SPC Oct 27, 2020 0600 UTC Day 1 Convective Outlook

SPC 1200Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1240 AM CDT Tue Oct 27 2020

Valid 271200Z - 281200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not expected across the contiguous United
States on Tuesday.

...Discussion...

Early-morning water-vapor imagery depicts a well-defined upper low
moving south toward the AZ/Mexico border. This feature is forecast
to begin advancing east along the international border later this
morning, then into extreme southwest NM by late afternoon. Very cold
continental surface high has settled into the central Plains with
the leading edge of this air mass now to the coastal plain of TX.
Latest model guidance continues to suggest low-level warm advection
will focus along a corridor from the Edwards Plateau-northwest
TX-central OK. This zone will be the primary area of concern for
elevated convection through the period.

Currently, the leading edge of large-scale forcing for ascent
appears to be spreading across the southern Rockies into far west
TX, per moistening observed at mid levels in water vapor imagery.
Scattered showers are now developing across the southern High Plains
in response, and these showers should eventually deepen sufficiently
for lightning. Much of this activity will develop atop sub-freezing
boundary-layer temperatures and significant icing may ultimately be
noted along the aforementioned corridor.

Farther southeast across the Gulf Coast region, a strong mid-level
Bermuda high will forcing deep southerly trajectories across the
Gulf Basin ahead of Hurricane Zeta. While Zeta will not reach the
central Gulf Coast during the day1 period, moisture will begin to
spread inland such that isolated thunderstorms will be possible,
despite the poor low-level lapse rates and overall weak buoyancy.

..Darrow.. 10/27/2020

Read more

from SPC Forecast Products https://www.spc.noaa.gov/products/outlook/day1otlk_1200.html