Re: July 2020
Posted: Fri Jul 24, 2020 9:32 am
FXUS64 KHGX 241000
AFDHGX
Area Forecast Discussion
National Weather Service Houston/Galveston TX
500 AM CDT Fri Jul 24 2020
.AVIATION...
As of 4 AM CDT, the central of Tropical Storm Hanna was located
near latitude 26.7 North, longitude 92.4 West and is moving
toward the west-northwest through tonight. Hanna`s center is
forecast to move into the Texas Coastal Bend on Saturday. As the
storm continues to approach the Texas Coast, rainbands generated
by Hanna will move across Southeast Texas and will result in
periods of SHRA/TSRA across portions of the CWA throughout the
TAF period.
This morning, ISO SH/TS moving across the coastal regions of the
CWA and the Gulf waters will affect GLS, LBX and possibly HOU from
time to time. Mainly VFR conditions expected, but there could be a
brief period of MVFR cigs developing in some sites early this
morning. Winds today will be turning E and increasing to 10-15 KTS
with some higher gusts. Winds over the southern portions of the
CWA will be a little higher in the afternoon. The SH/TS activity
will expand and intensify as the day progresses staring along the
coast and expanding into the northern portions of the CWA as
Hanna`s rainbands make their way across the CWA. Hanna still has a
chance to strengthen a little more before making landfall,
therefore expect a few modifications within the next several TAF
packages. 24
&&
.MARINE...
A Tropical Storm Warning remains in effect for Matagorda Bay and
the southern Gulf waters. A Tropical Storm Watch remains in effect
for Galveston Bay and the northern Gulf waters.
Winds and seas will be on the rise today as Tropical Storm Hanna
approaches the Texas Coast, resulting in dangerous marine
conditions across the bays and Gulf waters and hazardous
conditions along the beaches. Tides will also increase, which
may produce minor coastal flooding. Based on the current forecast
track, the strongest winds and highest seas should remain over
the Gulf waters adjacent to Matagorda Bay, within the Tropical
Storm Warning area. Southeast winds of 30 to 50 KTS with gusts up
to 60 KTS and seas of 8 to 14 can be expected from this evening
through late Saturday morning or early Saturday afternoon. A
gradual decrease in winds and seas can be expected Saturday
afternoon and Saturday night. Marine conditions should be within
the Caution flag criteria Sunday. Light onshore winds will return
early next week, increasing near the end of the workweek. 24
&&
.PREV DISCUSSION... /ISSUED 423 AM CDT Fri Jul 24 2020/
DISCUSSION...
Tropical Storm Hanna continues to strengthen, expand and get more
organized. The current NHC forecast indicates that the system will
move WNW this morning then begin to turn more westerly tonight
aiming it toward the Coastal Bend.
Tropical Storm Watch and Warning remain in effect for portions of
Southeast Texas.
One rain band has already developed before midnight from around
Liberty to Galveston and has shifted a little further southwest
and this is a good example of the size of the circulation
associated with Hanna. Scattered showers were developing across
the Upper Texas Coastal waters early this morning.
So for today expecting showers and thunderstorms to continue to
develop augmented by daytime heating jumping inland between 10am
and noon then continuing to expand inland throughout the
afternoon. Some brief heavy downpours will be possible with the
afternoon storms. As Hanna tracks west tonight and gets well south
of Matagorda rain chances and the threat for heavy rainfall
increases for the areas mainly south of the I-10 corridor to
Galveston Bay. Areas in Brazoria/Matagorda/Wharton/Jackson will be
the most under the gun for heavy rainfall and training of showers
and thunderstorms. A Flash Flood Watch will probably be issued
this afternoon to blanket these regions and areas south through
the Corpus Christi area and probably further south and west.
Currently thinking that 3-5" amounts with isolated amounts of 8+"
will be possible in the southwestern counties of SETX. As Hanna
nears the coast (on the current forecast track crossing the coast
between Corpus Christi and Brownsville Saturday 9am to 6pm -
though this is not set in stone) the threat of heavy rainfall
increases in our southwestern counties with strong moisture
advection/low level speed convergence/very high PW air 2.4-2.8"
that should be aimed into our Brazoria/Matagorda/Jackson county
area. In addition these areas could have a brief window for quick
spinup thunderstorms and possibly waterspouts over the marine
areas and possibly into these same counties 3-9 am Saturday
morning. Hanna should continue to move west or even southwest
after landfall sucking up the very rich moisture air into S TX
but even in SETX we will still have scattered to numerous showers
and thunderstorms moving into SETX Saturday night through Sunday.
