Severe Storm Outlook Narrative (AC)
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000
ACUS02 KWNS 251732
SWODY2
SPC AC 251730

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1230 PM CDT Thu Apr 25 2019

Valid 261200Z - 271200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM NORTH
CAROLINAS INTO THE MIDDLE ATLANTIC REGION...

...SUMMARY...
Thunderstorms capable of producing damaging wind and isolated
tornadoes are expected from North Carolina into the Middle Atlantic
Friday. Isolated damaging wind gusts are also possible over northern
Utah, southeast Idaho, southwest Wyoming and northwest Colorado.
Other storms may produce a few strong wind gusts over a portion of
the Florida Peninsula.

...Carolinas to the Middle Atlantic region...

Southern-stream shortwave trough will deamplify as it becomes
absorbed within the base of an amplifying northern-stream trough and
move off the Atlantic Seaboard early Friday. The northern-stream
trough will continue through the Carolinas and Middle Atlantic
region during the day accompanied by a cold front. Modest low-level
moisture with dewpoints in the upper 50s to lower 60s F will advect
through the warm sector along a 50 kt low-level jet. This in
conjunction with some cloud breaks will destabilize the boundary
layer with MLCAPE from 500-1000 J/kg possible. Some thunderstorms
may be ongoing along the NC coast early Friday in association with
the leading shortwave trough. Farther upstream, storms are expected
to intensify along and ahead of the cold front as the boundary layer
destabilizes from VA into NC and possibly as far south as SC.
Strengthening mid-upper wind profiles accompanying the
northern-stream shortwave trough will support 40-45 kt effective
bulk shear supportive of embedded organized structures with storms
developing within the evolving squall line and some supercells with
any storms developing ahead of the line. Damaging wind appears to be
the main threat,  but isolated tornadoes are also possible. Severe
threat should end by early evening as the cold front moves offshore.


...Northern Utah, southeast Idaho, southwest Wyoming and northwest
Colorado...

A low-amplitude northern-stream shortwave trough embedded within
fast flow will move southeast through the northern Rockies during
the day with trailing cold front extending south into the Great
Basin region. With modest low-level moisture (upper 30s to low 40s F
dewpoints) and steep lapse rates in place, diabatic warming should
boost MLCAPE to around 500+ J/kg during the afternoon. Thunderstorms
are expected to develop along and ahead of the front as the
atmosphere destabilizes. Deeply mixed boundary layers with
inverted-V profiles and strong winds through the convective layer
will support a risk for damaging wind as activity spreads east
during the afternoon.  A slight risk might be needed for this area
in day 1 updates.

...Florida Peninsula...

Thunderstorms will continue along trailing portion of the cold front
within a modest flow regime. These storms may be capable of
producing a few locally strong gusts into central FL. However, the
stronger forcing aloft will remain well north of this region, and
thermodynamic profiles aloft will become increasingly hostile for
thunderstorm maintenance as the mid-level dry slot impinges upon the
peninsula from the west.

...MAXIMUM RISK BY HAZARD...
Tornado:   5%     - Slight
Wind:     15%     - Slight
Hail:      5%     - Marginal

..Dial.. 04/25/2019

$$


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