Severe Storm Outlook Narrative (AC)
Issued by NWS
ACUS03 KWNS 300725
SPC AC 300723
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0223 AM CDT Sun Apr 30 2017
Valid 021200Z - 031200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
Thunderstorms will be possible from the western/central Gulf Coast
to the northern High Plains. While a few stronger storms may be
possible across the Texas Gulf Coast and southern Plains Tuesday
night, organized severe weather is not currently expected.
Broad cyclonic flow aloft will remain established across the Rockies
and points east through the period. Within this regime, one trough
will lift northeast from the Great Lakes towards the Canadian
Maritimes. Meanwhile, an upstream positively tilted trough will drop
southeast from the Rockies towards the southern/central Plains.
Ahead of this trough, the low-level mass response will feature
gradual moisture return northward across the Texas Gulf Coast and
adjacent portions of the southern Plains. Additionally, modest warm
advection late Tuesday into Tuesday night may yield elevated
convection across parts of Oklahoma and the Ozarks. While the 00Z
GFS is more aggressive with northward moisture return and suggests
the potential for a more substantive severe threat, it appears to be
an outlier relative to other guidance. In turn, convection is
currently expected to be relegated to areas of only weak/modest
elevated buoyancy Tuesday night. Thus, while some small hail appears
possible, a Marginal Risk is not introduced at this time.
Farther south, convection may develop late Tuesday night across
parts of the Texas Gulf Coast, likely in response to a subtle
impulse within the sub-tropical jet. While a few stronger cells may
be possible, guidance currently suggests most storms may remain
offshore. Combined with the unfavorable timing and subtle/uncertain
nature of this impulse, the potential for organized severe weather
appears too low for a Marginal Risk at this time.