Disturbed weather in GOM (Is INVEST 98L)

[TexWx]

https://www.ndbc.noaa.gov/station_page.php?station=42001 ....interesting a pressure drop along with some slight west winds. And the pictures don't show any storm around so doesn't look like it's from a TS?

Where is this?

[lrak]

https://www.ndbc.noaa.gov/station_page.php?station=42001 ....interesting a pressure drop along with some slight west winds. And the pictures don't show any storm around so doesn't look like it's from a TS?

Where is this?

25.961 N 89.650 W

[lrak]

42001 buoy now showing light WSW winds.

Winds are still WSW and pressure is 29.86 and holding. It's certainly broad and weak but certainly there. I wish NASA would address their satellite site...grrr It's like TV for me

8pm
NHC
A broad area of disorganized showers and thunderstorms over the
central and eastern Gulf of Mexico is associated with an upper-level
low and a weak surface trough. Some slight development of this
system is possible during the next couple of days while it moves
westward over the western Gulf of Mexico. The system is forecast to
move inland along the northwestern Gulf coast by late Monday or
Tuesday, and further development is not expected after that time.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...10 percent.

Seems like a copy paste to me

[cycloneye]

A broad area of disorganized showers and thunderstorms over the
central and eastern Gulf of Mexico is associated with an upper-level
low and a weak surface trough. Some slight development of this
system is possible during the next couple of days while it moves
westward over the western Gulf of Mexico. The system is forecast to
move inland along the northwestern Gulf coast by late Monday or
Tuesday, and further development is not expected after that time.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...10 percent.

[Steve]

This thread just made my day. Corpus Christi is about 6 inches below normal but the last Invest that past south of us gave some decent rains. Lawn is nice and green. You can tell that the trees and shrubs though need a soaking.

Forgot to ask, does anyone know why the Interactive Global Geostationary Weather Satellite website is stuck on Friday the 13th?

My daughter was in Pensacola today and said she was fist fighting waves. She doesn’t surf, just boogie boards, but maybe you’ll get some swells

[lrak]

This thread just made my day. Corpus Christi is about 6 inches below normal but the last Invest that past south of us gave some decent rains. Lawn is nice and green. You can tell that the trees and shrubs though need a soaking.

Forgot to ask, does anyone know why the Interactive Global Geostationary Weather Satellite website is stuck on Friday the 13th?

My daughter was in Pensacola today and said she was fist fighting waves. She doesn’t surf, just boogie boards, but maybe you’ll get some swells

Hope so,

Boogie board/surfing....I do both keep your girl in the water. It's really fun.

[underthwx]

Disturbed weather in the Gulf...or...the lack thereof...latest satellite image not too impressive...but I shall tread lightly, the NHC still has a percentage of development on it, which has to be paid attention to for sure.

[StruThiO]

 https://twitter.com/pppapin/status/1173421780649705472




 https://twitter.com/pppapin/status/1173422803904679936




 https://twitter.com/pppapin/status/1173424596852174848

[tailgater]

Pretty impressive blow up of T-Storms south of Intercoastal City. I see some inflow from the south on Shortwave IR. Might not have enough time to get classified but I’d certainly give it more than a 10% chance. I wouldn’t mind a shower here in south La. on it’s way Texas.

[CYCLONE MIKE]

Pretty impressive blow up of T-Storms south of Intercoastal City. I see some inflow from the south on Shortwave IR. Might not have enough time to get classified but I’d certainly give it more than a 10% chance. I wouldn’t mind a shower here in south La. on it’s way Texas.

We might be able to get a couple of showers out of this as it passes us by tomorrow morning. Latest hrrr does show a band moving in off the gulf and then west across our area in the morning. Will it happen, who knows.

[wxman22]

The 0z Euro is showing some very impressive rainfall totals across Southeast Texas... (30+ inches of rain)

[Garnetcat5]

No one here in Houston has brought up rain totals near 30 inches.

[cycloneye]

Disorganized showers and thunderstorms over the northwestern Gulf of
Mexico are associated with an upper-level low and a weak surface
trough. Little, if any, development of this system is expected
before it moves inland along the northwestern Gulf coast tonight or
Tuesday. Regardless of development, this system is expected to
produce locally heavy rainfall along portions of the central and
upper Texas coastal areas later this week.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...10 percent.

[SoupBone]

No one here in Houston has brought up rain totals near 30 inches.

Our paid pro-mets are forecasting 2-3", with some areas getting 6".

