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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, July 10, 2023

SPC Jul 10, 2023 1630 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1630Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Mon Jul 10 2023 Valid 101630Z - 111200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHWEST KS AND SOUTHWEST NE... ...SUMMARY... Scattered strong to severe thunderstorms and a couple of organizing storm clusters may pose a risk for large to very large hail and severe wind gusts across parts of the Upper Midwest into Great Plains this afternoon into tonight. ...Upper Midwest into Central Plains... Morning satellite imagery show several low-amplitude shortwave troughs moving through the northern periphery of the upper ridging extending from the southern High Plains into the northern Rockies. One of these shortwaves is moving into central SD, with continued southeastward motion towards the Mid MO Valley anticipated. In addition to this approaching shortwave trough, a cold front stretches from western SD eastward through southern MN and northern WI and then back northeastward across Upper MI. This boundary is expected to push gradually southward throughout the day, moving across much of SD, southern MN, and northern/central WI. Convergence along this boundary is expected to result in thunderstorm development during the late afternoon across southern MN and northern/central WI. Low 60s dewpoints are already in place in this area, with additional moisture advection helping to offset mixing throughout the day. As such, low 60s will likely still be in place later this afternoon, helping to support moderate buoyancy amid late afternoon temperatures in the upper 80s/low 90s. This region will also be on the southern edge of the stronger northwesterly flow aloft around the cyclone centered over northern Ontario. These environmental conditions should support robust updrafts along the front. Hail is possible with the initial development, but low-level lapse rates will likely support outflow-dominant storm structures, with upscale growth into one or more linear segment anticipated quickly. These convective lines are then expected to shift southward into more of central WI northern IA during the evening before dissipating amid nocturnal stabilization. Farther west (from the Mid MO Valley into NE), thunderstorms are expected to develop ahead of the primary frontal zone along a sharpening pre-frontal trough, with low-level convergence along the trough augmented by ascent attendant the approaching shortwave. Afternoon dewpoints along this trough will likely be in the mid 60s, supporting strong buoyancy amid steep mid-level lapse rates and surface temperatures in the low 90s. Robust shear will be in place as well, as strong southerly surface winds veer to northwesterly aloft. This environment should support supercells capable of large to very large hail and strong outflow. Some upscale growth is possible, with the resulting convective line moving south into southern NE. Another shortwave trough is moving into western CO, which is expected to aid in the development of thunderstorms along the lee trough in eastern CO, where the environment will be similar to that over NE. Initial supercells capable of large to very large hail and strong downdrafts are anticipated, before potential upscale growth in this area as well. Interaction between these more eastward-progressing storms and then more southward-progressing storms in NE is likely. The latest guidance suggests this interaction will lead to the development of a robust MCS capable of significant wind gusts. ...Southern High Plains... Afternoon thunderstorm development is anticipated across the higher terrain before then moving into the moderately unstable airmass downstream across eastern NM and west TX. The airmass across west TX will be characterized by greater low-level moisture/instability, supporting more robust updrafts and an increasing risk of a few severe storms. Large hail and damaging winds will be possible. These storms may persist for a few hours and spread into southwest OK before weakening. ...Central MT... A few strong to severe storms are possible across the region where modest destabilization and shear will be in place ahead of a lead short wave trough progressing into the northern Rockies. Initial development is anticipated across the higher terrain before then spreading into more of south-central Montana later this afternoon into tonight. ..Mosier/Weinman.. 07/10/2023 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)