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Thousands Urged to Evacuate Iowa Floods; Megi’s Threat to Taiwan Escalates

By: Bob Henson and Jeff Masters 10:12 PM GMT on September 26, 2016

Water from the Cedar River will overspread a large swath of Cedar Rapids, Iowa’s second-largest city, on Tuesday. Fed by massive rains over northeast Iowa during the past week, the flood crest of 23 feet projected on Monday afternoon for Tuesday afternoon would be the second-worst in city history--topped only by the 31 feet during the catastrophic flood of June 2008, and 3 feet higher than all other crests. Officials have strongly encouraged residents of about 5000 homes in central Cedar Rapids to evacuate ahead of the flood crest (see map at bottom of this post).


Figure 1. Iowa National Guard members walk past a local business covered in sandbags, Monday, Sept. 26, 2016, in Cedar Rapids, Iowa. Residents are waiting anxiously as a quickly rising Cedar River threatens to inundate their city with devastating floodwaters for the second time in eight years. Image credit: AP Photo/Charlie Neibergall.


The floods of 2008 eclipsed anything on record across eastern Iowa, particularly in Cedar Rapids and Iowa City. The estimated cost of that flood reached $10 billion, with more than 5000 homes and nearly 1000 business damaged. This time, the heaviest rains (more than 10” in 24 hours last Wednesday--see Figure 3 below) have been focused across the Cedar River basin north of Cedar Rapids, which is helping to keep the most serious flooding within that corridor, including Cedar Falls and Waterloo. Another plus: the flood crest heading toward Cedar Rapids in 2008 was boosted by an intense storm just one day before it peaked downtown. “That’s why the intensity of the flooding caught people by surprise. Nothing like that is in the cards [this time]” Witold Krajewski, director of the Iowa Flood Center, told me. In fact, the flood crest should arrive on Tuesday beneath sunny skies. “Because this event is well predicted, the city is well prepared,” said Krajewski.


Figure 2. An aerial image shows flood-affected areas on June 13, 2008 in Cedar Rapids, Iowa. Image credit: David Greedy/Getty Images.

Cedar Rapids since 2008: Progress and problems
In the wake of the 2008 floods, Cedar Rapids and surrounding Linn County took big strides toward preparing for future disaster. The city and county are among three pilot communities nationwide in the Resilient America project, organized by the National Academies to help communities build resilience and reduce the physical and economic toll of disasters. In Cedar Rapids, roughly 1400 flood-damaged homes were acquired by the city and removed over the last eight years. That action has already cut back on the destruction that this week’s flood might wreak. The city has also adopted a $625 million flood protection plan, including a series of new levees and floodwalls. However, these structures have yet to be built: federal funding has been authorized, but has not yet been provided. As a result, some of the areas restored in the wake of the 2008 flood are imperiled once again.

Citizen-volunteers have been pitching in this week, helping to put more than 250,000 sandbags in place to help stem the flood crest. A Facebook page devoted to the unfolding flood is helping connect people to the most pressing needs. About 100 volunteers spent Sunday removing almost 1000 seats from the historic Paramount Theatre in downtown Cedar Rapids. After being heavily damaged in 2008, the theatre was restored with federal, state, and local funds totalling $35 million.


Figure 3. A swath of 8” - 10” of rain fell on Wednesday, September 21, 2016, atop the northwest-to-southeast Cedar River basin. Enhanced by other rains over the past week, this flood crest has moved southeast past Waterloo and Cedar Falls and is now approaching Cedar Rapids (southeast of map domain). Image credit: Iowa Flood Information System/Iowa Flood Center.

A very out-of-season flood for eastern Iowa
September is not when Iowans are usually keeping an eye on flood risk. In fact, this is the first time on record that a flood of any magnitude (at least 12 feet) has been measured on the Cedar River at Cedar Rapids. Heavy rains are far more common during spring and summer across eastern Iowa. Climate change has been shown to exacerbate the intensity of the heaviest rainfall events in the United States and many other parts of the world, as warmer temperatures allow more moisture to evaporate into the atmosphere. Research led by Eugene Takle (Iowa State University) found that eastern Iowa has already seen a measurable rise in the number of days with rainfall that is typically too heavy for soils to absorb (1.25” in a 24-hour period). “We can logically conclude that enhanced streamflow and the potential for flooding are also rising,” Takle wrote. His research has also found a shift away from spring floods (as warmer spring temperatures allow for earlier snowmelt) and toward late-summer events. Storms in late summer tend to be oriented along northwest-to-southeast trajectories, which aligns them with river basins in eastern Iowa. “This seems to be the new norm for seasonal flood occurrence in the state,” noted Takle.


