Convective Outlook


SPC 1300Z Day 1 Outlook
Day 1 Outlook Image

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0740 AM CDT Sun Apr 05 2020

Valid 051300Z - 061200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Organized severe weather is not expected through tonight.

...Synopsis/Discussion...
In mid/upper levels, the large-scale pattern will be dominated by
persistent blockiness over northern Canada, related to a strong
anticyclone over the Arctic Islands.  To the southwest, split flow
will occur around a strong low slowly digging southeastward off the
northern CA coastline.  To the cyclone's east, broad fetch of
southwesterly flow will foster warm advection and increasing low/
middle-level moisture, beneath cold midtropospheric temperatures. 
Resulting marginal destabilization will spread across much of the
West, then as far as parts of the north-central Plains overnight,
supporting isolated to widely scattered, episodic, weak
thunderstorms. 

Downstream, moisture-channel imagery indicates a subtle perturbation
from the southern upper Great Lakes to the lower Ohio Valley.  This
feature should pivot gradually eastward/east-southeastward across
the interior Mid-Atlantic between 00-06Z.  Associated
destabilization aloft, overlying weak low-level moisture and
diurnally driven boundary-layer heating of higher terrain, may
promote isolated thunderstorms over parts of the central
Appalachians, with MLCAPE generally below 500 J/kg.  Well-mixed
subcloud layers suggest potential for locally gusty winds, but the
severe threat appears minimal.

In the southern stream, a convectively enhanced, low-amplitude, but
complex shortwave trough is evident in satellite imagery over the
north-central Gulf and adjoining coastal areas.  This feature should
proceed east-southeastward across the northeastern Gulf and FL
through the period.  In concert with diurnal heating, favorable
low-level moisture, and possible sea-breeze development later today,
a few thunderstorms may form over coastal south FL.  Despite
seemingly favorable deep/speed shear, weak instability above the
boundary layer should limit storm organization.

..Edwards.. 04/05/2020

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Updated 5 April 2020 | 7:45 am