Post by Briella - Houma on Jan 18, 2019 13:34:09 GMT -6
SPC outlook for Saturday:
Forecast Discussion
SPC AC 181712
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1112 AM CST Fri Jan 18 2019
Valid 191200Z - 201200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE GULF STATES...
...SUMMARY...
Scattered storms, some severe, are expected across parts of the Gulf
Coast states on Saturday with damaging wind gusts and perhaps a
tornado or two.
...Gulf Coast States...
Southern Rockies short-wave trough is forecast to dig into southeast
OK/TX region by the start of the day2 period as a strong 500mb speed
max translates across the Hill Country of central TX into the lower
MS Valley by 18z. Significant mid-level height falls will overspread
the Gulf States ahead of this feature and a pronounced surface front
is expected to progress to near the MS River shortly after sunrise.
Latest model guidance suggest significant boundary-layer moistening
will occur ahead of the front across MS into northern MS early in
the period. With dew points expected to rise into the lower 60s
thermal profiles should permit adequate buoyancy for potential
robust updrafts, especially given the strengthening shear profiles.
Large-scale forcing for ascent will be maximized ahead of the
surface low and there is some concern a few supercells could
develop. However, frontal forcing is expected to encourage linear
convective development and a strong/potentially severe squall line
should be the primary storm mode along the wind shift. Damaging
winds are the primary threat with convection that is forced east
ahead of the front.
During the overnight hours, favorable southwesterly trajectories
will allow moistening to occur across the southern FL Gulf coast
region. Forecast soundings suggest upwards of 1000 J/kg of
surface-based CAPE will develop in the FMY region ahead of the
front. For this reason have introduced severe probs south along the
FL Gulf coast to account for this late-night threat immediately
ahead of the cold front.
...MAXIMUM RISK BY HAZARD...
Tornado: 5% - Slight
Wind: 15% - Slight
Hail: <5% - None
Forecast Discussion
SPC AC 181712
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1112 AM CST Fri Jan 18 2019
Valid 191200Z - 201200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE GULF STATES...
...SUMMARY...
Scattered storms, some severe, are expected across parts of the Gulf
Coast states on Saturday with damaging wind gusts and perhaps a
tornado or two.
...Gulf Coast States...
Southern Rockies short-wave trough is forecast to dig into southeast
OK/TX region by the start of the day2 period as a strong 500mb speed
max translates across the Hill Country of central TX into the lower
MS Valley by 18z. Significant mid-level height falls will overspread
the Gulf States ahead of this feature and a pronounced surface front
is expected to progress to near the MS River shortly after sunrise.
Latest model guidance suggest significant boundary-layer moistening
will occur ahead of the front across MS into northern MS early in
the period. With dew points expected to rise into the lower 60s
thermal profiles should permit adequate buoyancy for potential
robust updrafts, especially given the strengthening shear profiles.
Large-scale forcing for ascent will be maximized ahead of the
surface low and there is some concern a few supercells could
develop. However, frontal forcing is expected to encourage linear
convective development and a strong/potentially severe squall line
should be the primary storm mode along the wind shift. Damaging
winds are the primary threat with convection that is forced east
ahead of the front.
During the overnight hours, favorable southwesterly trajectories
will allow moistening to occur across the southern FL Gulf coast
region. Forecast soundings suggest upwards of 1000 J/kg of
surface-based CAPE will develop in the FMY region ahead of the
front. For this reason have introduced severe probs south along the
FL Gulf coast to account for this late-night threat immediately
ahead of the cold front.
...MAXIMUM RISK BY HAZARD...
Tornado: 5% - Slight
Wind: 15% - Slight
Hail: <5% - None
