LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1115 PM CST Sun Feb 12 2023
Valid 131200Z - 141200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
The risk for severe thunderstorms appears negligible across the U.S.
Monday.
...Discussion...
Primary feature of concern this period is a notable upper low
currently located over the northern Baja Peninsula. This low is
forecast to eject across southern AZ during the day as a 90+kt 500mb
speed max translates across northern Mexico. Intense 12hr mid-level
height falls will develop ahead of this ejecting short wave late in
the period with values on the order of 240m expected Monday night
over the southern High Plains from the TX Panhandle into western KS.
Additionally, mid-level speed max should strengthen as it approaches
western OK/northwest TX. Low-level trajectories will become
favorable for transporting higher-quality moisture across the
western Gulf Basin into the southern Plains, though boundary-layer
dew points will likely remain inadequate for surface-based buoyancy
late in the period. Even so, PW values will increase markedly across
TX into OK during the latter half of the period such that elevated
convection is expected ahead of the Pacific front that will surge
into this region after 14/00z.
Isolated thunderstorms are also expected north of the jet across
much of the southwestern US from AZ into southwestern CO. Very cold
mid-level temperatures and steep lapse rates should result in
sufficient instability for diurnally-enhanced convection.
Another region where a few flashes of lightning may be noted is
along the Pacific Northwest Coast. Latest model guidance depicts a
very cold upper trough digging toward western WA/OR. Steepening
lapse rates north of the jet will maximize the onshore marine
influence with sufficient instability for low-topped convection. Low
freezing levels could support a few storms.
..Darrow/Thornton.. 02/13/2023
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