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000
FXUS64 KBRO 251757 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service BROWNSVILLE TX
1257 PM CDT WED MAY 25 2016

.DISCUSSION...Updated for latest aviation discussion below.

&&

.AVIATION...Ridging aloft still holding on but is in the process
of flattening as an upper-level low moves into SoCal. This has
allowed some high clouds to stream in from the E. Pacific. There
is also sufficient low-level moisture to support generally VFR
ceilings through the afternoon...possibly scattering out for a
time in the early evening. Breezy SE winds also expected thru the
afternoon.

Main challenge overnight is timing arrival of showers and possibly
thunderstorms into the terminals ahead of an upper-level impulse.
Short-term guidance in good agreement on this feature developing,
but hard to see it upstream in current satellite imagery. Due to
uncertainty, will just mention VCSH at MFE between 04-10Z and
06-12Z at HRL, though confidence is lower there. BRO could see
IFR CIG`s develop late tonight. Impulse should clear the
terminals by early tomorrow morning with low-end MVFR ceilings
lifting a bit by mid-morning.

&&

.PREV DISCUSSION... /issued 703 AM CDT WED MAY 25 2016/

DISCUSSION...Updated for latest aviation discussion below.

AVIATION...Surface obs indicate MVFR ceilings continue across
the RGV as a shallow moist layer is evident on the 00z BRO
sounding below the 940 mb level. The daytime heating and low
level mixing after sunrise will improve the conditions back to VFR
levels later this morning into this afternoon. Model forecast
soundings show another low level saturated layer reforming again
tonight into early Thurs morning. This will allow for more MVFR
ceilings to return once again from around 03-12z Thurs across the
RGV.

PREV DISCUSSION... /issued 449 AM CDT WED MAY 25 2016/

SHORT TERM (Today through Thursday): A strong 500 mb closed low
will be moving east out of the SO CAL today and tonight and will
move into the Four Corners area by midday Thurs. The 500 mb ridging
in place over the TX/Mex border region will in turn break down which
will allow a more divergent flow aloft to build in over the RGV
increasing the UVV. Deep layer moisture appears to increase as the
500 mb trough axis moves closer to the region. So expect the conv
potential to increase accordingly. Short term model pop guidance
differs greatly through the short term guidance from the NAM/GFS and
ECMWF. The ECMWF is the wettest of the third model sets with the NAM
coming in the driest with the GFS going more middle of the road.
Will hold the pops in the short term in the chc range closer to the
middle of the road GFS with the better pops concentrated over the
western counties closer to the better dynamics associated with the
500 mb trough.

The 07z Day 1 conv outlook from SPC places the western portions of
the cwa under a marginal risk of severe weather as sufficient CAPE
values/mid level and orographic lift could fuel some isold svr
storms if the cap could be broken later this afternoon and this
evening. Large hail and damaging winds will be the main threat.

Max temps will lower a bit on Thurs due to the increase cld cover
and conv chances. The NAM forecast temps are a bit warmer in
comparison to the GFS and ECMWF numbers and will opt to go closer
to the better consensus demonstrated by the MAV and ECMWF
numbers.

LONG TERM (Thursday Night through Tuesday): forecast reasoning
remains the same. A pair of deep 500 mb troughs transiting through
the western United States will establish a persistent southwest to
northeast mid-level flow over the BRO CWFA throughout the long
term portion of the forecast. Shortwaves riding within this flow
will initiate convection over the neighboring high terrain of
Mexico and also within Deep South Texas and the Rio Grande Valley.
Isolated to scattered showers and thunderstorms are forecast, and
successive shifts will need to monitor for the potential for
strong to severe thunderstorms, especially due to the already
existing potential for severe weather mentioned in the short term
forecast discussion above.

MARINE (Today through Thursday): The tightening PGF across the
lower TX Bay and Gulf waters due to the influence of the surface
lows developing across the central Plains states will maintain
pretty decent winds across coastline. This will hold the marine
conditions up close to SCEC criteria from Today through Thurs. Some
marginal SCA conditions could briefly develop but will not post an
SCA at this time.

Thursday night through Tuesday: strong winds and rough seas, with
likely Small Craft Advisory, are forecast Thursday night through
Saturday night with surface high pressure over the Gulf of Mexico
interacting with low pressure over the Central Plains and northern
Mexico. More moderate winds and seas, with Small Craft Exercise
caution possible, are anticipated Sunday through Tuesday as the
center of the high pressure system moves closer to the western
Gulf of Mexico and the Lower Texas Coast.

&&

.BRO Watches/Warnings/Advisories...
TX...None.
GM...None.
&&

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

53/64





000
FXUS64 KBRO 251203
AFDBRO

Area Forecast Discussion
National Weather Service BROWNSVILLE TX
703 AM CDT WED MAY 25 2016

.DISCUSSION...Updated for latest aviation discussion below.

