Tropical Storm Edouard

[NorthHillsWx]

Based on radar and some of the wind observations today with the highest gusts being recorded inland from port Arthur, Nederland, to Beaumont, it seems almost likely the storm continued to strengthen for a period after landfall, contrary to NHC estimates 

[NorthHillsWx]

Mesonet Station FW9014 in Livingston Texas just reported sustained TS winds at 39 mph with gusts into the mid 50s in the remnant core

Meanwhiloe Livingston Reservoir is reporting a sustained wind of 46 mph! I think the downgrade to TD came way too early based on these current observations of at least TS conditions 

[olafminesaw]

[Newman]

Some real bad flash flooding going on in that training band on the south side of Edouard. Radar estimates of up to 8" of rain in just the past 3 hours. Nearly 12-16" of rain total

[NorthHillsWx]

5 minutes ago, Newman said:

Some real bad flash flooding going on in that training band on the south side of Edouard. Radar estimates of up to 8" of rain in just the past 3 hours. Nearly 12-16" of rain total

Over 20” in places now, flash flood emergency issued 

[Windspeed]

Edouard's structure remains quite impressive this late AM. It doesn't appear these deep convective bands are going to let up anytime soon. It's no surprise that the rain totals are beginning to lead to flash flood emergencies.

[Windspeed]

Edouard isn't moving away from the juiced environment fast enough, and unfortunately, the mesoscales are showing deep intense training cells over the same locations this afternoon and evening. Some of these feeders may back'build towards the GOM. Flooding is going to become a big problem.

[olafminesaw]

10 minutes ago, Windspeed said:

Edouard isn't moving away from the juiced environment fast enough, and unfortunately, the mesoscales are showing deep intense training cells over the same locations this afternoon and evening. Some of these feeders may back'build towards the GOM. Flooding is going to become a big problem.


 

Ugh. Flashbacks to Harvey, albeit a much more compact system this time

[NorthHillsWx]

3 minutes ago, olafminesaw said:

Ugh. Flashbacks to Harvey, albeit a much more compact system this time

Some of the rates reported have rivaled Harvey (8”+ per hour) but thankfully the duration will not be near as long and obviously the size of the system is much more compact. Just another TS reminding us that wind speed isn’t always what should be the most important messaging about TS impacts. This one caught meteorologists off guard as pretty much everyone forecast a rapid decay of the circulation and no one mentioned 20”+ amounts that we are now seeing. Some 30” totals seem likely as 25-27” have already been reported with rain continuing, This is going to be a very memorable system for the areas impacted.

[Scott747]

This has more of an Allison feel as opposed to Harvey.

 

[WxWatcher007]

Incredibly impressive radar and satellite appearance. Given the wind observations you noted @NorthHillsWx, maybe a bit of Brown Ocean Effect slowing decay at least?

[GaWx]

9 minutes ago, WxWatcher007 said:

Incredibly impressive radar and satellite appearance. Given the wind observations you noted @NorthHillsWx, maybe a bit of Brown Ocean Effect slowing decay at least?

This slowness of decay seems to happen fairly often in this region per my memory.

[NorthHillsWx]

12 minutes ago, WxWatcher007 said:

Incredibly impressive radar and satellite appearance. Given the wind observations you noted @NorthHillsWx, maybe a bit of Brown Ocean Effect slowing decay at least?

It could be to an extent but this whole region is in some level of drought, so it would be highly unlikely a moist environment exists on the ground outside of what the storm has produced. I think more likely this is a function of an extremely unstable environment, low shear, and proximity to gulf moisture. This area has been known historically for producing similar occurrences of systems maintaining longer than expected so there might be some regional geography/proximity to the gulf that factors in for adequate moisture transport with minimal elevation to disrupt a surface low. Very very impressive storm, did not think we’d still be talking about this system much today 

[NorthHillsWx]

It’s been said but my goodness if this system had another day over water this might’ve been a major

[WxWatcher007]

39 minutes ago, GaWx said:

This slowness of decay seems to happen fairly often in this region per my memory.

 

37 minutes ago, NorthHillsWx said:

It could be to an extent but this whole region is in some level of drought, so it would be highly unlikely a moist environment exists on the ground outside of what the storm has produced. I think more likely this is a function of an extremely unstable environment, low shear, and proximity to gulf moisture. This area has been known historically for producing similar occurrences of systems maintaining longer than expected so there might be some regional geography/proximity to the gulf that factors in for adequate moisture transport with minimal elevation to disrupt a surface low. Very very impressive storm, did not think we’d still be talking about this system much today 

Thanks, guys. You’re probably right—more climo and unstable environment than anything else. Really interesting to watch. Hopefully the folks down there are staying safe—I don’t recall any forecasts for FFE level rainfall. 

[WEATHER53]

After it starts moving, where it supposed to go over next 2-4 days?

Thanks 

[GaWx]

5 hours ago, Scott747 said:

This has more of an Allison feel as opposed to Harvey.