Figure 4. Enhanced infrared satellite image of Typhoon Megi as of 2100Z (5:00 pm EDT) Monday, September 26, 2016. Image credit: RAMMB/CIRA/CSU.

Megi intensifying as it nears Taiwan
Typhoon Megi vaulted to Category 3 strength on Monday afternoon, heightening the risk to Taiwan. As of 18Z (2 pm EDT), Megi’s top sustained winds (averaged over 1 minute) were estimated at 115 mph by the Joint Typhoon Warning Center. Satellite imagery suggests that Megi has almost completed an eyewall replacement cycle, with its small eye from last weekend now superseded by a much larger but still-ragged eye, about 35 miles in diameter. The timing of this replacement cycle is bad news for Taiwan, as Megi has had just enough time to begin consolidating very intense, widespread thunderstorms around this newly formed eye. The 21Z Monday (5 pm EDT) forecast from JTWC brings Taiwan onshore with peak winds of at least 110 mph.


Figure 5. As of 18Z (2:00 pm EDT) Monday, September 26, the center of Typhoon Megi is projected to pass through central Taiwan between 06Z and 18Z Tuesday (2:00 pm Tuesday to 2:00 am Wednesday local time). Image credit: Central Weather Bureau, Taiwan.


Although Taiwan is experienced with typhoons—it gets three to four in a typical year--Megi will be striking the island head on, with its center passing through the heart of Taiwan. This will put the northern half of the island, which includes the capital of Taipei, in the more dangerous right-hand part of Megi. All signs point to Megi being an expensive and potentially deadly disaster for Taiwan, with wind damage, massive rainfall, and landslides a good bet across mountainous eastern Taiwan and major disruption in the capital city of Taipei, at the island’s north end. As of 2:20 am local time (2:20 pm EDT), 24-hour rains had already topped 200 mm (7.87”) at Taoyuan City, just west of Taiwan. Exacerbating the flood risk will be the saturated ground produced by heavy rain from Super Typhoon Meranti and Typhoon Malakas over the last two weeks.

On its predicted course, Megi would make a second landfall as a tropical storm along the coast of southeast China, not far south of where Meranti claimed at least 29 lives and caused at least $2.6 billion in damage.

Taiwan's typhoon history
According to EM-DAT, the international disaster database, the most damaging typhoon in Taiwan’s history was Typhoon Herb of 1996, which hit the island as a Category 4 super typhoon with 150 mph winds. The eye passed directly over the capital of Taipei, and the storm unleashed rains as high as 78.23”. Damage was estimated at $1.7 billion (2016 dollars), and the storm killed 73 people. The only other billion-dollar typhoon for the island was Typhoon Nari of 2001, which hit the island as a Category 2 storm with 100 mph winds, killing 104 and causing $1.1 billion in damage (2016 dollars.) Two typhoons have hit Taiwan at Category 5 strength. The first was Super Typhoon Joan, which made landfall in 1959 with 185 mph winds. Joan was Taiwan’s deadliest typhoon in recorded history, with 1046 deaths. The other Cat 5 was Super Typhoon Bilis, which intensified from a Category 2 storm with 105 mph winds to a Category 5 storm with 160 mph winds in the 30 hours before making landfall on the island on August 22, 2000. Bilis killed 14 people and did $134 million in damage to Taiwan. The island was hit by one major typhoon this year—Category 4 Super Typhoon Neparak—and by two major typhoons last year: Category 4 Typhoon Dujuan and Category 3 Typhoon Soudelor. The Central Weather Bureau of Taiwan has a list (in Chinese) of all the typhoons that have affected Taiwan.

Megi Links
Brian McNoldy has a continuously updating radar loop of Megi. It will be fascinating to watch as the storm makes landfall and gets deflected and distorted by the high mountains of Taiwan.

Stunning zoomed-in visible animation of Megi from September 26, 2016, from NOAA/RAMMB/Colorado State.

Storm chaser James Reynolds is in Taiwan and will be making live updates on Megi’s landfall on his Twitter feed.


Figure X. Satellite image of Invest 97L from Monday afternoon, September 26, 2016.