&&

.AVIATION...Surface obs indicate MVFR ceilings continue across
the RGV as a shallow moist layer is evident on the 00z BRO
sounding below the 940 mb level. The daytime heating and low
level mixing after sunrise will improve the conditions back to VFR
levels later this morning into this afternoon. Model forecast
soundings show another low level saturated layer reforming again
tonight into early Thurs morning. This will allow for more MVFR
ceilings to return once again from around 03-12z Thurs across the
RGV.

&&

.PREV DISCUSSION... /issued 449 AM CDT WED MAY 25 2016/

SHORT TERM (Today through Thursday): A strong 500 mb closed low
will be moving east out of the SO CAL today and tonight and will
move into the Four Corners area by midday Thurs. The 500 mb ridging
in place over the TX/Mex border region will in turn break down which
will allow a more divergent flow aloft to build in over the RGV
increasing the UVV. Deep layer moisture appears to increase as the
500 mb trough axis moves closer to the region. So expect the conv
potential to increase accordingly. Short term model pop guidance
differs greatly through the short term guidance from the NAM/GFS and
ECMWF. The ECMWF is the wettest of the third model sets with the NAM
coming in the driest with the GFS going more middle of the road.
Will hold the pops in the short term in the chc range closer to the
middle of the road GFS with the better pops concentrated over the
western counties closer to the better dynamics associated with the
500 mb trough.

The 07z Day 1 conv outlook from SPC places the western portions of
the cwa under a marginal risk of severe weather as sufficient CAPE
values/mid level and orographic lift could fuel some isold svr
storms if the cap could be broken later this afternoon and this
evening. Large hail and damaging winds will be the main threat.

Max temps will lower a bit on Thurs due to the increase cld cover
and conv chances. The NAM forecast temps are a bit warmer in
comparison to the GFS and ECMWF numbers and will opt to go closer
to the better consensus demonstrated by the MAV and ECMWF
numbers.

LONG TERM (Thursday Night through Tuesday): forecast reasoning
remains the same. A pair of deep 500 mb troughs transiting through
the western United States will establish a persistent southwest to
northeast mid-level flow over the BRO CWFA throughout the long
term portion of the forecast. Shortwaves riding within this flow
will initiate convection over the neighboring high terrain of
Mexico and also within Deep South Texas and the Rio Grande Valley.
Isolated to scattered showers and thunderstorms are forecast, and
successive shifts will need to monitor for the potential for
strong to severe thunderstorms, especially due to the already
existing potential for severe weather mentioned in the short term
forecast discussion above.

MARINE (Today through Thursday): The tightening PGF across the
lower TX Bay and Gulf waters due to the influence of the surface
lows developing across the central Plains states will maintain
pretty decent winds across coastline. This will hold the marine
conditions up close to SCEC criteria from Today through Thurs. Some
marginal SCA conditions could briefly develop but will not post an
SCA at this time.

Thursday night through Tuesday: strong winds and rough seas, with
likely Small Craft Advisory, are forecast Thursday night through
Saturday night with surface high pressure over the Gulf of Mexico
interacting with low pressure over the Central Plains and northern
Mexico. More moderate winds and seas, with Small Craft Exercise
caution possible, are anticipated Sunday through Tuesday as the
center of the high pressure system moves closer to the western
Gulf of Mexico and the Lower Texas Coast.

&&

.BRO Watches/Warnings/Advisories...
TX...None.
GM...None.
&&

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

Short term...60
Long term...66
Graphicast/upper air...65





000
FXUS64 KBRO 250022 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service BROWNSVILLE TX
722 PM CDT TUE MAY 24 2016

.DISCUSSION...Updated for latest aviation discussion below.
&&

.AVIATION...Satellite images and surface observations indicate
mostly mid to high clouds across the cwa with some low clouds
developing across the coastal section this evening. Ceilings were
near 1900ft at KPIL to near 4200ft at KHBV. Expect mvfr
conditions to develop late tonight into early Wednesday morning as
low level moisture continues to allow low clouds to develop along
the coast and move inland.
&&

.PREV DISCUSSION... /issued 237 PM CDT TUE MAY 24 2016/
SHORT TERM (Tonight through Wednesday Night): 500 mb ridging will
continue to be the main player in the forecast through Wednesday,
while a 500 mb trough/closed low digs across the western US and
another closed low moves across the northern plains. As the lows
translate east, leeside surface lows will be induced across the
plains. This will aide in strengthening the pressure gradient
across Deep South Texas resulting in breezy southeasterly winds.
Convection will be limited due to the ridging in place through
Wednesday. By Wednesday night, the ridge axis will have shifted
east and midlevel disturbances moving through the flow may fire up
convection over the Mexican plateau. Some of this activity may
move into the western portions of the CWA and as such have
maintained a slight chance for Wednesday night. Abundant cloud
cover today has slowed warming especially west and north, with
forecast high temperatures likely not being realized. Mostly
cloudy skies and moderate southeasterly winds tonight, will keep
overnight lows on the warm side with temperatures only dropping
into the mid to upper 70s. Although breezy south to southeasterly
winds are expected Wednesday and could help temperatures spike up
believe that the mostly cloudy skies could limit how high temps
go, so have nudged max temps down a degree or two.

