Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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FXUS64 KHGX 250246

Area Forecast Discussion
National Weather Service Houston/Galveston TX
946 PM CDT Sat Jun 24 2017

The rain activity has tapered off to isolated showers at 9:30 PM
with the most activity located near the front which was draped
across the northern counties of the forecast area. Isolated
showers were also occurring between Houston and Galveston near the
radar. Another area with scattered showers developing was along an
outflow boundary located along the west of Freeport.

Still expect isolated to scattered showers and thunderstorms
across Southeast Texas through the remainder of tonight. Numerous
weak boundaries set down by earlier convection, the main outflow
boundary along the coast and the front in the north will all be a
focus for development. PW/s from the 00Z soundings ranged from 1.7
inches at CRP to 2.0 at LCH. This indicated plenty of moisture
will be available. Model soundings show an increase in the PW
field throughout the night. The area will also be under a weak
upper level trough of low pressure.

Tweaked the rain chances downward for the remainder of this
evening. Kept rain chances as is for the overnight period.



.PREV DISCUSSION... /ISSUED 641 PM CDT Sat Jun 24 2017/

A rather diffuse frontal boundary seems to be meandering from
near Del Rio to Waco eastward into central LA. Basically the
gradient between mid 70 dewpoints to the south and mid 60
dewpoints to the north. Radar shows little if any convection over
the area with a few new showers developing near KPSN along the
front. Overall think that the boundary layer has been worked over
and stabilized by today`s convection that re-development of
convection will be a challenge. But then you glance at the latest
HRRR runs and start to think otherwise. Possible that between
02-03Z convection could develop along the front with some outflows
from KCLL to KCXO. For now there is no mention of convection but
quite possible that amendments will be needed to account for new
storms. Convection should stay north of KIAH but any outflows
could re-generate convection give the moist airmass.

Another scenario and is if convection does not develop, skies
could clear out enough that with clam winds and wet grounds, fog
could form over the area. SREF and even the GLAMP seem to suggest
this possibility so added mention of lower visibility for a couple
of hours.

Tomorrow looks to be possibly a repeat of today with late morning
convection forming and lasting into the afternoon. TAFs were
adjusted an hour or two for convection forming in the late
morning. Any MVFR/IFR conditions should improve during this time
as well with day time heating.


PREV DISCUSSION... /ISSUED 328 PM CDT Sat Jun 24 2017/

Onshore winds have slowly become more easterly this afternoon, as a
front pushes in from the north. Still continuing to monitor a
few showers straggling along the coast and also in Washington
County. Based on short time guidance, the best chance for possible
showers to develop tonight would be in the northern counties of
the CWA. Although, after the convection we saw earlier today
thinking that conditions have stabilized, which would put a
damper on the chance for wide spread development tonight. If this
pans out, PoPs will need to be lowered for the overnight period.
Conditions will definitely remain muggy, with forecast soundings
keeping PWs between 2.0 to 2.25 inches through Sunday morning, and
by late Sunday lowering to around 1.90 to 2.0 inches. With
convective temperatures remaining in the low to mid 80s over the
weekend and with such a saturated airmass lingering over SE TX,
the ingredients are there for shower and thunderstorm

Tomorrow, precip will most likely develop near leftover boundaries
from today as well as along a weak sea breeze that could push
onshore by late afternoon as we approach max temperatures. High
temperatures for Sunday through Tuesday will reach up into the mid
to upper 80s. There are also some higher values of vorticity that
will move across the region in the upper levels, that could help to
provide some lift first on Sunday afternoon and again late Tuesday.
Still low confidence in the timing and location of exactly where
this precip will end up over the next few days as most of the models
lack agreement in the locations of development.

SE TX remains centered between two upper level high pressure systems
through next Friday. Expecting winds to remain out of the east until
Wednesday, and then we will begin to see a return to onshore
flow. PWs will be lower by Wednesday with PoPs also lowering, as
an area of surface high pressure begins to move in from the east.
Therefore, max temperatures will be on the rise by late next week,
reaching into low 90s across much of SE TX.


A weak outflow boundary may result in a few showers and
thunderstorms across the nearshore waters this afternoon with a
brief period of offshore flow possible in its wake. Otherwise, light
to occasionally moderate east to southeast flow is expected across
the coastal waters through mid-week and this will help keep tide
levels 1-1.5 feet above normal over the next few days. In addition
to elevated tides, east to southeast flow will help promote an
increased risk for rip currents. A Beach Hazards Statement is in
effect through tonight for these strong rip currents and additional
Beach Hazards Statements may be needed at times through early next
week for elevated tides producing wave run up along Bolivar
Peninsula and increased rip current risk.

Lee troughing over the High Plains will result in onshore flow
strengthening to caution or possibly advisory criteria mid to late
next week.



College Station (CLL)      73  87  72  88  72 /  50  50  30  40  20
Houston (IAH)              75  89  73  87  73 /  40  50  40  50  20
Galveston (GLS)            79  86  78  85  78 /  30  40  40  50  40




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