97L slowly organizing over tropical Atlantic
As it continues hustling westward at about 20 mph, the tropical wave dubbed Invest 97L is gaining latitude and organization. At 2:00 pm EDT Monday, 97L was located about 950 miles east-southeast of the Windward Islands. Considerable spin was already evident in a large swath of scattered showers and thunderstorms on 97L’s north side. The National Hurricane Center has upped the odds of 97L’s developing into at least a tropical depression to 70% by Wednesday and 90% by Saturday. The large envelope of showers and thunderstorms around 97L will make it slower to develop, but potentially more powerful once it does.

A Hurricane Hunter flight is scheduled for Tuesday afternoon into 97L, and it would not surprising if it finds that 97L is already Tropical Storm Matthew by then. Models agree that 97L will track into the southeast Caribbean, and tropical storm conditions may spread across parts of the Lesser Antilles as it does so. As noted in our morning update, there remains huge uncertainty as to 97L’s future beyond that point. The 12Z Monday operational runs of the GFS, ECMWF, and UKMET models differ on how closely 97L might come to the north coast of South America, but they agree on the general idea of a sharp northward turn through the central Caribbean by the weekend or early next week. Should this turn materialize, a landfall on the East Coast of the U.S. or Canada would be a possibility, or 97L could even head out to sea. All this will hinge on how quickly one upper-level storm system moves through the eastern United States and how quickly the next one approaches. It is far too soon to know how those midlatitude storms will evolve, and we still can’t rule out the possibility that 97L will continue across the Caribbean much farther to the southwest. One thing we do know is that 97L will have at least some of the ingredients needed to become a powerful and dangerous hurricane, including very deep warm water through much of the Caribbean as well as sea surface temperatures at or near record-warm levels across the western Atlantic.

We’ll be back with our next update on the Atlantic and Pacific tropics by late morning Tuesday.

Bob Henson and Jeff Masters


Hurricane Flood

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

What is freaking me out the most as to 97L is all the model runs showing the drastic hard right turn to the North; I am used to seeing gentle curves in the tracks....................It looks so "unnatural" to to me........


Quoting 484. Bucsboltsfan:



The wind shear has gotten a lot worse since yesterday.
Don't trust the shear maps
Quoting 491. beell:



Thank you so very much for pointing out my "rudeness".
:/


¯\_(ツ)_/¯
Quoting 494. weathermanwannabe:

Cannot tell from the loops exactly where a dominant LLC might be located or whether some reformation under some of the convective bursts is happening....................Will be glad to see Recon out this afternoon to give us an idea of what is going on at the surface.  Will note hoowever that the wave axis has gained a few degrees in latitude since yesterday; looks like it will clear the North Coast of Venezuela at this rate.






Convection firing on the southern side
505. beell
Quoting 492. VAbeachhurricanes:



Beell you already causing problems today?


Yes. I would have 50,000 comments by now if I posted every knee-jerk thought that sailed through the space between my ears. Every once in a while one slips through!
506. MahFL
Quoting 501. weathermanwannabe:

What is freaking me out the most as to 97L is all the model runs showing the drastic hard left turn to the North.


Right turn, not left......
507. beell
Quoting 495. stormwatcherCI:

It was mentioned yesterday they are in St. Croix.


Thanks. Figured it was the islands. Just not sure which one.
Quoting 476. GeoffreyWPB:

AL, 97, 2016092712, , BEST, 0, 113N, 525W, 30, 1008, LO


I still think the center is just south of 12n
Quoting 505. beell:



Yes. I would have 50,000 comments by now if I posted every knee-jerk thought that sailed through the space between my ears. Every once in a while one slips through!


You can tell things are getting puckered around here, when you can get a ban for saying, "bye."

Happened to me yesterday.
Quoting 502. bupsin101:

Don't trust the shear maps


thank you some on here are this not getting it after what took place with KARL but with recon going out there we will getter better info on wind shear pluse a oh lot of other info
Im such an adrenaline junky. Prudent to pump it up watching these storms tho since i live on the coast. Gro, where are you with the scary pics?
Quoting 507. beell:



Thanks. Figured it was the islands. Just not sure which one.

Quoting 229. JKC:

I'm in St Croix. The Hurricane Hunters have arrived and are scheduled to fly into 97L Tuesday. Does anyone think the system is tracking more West/NW on the Satellite Imagery over the past few hours?
Quoting 500. intampa:

Local TV met in the Tampa area says a cold front expected to give us drier air in Tampa this weekend is what should keep the storm east of here next week??


Not at all. The front is expected to quickly retrograde back to the north. That is a solution the Euro is seeing.
Quoting 500. intampa:

Local TV met in the Tampa area says a cold front expected to give us drier air in Tampa this weekend is what should keep the storm east of here next week??


