DarkSky Temps | Gusts | WU KORD Data

CLICK for this month's BIG night sky ...




Cardinal SAT


Weather conditions on bar directly above are near Lakefront. Tabs under Moon Phases refer to O'Hare (official).

Archives for SPC Convective outlook are updated daily with a live map a the beginning of the article. Touch or click map to get possible update, and follow link at end of article for referral to NOAA/NWS Storm Prediction Center. Archives for Chicago's hourly weather data were updated 24-48 hours after end of each day prior to Dec. 2020.

Thursday, March 17, 2022

SPC Mar 17, 2022 2000 UTC Day 1 Convective Outlook

SPC 2000Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Thu Mar 17 2022 Valid 172000Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THROUGH THIS EVENING OVER PARTS OF OKLAHOMA AND NORTH TEXAS...AND LATE TONIGHT IN PARTS OF LOUISIANA AND SOUTHERN MISSISSIPPI...... ...SUMMARY... Threats for severe thunderstorms are expected late this afternoon into this evening over parts of Oklahoma and north Texas, and late tonight in parts of Louisiana and southern Mississippi. Large hail, damaging winds and a few tornadoes are possible. ...20z Update - Oklahoma... The Marginal and Slight risk areas have been expanded a small amount northward in central and north-central OK. Increasingly agitated CU is evident in visible satellite imagery over the past hour or so across western OK, to the northeast of the surface low (centered near CDS in northwest TX). Convection is expected to develop in the next 2-3 hours and spread north/northeast across parts of central and northern OK, posing a threat for large hail, locally strong gusts and perhaps a tornado. Other than this minor expansion of the risk area, the forecast philosophy remains unchanged from the prior outlook. ...LA/MS... No changes have been made to the outlook for the overnight severe threat across LA/MS. See previous discussion below for forecast details. ..Leitman.. 03/17/2022 .PREV DISCUSSION... /ISSUED 1130 AM CDT Thu Mar 17 2022/ ...OK/TX this afternoon/evening... Upper-level trough will move east across the southern Plains through tonight, with cold mid-level temperatures shifting east in tandem with modestly increasing low-level moisture. This will result in a relatively narrow axis of MLCAPE of 1500 to locally 2000 J/kg developing in advance of a surface low and dryline. Thunderstorm development is anticipated during the late afternoon/early evening time frame as MLCIN diminishes and large-scale ascent increases with the approach of the upper trough. Deep-layer shear will support some risk for supercell storm structures, and very steep mid-level lapse rates and substantial CAPE in the hail growth region support a risk for significant severe hail in addition to damaging gusts. Enlarged low-level hodographs and lowering LCLs early this evening will support at least some risk for a tornado before the onset of nocturnal cooling. Overall, the previous outlook reasoning remains on track and have made no changes to the severe probabilities in this area. ...LA/MS overnight... Thunderstorm development is expected late tonight within an increasing warm/moist advection regime as the upper trough shifts east and the marine/warm front lifts north. Strong low-mid level wind fields will result in effective shear values sufficient for supercell storms with a risk for all severe hazards. An increase in tornado probabilities was considered with this outlook over portions of southwest MS and southeast/east-central LA for the potential for surface-based storms near the warm front, where a conditional risk for a significant tornado will exist. However, with concerns regarding a tendency for veering 850 mb flow during the 08-12z time frame have opted to maintain current categorical/probabilistic risk levels and shift tornado probabilities north across portions of southern MS/east-central LA. Additional adjustments to the risk in this area may be needed in later outlooks. Read more CHECK UPDATE ZOOM GRAPHIC