LONG TERM (Saturday Night through next Thursday)...A cold front
will be exiting the southeastern Big Bend at the beginning of the
extended period as a transient upper trough pushes off the eastern
seaboard. A drier and slightly cooler airmass will move into the
forecast area for Sunday with high temperatures only reaching the
MID to upper 60s. With a cut-off low over the desert southwest,
the ridge will quickly rebuild over the deep south by late Sunday
into Monday, with high temperatures moderating back into the lower
to mid 70s.
00z guidance suite is in decent agreement with a slower and more
coherent ejection of the upper low out of the southwestern states
early next week. This should delay the arrival of precip from this
system until later on Tuesday, with the bulk of the precipitation
moving in for Wednesday. There remains disagreement on the intensity of the system as it impacts the forecast area, with the GFS
currently less bullish than the ECMWF in terms of INSTABILITY,
THUNDERSTORM chances, and QPF. For now, will mention ISOLATED thunderstorms for Tuesday night into Wednesday. The front will be slow to exit the area late Wednesday into Thursday as the upper ridge builds back over the region. At this time, significant cooling is not expected behind this system.