Scientific Forecaster Discussion
fxus64 khgx 230437
Area forecast discussion
National Weather Service Houston/Galveston Texas
1137 PM CDT Tue Oct 22 2019
Aviation [06z taf issuance]...
VFR/sky clear for most terminals through tonight. Winds haven't come
down quite as far as expected, but only needs some minor nudging
upwards. Doesn't change expectations for stronger and more
southeasterly winds tomorrow from mid-day into the early evening.
Late in the forecast period, lowering cloud bases are expected to
push in from the Gulf towards some terminals. Skies are still
expected to be mostly clear so not expecting any threat of
category changes, but do start to indicate some scraps of midlevel
clouds at the end of the tafs.
Previous discussion /issued 1009 PM CDT Tue Oct 22 2019/...
Short term [through wednesday]...
nice, tranquil wx should continue through Wednesday. Winds will
gradually veer to the east and southeast as surface high pressure
moves away from the area. 47
Long term [wednesday night through tuesday]...
surface high pressure over the south central Continental U.S. Is expected to
continue to push northeastward by Wednesday night, giving way to a
developing center of low pressure along the leeside of the Rocky
Mountains. Global models continue to disagree significantly
regarding the development of a surface cold front extending from
this feature as it moves into southeast Texas this weekend. Both the NAM
and GFS solutions develop an upper trough over the Central Plains,
which propagates rapidly to the east by Saturday afternoon. Onshore
flow at the surface quickly turns to the north/northeast as a
result, cutting off Gulf moisture advection and keeping a weak
coastal low offshore. Conversely, the European model (ecmwf) and Canadian solutions
produce a closed upper-level low which becomes cutoff over the Texas
Panhandle and pushes much more slowly eastward through the region.
This allows for the onshore movement of the aforementioned weak low,
which brings with it increased precipitation coverage and intensity
on Friday and Saturday. While the most recent European model (ecmwf) run has sped
things up a bit, confidence in the weekend forecast remains fairly
low considering the widespread differences across guidance sources.
Current leanings are towards the slower European model (ecmwf)/Canadian solutions,
but low confidence will remain until a stronger consensus has been
Surface high pressure and relatively benign weather conditions
look to reenter the picture by next week, with highs in the mid
70s and lows in the upper 50s to lower 60s expected through
moderate northeast winds will gradually veer to the east tonight
then east southeast on Wednesday. Will maintain current scec/Small Craft Advisory
configuration offshore tonight...which may need to be extended
Increasing fetch of moderate E/se winds will drive tide levels
back up late night and persist into the remainder of the work week
until the next front pushes off the coast. Minor coastal flooding
is a possibility around each high tide cycle into Friday morning.
Building surf will also increase the risk of rip currents along
area beaches. Will be issuing a beach hazards statement for
tonight and Wed morning to incorporate both for now. However,
this may eventually need to be upgraded to a coastal flood
advisory later Wednesday and forward should the water levels
and coastal flood threat further increase.
Look for unsettled weather across the coastal waters Thursday
night into Friday ahead of the next storm system and associated
cold front. There is some uncertainty as to exactly when it will
push off the coast, but should be sometime between early Friday
morning or afternoon. Strong offshore winds can be expected in its
wake through Saturday. 47
Preliminary point temps/pops...
College Station (cll) 50 83 59 79 53 / 0 0 0 30 70
Houston (iah) 54 81 61 78 59 / 0 0 0 20 60
Galveston (gls) 66 79 71 78 65 / 0 0 0 30 80
GM...small craft should exercise caution until 4 am CDT Wednesday for
the following zones: coastal waters from Freeport to
Matagorda Ship Channel Texas out 20 nm...coastal waters from
High Island to Freeport Texas out 20 nm.
Small Craft Advisory until 4 am CDT Wednesday for the following
zones: waters from Freeport to Matagorda Ship Channel Texas
from 20 to 60 nm...waters from High Island to Freeport Texas
from 20 to 60 nm.