[bohaiboy]

I don't recall them forecasting as much for Harvey early on either, although some of the models were showing it. Houston is a scary place with that much rain even hinted at. Sure the local mets don't want to insight panic. These systems tend to sit with little movement. I have worked in Houston all summer, and really little rain IMHO compared to the previous 25 years here.

In this case lets hope the local mets are correct.

[SoupBone]

I don't recall them forecasting as much for Harvey early on either, although some of the models were showing it. Houston is a scary place with that much rain even hinted at. Sure the local mets don't want to insight panic. These systems tend to sit with little movement. I have worked in Houston all summer, and really little rain IMHO compared to the previous 25 years here.

In this case lets hope the local mets are correct.

These aren't local mets, these are a group of tenured professional meteorologists that we pay for internally. If they thought a 30" forecast would have even a slight chance of verifying, we'd get it in our morning package. Obviously, with weather anything can happen, and people are still spooked because of Harvey. That's understandable. I don't know what the public mets are forecasting, anyone?

[srainhoutx]

I don't recall them forecasting as much for Harvey early on either, although some of the models were showing it. Houston is a scary place with that much rain even hinted at. Sure the local mets don't want to insight panic. These systems tend to sit with little movement. I have worked in Houston all summer, and really little rain IMHO compared to the previous 25 years here.

In this case lets hope the local mets are correct.

These aren't local mets, these are a group of tenured professional meteorologists that we pay for internally. If they thought a 30" forecast would have even a slight chance of verifying, we'd get it in our morning package. Obviously, with weather anything can happen, and people are still spooked because of Harvey. That's understandable. I don't know what the public mets are forecasting, anyone?

HGX in coordination with the WPC is forecasting 6 to 9 inches with isolated totals of 12 inches. In both or their morning Updates, NWS and WPC acknowledged that there were some indications of higher totals and possibly significantly higher and that Excessive Rainfall in their future Outlooks likely will be increased to Medium at least. I tend to favor the WPC QPF folks in their forecasts at this range...

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
432 AM EDT Mon Sep 16 2019

Day 1
Valid 12Z Mon Sep 16 2019 - 12Z Tue Sep 17 2019

...A MARGINAL RISK OF EXCESSIVE RAINFALL EXISTS FOR PORTIONS OF
THE TEXAS AND LOUISIANA COASTAL PLAINS...

...TX/LA coasts...
A tropical disturbance is moving parallel to, but offshore, the LA
coast at this time. Model guidance takes it generally westward,
nearing the Middle and Upper TX coasts by Tuesday morning. Inflow
at 850 hPa around the system is forecast to be 20-30 kts, roughly
50% above the 850-400 hPa mean wind. Precipitable water values of
2-2.25" should overspread the region from east to west. ML CAPE
around the system is 1500-2500 J/kg. The ingredients are there
for heavy rainfall -- the question is how far into LA the
instability gradient invades this morning and for portions of the
TX coast tonight/Tuesday morning. This morning, issues are
possible across southeast LA, south of Lake Pontchartrain -- this
portion of the Marginal Risk is new to this issuance and was
collaborated with LIX/the Slidell LA forecast office. Late
tonight into early Tuesday morning, the threat shifts to the
Middle and Upper TX coast. Much of the region has been dry
lately, so initial rainfall should be welcome. However, this
environment could support 3" an hour rain totals should cells
move/form ashore and merge or train, which would be problematic
outside of wetlands, with urban areas the most sensitive.

Roth


Day 2
Valid 12Z Tue Sep 17 2019 - 12Z Wed Sep 18 2019

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR THE MIDDLE AND
UPPER TEXAS COAST...

...Texas Coast...
A disturbance in the northern Gulf of Mexico will attempt to
organize, at least subtly, as it moves westward onto the upper
Texas Coast. There remains considerable disagreement into how
organized this system will become, and how far south it will
advect, but the general trend has been for an uptick in model QPF,
especially beyond this day 2 period. On Tuesday and Tuesday night,
the 500mb trough and associated vort lobe will move westward to be
along the TX coast late in the period, while the 850-700mb low
lifts slowly northward. The decreasing spatial distance between
these features should lead to some strengthening, while the
subsequent intensifying inflow will drive higher PWAT air onshore
in conjunction with WAA/MLCape development. PWATs nearing 2.25"
and MLCape rising to above 1000 J/kg will support increasing
coverage of convective rain bands, some of which may train onto
the central and upper Texas Coast. The most clustered model signal
is for the heaviest rainfall in this area, and while total QPF on
day 2 should be generally 1-3" along the immediate coast where
frictional convergence will enhance ascent, rain rates may at
times touch 2"/hr which could lead to isolated flash flooding. The
SLGT risk has been expanded very slightly northeast to encompass
the Houston area for its more sensitive FFG, with a MRGL risk
extending inland and enclosing the SLGT risk area.


