Convective Outlook

SPC 2000Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0147 PM CST Sat Dec 07 2024

Valid 072000Z - 081200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not expected through tonight.

...20z Update...
No changes. Weak mid-level warm advection will continue to support
isolated thunderstorms through this afternoon across parts of
central and eastern TX. Recent Hi-res guidance also suggests storms
will gradually decrease in coverage with lightning becoming more
sporadic through tonight.

Isolated thunderstorms are possible over parts of the Pacific
Northwest with weak buoyancy and steepening mid-level lapse rates
ahead of the advancing Pacific Trough. Severe storms are not
expected, see the prior discussion.

..Lyons.. 12/07/2024

.PREV DISCUSSION... /ISSUED 1029 AM CST Sat Dec 07 2024/

...TX...
Broad southwest flow aloft will maintain mid-level warm/moist
advection and persistent showers and isolated thunderstorms through
the forecast period.  It appears the highest probability of
lightning will be this afternoon, with decreasing coverage after
dark.  No severe storms are expected.

...Northwest WA...
A few thunderstorms are possible this evening and tonight over
northwest WA as a progressive upper trough and associated cold
pocket aloft moves into the area.

Updated 7 December 2024 | 1:51 pm

SPC 1930Z Day 3 Outlook

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0121 PM CST Sat Dec 07 2024

Valid 091200Z - 101200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms are possible from the Lower Mississippi Valley into
much of Alabama and the Florida Panhandle on Monday. The probability
for severe thunderstorms is low.

...Synopsis...
A broad mid-level trough will deepen across the central CONUS,
encouraging appreciable low-level moisture return across portions of
the Lower MS Valley into the Southeast on Monday. The approaching
mid-level trough, and increasing low-level flow/advection over the
Lower MS Valley, will result in strengthening vertical wind shear,
depicted as modestly curved but elongated hodographs in forecast
soundings. However, tropospheric lapse rates are forecast to be
poor, with forecast soundings depicting thin SBCAPE under 500 J/kg,
constrained mainly below 500 mb. As such, buoyancy continues to
appear too scant for the introduction of severe probabilities this
outlook. However, given the available wind shear and adequate
synoptic forcing for thunderstorms, the need for severe
probabilities may increase over the Lower MS Valley if greater
buoyancy than what is forecast becomes apparent.

..Squitieri.. 12/07/2024

Updated 7 December 2024 | 1:23 pm

SPC 1730Z Day 2 Outlook

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1045 AM CST Sat Dec 07 2024

Valid 081200Z - 091200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms are still possible from southeast Texas into the Lower
Mississippi Valley and Mid-South on Sunday. The probability for
severe thunderstorms remains very low.

...Synopsis...
A mid-level trough will rapidly eject into the Southern Plains and
impinge on the TN Valley while preceding a larger upper trough that
is poised to overspread the central and northern CONUS tomorrow
(Sunday). The approach of the Southern Plains mid-level trough will
encourage broad low-level warm-air/moisture advection across
portions of the Lower MS Valley into the TN Valley regions. Latest
guidance consensus continues to depict a warm-sector characterized
by scant buoyancy, with widespread rainfall and embedded elevated
thunderstorms expected to overspread the Lower MS and TN Valleys
Sunday into Sunday night. High-resolution guidance consensus hints
at the possibility of 100-500 J/kg SBCAPE over southern LA by
afternoon peak heating, amid curved and elongated hodographs. While
a rotating storm or perhaps brief tornado cannot be completely ruled
out, the lack of confidence in developing surface-based buoyancy
precludes severe probabilities this outlook.

..Squitieri.. 12/07/2024

Updated 7 December 2024 | 10:49 am

SPC 1630Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1029 AM CST Sat Dec 07 2024

Valid 071630Z - 081200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not expected through tonight.

...TX...
Broad southwest flow aloft will maintain mid-level warm/moist
advection and persistent showers and isolated thunderstorms through
the forecast period.  It appears the highest probability of
lightning will be this afternoon, with decreasing coverage after
dark.  No severe storms are expected.

...Northwest WA...
A few thunderstorms are possible this evening and tonight over
northwest WA as a progressive upper trough and associated cold
pocket aloft moves into the area.

..Hart/Dean.. 12/07/2024

Updated 7 December 2024 | 10:33 am