Much of the guidance continues to point to a second band/surge of
moisture moving out of the central Gulf toward the coast of LA/TX
Sunday so threat of locally heavy rain should continue on Sunday.
Confidence on Monday through Wednesday diminishes depending on the
track of the remnants of Hanna and how much deep tropical
moisture still remains over the Gulf as well as how far south the
upper trough dropping into the Ohio valley progresses.
Of note Tuesday and Wednesday temperatures should jump back to
seasonal or above normal temperatures and by Thursday and Friday
above normal temperatures are expected.
Strong onshore winds will also increase tide levels from around 1
foot above normal this morning to 1 to 3 feet for the Matagorda
Bay area and 1 to 2 feet for the San Luis Pass area northeastward
tonight/Saturday. This will lead to beach flooding and possibly
some impacts to the more coastal flood prone areas such as Highway
87, Blue Water Highway near Freeport and the southern coastal
areas surrounding Matagorda Bay. Tides should lower Sunday night
and Monday.
45
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 96 77 91 76 87 / 30 40 70 20 70
Houston (IAH) 92 78 87 77 85 / 70 70 80 40 70
Galveston (GLS) 85 82 84 82 83 / 50 90 100 70 80
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Tropical Storm Warning for the following zones: Brazoria
Islands...Coastal Brazoria...Coastal Jackson...Coastal
Matagorda...Inland Jackson...Inland Matagorda...Matagorda
Islands.
Tropical Storm Watch for the following zones: Coastal
Galveston...Coastal Harris...Galveston Island and Bolivar
Peninsula...Inland Brazoria...Inland Galveston...Wharton.
GM...Tropical Storm Warning for the following zones: Coastal waters
from Freeport to Matagorda Ship Channel TX out 20 NM...
Matagorda Bay...Waters from Freeport to Matagorda Ship
Channel TX from 20 to 60 NM.
Tropical Storm Watch for the following zones: Coastal waters
from High Island to Freeport TX out 20 NM...Galveston Bay...
Waters from High Island to Freeport TX from 20 to 60 NM.
&&
$$
Discussion...45
Aviation/Marine...24
AFDHGX
Area Forecast Discussion
National Weather Service Houston/Galveston TX
500 AM CDT Fri Jul 24 2020
.AVIATION...
As of 4 AM CDT, the central of Tropical Storm Hanna was located
near latitude 26.7 North, longitude 92.4 West and is moving
toward the west-northwest through tonight. Hanna`s center is
forecast to move into the Texas Coastal Bend on Saturday. As the
storm continues to approach the Texas Coast, rainbands generated
by Hanna will move across Southeast Texas and will result in
periods of SHRA/TSRA across portions of the CWA throughout the
TAF period.
This morning, ISO SH/TS moving across the coastal regions of the
CWA and the Gulf waters will affect GLS, LBX and possibly HOU from
time to time. Mainly VFR conditions expected, but there could be a
brief period of MVFR cigs developing in some sites early this
morning. Winds today will be turning E and increasing to 10-15 KTS
with some higher gusts. Winds over the southern portions of the
CWA will be a little higher in the afternoon. The SH/TS activity
will expand and intensify as the day progresses staring along the
coast and expanding into the northern portions of the CWA as
Hanna`s rainbands make their way across the CWA. Hanna still has a
chance to strengthen a little more before making landfall,
therefore expect a few modifications within the next several TAF
packages. 24
&&
.MARINE...
A Tropical Storm Warning remains in effect for Matagorda Bay and
the southern Gulf waters. A Tropical Storm Watch remains in effect
for Galveston Bay and the northern Gulf waters.
Winds and seas will be on the rise today as Tropical Storm Hanna
approaches the Texas Coast, resulting in dangerous marine
conditions across the bays and Gulf waters and hazardous
conditions along the beaches. Tides will also increase, which
may produce minor coastal flooding. Based on the current forecast
track, the strongest winds and highest seas should remain over
the Gulf waters adjacent to Matagorda Bay, within the Tropical
Storm Warning area. Southeast winds of 30 to 50 KTS with gusts up
to 60 KTS and seas of 8 to 14 can be expected from this evening
through late Saturday morning or early Saturday afternoon. A
gradual decrease in winds and seas can be expected Saturday
afternoon and Saturday night. Marine conditions should be within
the Caution flag criteria Sunday. Light onshore winds will return
early next week, increasing near the end of the workweek. 24
&&
.PREV DISCUSSION... /ISSUED 423 AM CDT Fri Jul 24 2020/
DISCUSSION...