The strength of this front and the reinforcing front to come behind it will determine how far west the system gets.
Quoting 494. weathermanwannabe:

Cannot tell from the loops exactly where a dominant LLC might be located or whether some reformation under some of the convective bursts is happening....................Will be glad to see Recon out this afternoon to give us an idea of what is going on at the surface.  Will note however that the wave axis has gained a few degrees in latitude since yesterday; looks like it will clear the North Coast of Venezuela at this rate.






The magical 55 w line expect convection to blow up
Quoting 509. nash36:



You can tell things are getting puckered around here, when you can get a ban for saying, "bye."

Happened to me yesterday.


So posting "bye felecia" would not be a good idea??

LOL
Quoting 513. Bucsboltsfan:



Not at all. The front is expected to quickly retrograde back to the north. That is a solution the Euro is seeing.


The trough are going to turn the system to the north. The question is where will the system make this turn. The 00Z Euro makes the turn further to the west than most the other models.
But all the models are forecasting a turn to the north that is caused by the troughs diving down across the eastern U.S.

Low pressure systems seek out low pressure. That is why tropical systems turn and merge with approaching troughs.
Water vapor making a good case for NW >NE and U.S. can wave bye-bye birdie to 97L... On the other side of the coin, if 97L misses the train... and if I am to believe the NWS Norman forecast... no trough digging deep across "the middle" for at least a week after the one heading SE now.

Sept 27, 2016 0645 cdt


images credit: NOAA
Sept 27, 2016 0830 0730 cdt

image credit: UNISYS

Quoting 506. MahFL:



Right turn, not left......
Corrected...........Thanks.
520. beell
Quoting 509. nash36:



You can tell things are getting puckered around here, when you can get a ban for saying, "bye."

Happened to me yesterday.


That made me laugh, Nash. Sorry to hear that. Onward & Upward!
If 97L does cross Cuba there is less terrain to deal with compared to Hispanola, may not slow it down as much depending on the upper level environment. Im more concerned if this stays much weaker through the next 4 days then GFS shows, it will less likely feel any pull from the north to be lifted out. This to me will be a real threat to the U.S I just hope a trough can save us.
12Z plots shift a bit to the W with some models shifted S as well those models that shoot N still do but it has also shift slightly W
Here is the big picture and you can see the approaching trof, and particularly the area to the North of Cuba and Hispanola, which should pick up the storm and take if to the North, missing the US, per the current model guidance unless the storm stays weak and misses the train as mentioned below by Cat5 and Barefoot due to a lack of stacking into the mid and upper levels so it can "feel" the steering influence of the trof:




Quoting 510. thetwilightzone:



thank you some on here are this not getting it after what took place with KARL but with recon going out there we will getter better info on wind shear pluse a oh lot of other info


Yes they will be heading out around 11, better data in the models too.
Not many comments on the flooding threat in Iowa ..

Here (on youtube) a (blurry) live cam of Cedar River at Downtown Cedar Rapids.

Crest of the flood is to happen soon. Folks in the comment section say that the forecast has been lowered to 22ft (instead of 23ft) though. So they might have dodged a bullet.

Edit:
Looks like folks watching invests huh, y'all hold the fort down. Not watching anything till there's a named storm out there. lol ;)
Quoting 527. RitaEvac:

Looks like folks watching invests huh, y'all hold the fort down. Not watching anything till there's a named storm out there. lol ;)


You've posted this several times. I don't know why it bothers you because people are tracking weather systems.
530. beell
Dr. M and/or Mr. H mentioned the possibility of some dry air advecting off the continent of South America the other day.

The morning sounding from Barbados. Dry. ADDED: although the source may be in question.
Southwesterly 850-200 mb shear ahead of 97L AOA 25 knots-although this may be in part, associated with the western edge of the ULAC travelling in tandem with the disturbance and not as bad as shear lying in wait.

Quoting 529. luvtogolf:



You've posted this several times. I don't know why it bothers you because people are tracking weather systems.


You mean...tracking models.
Quoting 501. weathermanwannabe:

What is freaking me out the most as to 97L is all the model runs showing the drastic hard right turn to the North; I am used to seeing gentle curves in the tracks....................It looks so "unnatural" to to me........




initiation point are way off to the south.
Michael Ventrice ‏@MJVentrice 42 minutes ago

Only 10% of 0Z ECMWF Ensembles pushing invest #97L to a Major Hurricane intensity. This is pretty bullish as this field is usually 0%.

Quoting 531. RitaEvac:



You mean...tracking models.


