KevinH
Member
Just saw that the SPC has highlighted Sunday soooo HERE WE GO! lol
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0244 AM CST Tue Feb 21 2023
Valid 241200Z - 011200Z
...DISCUSSION...
Strong west/southwest flow aloft will exist over the CONUS on
Fri/D4, with an upper high over FL and a large-scale upper trough
over the West. High pressure will be centered over the northern
Plains in the wake of an upper wave exiting the Northeast, with a
cold front roughly from central TX eastward across the Gulf Coast
states. Subtle height rises will occur across the frontal region as
the FL high retrogrades across the Gulf of Mexico. Scattered showers
and weak thunderstorms may occur in this region, mainly north of the
surface boundary with weak instability and little severe risk.
On Sat/D5, an upper low will move across southern CA, while a wave
amplifies in the northwesterly flow over the northern Plains. This
will reinforce high pressure over the Plains and upper/middle MS
Valley, while the boundary across the Gulf Coast states gradually
makes northward progress with a few showers and weak thunderstorms
within that east-west zone from TX into the Carolinas.
By Sun/D6, models are in relatively good agreement showing the upper
low moving east across the Four Corners states with height falls
into the central and southern Plains by 00Z Mon. Surface
moisture/60s F dewpoints will likely surge northward ahead of the
shortwave trough, with low pressure over the central High Plains
Sun/D6 afternoon, deepening as it pivots into IA during the evening.
MUCAPE around 1000 J/kg appears likely from parts of western KS into
OK, and shear will favor supercells beneath a 50 kt low-level jet.
Initial supercells from the surface low southward along the dryline
will favor large hail and a few tornadoes, with damaging wind threat
extending eastward across KS and OK through evening as storms
possibly become linear. As such, a 15% severe area has been added.
Predictability decreases on Mon/D7 as the upper trough moves toward
the Great Lakes, and a surface boundary trails southwestward into
the lower MS Valley. Here, a plume of mid to upper 60s F dewpoints
will likely remain, beneath 50-60 kt midlevel southwesterlies which
will mean a larger component of the deep-layer shear parallel to the
boundary. Instability will be less by this time owing to relatively
warmer midlevel temperatures, but at least some damaging wind
potential may eventually be noted with storms expected along the
cold front. This front is expected to push offshore by Tue/D8, with
lessening threat of severe storms.
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0244 AM CST Tue Feb 21 2023
Valid 241200Z - 011200Z
...DISCUSSION...
Strong west/southwest flow aloft will exist over the CONUS on
Fri/D4, with an upper high over FL and a large-scale upper trough
over the West. High pressure will be centered over the northern
Plains in the wake of an upper wave exiting the Northeast, with a
cold front roughly from central TX eastward across the Gulf Coast
states. Subtle height rises will occur across the frontal region as
the FL high retrogrades across the Gulf of Mexico. Scattered showers
and weak thunderstorms may occur in this region, mainly north of the
surface boundary with weak instability and little severe risk.
On Sat/D5, an upper low will move across southern CA, while a wave
amplifies in the northwesterly flow over the northern Plains. This
will reinforce high pressure over the Plains and upper/middle MS
Valley, while the boundary across the Gulf Coast states gradually
makes northward progress with a few showers and weak thunderstorms
within that east-west zone from TX into the Carolinas.
By Sun/D6, models are in relatively good agreement showing the upper
low moving east across the Four Corners states with height falls
into the central and southern Plains by 00Z Mon. Surface
moisture/60s F dewpoints will likely surge northward ahead of the
shortwave trough, with low pressure over the central High Plains
Sun/D6 afternoon, deepening as it pivots into IA during the evening.
MUCAPE around 1000 J/kg appears likely from parts of western KS into
OK, and shear will favor supercells beneath a 50 kt low-level jet.
Initial supercells from the surface low southward along the dryline
will favor large hail and a few tornadoes, with damaging wind threat
extending eastward across KS and OK through evening as storms
possibly become linear. As such, a 15% severe area has been added.
Predictability decreases on Mon/D7 as the upper trough moves toward
the Great Lakes, and a surface boundary trails southwestward into
the lower MS Valley. Here, a plume of mid to upper 60s F dewpoints
will likely remain, beneath 50-60 kt midlevel southwesterlies which
will mean a larger component of the deep-layer shear parallel to the
boundary. Instability will be less by this time owing to relatively
warmer midlevel temperatures, but at least some damaging wind
potential may eventually be noted with storms expected along the
cold front. This front is expected to push offshore by Tue/D8, with
lessening threat of severe storms.
