Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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000
FXUS64 KHGX 202112
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
412 PM CDT Sun Aug 20 2017

.DISCUSSION...
Early afternoon coastal convection that flared up over Chambers
...Galveston and Brazoria Counties aided in regulating heat
indices to under Advisory criteria. Towering Cu/Cbs and their
subsequent cooling rain and outflow(s) kept many ambient
temperatures in the lower 90s and...with dew points in the middle
70s...allowed heat indices to top out between 100 and 105 F
degrees. Today`s near coastal enhanced storm activity a sign of
what we can expect in the coming days. The approach and eventual
stall of broad cyclonic Gulf circulation will tap into a greater
than 1.8 inch pw plume creeping in from the east and produce
daytime scattered showers and thunderstorms. The higher chances
for late morning into afternoon TSRA activity will be generally
focused along and south of an I-10/Highway 59 corridor tomorrow
and Tuesday. Thicker cloud cover and precipitation/damp grounds
will have subtle (relative cooling) effects on daytime temperatures.
As dew points will still remain in the middle to upper 70s (mid
to upper 60s within any area lucky enough to experience outflow
air)...lower to middle 90s maximum temperatures will likely keep
heat indices at or under 105 F. As has been the case the last
couple of days SPS versus Heat Advisories should remain the norm.

The broad western Gulf low or inverted trough will come ashore by
early Wednesday. Although upper ridging will generally rule the
synoptic over eastern Texas...an approaching Southern Plains
boundary reaching the Red River Valley at mid-week may be the
impetus that keeps at least low end POPs in place through week`s
close. Per weaker winds brought on by upper ridging and it being
late August...anticipating a more active mid to late work week
sea/bay breeze boundary. Either convection and its subsequent
outflow fronts emanating from and along these late AM/early PM
meso boundaries...or residual boundaries laying around from
previous day`s activity...may interact with this aforementioned
northeastern Texas front to produce more widespread northern
county convection on Thursday. Rain chances stay fairly high to
close out the week to account for the above forcing within a
continued heated and very moist late August environment. 31

&&

.Tropical...
The remnants of Harvey...now a wave over the northwestern Caribbean
Sea...is forecast to meander west towards the Honduras/Nicaragua
coastlines. Models do have this feature moving back into the
southern Bay of Campeche by early Thursday. A brief strengthening
is then forecast with a short jog across the far southern Bay of
Campeche with a progged landfall over the Tampico area Friday. As
of now...there is no immediate concern that Harvey will impact
Texas or its neighboring waters. 31

&&

.MARINE...
2-3ft seas and a light-moderate onshore flow will continue for the
next several days. Scattered late night and morning showers and
thunderstorms can be expected for much of the week.  47

&&


.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      76  97  75  98  76 /  10  20  10  20  10
Houston (IAH)              76  93  77  94  76 /  10  40  10  40  10
Galveston (GLS)            84  89  82  90  81 /  10  30  10  20  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$

Discussion...31/47



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