Wrong. It's tracking a weather system. Models are just one tool used. We use satellites, surface, wind shear, steering etc. to track a system.

So I guess if there was an invest in the central GOM with steering flow pointing to Texas you would totally ignore until it got named?
535. beell
Quoting 455. NunoLava1998:


There's just a lack of convection. There's a circulation in that part.


Look at it close. Those low clouds are moving south or southwest.



Way too close for comfort. Please OTS with a right hand hook off OBX. I just don't think that is going to happen. I think the GFS will trend begrudgingly slightly west and the Euro begrudgingly slightly east until we have an imminent threat to the CONUS. All IMO. We should have a pretty solid Cone by Friday.

Let's hope Monster Matt never forms and 2016 continues to be the year of the system that can't get its act together. Best case scenario.

Quoting 525. GeoffreyWPB:


Quoting 517. Sfloridacat5:



The trough are going to turn the system to the north. The question is where will the system make this turn. The 00Z Euro makes the turn further to the west than most the other models.
But all the models are forecasting a turn to the north that is caused by the troughs diving down across the eastern U.S.

Low pressure systems seek out low pressure. That is why tropical systems turn and merge with approaching troughs.
Isn't that just so true of life in general?
:)
Megi update :-(
Taiwan's third typhoon of the month kills at least four, injures hundreds
by Reuters, Tuesday, 27 September 2016 11:27 GMT

Hottest September day in half a century as influence of Typhoon Megi brings 'serious' air pollution to Hong Kong
Air Quality Health Index in Tuen Mun and Tung Chung hits highest level and temperature reaches 36 degrees Celsius in Happy Valley as storm slams into Taiwan
PUBLISHED : Tuesday, 27 September, 2016
Quoting 535. beell:



Look at it close. Those low clouds are moving south or southwest.


So where is the center located ?


looks like a moist environment to me.
97L looks to be consolidating around 13N 53W.

Compare to Ivan.
11.2N 53.4W

Compare to Charlie - initial position
11.7N
61.1W

Much further north.
1 Hour until lift off, then we will have something to watch.

Quoting 539. bupsin101:

So where is the center located ?


Based on what I see in satellite imagery, it appears to be around 12.8N 52.7W moving nearly due west at this time. I mean, that is where is see the best consolidation/ greatest spin.
when is recon going in today?
545. beell
Quoting 539. bupsin101:

So where is the center located ?


At that time, I had guessed 12.5N, 51.5W

Not long after that, Taz posted this:
27/1145 UTC 12.4N 52.0W T1.5/1.5 97L -- Atlantic

Close enough?



Quoting 483. weathermanwannabe:



That is the plausible alternative if it reaches the Western Caribbean intact as a good looking wave (rather then developing and leaving the Caribbean to the North)

I have little question that this storm will become Matthew within the next 48 hours, but you are right I dont foresee much strengthening of this system till it reaches the Central Caribbean and slow back down in response to the weakness caused by the trough. Then conditions will become ripe for intensification as it gains latitude. Looking at the Euro I would agree with its solution while its in the Caribbean. I'm not speculating on any US impacts but Hispaniola Jamaica and Cuba needs to watch this thing very closely.
Quoting 535. beell:



Look at it close. Those low clouds are moving south or southwest.




Looks to me the (as I see it, closed) center is N and E of the NE tip of your yellow line. Maybe 12.8 and 52.4... Butt who nose... and we shall see when HH goes in.

Add: of course I'm looking at the end of current loop, 0845, vs 0645 cdt.
Quoting 545. beell:



At that time, I had guessed 12.5N, 51.5W

Not long after that, Taz posted this:
27/1145 UTC 12.4N 52.0W T1.5/1.5 97L -- Atlantic

Close enough?




Wow great
I hope we do not have the multiple centers again...Although that may not be a bad thing...I ,m not sure..

Quoting 543. ecflweatherfan:



Based on what I see in satellite imagery, it appears to be around 12.8N 52.7W moving nearly due west at this time. I mean, that is where is see the best consolidation/ greatest spin.
I still see a spin around 11.6n
I have seen the same occurrence over and over again this year with blobs that are moving to fast. I just don't see 97L organizing much if any at the fast forward speed of 20 mph. The real possible scenario is it will stay weak and disorganized and totally miss the trough that is not as strong as many models predict. The trough will retrograde back a lot faster to the north and we we have a weak system headed west. We shall see in time and with recon headed into 97L. As always conditions change rapidly.
Quoting 549. hydrus:

I hope we do not have the multiple centers again...Although that may not be a bad thing...I ,m not sure..





