Post by SKYSUMMIT on May 7, 2020 6:16:13 GMT -6
Just looking at tomorrow, the SPC has highlighted much of west Louisiana as a Slight Risk.
...Southern TX...LA and southwest MS...
Convection will likely be ongoing Friday morning from southeast OK
into adjacent portions of AR/TX in the vicinity of a cold front.
This convection will likely be elevated and to the cool side of the
surface boundary. Ahead of the front, mid/upper 60s F dewpoints will
reside across much of central/southern TX into LA. Southwesterly low
level flow will transport Gulf moisture eastward through the
afternoon into southern MS just prior to frontal passage. Most
guidance suggests that convection should intensify or redevelop
along the front from northern/central LA southwestward into east TX
during the late morning/early afternoon. Strong heating and midlevel
lapse rates around 7.5-8 C/km will result in moderate MLCAPE and
surface-based convection. Steep lapse rates should support some
large hail, through this will be dependent on storm mode remaining
somewhat discrete. Strong forcing along the front and deep-layer
flow parallel to the boundary will likely result in storms quickly
taking on a linear mode, increasing the potential for damaging wind
gusts.
There is some uncertainty with regards to the north and eastward
extent of the severe threat. Morning frontal position and ongoing
convection will play a role in this, as will eastward extent of
higher surface dewpoints ahead of the front. The cold front should
move offshore from the upper TX/LA/MS coasts around 00-03z.
Further to the west/southwest, rich Gulf moisture will be in place
across south TX with dewpoints in the upper 60s to low 70s expected.
A plume of steep midlevel lapse rates emanating from the Mexican
Plateau will reside over the region, with values between 8-9 C/km
possible. Strong afternoon heating into the mid 80s to low 90s F
will result in strong instability and steep low-level lapse rates.
While forcing and deep layer flow will be weaker across this area,
at least a conditional threat for a severe storm or two will exist.
If storm develop, large hail and strong downburst winds would be
possible.
...Southern TX...LA and southwest MS...
Convection will likely be ongoing Friday morning from southeast OK
into adjacent portions of AR/TX in the vicinity of a cold front.
This convection will likely be elevated and to the cool side of the
surface boundary. Ahead of the front, mid/upper 60s F dewpoints will
reside across much of central/southern TX into LA. Southwesterly low
level flow will transport Gulf moisture eastward through the
afternoon into southern MS just prior to frontal passage. Most
guidance suggests that convection should intensify or redevelop
along the front from northern/central LA southwestward into east TX
during the late morning/early afternoon. Strong heating and midlevel
lapse rates around 7.5-8 C/km will result in moderate MLCAPE and
surface-based convection. Steep lapse rates should support some
large hail, through this will be dependent on storm mode remaining
somewhat discrete. Strong forcing along the front and deep-layer
flow parallel to the boundary will likely result in storms quickly
taking on a linear mode, increasing the potential for damaging wind
gusts.
There is some uncertainty with regards to the north and eastward
extent of the severe threat. Morning frontal position and ongoing
convection will play a role in this, as will eastward extent of
higher surface dewpoints ahead of the front. The cold front should
move offshore from the upper TX/LA/MS coasts around 00-03z.
Further to the west/southwest, rich Gulf moisture will be in place
across south TX with dewpoints in the upper 60s to low 70s expected.
A plume of steep midlevel lapse rates emanating from the Mexican
Plateau will reside over the region, with values between 8-9 C/km
possible. Strong afternoon heating into the mid 80s to low 90s F
will result in strong instability and steep low-level lapse rates.
While forcing and deep layer flow will be weaker across this area,
at least a conditional threat for a severe storm or two will exist.
If storm develop, large hail and strong downburst winds would be
possible.