Tropical Storm Hanna continues to strengthen, expand and get more
organized. The current NHC forecast indicates that the system will
move WNW this morning then begin to turn more westerly tonight
aiming it toward the Coastal Bend.
Tropical Storm Watch and Warning remain in effect for portions of
Southeast Texas.
One rain band has already developed before midnight from around
Liberty to Galveston and has shifted a little further southwest
and this is a good example of the size of the circulation
associated with Hanna. Scattered showers were developing across
the Upper Texas Coastal waters early this morning.
So for today expecting showers and thunderstorms to continue to
develop augmented by daytime heating jumping inland between 10am
and noon then continuing to expand inland throughout the
afternoon. Some brief heavy downpours will be possible with the
afternoon storms. As Hanna tracks west tonight and gets well south
of Matagorda rain chances and the threat for heavy rainfall
increases for the areas mainly south of the I-10 corridor to
Galveston Bay. Areas in Brazoria/Matagorda/Wharton/Jackson will be
the most under the gun for heavy rainfall and training of showers
and thunderstorms. A Flash Flood Watch will probably be issued
this afternoon to blanket these regions and areas south through
the Corpus Christi area and probably further south and west.
Currently thinking that 3-5" amounts with isolated amounts of 8+"
will be possible in the southwestern counties of SETX. As Hanna
nears the coast (on the current forecast track crossing the coast
between Corpus Christi and Brownsville Saturday 9am to 6pm -
though this is not set in stone) the threat of heavy rainfall
increases in our southwestern counties with strong moisture
advection/low level speed convergence/very high PW air 2.4-2.8"
that should be aimed into our Brazoria/Matagorda/Jackson county
area. In addition these areas could have a brief window for quick
spinup thunderstorms and possibly waterspouts over the marine
areas and possibly into these same counties 3-9 am Saturday
morning. Hanna should continue to move west or even southwest
after landfall sucking up the very rich moisture air into S TX
but even in SETX we will still have scattered to numerous showers
and thunderstorms moving into SETX Saturday night through Sunday.
Much of the guidance continues to point to a second band/surge of
moisture moving out of the central Gulf toward the coast of LA/TX
Sunday so threat of locally heavy rain should continue on Sunday.
Confidence on Monday through Wednesday diminishes depending on the
track of the remnants of Hanna and how much deep tropical
moisture still remains over the Gulf as well as how far south the
upper trough dropping into the Ohio valley progresses.
Of note Tuesday and Wednesday temperatures should jump back to
seasonal or above normal temperatures and by Thursday and Friday
above normal temperatures are expected.
Strong onshore winds will also increase tide levels from around 1
foot above normal this morning to 1 to 3 feet for the Matagorda
Bay area and 1 to 2 feet for the San Luis Pass area northeastward
tonight/Saturday. This will lead to beach flooding and possibly
some impacts to the more coastal flood prone areas such as Highway
87, Blue Water Highway near Freeport and the southern coastal
areas surrounding Matagorda Bay. Tides should lower Sunday night
and Monday.
45
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 96 77 91 76 87 / 30 40 70 20 70
Houston (IAH) 92 78 87 77 85 / 70 70 80 40 70
Galveston (GLS) 85 82 84 82 83 / 50 90 100 70 80
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Tropical Storm Warning for the following zones: Brazoria
Islands...Coastal Brazoria...Coastal Jackson...Coastal
Matagorda...Inland Jackson...Inland Matagorda...Matagorda
Islands.
Tropical Storm Watch for the following zones: Coastal
Galveston...Coastal Harris...Galveston Island and Bolivar
Peninsula...Inland Brazoria...Inland Galveston...Wharton.
GM...Tropical Storm Warning for the following zones: Coastal waters
from Freeport to Matagorda Ship Channel TX out 20 NM...
Matagorda Bay...Waters from Freeport to Matagorda Ship
Channel TX from 20 to 60 NM.
Tropical Storm Watch for the following zones: Coastal waters
from High Island to Freeport TX out 20 NM...Galveston Bay...
Waters from High Island to Freeport TX from 20 to 60 NM.
&&
$$
Discussion...45
Aviation/Marine...24