With large circulations like this there will almost always be multiple vort maxes rotating around a broader center. Just depends on which one can become dominant.
WHCA31 TAPA
TROPICAL DISTURBANCE ALERT STATEMENT
ANTIGUA AND BARBUDA METEOROLOGICAL SERVICES
6:30 AM ECT TUE, SEP 27, 2016

THIS IS FOR THE LEEWARD ISLANDS AND BRITISH VIRGIN ISLANDS

SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A BROAD AREA OF LOW PRESSURE LOCATED ABOUT 600 MILES EAST-SOUTHEAST OF THE WINDWARD ISLANDS, CONTINUE TO SHOW SIGNS OF ORGANIZATION AND A TROPICAL CYCLONE COULD BE FORMING. IF THIS TREND CONTINUES, THEN A TROPICAL DEPRESSION OR A TROPICAL STORM WOULD LIKELY FORM LATER TODAY WHILE THE SYSTEM MOVES WEST-NORTHWESTWARDS TO WESTWARDS AT ABOUT 20MPH. AS A RESULT, WATCHES AND WARNINGS COULD BE REQUIRED AT ANY TIME.

REGARDLESS OF DEVELOPMENT, HEAVY RAINS AND STRONG GUSTY WINDS POSSIBLY TO TROPICAL STORM FORCE, ARE EXPECTED TO SPREAD MAINLY OVER THE WINDWARD ISLANDS AND PORTIONS OF THE SOUTHERN LESSER ANTILLES BEGINNING TONIGHT AND CONTINUING INTO WEDNESDAY. AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT IS SCHEDULED TO INVESTIGATE THE DISTURBANCE THIS AFTERNOON.

WHEREAS THIS DISTURBANCE HAS A GREATER CHANCE OF AFFECTING THE WINDWARDS ISLANDS, RESIDENTS OF THE LEEWARD ISLANDS SHOULD CLOSELY MONITOR THE PROGRESS OF THIS SYSTEM

FORECASTER LENARD JOSIAH
Quoting 534. luvtogolf:



Wrong. It's tracking a weather system. Models are just one tool used. We use satellites, surface, wind shear, steering etc. to track a system.

So I guess if there was an invest in the central GOM with steering flow pointing to Texas you would totally ignore until it got named?


Yep
Quoting 549. hydrus:

I hope we do not have the multiple centers again...Although that may not be a bad thing...I ,m not sure..




Banding in the increase to the south of the system. Previously there was almost nothing.
Quoting 543. ecflweatherfan:



Based on what I see in satellite imagery, it appears to be around 12.8N 52.7W moving nearly due west at this time. I mean, that is where is see the best consolidation/ greatest spin.
12.5-12.8...?
For a system with so robust a circulation 97L has a very poor satellite presentation. What convection there is appears to be separating to the NE and SW of the area of lowest pressure and this is not a sign of a developing tropical cyclone.
The center is almost convection free and there is no building CDO.

It will be interesting to see what recon finds when it gets there.
Tricky, tricky, tricky. The EURO, as expected moved a little west. The GFS ensembles are still moving the system a little earlier to the north. It is obvious most other models are not in agreement with this, turning 97L north a little later. This actually has been the case for a number of days. This would allow for 97L to become a stronger system from the central Caribbean. Changing the dynamics would further the problems for a solution on all models. I would definitely go with the trend of a system moving further west in the Caribbean. By looking at the low which is expected to dip down and pick up 97L, may move out further northeast and not affect 97L for that long. I will post some scary images in a few minutes.

559. IDTH

Quoting 557. kmanislander:

For a system with so robust a circulation 97L has a very poor satellite presentation. What convection there is appears to be separating to the NE and SW of the area of lowest pressure and this is not a sign of a developing tropical cyclone.
The center is almost convection free and there is no building CDO.

It will be interesting to see what recon finds when it gets there.
I'm not sure you will see a CDO until the system slows forward speed and begins to stack vertcally...
Quoting 549. hydrus:

I hope we do not have the multiple centers again...Although that may not be a bad thing...I ,m not sure..




