- Day Three
acus03 kwns 210705
Storm Prediction Center ac 210704
Day 3 convective outlook
National Weather Service Storm Prediction Center Norman OK
0204 am CDT Mon Oct 21 2019
Valid 231200z - 241200z
..no severe thunderstorm areas forecast...
the risk for severe thunderstorms appears negligible across the
U.S., Wednesday through Wednesday night.
The center of a broad and deep, but slowly filling, cyclone is
generally forecast to continue to slowly migrate across northern
Ontario into Hudson Bay during this period, while a modest secondary
low migrates from southern New England into the Canadian Maritimes.
The trailing cold front appears likely to stall and weaken across
the central and southern Florida Peninsula, beneath mid-level
To the west, models indicate that amplified mid-level ridging over
the mid-latitude eastern Pacific may take on more of a positive
tilt, building east-northeastward into British Columbia and the
Pacific northwest. As this occurs, a downstream short wave trough,
initially digging across the northern U.S. Rockies, may gradually
split, with the more vigorous southern portion turning more sharply
southward toward the southern rockies/High Plains.
In response to these latter developments, cold surface ridging is
forecast to build across the northern rockies, and nose eastward and
southward across much of the northern and Central Plains. There may
be a weak to modest southerly return flow of moisture into the
vicinity of a strengthening frontal zone, on the leading edge of the
colder air, across parts of the Southern Plains by 12z Thursday.
This may be accompanied by sufficient destabilization to contribute
to at least some potential for a few thunderstorms, but probably not
enough to support an appreciable risk for severe storms.