LONG TERM (Thursday through Tuesday):
The H5 trough finally ejects eastward later in the week as the
next trough sweeps through the four corners region. This puts the
region in better dynamics Thursday into Friday, during which time
impulses will sweep around the southern end of the trough and
across Texas. Models have similar timing of these impulses, moving
across south Texas Thursday evening and Friday evening. This
should be able to tap some moisture and daytime heating
instability to spark showers and thunderstorms. Most of the
strongest activity won`t happen until the impulse is further into
Texas, but the area could see some briefly strong storms both
evenings. The trough axis passes late Friday night, with weak
ridging and drier air bringing back the capping inversion to the
region for most of the weekend. There may be enough moisture
trapped close to the sfc to spark a few diurnal seabreeze-induced
showers early next week, depending on where the capping inversion
settles.

MARINE:
Strengthening low pressure over the plains combining with high
pressure over the Gulf of Mexico will result in the pressure
gradient tightening across the lower Texas coastal waters.
Moderate southeasterly winds and moderate seas are expected with
small craft exercise caution conditions prevailing across the Gulf
Waters through the period and the Laguna Madre Wednesday afternoon
and evening.
&&

.BRO Watches/Warnings/Advisories...
TX...None.
GM...None.
&&

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

61/59





000
FXUS64 KBRO 241711
AFDBRO

Area Forecast Discussion
National Weather Service BROWNSVILLE TX
1211 PM CDT TUE MAY 24 2016

.DISCUSSION...Updated for latest aviation discussion below.

&&

.AVIATION...VFR conditions will prevail at local TAF sites through
the evening hours. Gusty southeasterly winds are expected this
afternoon as the pressure gradient tightens across the region with
winds slowly subsiding this evening. MVFR ceilings will develop
overnight with ceilings between 1500 and 2500 feet. GFS continues
to indicate IFR ceilings overnight, but confidence is low in that
solution at this time. Patchy MVFR visibilities are possible again
Wednesday morning. Southeasterly winds increase by mid-morning
Wednesday with gusts up to 25 knots possible.

&&

.PREV DISCUSSION... /issued 709 AM CDT TUE MAY 24 2016/

DISCUSSION...Updated for latest aviation discussion below.

AVIATION...Surface troffing over the central portion of the
country will increase the s-se surface winds later today after
sunrise resulting in breezier conditions. This combined with
daytime heating will mix out the low levels of the atms allowing
vfr conditions to prevail through the first half of the current
taf set. NAM Forecast soundings indicate that another low level
moist layer will reform over the RGV from 06-12z Wed morning
allowing for more mvfr ceilings to reform. GFS numerical guidance
wants to take ceilings down to IFR levels tonight while the NAM is
a bit more optimistic keeping overnight ceilings at MVFR levels.
Will opt for the NAM guidance ceilings for tomorrow morning.

PREV DISCUSSION... /issued 442 AM CDT TUE MAY 24 2016/

SHORT TERM (Now through Wednesday): 500 mb ridging will continue
to dominate the south central plains states through Wed. A strong
500 mb closed low will dig down over the western states. This in
addition to the formation of another mid level closed low over the
upper Midwest will strengthen a series of surface lows over the
central plains states. This will tighten up the pgf over RGV
increasing the s-se surface flow. The 00z BRO sounding shows a more
stable and drier atms in place over the area with a MUCAPE of 2592
j/kg with a PWAT of 1.8 inches. So the persistent mid level ridging
will limit the conv potential through Wed. The NAM tries to bump up
the pops for Wed to around slgt chc while the GFS and ECMWF guidance
holds the pops to the single digits. See no reason why the NAM is
increasing the pops for Wednesday so will go with the single digits
through the short term period.

Mid and High level cld cover yesterday held down the afternoon high
temps a bit. Numerical guidance is holding the temps near
persistence through the short term. Will nudge up the high temps a
few degrees over today and Wed as expect the stronger more southerly
flow may increase the high temps a bit due to more downsloping off
of the higher terrain in NE Mexico.