...Pacific Northwest...
A short duration atmospheric river will move onshore the Pacific
Northwest Tuesday, bringing a round of heavy rainfall from coastal
areas of northwest California north through Vancouver Island. This
will be associated with a deep northern stream upper trough
digging southeast from the Gulf of Alaska and an attendant cold
front. PWATs may briefly exceed 1.25", especially along the Oregon
Coast, which is as much as 2 standard deviations above the
climatological mean for mid-September. Despite the expected lack
of instability, robust moisture transport on an 850mb jet
approaching 50 kts will impinge orthogonally into the Coastal
Ranges, and ECENS rainfall probabilities show a high risk for more
than 1", and even low-end probabilities for 3" in the terrain,
where isolated higher amounts are likely in the favored W/SW
upslope regions. In general, this rainfall could be more
beneficial than hazardous due to antecedent dry conditions, but
rain rates potentially exceeding 0.5"/hr could produce isolated
flash flooding, especially in any sensitive terrain or along burn
scars, and the MRGL risk was left unchanged from previous.


...Minnesota...
Convection expected to blossom within a narrow warm sector
associated with a frontal system late Tuesday night into
Wednesday. This system will advect E/NE beneath a potent shortwave
ejecting from the Northwest, with deep SW flow ahead of this
feature drawing moisture and instability northward. PWATs are
forecast to climb to/above 1.75 inches, 2-3 standard deviations
above the climo mean, and near daily highs for September 18th.
Although most of the activity is expected well after diurnal
heating, a robust LLJ approaching 50 kts will drive strong WAA and
increasing MUCape to fuel thunderstorms after 00Z/18 across the
Upper Midwest. In addition to the synoptic ascent through height
falls ahead of the shortwave, the 850mb LLJ is progged to be more
than twice the cloud layer mean wind, suggesting intense low-level
omega to further drive lift. While storm motions are likely to be
rapid to the northeast noted by 0-6km mean wind forecasts of 20-30
kts, deep layer unidirectional shear along the boundary supports
training potential with rain rates becoming more efficient as warm
cloud depths rise towards 13kft. Across this region, 3-hr FFG is
generally 1.5-2.5", so where training of the heaviest rain rates
can occur, flash flooding will be possible, and have added a MRGL
risk after coordination with DLH/MPX focused in the 18/00Z-12Z
timeframe before the LLJ veers to reduce the moisture confluence.

Weiss

Day 3
Valid 12Z Wed Sep 18 2019 - 12Z Thu Sep 19 2019

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR THE MIDDLE AND
UPPER TEXAS COAST...

An area of low pressure across the northern Gulf of Mexico will
attempt to organize Wednesday along the TX coast, bringing
increasing chances for heavy rainfall across the area. The
guidance continues to show a wide variation in solutions, but the
trend this morning has been for an increase and shift eastward in
QPF in the global consensus. Although the environment looks
extremely favorable for heavy rain with PWATs over 2.25" and
MUCape pushing 2000 J/kg, placing the axis of heaviest QPF remains
difficult. Additionally, some of these enhanced rainfall totals
noted in recent guidance could be overdone and based on a more
developed system, which may not come to fruition if the mid-level
and low-level centers cannot congeal.

However, whether the system develops or not, heavy rainfall is
looking increasingly likely along the coast due to robust
advection of tropical moisture into Texas as the mid-level trough
shifts inland. In this favorable thermodynamic environment, ascent
will gradually intensify beneath increasing diffluence aloft and
forced low-level ascent due to frictional convergence along the
land-sea interface and through weak 0-6km mean flow being impinged
upon by 850mb winds 2-3 times stronger. As PWATs and instability
climb, rainfall rates will intensify and may reach 2"/hr at times,
with training likely through strong moisture confluence and
unidirectional shear. Additionally, the system, regardless of
organization, will likely move very slowly as it becomes trapped
beneath a ridge with +1 to +2 mid-level height anomalies which
will only enhance the temporal duration of heavy rainfall.

The recent ECENS rainfall probabilities suggest a high risk for
1-3" in 24-hrs, with low-end probabilities for 5" or more. A SLGT
risk has been added for much of the central and upper Texas coast,
with a MRGL risk extending as far west as the Balcones Escarpment
and I-35 corridor, but the greatest risk for heavy rain does
appear to be focusing nearer the coast. After discussion with the
local WFOs (CRP/EWX/HGX) have opted to cap the risk at SLGT for
now due to uncertainty, but it is possible, if not likely, that
higher risks will be needed with later updates, especially if this
wetter trend continues.


