Area Forecast Discussion
Issued by NWS Houston/Galveston, TX
FXUS64 KHGX 202020
Area Forecast Discussion
National Weather Service Houston/Galveston TX
320 PM CDT Thu Oct 20 2016
Showers and a couple storms will continue to be an issue over the
next several hours as a cold front works through SE Texas. After
that clears, the main forecast question will look to how dry and
cool the post-frontal airmass gets for the weekend. For Sunday and
beyond, we slowly return to temperatures in the mid to upper 80s
and higher humidity as onshore flow re-establishes under a
building upper ridge.
Radar shows three distinct bands of precipitation oriented NE to
SW across the area. The lead band is the most vigorous and is near
the shoreline at 3pm, while the middle band is moving through
metro Houston at the same time. It appears to have been undercut
by the front which is just southeast, and is weakening with a lack
of elevated instability. The third band has largely decayed, but
some light showers may still be reaching the ground.
The front is only moving quickly enough to blunt highs today
a few degrees, but gusty north winds should bring in plenty of
cold air advection to bring tonight`s lows into the 50s for most
while skies quickly clear. Winds are high enough to be very
marginal for a wind advisory on the coast to match the small craft
advisory over the waters. For now decided to leave it be, but the
evening shift may need to issue one if winds are even just a
little stronger than expected.
Friday through the weekend...
Colder, drier air will give a respite from the extended summer-
like pattern we`ve seen extend well into October. However, don`t
get too attached. The upper ridge looks to build back over the
weekend, with onshore flow coming back in place late Saturday. As
such, Friday night looks to be quite cool with a gradual warming
trend each day of the weekend. It`s probably worth noting that
despite this significant front, temperatures are only being
dropped to near or just below seasonal averages.
The summer pattern returns, and temperatures look to slowly slide
their way back into the middle 80s and dewpoints back into the
60s. For now, have left conditions dry, but return moisture may
eventually be sufficient enough around coastal areas to allow for
some isolated to scattered diurnal shower development. Models
today keep the ridge tougher late into the week, and have
significantly backed off the big Southwest cutoff to come closer
in appearance to the NAEFS mean. So for the time being, we can
erase "here be monsters" from the frontiers of the forecast.
Showers and a few storms along a cold front will push off the coast
this afternoon. Gusty and dry conditions are expected behind the
front. Northeasterly winds of 20-25 knots and gusts up to 35 knots
are expected overnight tonight and into Friday along with seas of 5
to 9 feet. A small craft advisory is in effect from 7 PM this
evening until 7 PM Friday evening. Winds should slacken and seas
will begin to subside overnight Friday night as high pressure
settles in. A gradual shift to onshore flow will occur through the
weekend as the high pressure slides eastward. 11
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 81 52 79 51 79 / 40 0 0 0 0
Houston (IAH) 83 55 78 52 80 / 30 10 0 0 0
Galveston (GLS) 80 66 77 64 77 / 50 10 0 0 0
GM...Small Craft Advisory from 7 PM this evening to 7 PM CDT Friday
FOR THE FOLLOWING ZONES: Coastal waters from Freeport to
the Matagorda Ship Channel out 20 NM...Coastal waters from
High Island to Freeport out 20 NM...Galveston Bay...
Matagorda Bay...Waters from Freeport to the Matagorda Ship
Channel from 20 to 60 NM...Waters from High Island to
Freeport from 20 to 60 NM.