LONG TERM (Wednesday Night through Monday): Isolated to scattered
showers and thunderstorms are anticipated throughout the entire
long term forecast period. This convection will be the result of
mid-level disturbances riding over Deep South Texas and the Rio
Grande Valley within a persistent west-southwest to east-northeast
flow. With deep troughiness prevailing over the western United
States, most of the expected convection will likely originate over
the neighboring high terrain of Mexico before advecting into the
BRO CWFA. These showers and thunderstorms will need to be monitored
for strong to severe intensity given similar convective trends over
the past few weeks.

MARINE (Now through Wednesday): Buoy020 reports a SSE wind
around 16 knots with swells around 4 ft with MTRPIL reporting a SE
wind around 7 knots. The pgf will remain moderate to strong over
the bay and gulf waters through Wed which will keep the winds and
seas near SCEC territory.

Wednesday night through Monday: Small Craft Advisory winds and/or
seas continue to be anticipated through a majority of the period
with high pressure over the Gulf of Mexico interacting with low
pressure over the Central Plains and thermal low pressure over
northern Mexico. Marine conditions will gradually improve during
the weekend and by the end of the forecast period, with moderate
winds and seas expected, as the center of surface high pressure
shifts closer to the Lower Texas Coast.

&&

.BRO Watches/Warnings/Advisories...
TX...None.
GM...None.
&&

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

58/64





000
FXUS64 KBRO 240942
AFDBRO

Area Forecast Discussion
National Weather Service BROWNSVILLE TX
442 AM CDT TUE MAY 24 2016

.SHORT TERM (Now through Wednesday): 500 mb ridging will continue
to dominate the south central plains states through Wed. A strong
500 mb closed low will dig down over the western states. This in
addition to the formation of another mid level closed low over the
upper Midwest will strengthen a series of surface lows over the
central plains states. This will tighten up the pgf over RGV
increasing the s-se surface flow. The 00z BRO sounding shows a more
stable and drier atms in place over the area with a MUCAPE of 2592
j/kg with a PWAT of 1.8 inches. So the persistent mid level ridging
will limit the conv potential through Wed. The NAM tries to bump up
the pops for Wed to around slgt chc while the GFS and ECMWF guidance
holds the pops to the single digits. See no reason why the NAM is
increasing the pops for Wednesday so will go with the single digits
through the short term period.

Mid and High level cld cover yesterday held down the afternoon high
temps a bit. Numerical guidance is holding the temps near
persistence through the short term. Will nudge up the high temps a
few degrees over today and Wed as expect the stronger more southerly
flow may increase the high temps a bit due to more downsloping off
of the higher terrain in NE Mexico.

.LONG TERM (Wednesday Night through Monday): Isolated to scattered
showers and thunderstorms are anticipated throughout the entire
long term forecast period. This convection will be the result of
mid-level disturbances riding over Deep South Texas and the Rio
Grande Valley within a persistent west-southwest to east-northeast
flow. With deep troughiness prevailing over the western United
States, most of the expected convection will likely originate over
the neighboring high terrain of Mexico before advecting into the
BRO CWFA. These showers and thunderstorms will need to be monitored
for strong to severe intensity given similar convective trends over
the past few weeks.
&&

.MARINE (Now through Wednesday): Buoy020 reports a SSE wind
around 16 knots with swells around 4 ft with MTRPIL reporting a SE
wind around 7 knots. The pgf will remain moderate to strong over
the bay and gulf waters through Wed which will keep the winds and
seas near SCEC territory.

Wednesday night through Monday: Small Craft Advisory winds and/or
seas continue to be anticipated through a majority of the period
with high pressure over the Gulf of Mexico interacting with low
pressure over the Central Plains and thermal low pressure over
northern Mexico. Marine conditions will gradually improve during
the weekend and by the end of the forecast period, with moderate
winds and seas expected, as the center of surface high pressure
shifts closer to the Lower Texas Coast.
&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  91  80  89  78 /  10   0  10  20
BROWNSVILLE          91  79  91  77 /  10   0  10  20
HARLINGEN            93  79  94  78 /  10   0  10  20
MCALLEN              95  78  96  78 /  10   0  10  20
RIO GRANDE CITY      98  78 100  78 /  10   0  10  20
SOUTH PADRE ISLAND   83  80  84  79 /  10   0  10  20
&&

.BRO Watches/Warnings/Advisories...None.
&&

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

Short term...Speece-60
Long term...Tomaselli-66
WX4PPT/Meso...Birchfield-65





000
FXUS64 KBRO 232331 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service BROWNSVILLE TX
631 PM CDT MON MAY 23 2016

.DISCUSSION...Updated for latest aviation discussion below.