Weiss

[SoupBone]

I don't recall them forecasting as much for Harvey early on either, although some of the models were showing it. Houston is a scary place with that much rain even hinted at. Sure the local mets don't want to insight panic. These systems tend to sit with little movement. I have worked in Houston all summer, and really little rain IMHO compared to the previous 25 years here.

In this case lets hope the local mets are correct.

These aren't local mets, these are a group of tenured professional meteorologists that we pay for internally. If they thought a 30" forecast would have even a slight chance of verifying, we'd get it in our morning package. Obviously, with weather anything can happen, and people are still spooked because of Harvey. That's understandable. I don't know what the public mets are forecasting, anyone?

HGX in coordination with the WPC is forecasting 6 to 9 inches with isolated totals of 12 inches. In both or their morning Updates, NWS and WPC acknowledged that there were some indications of higher totals and possibly significantly higher and that Excessive Rainfall in their future Outlooks likely will be increased to Medium at least. I tend to favor the WPC QPF folks in their forecasts at this range...

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
432 AM EDT Mon Sep 16 2019

Day 1
Valid 12Z Mon Sep 16 2019 - 12Z Tue Sep 17 2019

...A MARGINAL RISK OF EXCESSIVE RAINFALL EXISTS FOR PORTIONS OF
THE TEXAS AND LOUISIANA COASTAL PLAINS...

...TX/LA coasts...
A tropical disturbance is moving parallel to, but offshore, the LA
coast at this time. Model guidance takes it generally westward,
nearing the Middle and Upper TX coasts by Tuesday morning. Inflow
at 850 hPa around the system is forecast to be 20-30 kts, roughly
50% above the 850-400 hPa mean wind. Precipitable water values of
2-2.25" should overspread the region from east to west. ML CAPE
around the system is 1500-2500 J/kg. The ingredients are there
for heavy rainfall -- the question is how far into LA the
instability gradient invades this morning and for portions of the
TX coast tonight/Tuesday morning. This morning, issues are
possible across southeast LA, south of Lake Pontchartrain -- this
portion of the Marginal Risk is new to this issuance and was
collaborated with LIX/the Slidell LA forecast office. Late
tonight into early Tuesday morning, the threat shifts to the
Middle and Upper TX coast. Much of the region has been dry
lately, so initial rainfall should be welcome. However, this
environment could support 3" an hour rain totals should cells
move/form ashore and merge or train, which would be problematic
outside of wetlands, with urban areas the most sensitive.

Roth


Day 2
Valid 12Z Tue Sep 17 2019 - 12Z Wed Sep 18 2019

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR THE MIDDLE AND
UPPER TEXAS COAST...

...Texas Coast...
A disturbance in the northern Gulf of Mexico will attempt to
organize, at least subtly, as it moves westward onto the upper
Texas Coast. There remains considerable disagreement into how
organized this system will become, and how far south it will
advect, but the general trend has been for an uptick in model QPF,
especially beyond this day 2 period. On Tuesday and Tuesday night,
the 500mb trough and associated vort lobe will move westward to be
along the TX coast late in the period, while the 850-700mb low
lifts slowly northward. The decreasing spatial distance between
these features should lead to some strengthening, while the
subsequent intensifying inflow will drive higher PWAT air onshore
in conjunction with WAA/MLCape development. PWATs nearing 2.25"
and MLCape rising to above 1000 J/kg will support increasing
coverage of convective rain bands, some of which may train onto
the central and upper Texas Coast. The most clustered model signal
is for the heaviest rainfall in this area, and while total QPF on
day 2 should be generally 1-3" along the immediate coast where
frictional convergence will enhance ascent, rain rates may at
times touch 2"/hr which could lead to isolated flash flooding. The
SLGT risk has been expanded very slightly northeast to encompass
the Houston area for its more sensitive FFG, with a MRGL risk
extending inland and enclosing the SLGT risk area.


...Pacific Northwest...
A short duration atmospheric river will move onshore the Pacific
Northwest Tuesday, bringing a round of heavy rainfall from coastal
areas of northwest California north through Vancouver Island. This
will be associated with a deep northern stream upper trough
digging southeast from the Gulf of Alaska and an attendant cold
front. PWATs may briefly exceed 1.25", especially along the Oregon
Coast, which is as much as 2 standard deviations above the
climatological mean for mid-September. Despite the expected lack
of instability, robust moisture transport on an 850mb jet
approaching 50 kts will impinge orthogonally into the Coastal
Ranges, and ECENS rainfall probabilities show a high risk for more
than 1", and even low-end probabilities for 3" in the terrain,
where isolated higher amounts are likely in the favored W/SW
upslope regions. In general, this rainfall could be more
beneficial than hazardous due to antecedent dry conditions, but
rain rates potentially exceeding 0.5"/hr could produce isolated
flash flooding, especially in any sensitive terrain or along burn
scars, and the MRGL risk was left unchanged from previous.


