Severe Storm Outlook Narrative (AC)
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000
ACUS03 KWNS 170738
SWODY3
SPC AC 170737

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0137 AM CST Sun Dec 17 2017

Valid 191200Z - 201200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE MIDDLE TO UPPER TEXAS COAST INTO SOUTHEAST TEXAS...

...SUMMARY...
Scattered thunderstorms will be possible on Tuesday from the
southern Plains eastward into parts of the lower Mississippi Valley.
A marginal severe threat may develop across parts of the middle to
upper Texas Coast into southeast Texas.

...Middle to Upper Texas Coast/Southeast Texas...
An upper-level low will move from eastern New Mexico eastward into
the southern Plains on Tuesday as an associated upper-level trough
moves from northern Mexico into central Texas. Moisture advection is
forecast to increase ahead of the trough across the middle to upper
Texas Coast as a 30 to 40 kt low-level jet develops Monday morning.
A cold front is forecast to move into east Texas as scattered
thunderstorm development takes place along and ahead of the front
during the day. NAM and GFS forecast soundings for Houston gradually
increase MLCAPE to around 1000 J/kg by midday. This combined with 40
to 50 kt of deep-layer shear and strong low-level shear associated
with the low-level jet, will be sufficient for a marginal severe
threat. Given the strong shear environment, a marginal tornado
threat would be possible. A few strong wind gusts may also occur.
Any severe threat will probably remain concentrated in southeast
Texas Tuesday afternoon where the most instability is forecast. The
severe potential should diminish from west to east as the front
moves eastward.

..Broyles.. 12/17/2017

$$



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