 

Is there any chance that Edouard could be retired due to heavy rains, which caused Allison to be retired?

[olafminesaw]

46 minutes ago, GaWx said:

Is there any chance that Edouard could be retired due to heavy rains, which caused Allison to be retired?

I doubt it given the limited scope, maybe different if the band had parked over a major city

[WxWatcher007]

Found this interesting 

 

[NorthHillsWx]

2 hours ago, WxWatcher007 said:

Found this interesting 

 

Couldn’t you say that about every tropical system though? And the brown ocean effect here was what supposedly kept the circulation intact, enhanced the rain that this speaks to. So this is saying the storm caused the brown ocean effect but how was it able to sustain long enough for that to happen? Also, surface temps (and what the rain water temp would be) during the heaviest rainfall were in the mid to upper 70’s, below what would be sufficient for tropical processes. This to me is lazy. There are other processes here 

[LongBeachSurfFreak]

Couldn’t you say that about every tropical system though? And the brown ocean effect here was what supposedly kept the circulation intact, enhanced the rain that this speaks to. So this is saying the storm caused the brown ocean effect but how was it able to sustain long enough for that to happen? Also, surface temps (and what the rain water temp would be) during the heaviest rainfall were in the mid to upper 70’s, below what would be sufficient for tropical processes. This to me is lazy. There are other processes here 

Anyone take a look at lapse rates? It also had decent inflow off of peak warm gulf waters.


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[WxWatcher007]

4 hours ago, NorthHillsWx said:

Couldn’t you say that about every tropical system though? And the brown ocean effect here was what supposedly kept the circulation intact, enhanced the rain that this speaks to. So this is saying the storm caused the brown ocean effect but how was it able to sustain long enough for that to happen? Also, surface temps (and what the rain water temp would be) during the heaviest rainfall were in the mid to upper 70’s, below what would be sufficient for tropical processes. This to me is lazy. There are other processes here 

 

3 hours ago, LongBeachSurfFreak said:

Anyone take a look at lapse rates? It also had decent inflow off of peak warm gulf waters.


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I think Wx Twitter is going in circles because this will be the last Atlantic TC we see in a while.  

[LongBeachSurfFreak]

I think Wx Twitter is going in circles because this will be the last Atlantic TC we see in a while.  

Next year should make up for it with a Nina, assuming the mdr warms back up. But yeah this season was dead on arrival.


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[vortex95]

13 hours ago, NorthHillsWx said:

Couldn’t you say that about every tropical system though? And the brown ocean effect here was what supposedly kept the circulation intact, enhanced the rain that this speaks to. So this is saying the storm caused the brown ocean effect but how was it able to sustain long enough for that to happen? Also, surface temps (and what the rain water temp would be) during the heaviest rainfall were in the mid to upper 70’s, below what would be sufficient for tropical processes. This to me is lazy. There are other processes here 

There is another effect overlooked here, actually two.

1) I would argue there is a "tropical landscape effect," meaning lowlands/swamps/marshes and a general tropical marine air mass that is not far inland provides at least neutral moisture/latent heat to keep things going better or maintain than say and area that is not like that, but not a desert either (brown ocean effect).

2) Look at the mid-level WV loop for the past 3 days.  One, you have a trough nearly stationary over NE Mexico.  Two, watch what happens over the FL PH.  An upper low cuts off and deepens.  Now look at the 250 mb analysis.  I attached the 02/00z ECMWF fcst 03 hr 250 mb.  Edouard moved directly under a large upper level ridge center.  Note that a small cyclonic center is right over Edouard's center, but that is ok b/c TCs often has a tiny cyclonic low even at this level.

So upper level conditions became nearly ideal aloft for outflow given two upper troughs either side of the TC, and a upper level ridge directly over it.  This can and does result in intensification at times, at least the mid-level circulation and for satellite presentation, for a TC moving inland.  Recall before Edouard's landfall, there was some shear evident, and the convection was pulsing in blobs.  At 1230z on landfall day, after struggling a bit satellite, a big blow up of convection occurred directly over the center, and radiated out uniformly, which is a solid sign of intensification, and often this is due to an improvement of the overall environment,  In this case, the small amount of shear likely lessened, and that resulted in less dry air being pushed into the core, so Edouard "made its move," so to speak. 

And once inland, continued improvement aloft and the dry slots on radar vanished, and we got a solid/coherent precip swirl area, as tiny as it was!  Overall radar presentation improved *after* landfall!

So the brown ocean effect, or the "tropical landscape effect," does not tell the entire story I think. When upper level conditions improve markedly at and after landfall, this positive offset can intensifies the TC, or slow weakening.  In Edouard's case, since it was a mdt-strong TS at landfall, it has not much to "lose," so to speak, say compared to a Cat 3 landfall.  Yes, sfc winds will come down regardless b/c of friction, but system itself structurally improve, and I think this is what happened to Edouard.  

I'll give some actual historical examples in the next post.

