SEVERE WX THREAT Sunday: Could be widespread wind damage...
Posted: Fri Nov 21, 2003 1:31 pm
Good afternoon everyone. While wintry weather is one big topic regarding this weekend's storm system, a second topic will be severe weather. Severe weather could potentially be widespread with widespread damaging wind being the main threat later in the day on Sunday.
http://www.spc.noaa.gov/products/outlook/day3otlk.html shows the day 3 outlook from the storm prediction center in Norman, Oklahoma. Severe weather threat exists from lower Michigan southward into Missouri, Illinois, Arkansas, and even down into places that does not need severe weather, east Texas, Louisiana and even Alabama once again. A digging upper trough will shift eastward from the central Rockies eastward into the Middle Mississppi Valley through the day on Sunday. A 120 knot mid level jet will be in place along with the system becoming negatively tilted. The events described above combined with the huge thermal or temperature gradient will hence intensify the surface low pressure area. As the low pressure moves rapidly from the central plains to the northern Great Lakes region through the day Sunday, the trailing cold front will accelerate eastward as well. Colder drier air behind the cold front will combine with warm moist air ahead of the front. That combined with some instability and very strong dynamic forcing aloft will enhance the severe weather potential. The main severe weather mode will be damaging winds as most of the storms will form into a big squall line. Some lightning is possible, but many of the storms will be low topped. It will not take much thunderstorm activity to enhance the downward transfer of the winds because winds aloft, even 5000 feet above the ground will be above severe criteria. 120 knot mid level jet, even higher winds in the upper levels. Certainly this all points to a widespread very damaging wind event Sunday afternoon into Sunday night.
Cities in the path of this severe weather threat include Quad Cities, Chicago, Green Bay, St Louis, Little Rock, Memphis, New Orleans, Houston, Beaumont, and Jackson as well. All persons in and around this area should prepare to seek shelter on the lowest floor of their home or business if a severe thunderstorm or tornado warning is issued. Widespread damaging winds are a possibility and can be as damaging if not even more damaging than an actual tornado because damaging straightline winds have a bigger width than tornadoes do. Preparations are not a bad idea also just in case widespread severe weather becomes a more immient threat.
Stay tuned.
Jim
http://www.spc.noaa.gov/products/outlook/day3otlk.html shows the day 3 outlook from the storm prediction center in Norman, Oklahoma. Severe weather threat exists from lower Michigan southward into Missouri, Illinois, Arkansas, and even down into places that does not need severe weather, east Texas, Louisiana and even Alabama once again. A digging upper trough will shift eastward from the central Rockies eastward into the Middle Mississppi Valley through the day on Sunday. A 120 knot mid level jet will be in place along with the system becoming negatively tilted. The events described above combined with the huge thermal or temperature gradient will hence intensify the surface low pressure area. As the low pressure moves rapidly from the central plains to the northern Great Lakes region through the day Sunday, the trailing cold front will accelerate eastward as well. Colder drier air behind the cold front will combine with warm moist air ahead of the front. That combined with some instability and very strong dynamic forcing aloft will enhance the severe weather potential. The main severe weather mode will be damaging winds as most of the storms will form into a big squall line. Some lightning is possible, but many of the storms will be low topped. It will not take much thunderstorm activity to enhance the downward transfer of the winds because winds aloft, even 5000 feet above the ground will be above severe criteria. 120 knot mid level jet, even higher winds in the upper levels. Certainly this all points to a widespread very damaging wind event Sunday afternoon into Sunday night.
Cities in the path of this severe weather threat include Quad Cities, Chicago, Green Bay, St Louis, Little Rock, Memphis, New Orleans, Houston, Beaumont, and Jackson as well. All persons in and around this area should prepare to seek shelter on the lowest floor of their home or business if a severe thunderstorm or tornado warning is issued. Widespread damaging winds are a possibility and can be as damaging if not even more damaging than an actual tornado because damaging straightline winds have a bigger width than tornadoes do. Preparations are not a bad idea also just in case widespread severe weather becomes a more immient threat.
Stay tuned.
Jim