level southwesterly flow should be maintained Saturday across much of the Northeast and Mid-Atlantic ahead of a positively tilted upper trough. At the surface, a weak low is forecast to develop from the lower Great Lakes across NY and into southern New England by Saturday evening. A cold front should extend southwestward from this surface low across the Mid-Atlantic and into the central Appalachians, while a weak warm front extends across southern NY and southern New England. Current expectations are for multiple clusters of storms to develop along/ahead of the cold front and a pre-frontal trough through the day, and subsequently move eastward across the warm sector. Low/mid-level flow should not be overly strong, but generally 20-30 kt of deep-layer shear should be sufficient for modest updraft organization and mainly a multicell/cluster storm mode. Daytime heating of the moist low-level airmass ahead of these storms will likely foster steepened low-level lapse rates and moderate to strong instability, particularly across the Mid-Atlantic east of the Appalachian and Blue Ridge Mountains. Isolated damaging wind gusts should be the main threat. Both low-level and deep-layer shear may be slightly stronger across southern NY/New England, and marginal supercells posing both an damaging wind and brief tornado threat appear possible, particularly in the vicinity of the weak warm front. ...Northern/Central Plains... A large-scale upper ridge should build over the Rockies and adjacent High Plains on Saturday. Still, a swath of modestly enhanced mid-level northwesterlies will likely remain across parts of the northern/central Plains through the period. Initially high-based storms over the higher terrain of the central Rockies should develop eastward through Saturday afternoon and evening. Other storms may also develop across the northern High Plains along/east of a weak surface lee trough. Any storms that can persist should encounter greater low-level moisture and related boundary-layer instability east of the surface trough. Even though the mid-level northwesterly flow is expected to remain fairly modest, a strongly veering wind profile with height will support enough deep-layer shear for organized storms, including multicell clusters and supercells. Both isolated large hail and severe wind gusts may occur with this activity through Saturday evening. ..Gleason.. 07/16/2021 Read more LIVE:
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)