That could be. It looks very elongated to me. I've been getting to like the nullschool wind map, and I usually feel it's accurate enough for general guidance, but today, it's seemingly completely off as far as latitude. It does indicate a broad circulation however and in my eyes, is what I see on satellites. Also, it shows the mid level center displaced to the north, which also looks evident to me on satellite, given the stronger convection displaced north of the center and the presence of what appears to be 15 kts or so of shear. I do like the banding forming, which should aid in the development of a solid surface circulation. Time will tell where that may occur. IMO, right now, there's no trackable low level circulation, but broad turning with weak surface winds. I would say there's likely already ts force winds in that heavy band of convection to the north and the system as a whole looks robust and healthy.
565. MahFL
Quoting 539. bupsin101:

So where is the center located ?


97L does not yet have a closed center.
Quoting 558. Grothar:

Tricky, tricky, tricky. The EURO, as expected moved a little west. The GFS ensembles are still moving the system a little earlier to the north. It is obvious most other models are not in agreement with this, turning 97L north a little later. This actually has been the case for a number of days. This would allow for 97L to become a stronger system from the central Caribbean. Changing the dynamics would further the problems for a solution on all models. I would definitely go with the trend of a system moving further west in the Caribbean. By looking at the low which is expected to dip down and pick up 97L, may move out further northeast and not affect 97L for that long. I will post some scary images in a few minutes.




Scary Images? It's so close to Halloween; can't wait. In reality I do hope this system gets pushed northeastward by the trough; however, I am hearing that the trough may not be as powerful as thought yesterday and may not be able to push out a weaker system in the South Central Caribbean so I agree with you.
Quoting 557. kmanislander:

For a system with so robust a circulation 97L has a very poor satellite presentation. What convection there is appears to be separating to the NE and SW of the area of lowest pressure and this is not a sign of a developing tropical cyclone.
The center is almost convection free and there is no building CDO.

It will be interesting to see what recon finds when it gets there.


It's probably thanks to shear. Again, I can see this storm busting entirely due to strong shear that models fail to see(as with Karl). Been the story of the season for years now.

Honestly I do not believe any forecast anymore, I just wait and see.
Quoting 560. SoFLRoofguy:

I'm not sure you will see a CDO until the system slows forward speed and begins to stack vertcally...


I wasn't expecting to see a CDO at this stage. Note that I said there is no building CDO. As for stacking it looks pretty good in that department. Recon could find a TD, TS or open wave. Take your pick :-).
569. MahFL
Quoting 560. SoFLRoofguy:

I'm not sure you will see a CDO until the system slows forward speed and begins to stack vertcally...


It's pretty stacked already :


570. IDTH
Quoting 558. Grothar:

Tricky, tricky, tricky. The EURO, as expected moved a little west. The GFS ensembles are still moving the system a little earlier to the north. It is obvious most other models are not in agreement with this, turning 97L north a little later. This actually has been the case for a number of days. This would allow for 97L to become a stronger system from the central Caribbean. Changing the dynamics would further the problems for a solution on all models. I would definitely go with the trend of a system moving further west in the Caribbean. By looking at the low which is expected to dip down and pick up 97L, may move out further northeast and not affect 97L for that long. I will post some scary images in a few minutes.



I'm honestly siding with the Euro because I believe the GFS might be overdoing the intensity which leads to the northern movement.
Quoting 544. chrisdscane:

when is recon going in today?



11:00. You can also go to the NHC's website and they list all of the scheduled recon flights.
Quoting 568. kmanislander:



I wasn't expecting to see a CDO at this stage. Note that I said there is no building CDO. As for stacking it looks pretty good in that department. Recon could find a TD, TS or open wave. Take your pick :-).

TD.
Quoting 567. LostTomorrows:



It's probably thanks to shear. Again, I can see this storm busting entirely due to strong shear that models fail to see(as with Karl). Been the story of the season for years now.

Honestly I do not believe any forecast anymore, I just wait and see.


I've been talking about the shear for 4 days and was told on here it would not be an issue.
Here is Megi piling the black carbon and pollutants along China.


Quoting 509. nash36:



You can tell things are getting puckered around here, when you can get a ban for saying, "bye."

Happened to me yesterday.
Your comment was removed not for what you said but for what you quoted...

Thanks for flagging inappropriate material this morning everyone:)
575. IDTH

Maybe that front moving through the US will shove it west if it moves north and into the Florida Georgia coast? I know nothing but speculation though, so probably not.
Quoting 570. IDTH:


I'm honestly siding with the Euro because I believe the GFS might be overdoing the intensity which leads to the northern movement.


Yes I believe so as well
Quoting 570. IDTH:


I'm honestly siding with the Euro because I believe the GFS might be overdoing the intensity which leads to the northern movement.


I'm in the same camp.
GEOS-5 showing maybe a minimal to mind-strength tropical storm hitting some Windward Islands Wednesday.

