Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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FXUS64 KHGX 301418

Area Forecast Discussion
National Weather Service Houston/Galveston TX
918 AM CDT SAT JUL 30 2016

Only minor tweaks were made to the forecast to account for current
obs. A few showers have sprung up over the offshore waters so far
this morning. Expect isolated to scattered showers and
thunderstorms to move inland beginning late this morning into the
early afternoon, with the greatest rain chances closer to the
coast. Highs are forecast to range from the upper 80s at the coast
to the mid 90s inland with heat indices around 100-106. 11



Skies have remained clear so far early this morning, but still
expecting some lower ceilings for a time, particularly in the
north which should drop into MVFR again. In the meantime, a few
showers and storms have popped up right on the coast around
Matagorda Bay, which may be a signal that most guidance is correct
in limiting convection today to the southwest. Still bring some
VCTS up through HOU, but think that subsidence will prove stronger
north and east of there. Any convection should end quickly towards
evening, while skies become mostly to fully clear.



Radar this morning only shows a few showers developing in the Gulf
which is less than the last few mornings. Based off upper air
analysis from the 00z soundings and water vapor imagery, the upper
level pattern has not changed too much from yesterday. Upper level
ridge remains over the Desert SW and off the coast of the
Carolinas with a weakness over Texas and the N Gulf Coast. Upper
level trough was moving through the Ohio River valley with the
trough axis stretching back to the SW into Texas. This means there
really is not a lot of subsidence in the atmosphere from the
ridging yet and diurnal heating with sea breeze forcing will be
enough to initiate convection. Problem today is that the
atmosphere is a bit drier with precipitable water values around
1.6 to 1.9 inches based on the 00Z CRP/LCh soundings. Soundings
still support convective temps in the low/mid 90s but coverage may
be limited due to the decrease in moisture. Forecast will keep 30
PoPs mainly along the coast today and tomorrow as the pattern will
be similar tomorrow. Actually models are showing an increase in
moisture tomorrow so there could be slightly more coverage
tomorrow than today.

Synoptic models are still on track with building 594/595 DM 500mb
ridge over the N Gulf and SE Texas on Monday. Ridging will persist
through Thursday when heights begin to lower again. Forecast will
call for no rain chances through Wednesday and then bring a slight
chance of rain for Thursday as the sea breeze should become more
active with initiating convection. Precipitable water values also
increase back close to 2 inches by Thursday which is more
favorable environment for convection. Deep moisture will continue
over the area for the end of the coming week and support decent
rain chances.

Looking into the tropical Atlantic basin, there are a couple of
tropical waves to track. The first is quickly moving west near 15N
50W and could move into the Caribbean/S Gulf by the end of the
coming week. This seems to be what the GFS and ECMWF are resolving
but keeping any low pressure center disorganized. Still way too
far out to discuss any details. The second wave is SW of the Cape
Verde islands. Both waves will be encountering wind shear and
environments that will limit tropical development. Still a good
reminder to monitor tropical activity and check preparedness.


The general nature of winds through the first of half next week will
be light to occasionally moderate onshore winds. Late at night to
very early in the morning, it is possible that winds near the coast
will become more variable or even briefly offshore with a weak land
breeze, but this would be the only real potential for deviation from
the general trend. Tide levels should continue to remain around or a
little more than 0.5 feet above normal Saturday. At the very end of
next week, there is potential for a tropical disturbance in the
southern Gulf of Mexico. However, at this range, there is very
little confidence in the exact location or strength of such a
feature. Given what is known now, mariners should continue to keep
up with the latest forecast information and think about potential
contingency plans for late next week that could be implemented
later when confidence in a particular forecast scenario increases.



College Station (CLL)      97  77  96  77  97 /  10  10  10  10  10
Houston (IAH)              96  78  95  78  96 /  30  10  30  10  10
Galveston (GLS)            91  82  91  82  91 /  20  10  20  10  10




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