National Weather Service Raw Text Product

Displaying AFOS PIL: AFDHGX Received: 2018-08-21 17:23 UTC


940 
FXUS64 KHGX 211723
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1223 PM CDT Tue Aug 21 2018

.AVIATION...
VFR conditions across all terminals right now with a stationary
boundary located to the north of the area. Showers and
thunderstorms will develop south of the boundary this afternoon,
and outflow from these storms will likely intersect the seabreeze
over the Metro terminals late this afternoon/early this evening.
With the strongest storms, expect gusty winds up to 30 mph,
frequent lightning, and heavy rainfall. There is the potential
for the storms to last until 03z tonight, but will update TAFs 
according to trends once convection develops. VFR behind the 
storms, but low ceilings and patchy fog are possible in the early 
morning outside of the Metro areas. VFR conditions expected 
throughout the day tomorrow.

22

&&

.PREV DISCUSSION... /ISSUED 1040 AM CDT Tue Aug 21 2018/ 

UPDATE...
All quiet on the homefront with the radar kicking into clear air
mode. Today's forecast is for this to change over the next few 
hours, or once we warm into the lower 90s. A synoptic scale 
boundary draped across the far northern CWA and a weak lower level
convergence zone across our coastal counties will likely be two 
areas of early afternoon convective focus. With upper ridging 
backing off to the west, near 2 inch pwat moisture and an unstable
atmosphere supporting 6 degree C lower 3 km lapse rates, would 
say that we are ripe for the widespread blossoming of late morning
through early evening showers and thunderstorms. North and south 
convective outflow meeting in the middle for a near 40 percent
(possibly slightly greater) areal precipitation coverage. Steep 
lower level lapse rates and higher cloud bases creating inverted-V
signatures that are usually indicative of strong downburst winds.
Thus, today's stronger and more organized storms have the potential
to put down greater than 30 mph winds (in gust). 

31

PREV DISCUSSION... /ISSUED 520 AM CDT Tue Aug 21 2018/ 

DISCUSSION...
The weak cold front draped across the far northern counties of SE
TX is expected to vacillate over the CWA today/tonight...and then
act as a focus for scattered mainly daytime activity. Have increased
POPS a bit for the near-term in response. Given the expected 
development (and the associated clouds), we could escape the heat 
advisory for this afternoon/early evening (that has been a bit of 
a fixture of previous days). 

This front should finally push through the area this evening into
the overnight hours as its associated upper low/trof tracks further
to the NE. In its wake, very broad upper ridging aloft will be 
building in from the west...then eventually expanding east to en- 
compass the Southern Plains into the SE U.S. for the remainder of 
the week. Warmer temperatures and low/nil POPS to prevail. 

Rain chances will return by the weekend as the upper ridge begins
to drift further E and NE with time. This should allow for the return
of slightly deeper moisture from the Gulf...and with daytime 
heating/seabreeze, isolated to widely scattered activity could develop
(mainly coastal/southern half of SE TX) starting Sat. 41

MARINE... 
A weak cold front should move into SETX today sagging southward 
through the afternoon reinforced by thunderstorms and outflow. This 
should end the southerly flow with a windshift to the north late 
tonight/early Wednesday across the bays and nearshore waters. At 
this time it appears that front should move through the offshore 
coastal waters Thursday then washout and lift back north. Winds 
across the UTCW should be light this afternoon through Saturday 
morning. Southerly flow strengthens Saturday night and then a more 
diurnal pattern returns to the area with slightly stronger winds 
overnight and lighter during the day. 45

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      98  77 101  74 101 /  40  30  10  10  10 
Houston (IAH)              97  77 100  76  99 /  40  30  10  10  10 
Galveston (GLS)            91  81  93  80  92 /  20  20  20  10  10 

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...High Rip Current Risk until 9 PM CDT this evening for the 
     following zones: Brazoria Islands...Galveston Island and 
     Bolivar Peninsula...Matagorda Islands.

GM...NONE.
&&

$$

Discussion...31
Aviation/Marine...22