...Minnesota...
Convection expected to blossom within a narrow warm sector
associated with a frontal system late Tuesday night into
Wednesday. This system will advect E/NE beneath a potent shortwave
ejecting from the Northwest, with deep SW flow ahead of this
feature drawing moisture and instability northward. PWATs are
forecast to climb to/above 1.75 inches, 2-3 standard deviations
above the climo mean, and near daily highs for September 18th.
Although most of the activity is expected well after diurnal
heating, a robust LLJ approaching 50 kts will drive strong WAA and
increasing MUCape to fuel thunderstorms after 00Z/18 across the
Upper Midwest. In addition to the synoptic ascent through height
falls ahead of the shortwave, the 850mb LLJ is progged to be more
than twice the cloud layer mean wind, suggesting intense low-level
omega to further drive lift. While storm motions are likely to be
rapid to the northeast noted by 0-6km mean wind forecasts of 20-30
kts, deep layer unidirectional shear along the boundary supports
training potential with rain rates becoming more efficient as warm
cloud depths rise towards 13kft. Across this region, 3-hr FFG is
generally 1.5-2.5", so where training of the heaviest rain rates
can occur, flash flooding will be possible, and have added a MRGL
risk after coordination with DLH/MPX focused in the 18/00Z-12Z
timeframe before the LLJ veers to reduce the moisture confluence.

Weiss

Day 3
Valid 12Z Wed Sep 18 2019 - 12Z Thu Sep 19 2019

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR THE MIDDLE AND
UPPER TEXAS COAST...

An area of low pressure across the northern Gulf of Mexico will
attempt to organize Wednesday along the TX coast, bringing
increasing chances for heavy rainfall across the area. The
guidance continues to show a wide variation in solutions, but the
trend this morning has been for an increase and shift eastward in
QPF in the global consensus. Although the environment looks
extremely favorable for heavy rain with PWATs over 2.25" and
MUCape pushing 2000 J/kg, placing the axis of heaviest QPF remains
difficult. Additionally, some of these enhanced rainfall totals
noted in recent guidance could be overdone and based on a more
developed system, which may not come to fruition if the mid-level
and low-level centers cannot congeal.

However, whether the system develops or not, heavy rainfall is
looking increasingly likely along the coast due to robust
advection of tropical moisture into Texas as the mid-level trough
shifts inland. In this favorable thermodynamic environment, ascent
will gradually intensify beneath increasing diffluence aloft and
forced low-level ascent due to frictional convergence along the
land-sea interface and through weak 0-6km mean flow being impinged
upon by 850mb winds 2-3 times stronger. As PWATs and instability
climb, rainfall rates will intensify and may reach 2"/hr at times,
with training likely through strong moisture confluence and
unidirectional shear. Additionally, the system, regardless of
organization, will likely move very slowly as it becomes trapped
beneath a ridge with +1 to +2 mid-level height anomalies which
will only enhance the temporal duration of heavy rainfall.

The recent ECENS rainfall probabilities suggest a high risk for
1-3" in 24-hrs, with low-end probabilities for 5" or more. A SLGT
risk has been added for much of the central and upper Texas coast,
with a MRGL risk extending as far west as the Balcones Escarpment
and I-35 corridor, but the greatest risk for heavy rain does
appear to be focusing nearer the coast. After discussion with the
local WFOs (CRP/EWX/HGX) have opted to cap the risk at SLGT for
now due to uncertainty, but it is possible, if not likely, that
higher risks will be needed with later updates, especially if this
wetter trend continues.


Weiss

SLGT is only around a 10% chance, right?

[Senobia]

The 0z Euro is showing some very impressive rainfall totals across Southeast Texas... (30+ inches of rain)

https://i.ibb.co/wWNsQy2/us-model-en-087-0-modez-2019091600-99-490-220.png

No.
Just....no.

[stormlover2013]

No one here in Houston has brought up rain totals near 30 inches.

Our paid pro-mets are forecasting 2-3", with some areas getting 6".

They aren't fully on board yet, if the 12z shows what the 00z run was last night then that number will go up, they are being Conservative right now