---model discussion---
The 08/00z and 07/18z NAM runs exhibit a too-cool bias with surface
temperatures east of the dryline across north-central TX (low to mid
70s near DFW metro), specifically near the I-35 corridor. Moreover,
it is likely strong heating will occur across central and north TX
during the day with temperatures at least 90 F west of the dryline
and into the middle 80s to the east in the warm sector. As a
result, ARW-based convection-allowing models (based on the parent
ARW model) are likely misrepresenting thunderstorm potential across
TX during the 21z-03z period. Conversely, the 08/00z and 07/18z GFS
runs are showing excessive boundary-layer mixing and a too-warm bias
across north-central TX with the dryline likely displaced too far
east compared to its likely position near I-35 by late afternoon.
The 07/12z ECMWF appears superior to the NAM/GFS in this regard with
adequate boundary-layer mixing implied by the warmer surface
temperatures (mid 80s F). This forecast across the southern Great
Plains coincides with model output similar to the ECWMF in recent
model runs.