[vortex95]

3 hours ago, WxWatcher007 said:

 

I think Wx Twitter is going in circles because this will be the last Atlantic TC we see in a while.  

But we have Lowell and HI for it all to focus on now.  Let the games (hysterics) begin!

[vortex95]

Some historical cases where RI cycle/markedly improved upper-level outflow at and after landfall.

Andrew Aug 1992 S FL
Andrew was undergoing RI at at landfall, and the eye was actually 1 C warmer 1 hr after landfall.  I recall the last recon pressure was 932 mb, and they estimated 926 mb for landfall, but readings on land n the eye found 922 mb in post-storm analysis.

Charley Aug 2004 SW FL
Charley was undergoing RI those last 12 hours up until landfall as upper-level outflow was improving due to favorable trough interaction upon recurvature.  A very compact hurricane that maintained its inner core w/ usually high winds well inland all the way to MCO (G108mph there).

Fay Aug 2008 SW FL
Fay was a disorganized TS at landfall, but in the next 6 hours, satellite presentation improved big time, and eye formed on sat/radar, and its symmetry was outstanding (on the VIS image link below, it even developed a subsidence ring around its CDO, which is a telltale sign of strong TC on sat).  It was the only time I have seen NHC increase the winds for a TC significantly inland (60 to 65 mph - winds over Lake Okeechobee).

https://upload.wikimedia.org/wikipedia/commons/thumb/5/50/Fay_19_aug_2008_1615Z_Cropped.jpg/960px-Fay_19_aug_2008_1615Z_Cropped.jpg?utm_source=en.wikipedia.org&utm_campaign=imageinfo&utm_content=thumbnail

http://ultimatechase.com/chase_accounts/Images/Tropical_Storm_Fay/RAD_KMLB_N0R_ANI.gif


Harvey Aug 2017 TX
Harvey was undergoing RI those last 12 hr to landfall, and the eye remains intact very well some distance inland.  Look at this EIR loop of Harvey,  Very strong, practically ideal, upper-level outflow develops not long before and after landfall as evidenced by the large anticyclone cirrus plume.
https://www.youtube.com/watch?v=8qjhW6lxkws

These are just some examples.  There are many others.
 

[NorthHillsWx]

6 hours ago, vortex95 said:

Some historical cases where RI cycle/markedly improved upper-level outflow at and after landfall.

Andrew Aug 1992 S FL
Andrew was undergoing RI at at landfall, and the eye was actually 1 C warmer 1 hr after landfall.  I recall the last recon pressure was 932 mb, and they estimated 926 mb for landfall, but readings on land n the eye found 922 mb in post-storm analysis.

Charley Aug 2004 SW FL
Charley was undergoing RI those last 12 hours up until landfall as upper-level outflow was improving due to favorable trough interaction upon recurvature.  A very compact hurricane that maintained its inner core w/ usually high winds well inland all the way to MCO (G108mph there).

Fay Aug 2008 SW FL
Fay was a disorganized TS at landfall, but in the next 6 hours, satellite presentation improved big time, and eye formed on sat/radar, and its symmetry was outstanding (on the VIS image link below, it even developed a subsidence ring around its CDO, which is a telltale sign of strong TC on sat).  It was the only time I have seen NHC increase the winds for a TC significantly inland (60 to 65 mph - winds over Lake Okeechobee).

https://upload.wikimedia.org/wikipedia/commons/thumb/5/50/Fay_19_aug_2008_1615Z_Cropped.jpg/960px-Fay_19_aug_2008_1615Z_Cropped.jpg?utm_source=en.wikipedia.org&utm_campaign=imageinfo&utm_content=thumbnail

http://ultimatechase.com/chase_accounts/Images/Tropical_Storm_Fay/RAD_KMLB_N0R_ANI.gif


Harvey Aug 2017 TX
Harvey was undergoing RI those last 12 hr to landfall, and the eye remains intact very well some distance inland.  Look at this EIR loop of Harvey,  Very strong, practically ideal, upper-level outflow develops not long before and after landfall as evidenced by the large anticyclone cirrus plume.
https://www.youtube.com/watch?v=8qjhW6lxkws

These are just some examples.  There are many others.
 

Key to all these is RI or last minute organization right before LF. Great examples. I think S FL gets some brown ocean effect simply due to the swampiness/ever present water of that part of the state. Wilma and Katrina are other examples of storms that did not weaken over S FL.

[bigtenfan]

I believe that it was Joe Bastardi that said around the time that Katrina hit Florida that a strenghening Cat 1 storm could cause more damage than a stable or weakening  Cat 3 storm?

[LongBeachSurfFreak]

I believe that it was Joe Bastardi that said around the time that Katrina hit Florida that a strenghening Cat 1 storm could cause more damage than a stable or weakening  Cat 3 storm?

Wind wise it’s not far off, but surge is a different story. A weaking cat 3 has imbedded surge while a strenthing cat 1 has yet to really form a large surge.


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