Convective Outlook

SPC 2000Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0300 PM CDT Tue Oct 15 2019

Valid 152000Z - 161200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
TEXAS INTO THE OZARKS...AND ALONG PORTIONS OF THE GULF COAST...

...SUMMARY...
Isolated severe thunderstorms will remain possible this afternoon
and evening from parts of Texas into the Ozarks, and along portions
of the Gulf Coast.

...20Z Update...
Generally minor changes have been made to the Marginal Risk across
parts of TX and southeastern OK to account for observational trends
and short-term model guidance. A small area of stronger diurnal
heating is supporting a narrow corridor of 1500-2000 J/kg of MLCAPE
across parts of southeastern OK into northeast TX. At least isolated
storms are still expected to form across this region within the next
few hours along a southeastward-moving cold front. Strong mid-level
westerly flow and around 45-55 kt of effective bulk shear will
likely promote organized updrafts, with all severe hazards possible.
However, widespread low clouds have limited heating and instability
farther east into southern AR and east TX. Current expectations are
for the overall severe threat to remain rather isolated through the
early evening across this region, before instability weakens even
further with the loss of daytime heating.

Farther east, low-topped storms across southern AL and the FL
Panhandle to the south of a warm front may continue to pose mainly
an isolated strong/gusty wind threat. See Mesoscale Discussion 2068
for more information on the near-term severe threat across this
region.

..Gleason.. 10/15/2019

.PREV DISCUSSION... /ISSUED 1056 AM CDT Tue Oct 15 2019/

...Southeast OK into the Gulf Coast region...
Morning surface analysis shows a diffuse surface boundary extending
from southern AL/MS into parts of LA/AR and eastern OK.  Persistent
clouds and precipitation along and north of the boundary will limit
it's northward progress today.  But ample low-level moisture south
of the front and the potential for a little heating will likely
result in scattered afternoon thunderstorms throughout this axis. 
The area with greatest confidence of more intense storms extends
from southeast OK into southwest AR/northeast TX and northern LA -
where the strongest heating and vertical shear profiles will exist. 
Rotating storms capable of gusty/damaging winds and hail are
possible.  But even here, weak low-level winds will limit the
overall severe threat.  

...AR/MO...
A few thunderstorms are forecast to develop this afternoon and
evening along a cold front sagging into parts of western AR and
southeast MO.  Instability will be quite weak, limiting the
organized severe risk.  However, sufficient wind speeds aloft and
large-scale forcing will pose a risk of a few storms capable of
gusty/damaging winds.

...TX...
A band of strong westerly midlevel winds extends across TX today,
where a weak CAP and moderate CAPE will develop.  12z CAM solutions
generally agree that scattered thunderstorms will develop along an
axis from the Big Bend region into central and east TX this
afternoon and evening.  The initial storms may be occasionally
intense with a risk of hail and gusty winds.  Any severe threat
should weaken by mid-evening as diurnal cooling commences.

Updated 15 October 2019 | 3:09 pm