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, February 26, 2023

SPC Feb 26, 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 1158 PM CST Sat Feb 25 2023 Valid 261200Z - 271200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF WESTERN NORTH TEXAS AND WESTERN OKLAHOMA... ...SUMMARY... A significant damaging wind event is expected from the eastern Texas Panhandle into much of Oklahoma and southeast Kansas late this afternoon through this evening. Gusts greater than 75 mph will be possible. Additionally, a few tornadoes will be possible. A couple strong (EF-2+ intensity) tornadoes appear most probable over parts of western North Texas into southwest Oklahoma. A damaging wind threat will continue into parts of Missouri overnight. ...Synopsis... A potent, negatively tilted midlevel trough will eject eastward into the southern/central Plains late this afternoon and evening, and become positioned over the Mid-MS Valley by Monday morning. Extreme vertical shear will overspread the southern Plains vicinity ahead of a deepening surface low and eastward-advancing cold front. Strong forcing for ascent along the cold front and within a 100+ kt 500 mb jet streak will aid in rapidly developing convection by late afternoon across the eastern TX panhandle amid modest boundary-layer moisture. Initially semi-discrete supercells will pose a risk for tornadoes, a couple potentially strong (EF-2+ intensity) early in the event across parts of western North TX into southwest OK. Supercells are then expected to grow upscale into a fast-moving linear convective system shifting east/northeast across much of OK and southeast KS. Linear convection and strong gusts are expected to continue northeast overnight across MO and into western IL. ...TX/OK/KS... Increasing southerly low-level flow will transport mid/upper 50s dewpoints into far southern KS by 00z. Near-60 F dewpoints are possible as far north as the I-40 corridor in OK by late afternoon. While the main synoptic surface low is forecast to deepen and spread east/northeast across the central Plains, several members of 00z deterministic guidance suite suggest a meso-low may develop in southwest OK, near the OK/TX border. A corridor of relatively greater tornado potential will exist near this triple point feature where a higher-quality warm sector will reside. Surface-based instability will be maximized within this corridor, with SBCAPE around 500-1000 J/kg forecast. A couple of strong tornadoes will be possible within a corridor of enhanced low-level shear, very large, favorably curved hodographs, and 0-1 km SRH values increasing to near 500 m2/s2 as an 850 mb low-level jet strengthens to 65+ kt. As initial convection spreads eastward across western OK, upscale development into a fast moving line of storms is expected. Capping will prevent open warm sector convection for the most part, with strong forcing along the cold front overcoming the cap and being the main forcing mechanism for convection. Intense mass flux along the front, combined with extreme vertical shear is expected to be sufficient for widespread severe and damaging gusts despite SBCAPE values generally at or below 500 J/kg. Some threat for mesovortex tornadoes will exist, but this threat may be mitigated by modest low-level thermodynamics further east later in the evening. ...MO/IL... Significant severe gusts may persist as convection spreads east into MO through the early overnight period. However, instability will become meager with northeast extent. Nevertheless, intense vertical shear will continue to overspread the region and at least modest lapse rates are present in forecast soundings. Strong gusts may approach the Mid-MS Valley by Monday morning. ..Leitman/Squitieri.. 02/26/2023 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)