Valid 091200Z – 101200Z
…NO SEVERE THUNDERSTORM AREAS FORECAST…
Severe thunderstorms are not expected Thursday and Thursday night.
Strong short-wave trough off the Pacific coast will dig southeast
toward the lower CO River Valley by 10/00z, then into northern
Mexico by the end of the period. Significant height falls will
spread across the southwestern US into far west TX by sunrise
Friday. In response to this approaching short wave, sustained LLJ
across the southern Plains will allow much higher-PW air mass to
advance north across TX into southern OK where lower 60s surface dew
points should be noted by the end of the period.
During the first half of the period, weak short-wave ridging should
dominate OK into MO. As a result, low-level warm advection will be
the primary forcing mechanism for potential convective development.
Latest thinking is shallow convection will gradually deepen during
the late afternoon/evening as elevated buoyancy increases across
this region through moisture advection. Forecast soundings suggest
adequate instability for elevated thunderstorms along a corridor
from southeast OK into IN. At this time it appears updrafts will be
too weak to warrant any meaningful threat for severe hail.
Late in the period, large-scale forcing will begin to affect western
plume of higher PW across northwest TX into southwestern OK. There
is some concern that convection may develop by the end of the period
across this region; however, greater probabilities for deep
convection will be during the day2 period.
Isolated thunderstorms may also develop across southeast AZ as mid
levels cool and lapse rates steepen within the digging trough.