&&

.AVIATION...vfr conditions to prevail through much of the evening.
low level inversion to strengthen before or shortly after midnight
with mvfr stratus layer to reform between 1500-2500 feet and last
through mid morning tuesday. patchy mvfr may form in some limited
location however confidence is low with moderate southeast winds
remaining around 10 kts all night. southeast to south winds
increase later tuesday morning with gust up to 25 knots.

&&

.PREV DISCUSSION... /issued 246 PM CDT MON MAY 23 2016/

SHORT TERM (Tonight through Tuesday Night): Tranquil forecast for
the next 36 hours as H5 ridge dominates South Texas. Drier air
continues to feed into midlevels, with dry air all the way down to
4000 feet...with deeper moisture trapped underneath. H7
temperatures remaining above 12C will also help to cap off the
atmosphere, keeping rain chances out of the picture. LLVL moisture
still able to bubble up under the cap, so skies will remain mostly
cloudy today and again tomorrow. Low pressure across the Permian
Basin will interact with high pressure across the eastern U.S. to
bring gusty SE winds during the day tomorrow. Forecast guidance
for temperatures looks good through the next 36 hours, so minimal
changes needed, with highs tomorrow in the mid 90s and lows
tonight and tomorrow in the upper 70s.

LONG TERM (Wednesday through Monday): On Wednesday, the center
of upper level high pressure will migrate west to east just to
south of Brownsville that will bring one last day that is
precipitation-free to the Rio Grande Valley. On Wednesday night,
thunderstorms look to fire over the Sierra Madre in old Mexico and
drift east into the valley. On Thursday, the upper level high
pressure will begin to break down and move east into the western
Gulf of Mexico. Additionally, a weak shortwave trough will move
across the forecast area from west to east and this will bring
increased chances of thunderstorms to the region Thursday
afternoon/evening. Weak low pressure will remain over deep south
Texas on Friday with continued chances of showers/thunderstorms.
Though temperatures will remain somewhat above normal in the Wed-
Fri time frame, additional cloud cover and lower
heights/thicknesses will cut a couple of degrees off of daytime
highs Thu-Fri. Hot days with humid conditions all hours will
persist.

On Saturday, the Rio Grande Valley will once again come under the
influence of a weak ridge of high pressure extending up from
central Mexico, and the ridge looks to hang around through Monday.
Temperatures will generally remain somewhat above normal across
the entire region for the three day period. Despite the developing
ridge of high pressure slight chances of showers/thunderstorms
will continue through the end of the long term forecast period.

MARINE (Now through Tuesday night): Considerable interaction
between low pressure across West Texas and high pressure across
the eastern U.S. will cause southeasterly winds to continue to be
gusty across the marine areas through the next 36 hours. The
southeasterly fetch extends across most of the western Gulf, so
this will continue to create longer period swells. Seas currently
around 5 feet will remain at this state through tomorrow night.

Wednesday through Monday: Small Craft Advisory winds and seas
will dominate through a majority of the period with high pressure
over the Gulf of Mexico interacting intensely with thermal low
pressure over northern Mexico and low pressure in the Central
Plains. Wind and sea conditions may improve in the Sun-Mon time
frame, but Small Craft Exercise Caution may still be needed.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  78  91  79  89 /  10  10   0   0
BROWNSVILLE          78  92  78  91 /  10  10   0   0
HARLINGEN            78  93  79  94 /  10  10   0   0
MCALLEN              78  94  79  97 /  10  10   0   0
RIO GRANDE CITY      76  98  76 100 /  10  10   0   0
SOUTH PADRE ISLAND   78  83  76  84 /  10  10   0   0

&&

.BRO Watches/Warnings/Advisories...
TX...None.
GM...None.
&&

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

59/99





000
FXUS64 KBRO 231946
AFDBRO

Area Forecast Discussion
National Weather Service BROWNSVILLE TX
246 PM CDT MON MAY 23 2016

.SHORT TERM (Tonight through Tuesday Night): Tranquil forecast for
the next 36 hours as H5 ridge dominates South Texas. Drier air
continues to feed into midlevels, with dry air all the way down to
4000 feet...with deeper moisture trapped underneath. H7
temperatures remaining above 12C will also help to cap off the
atmosphere, keeping rain chances out of the picture. LLVL moisture
still able to bubble up under the cap, so skies will remain mostly
cloudy today and again tomorrow. Low pressure across the Permian
Basin will interact with high pressure across the eastern U.S. to
bring gusty SE winds during the day tomorrow. Forecast guidance
for temperatures looks good through the next 36 hours, so minimal
changes needed, with highs tomorrow in the mid 90s and lows
tonight and tomorrow in the upper 70s.

