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Day 2 Outlook Categorical Probabilistic
Categorical Day2 1730Z Outlook

Images courtesy of the NWS Storm Prediction Center
 Forecast Discussion

ACUS02 KWNS 181717
SPC AC 181716

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1116 AM CST Tue Feb 18 2020

Valid 191200Z - 201200Z


Isolated thunderstorms are possible Wednesday, from portions of the
Florida Panhandle to the coastal Carolinas. These storms are not
expected to be severe.

Enhanced westerly flow aloft is anticipated Wednesday morning across
the central and eastern CONUS, downstream of the more split-flow
pattern expected across the western CONUS. A fairly progressive
upper pattern is forecast throughout the day, with a northern stream
shortwave ridge moving through the Pacific Northwest and into the
northern Great Basin and a low-amplitude shortwave trough moving
across southern CA and much of the Southwest. A northern-stream
shortwave trough will precede the ridge, moving across the northern
Plains and upper MS Valley.

At the surface, a cold front will likely extend from the central NC
coast southwestward into deep South TX early Wednesday morning. This
front is expected to continue southeastward throughout the day as
high pressure shifts from the northern Plains towards the mid MS
Valley. As a result, a cold and dry air mass will cover much of the
Lower 48 states. The only exception is the ahead of the front from
the central Gulf Coast to the southern Mid-Atlantic Coast. A few
lightning flashes are possible within any deeper convection along
and just ahead of the front.

Recent guidance also suggests a fast-moving, low-amplitude shortwave
may eject out of northern Mexico across TX and into the lower MS
Valley (ahead of the southern-stream shortwave trough mentioned
above). Lift associated with this system will likely result in a
large area of showers across TX during the afternoon and evening,
and across the lower MS Valley later Wednesday night. Poor lapse
rates will limit instability but a few embedded lightning flashes
are possible with deeper convective cores. Coverage is currently
expected to remain below 10%.

..Mosier.. 02/18/2020