Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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FXUS64 KHGX 230852
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
352 AM CDT Sun Apr 23 2017

.DISCUSSION...
High pressure building into the region early this morning ushering
in much drier and cooler air. Today should be Chamber of Commerce
weather with mostly sunny skies...northerly winds of 5-15 mph and
highs only reaching the lower to mid 70s. Quite the change from
the last few days of unusually warm and moist air for this time of
year. The high pressure system moves out into the Gulf Monday
changing winds from light and variable to light southerly and
starting the week off with pleasant weather. As the week
progresses temperatures will again climb back well above normal
and moisture will increase. A fast moving Pacific disturbance will
race east through the area Tuesday with an increase in clouds. A
quick dip in the jetstream on Wednesday will help to push a very
weak cold front down into the region - and could bring scattered
showers and thunderstorms to at least the northernmost portions of
the area. How strong the cap gets by that point should dictate the
southward extent of the storms given the pattern of late...it may
be strong enough to hamper deep convection as far north as
Huntsville. Models have really been struggling with the flow
across the north Pacific and ridging off the West Coast the last
few days and hence the timing and strength of the system crossing
the central Rockies has been varying quite a bit and these
dilemmas are evident with the Wednesday system. Some taking all
the way to nearshore waters and some stalling it just inland which
is a big change from runs 36-24 hours ago. In general though once
the system swings by Wednesday - heights rebound and it should
get hot. Thursday and Friday afternoon temperatures of 85-90
should be the norm with low level moisture trapped beneath a
potent cap. This will likely lead to some elevated heat index
readings of 92-99 degrees Thursday afternoon and again Friday.
Some rain relief should be headed toward the region next weekend
with a deepening upper trough over the 4 corners area that ejects
out and swings a cold front into and through the region with a
good chance of seeing widespread rainfall and maybe even some
strong springtime thunderstorms. But of course that is a week away
and the forecast is bound to change that far out.

Don`t forget the sunscreen if you are going to be out and about
today enjoying the gorgeous weather.

45

&&
.MARINE...
Strong offshore flow continues across the bays and Gulf waters early
this morning in the wake of yesterday`s cold front. Elevated winds
are expected to persist through most of the morning, decreasing
later this afternoon and evening as surface ridging builds farther
into Texas. Have extended the Small Craft Advisory through 4 PM for
the Gulf waters with 5 to 7 feet waves persisting through mid-
afternoon. Northwest winds across the upper Galveston Bay have
resulted in tides falling near to slightly below astronomical
levels. Water levels may fall to near 1.5-2 feet below astronomical
tides, but a Low Water Advisory is not expected at this time given
astronomical tides around 1-1.5 feet above MLLW.

Onshore flow is expected to resume late Monday as surface ridging
slides east of the region, strengthening to caution or advisory
levels on Tuesday ahead of a cold front that may approach the coast
Wednesday. Medium range guidance indicates the possibility of this
cold front pushing just off the coast late Wednesday, but any
offshore flow would be brief as a storm system develops over the
High Plains late week and promotes increasing onshore flow. As this
storm system ejects eastward late this week, another cold front may
make a run for the northwest Gulf.

Huffman

&&


&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      72  49  80  59  85 /   0   0   0   0   0
Houston (IAH)              74  52  83  61  85 /   0   0   0   0  10
Galveston (GLS)            73  63  75  69  78 /   0   0   0   0  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...Small Craft Advisory until 10 AM CDT this morning for the
     following zones: Galveston Bay...Matagorda Bay.

     SMALL CRAFT SHOULD EXERCISE CAUTION from 10 AM CDT this morning
     through this afternoon for the following zones: Galveston
     Bay...Matagorda Bay.

     Small Craft Advisory until 4 PM CDT this afternoon 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...Waters from Freeport to the
     Matagorda Ship Channel from 20 to 60 NM...Waters from High
     Island to Freeport from 20 to 60 NM.

     SMALL CRAFT SHOULD EXERCISE CAUTION from this afternoon through
     this evening 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...Waters from
     Freeport to the Matagorda Ship Channel from 20 to 60 NM...
     Waters from High Island to Freeport from 20 to 60 NM.

&&

$$

Discussion...45
Aviation/Marine...14


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