.LONG TERM (Wednesday through Monday): On Wednesday, the center
of upper level high pressure will migrate west to east just to
south of Brownsville that will bring one last day that is
precipitation-free to the Rio Grande Valley. On Wednesday night,
thunderstorms look to fire over the Sierra Madre in old Mexico and
drift east into the valley. On Thursday, the upper level high
pressure will begin to break down and move east into the western
Gulf of Mexico. Additionally, a weak shortwave trough will move
across the forecast area from west to east and this will bring
increased chances of thunderstorms to the region Thursday
afternoon/evening. Weak low pressure will remain over deep south
Texas on Friday with continued chances of showers/thunderstorms.
Though temperatures will remain somewhat above normal in the Wed-
Fri time frame, additional cloud cover and lower
heights/thicknesses will cut a couple of degrees off of daytime
highs Thu-Fri. Hot days with humid conditions all hours will
persist.

On Saturday, the Rio Grande Valley will once again come under the
influence of a weak ridge of high pressure extending up from
central Mexico, and the ridge looks to hang around through Monday.
Temperatures will generally remain somewhat above normal across
the entire region for the three day period. Despite the developing
ridge of high pressure slight chances of showers/thunderstorms
will continue through the end of the long term forecast period.

&&

.MARINE (Now through Tuesday night): Considerable interaction
between low pressure across West Texas and high pressure across
the eastern U.S. will cause southeasterly winds to continue to be
gusty across the marine areas through the next 36 hours. The
southeasterly fetch extends across most of the western Gulf, so
this will continue to create longer period swells. Seas currently
around 5 feet will remain at this state through tomorrow night.

Wednesday through Monday: Small Craft Advisory winds and seas
will dominate through a majority of the period with high pressure
over the Gulf of Mexico interacting intensely with thermal low
pressure over northern Mexico and low pressure in the Central
Plains. Wind and sea conditions may improve in the Sun-Mon time
frame, but Small Craft Exercise Caution may still be needed.

&&

.BRO Watches/Warnings/Advisories...
TX...None.
GM...None.
&&

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

19/64





000
FXUS64 KBRO 231750 AAB
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service BROWNSVILLE TX
1250 PM CDT MON MAY 23 2016

.DISCUSSION...Updated for latest aviation discussion below.

&&

.AVIATION...CU field remains thick this morning due to moisture
stuck in the lowest levels. Mixing of drier air aloft will thin
the CU field later this afternoon, but TEMPO bkn025 may still
occur in the next couple hours. With drier air already down to
4000 feet this morning, cloud cover will have less vertical
development, so no showers are forecast in the region. Lower
clouds will return overnight, generally MVFR. Expect winds to drop
to around 10 knots overnight, which should keep any fog formation
from getting dense. Another day of thick lower clouds tomorrow,
while winds increase again to around 15kts.

&&

.PREV DISCUSSION... /issued 700 AM CDT MON MAY 23 2016/

DISCUSSION...Updated for latest aviation discussion below.

AVIATION...IR satl imagery and surface obs indicate some ragged
low level cld cover around the RGV reducing ceilings down to MVFR
levels in many areas. After sunrise the daytime heating and low
level mixing will allow for a return to VFR levels through the
afternoon and early evening hours. Lingering moisture later
tonight will allow for a return of more mvfr or ifr ceilings late
in the current taf period.

PREV DISCUSSION... /issued 414 AM CDT MON MAY 23 2016/

SHORT TERM (Now through Tuesday): 500 mb ridging will be steadily
strengthening over south Texas and northern Mexico through Mon and
Tues. This will increase the subsidence and will decrease the
instability and PWAT throughout the short term period limiting the
conv potential. The higher terrain of northeast Mexico may provide
enough orographic lift during the max heating on both Mon and Tues
to fire some conv to our southwest. At this time do not expect this
conv to survive long enough to move into the RGV. The NAM/GFS and
ECWMF guidance all place pops through the short range period in the
single digits and will stick with these values considering the
strength of the 500 mb ridge axis.

The 1000-500 mb thickness values will be gradually increasing at the
500 mb ridge axis strengthens. So expect temps to gradually increase
through Tues. MAV/MET and ECMWF temp guidance are in pretty close
agreement in the short term. Will go with a general blend of the
these model sets for highs/lows through Tues.

LONG TERM (Tuesday Night through Sunday): No significant changes
to the long term portion of the forecast. Isolated to scattered
showers and thunderstorms are forecast from Wednesday night
through Sunday courtesy of a pair of closed 500 mb low pressure
systems over the western United States producing a west-southwest
to east-northeast mid-level flow over the BRO CWFA. Since much of
the convection is likely to initiate over the neighboring higher
terrain of Mexico and then advect into Deep South Texas and the
Rio Grande Valley, future shifts will need to monitor for the
potential for severe thunderstorms during the aforementioned time
period.

