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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.

Monday, April 4, 2022

SPC Apr 4, 2022 2000 UTC Day 1 Convective Outlook

SPC 2000Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Mon Apr 04 2022 Valid 042000Z - 051200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTH TEXAS EAST-SOUTHEASTWARD TO THE CENTRAL AND SOUTHERN MISSISSIPPI VICINITY... ...SUMMARY... Severe storms are forecast to spread from North Texas this afternoon and evening, eastward toward the lower Mississippi Valley overnight. Severe wind gusts, some possibly over 75 mph, large to very large hail, and tornadoes are possible. ...Discussion... Current evolution of new convection over western North Texas is in line with expectations, lending confidence that the ongoing outlook reasoning and areas remain reflective of the anticipated evolution of the convective/severe risk. As such, no appreciable changes appear necessary at this time. ..Goss.. 04/04/2022 .PREV DISCUSSION... /ISSUED 1127 AM CDT Mon Apr 04 2022/ ...Northwest/North TX late this afternoon into this evening... Surface low currently over northwest TX is expected to gradually deepen throughout the day as an attendant front pushes southeastward. Moisture will continue to return ahead of the low/front, likely bringing mid 60s dewpoints in North TX by early this evening. Forcing for ascent near the low will be augmented by large-scale lift attendant to approaching shortwave trough, fostering convective initiation across northwest TX this afternoon. Low-level to mid-level winds are not expected to be overly strong, but notable veering with height and strong upper-level flow results in overall profiles supportive of supercells. Given the linear forcing and thermodynamic conditions favoring strong cold pools, a quick transition into a convective line is anticipated. However, there should be a window before this occurs for a more discrete mode, with some potential for updrafts capable of all severe hazards, including very large hail and a tornado or two. ...North/Northeast/East TX across LA into southern MS this evening and overnight... The initially more discrete mode expected over northwest TX (discussed above) should quickly transition into an organized convective line as both low-level moisture and low-level flow increase ahead of it this evening. A warm front will be retreating ahead of the line (demarcated relatively well by the 60 deg F isodrosotherm), and a corridor of greater severe potential is anticipated along and just south of this feature. The linear convective mode/strong cold pool, coupled with continued large-scale forcing for ascent and expected updraft/downdraft augmentation near the warm front, suggests the potential for significant wind gusts (i.e. 74+ mph) exists with this line. The potential for embedded QLCS tornadoes also exists, particularly later in the evening and overnight across northern LA and southwest MS. The convective line should remain organized as it moves into this region, and the low-level flow is expected to strengthen. These factors combined with favorable low-level moisture suggest the potential for embedded QLCS tornadoes may actually increase overnight into early tomorrow morning from northern LA into southwestern MS. ...Elsewhere in OK/TX... Thunderstorms north of the outflow boundary and behind the front today -- mainly over OK and northwest TX -- may produce sporadic, marginally severe hail. Isolated severe thunderstorms developing this evening over the Serranias del Burro of northern Coahuila also may reach nearby parts of south TX, potentially producing large hail and locally severe winds. The eastward progress of any such convection crossing the Rio Grande will be limited by MLCINH related to a combination of the basal EML inversion and nocturnal near-surface cooling. ...FL Peninsula... Remnant frontal boundary currently extending across the central FL Peninsula is expected to further dilute throughout the day as moisture returns northward. Moderate instability is anticipated south of this retreating boundary as temperatures warm in to the upper 70s/low 80s amid mid 60s dewpoints. Fairly steep mid-level lapse rates will also be in place, fostered by relatively cold mid-level temperatures (around -14 C at 500 mb). Primary forcing for storm initiation will be sea breeze boundaries with effective vertical shear around 20-30 kt favoring a multicellular storm mode. Given the moderate buoyancy, a few stronger storms capable of damaging downbursts and isolated hail may develop, especially as a result of cell mergers/interactions. Read more CHECK UPDATE ZOOM GRAPHIC