Severe Storm Outlook Narrative (AC)
Issued by NWS
ACUS02 KWNS 211723
SPC AC 211722
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1122 AM CST Tue Feb 21 2017
Valid 221200Z - 231200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
Severe weather is not expected across the contiguous United States
A belt of enhanced west/southwesterly mid-level flow will stretch
from southern/central California to the Upper Midwest during the
day, as a trough continues to overspread the Pacific Northwest.
Farther east, another impulse will translate eastward from the
northern Plains to the upper Great Lakes. Across the southeastern
US, a weakening mid/upper low will cross the Florida peninsula late
in the period. The surface response will feature a cold front
gradually progressing southward over portions of the southern Great
Basin, while another front pushes southeastward across the northern
Plains and Upper Midwest.
Despite the weakening nature of the mid/upper low, cooling aloft and
increasing low-level moisture will support enough buoyancy for
scattered thunderstorms across the peninsula during the day.
Relatively weak low-level flow and marginal buoyancy are expected to
preclude a threat of severe thunderstorms.
Cold mid-level temperatures (around -34 to -38 C) will come ashore
the coast during the period. Despite cool surface conditions and low
dew points, steep low/mid-level lapse rates should encourage the
development of isolated thunderstorms during the afternoon.