MARINE (Now through Tuesday): Buoy020 reports a SSE wind around 8
knots with swells around 3 feet. The PGF will be strengthening over
the lower TX bay and Gulf waters through Tuesday as an elongated
frontal system remains elongated over the central states. This may
push the marine conditions up close to SCEC criteria later tonight
into Tues.

Tuesday night through Sunday: Small Craft Advisory winds and seas
will dominate through a majority of the period with high pressure
over the Gulf of Mexico interacting intensely with thermal low
pressure over northern Mexico and low pressure in the Central
Plains. Wind and sea conditions may improve during the final 24
hours of the forecast period, but Small Craft Exercise Caution may
still be needed.

&&

.BRO Watches/Warnings/Advisories...
TX...None.
GM...None.
&&

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

64





000
FXUS64 KBRO 231200 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service BROWNSVILLE TX
700 AM CDT MON MAY 23 2016

.DISCUSSION...Updated for latest aviation discussion below.

&&

.AVIATION...IR satl imagery and surface obs indicate some ragged
low level cld cover around the RGV reducing ceilings down to MVFR
levels in many areas. After sunrise the daytime heating and low
level mixing will allow for a return to VFR levels through the
afternoon and early evening hours. Lingering moisture later
tonight will allow for a return of more mvfr or ifr ceilings late
in the current taf period.

&&

.PREV DISCUSSION... /issued 414 AM CDT MON MAY 23 2016/

SHORT TERM (Now through Tuesday): 500 mb ridging will be steadily
strengthening over south Texas and northern Mexico through Mon and
Tues. This will increase the subsidence and will decrease the
instability and PWAT throughout the short term period limiting the
conv potential. The higher terrain of northeast Mexico may provide
enough orographic lift during the max heating on both Mon and Tues
to fire some conv to our southwest. At this time do not expect this
conv to survive long enough to move into the RGV. The NAM/GFS and
ECWMF guidance all place pops through the short range period in the
single digits and will stick with these values considering the
strength of the 500 mb ridge axis.

The 1000-500 mb thickness values will be gradually increasing at the
500 mb ridge axis strengthens. So expect temps to gradually increase
through Tues. MAV/MET and ECMWF temp guidance are in pretty close
agreement in the short term. Will go with a general blend of the
these model sets for highs/lows through Tues.

LONG TERM (Tuesday Night through Sunday): No significant changes
to the long term portion of the forecast. Isolated to scattered
showers and thunderstorms are forecast from Wednesday night
through Sunday courtesy of a pair of closed 500 mb low pressure
systems over the western United States producing a west-southwest
to east-northeast mid-level flow over the BRO CWFA. Since much of
the convection is likely to initiate over the neighboring higher
terrain of Mexico and then advect into Deep South Texas and the
Rio Grande Valley, future shifts will need to monitor for the
potential for severe thunderstorms during the aforementioned time
period.

MARINE (Now through Tuesday): Buoy020 reports a SSE wind around 8
knots with swells around 3 feet. The PGF will be strengthening over
the lower TX bay and Gulf waters through Tuesday as an elongated
frontal system remains elongated over the central states. This may
push the marine conditions up close to SCEC criteria later tonight
into Tues.

Tuesday night through Sunday: Small Craft Advisory winds and seas
will dominate through a majority of the period with high pressure
over the Gulf of Mexico interacting intensely with thermal low
pressure over northern Mexico and low pressure in the Central
Plains. Wind and sea conditions may improve during the final 24
hours of the forecast period, but Small Craft Exercise Caution may
still be needed.

&&

.BRO Watches/Warnings/Advisories...
TX...None.
GM...None.
&&

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

Short Term...60
Long Term...66
Graphicast/Upper Air...64





000
FXUS64 KBRO 230730 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service BROWNSVILLE TX
230 AM CDT MON MAY 23 2016

.DISCUSSION...Updated for latest aviation discussion below.

&&

.AVIATION...The 00z BRO sounding showed a fairly moist and
unstable atms in place over the RGV with CAPEs >4000 j/kg and a
PWAT >2.00. IR satl imagery shows plenty of high level debris cld
cover advecting over the RGV from the northwest. Surface obs
indicate some ragged low level cld cover is forming up around the
RGV reducing ceilings down to MVFR levels. Will include some
mention of brief reductions to IFR levels over the next few hours.
After sunrise the daytime heating and low level mixing will allow
for a return to VFR levels through the afternoon and early evening
hours. Lingering moisture later tonight will allow for a return of
more mvfr or ifr ceilings late in the current taf period.

