Scientific Forecaster Discussion
fxus64 khgx 180127
Area forecast discussion
National Weather Service Houston/Galveston Texas
827 PM CDT Fri Aug 17 2018
Near term [through tonight]...
Upper level ridge doing its thing today keeping thunderstorm
activity away and high temperatures in the upper 90s. Heat index
hit right at heat advisory criteria this afternoon around
106-108f. Overall trend in the forecast looks on track so only
minor updates for the ongoing trends.
Previous discussion /issued 652 PM CDT Fri Aug 17 2018/...
isolated shower activity is contained to the coastal counties and
offshore waters this afternoon. Any thunderstorm development will
have to fight against a moderate capping inversion at 700 mb, so
any enhancement in activity along the seabreeze will be local and
brief. High temperatures today will once again reach the mid to
upper 90s, but dew points have mixed out more than this time
yesterday due to winds backing to southeasterly this afternoon.
Therefore, a heat advisory has not been issued. The pattern of
high temperatures in the mid to upper 90s and heat index values of
100-105 will continue through early next week thanks to a
dominating upper level ridge.
The ridge slowly begins to drift westward late this weekend and
early next week. Tuesday into Wednesday, a trough from the pac northwest
will dig down into the Southern Plains and Mississippi Valley.
Models are currently progging the associated weak surface cold
front to progress through southeast Texas, but minimal upper level
support gives cause for healthy skepticism. Therefore, pops were
kept generally at or below 50% due to lack of confidence at this
time. The ridge stays situated over West Texas/Four Corners through
the end of next week. Some guidance allows an inverted trough to
build over south Texas, which will increase rain chances for the
end of next week. Low confidence in timing or extent of the
inverted trough has kept pops capped at 30%.
Aviation [00z taf issuance]...
Sea breeze moving inland has caused winds to increase a bit
across some of the coastal and Houston terminals. Winds should
decouple tonight. Winds may not become calm but close to 5kts in
most areas. Winds should start out SW tomorrow morning and turn
S/southeast by afternoon with the sea breeze. VFR conditions are expected
for ceilings and visibility.
for the next few days, look for winds to continue a typical
summertime pattern of generally onshore flow and isolated showers
and thunderstorms, with land/sea-breeze adjustments in the
afternoon and overnight. Wind speeds will be mostly light to
moderate, but as low pressure develops in the far western portion
of the state and tightens the pressure gradient, wind speeds
should nudge upwards as well. This may require a scec in portions
of the Gulf, primarily off Matagorda Bay, Sunday night into
Monday. Finally, a cold front will work towards southeast Texas in
the early to middle portions of next week, though impacts to
marine areas are likely to be more limited than the land.
Preliminary point temps/pops...
College Station (cll) 76 99 76 98 77 / 10 10 0 10 10
Houston (iah) 78 96 78 94 79 / 10 10 0 10 10
Galveston (gls) 83 89 82 89 83 / 10 10 10 10 10