&&

.PREV DISCUSSION... /issued 642 PM CDT SUN MAY 22 2016/

DISCUSSION...Updated for latest /00z/ aviation discussion below.

AVIATION...In general, same forecast different day. With the
expectation that convection well east of the Lower Valley
terminals will remain far enough offshore that boundaries will
have little to work on well after sunset, have generally
maintained the current forecast with just minor tweaks to ceiling
(a little lower) and wind (also a little lower) based on latest
GFS-20 soundings as well as current low level winds which are at
or below 15 knots on the Brownsville release.

A pocket of LIFR to VLIFR visibility dropped onto the Harlingen
field early this morning, and while that can`t be ruled out again
tonight don`t have the confidence to make a highly localized by
highly influential forecast for early morning landings this time
around. Instead, gave a nod and dropped to 2 statute miles for a
four hour window around daybreak.

Otherwise, southeast gradient increases just a hair on Monday
which should produce a little more gustiness by afternoon. As for
cloud cover, today was more broken than scattered and based on
persistence and Monday`s time-height cross sections elected to go
broken for prevailing with TEMPO scattered conditions, all VFR.
The continued advection of whatever is left from spring agricultural
burning in Mexico and Central America will keep plenty of haze
around, but expect visibility after mixing begins to once again
rise to 8 statute miles or so.
52/BSG

PREV DISCUSSION... /issued 235 PM CDT SUN MAY 22 2016/

SHORT TERM (Tonight through Monday Night): Generally a more tranquil
period during the next 36 hours as H5 ridge dominates Texas,
deflecting systems into the Central Plains. A few showers trying to
develop ATTM along the weak seabreeze, fueled by still ample sfc
moisture. This is being held back from significant development by
dry capping air above H7, so any showers that do form this afternoon
will be brief. Moisture decreases overnight tonight aloft, further
solidifying the cap. Have kept out PoP chances tonight and tomorrow
as a result. Temperatures tonight only fall to the upper 70s as
summertime humidity becomes entrenched in the region. Highs tomorrow
are a reasonable blend of models, sticking near the current
temperature trends from the past several days, reaching a degree or
two above normal.

LONG TERM (Tuesday through Sunday): At the beginning of the
period, strong upper level high pressure will be centered over
west central old Mexico with a ridge axis extending north-
northeast across northeast old Mexico/southwest Texas. The upper
ridging will continue to keep a lid on any shower/thunderstorm
development across deep south Texas as noted at the end of the
short term period. At the same time, strong subsidence associated
with the upper ridging will bring somewhat higher
heights/thicknesses for higher temperatures that will already have
been at somewhat above normal values for the preceding day or two.
This will simply lead to hot and humid conditions. Precipitation-
free, as well as hot and humid, conditions with above normal
temperatures will continue into Wednesday as the upper high to our
south transitions to east central old Mexico with the extending
upper ridge axis moving over the lower Texas coast.

On Thursday, the upper ridge looks to move east of deep south
Texas into the western Gulf of Mexico and begins to break down as
a broad upper trough over the western U.S. begins to slowly dig
southward toward the U.S./Mexico border. Will reintroduce low chances
of precipitation to the forecast for Thursday in the form of sea
breeze induced showers/thunderstorms mainly over the east half of
the forecast area during the day. Low chances of
showers/thunderstorms are then possible Thursday afternoon/evening
across mostly western portions of the forecast area as convection
forms over the Sierra Madre and propogates eastward toward the
valley. Somewhat lower heights/thicknesses will allow temperatures
to cool a little bit on Thursday and settle in around near normal
values...but it will still be hot and humid. Low chances of
precipitation will hang around for all of the Rio Grande Valley
into Friday while temperatures remain near normal as the broad
trough of low pressure over the western U.S. continues to dig
southward.

For Saturday and Sunday, a ridge of high pressure reasserts itself
over northeast old Mexico/deep south Texas once again with
precipitation-free conditions expected. Temperatures will rise to
somewhat above normal values again through the weekend due to the
building high pressure for more hot and humid weather.

MARINE Now through Monday night: Broad sfc high across the
eastern third of the nation will provide a long fetch of
southeasterly flow across the western Gulf. With low pressure along
the lee of the Rockies, flow will remain modest through the next 36
hours, with winds around 15kts. This and the long fetch will
continue to agitate seas, with wave heights of 4 to 5 feet.

Tuesday through Sunday: Small Craft Exercise Caution and/or
Small Craft Advisories are likely to be needed for the Lower
Texas coastal waters through the period to account for strong
winds and rough seas as a relatively tight pressure gradient
remains in place.

&&

.BRO Watches/Warnings/Advisories...
TX...None.
GM...None.
&&

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

Short Term...60
Long Term...66





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