Still raking South America pretty hard on Friday..

& devastating Jamaica next Tuesday.

After that today has shifted a little north where it rides right under Cuba over Cayman Islands and then threads the needle between Cuba and Yucatan.

Quoting 568. kmanislander:



I wasn't expecting to see a CDO at this stage. Note that I said there is no building CDO. As for stacking it looks pretty good in that department. Recon could find a TD, TS or open wave. Take your pick :-).

I'm leaning towards recon finding an open wave because ASCAT showed the circulation was broad and poorly defined earlier. But maybe they will find a small circulation, you never know.
97L looks good today, consolidating nicely. Can't wait for recon to get a proper fix on the center. I believe it's around 12.5N, 52.5W - with the convective burst starting to wrap around.

Interesting to see a shift west with the Euro. Most of the ensembles are further west than the operational as well...

The UKMET is in agreement with the Euro and is further west. The GFS is currently the outlier. Can't wait to get some solid info on the storm though and where the exact center is consolidating. Could cause dramatics shifts in model runs.
Quoting 576. Grothar:




Not the best analog but late-September at least.

Quoting 575. IDTH:


As some has been saying for the last couple of days, wind shear is not very favorable for rapid development of 97L currently. I dont think conditions will improve until it crosses 70W in about another 48-72 hours. That doesn't mean this system wont develop which I think its very close to doing but will struggle to strengthen. However, unlike previous system it has a large moisture envelop and a large, very robust circulation that will keep it going verse previous storms (ex: Chantal). I expect the models the models particularly the GFS to shift west as a result.
Good morning all. Key West's Radar has been down since Friday. This is the Miami Long Range showing a nice rotating storm coming into the Lower Keys...

Although the convection is not that impressive, the cloud pattern and banding is becoming more evident. The only question I have is this a closed low or is it open with competing centers?
4 min to departure.
so given the shear its now facing and what its going to have to face over the next 3 days it will be an open wave in the eastern central carib then by day 4 s/se of Jamaica it starts it turn and starts to develop in weakening shear passing near Jamaica/Cayman then over Cuba which will kill it again then back over open water in the Florida straits then???
Quoting 590. 19N81W:

so given the shear its now facing and what its going to have to face over the next 3 days it will be an open wave in the eastern central carib then by day 4 s/se of Jamaica it starts it turn and starts to develop in weakening shear passing near Jamaica/Cayman then over Cuba which will kill it again then back over open water in the Florida straits then???


You've got it all figured out:)
Ok, so basically stronger storm...GFS and weaker storm Euro....

I think I will go with the Euro only because the way these storms been going this year.
You think someone was having fun with their T-Square.

Quoting 582. Grothar:






;) JK

UKMET and ECMWX both show that dive wsw near the north coast of Colombia.
97L is tilted slightly from SW to NE with the 700 mb circulation displaced from the 850 mb. Although not perfectly stacked it does have a good signature extending upwards into the higher levels of the atmosphere. This displacement is probably what accounts for those who see the "center" farther to the N than the low being tracked.

Shear is the culprit at work here. 20 knots at this time but stronger to the immediate West.
On its way:

URNT15 KNHC 271508
AF303 01FFA INVEST HDOB 02 20160927
Quoting 581. Grothar:




Yeah, that would not be good.
HELLO everyone! Weak system stays south and moves further West. If 97L is not a Named System before reaching the Caribbean. The JOHN HOPE factor will apply! It won't develop until reaching the Central Caribbean and then it will miss the first trough. The EURO would then be correct!
Quoting 595. kmanislander:

97L is tilted slightly from SW to NE with the 700 mb circulation displaced from the 850 mb. Although not perfectly stacked it does have a good signature extending upwards into the higher levels of the atmosphere. This displacement is probably what accounts for those who see the "center" farther to the N than the low being tracked.

Shear is the culprit at work here.


I agree... some SW to Southerly shear from my point of view.
Recon has taken off, we will have some answers soon.

Quoting 590. 19N81W:

so given the shear its now facing and what its going to have to face over the next 3 days it will be an open wave in the eastern central carib then by day 4 s/se of Jamaica it starts it turn and starts to develop in weakening shear passing near Jamaica/Cayman then over Cuba which will kill it again then back over open water in the Florida straits then???

Shear will improve by day 3 as an upper level anticyclone establishes itself over top the system. As it slowly gains latitude due to the trough. Trade winds from the Eastern Caribbean will cause air to pile upward and allow 97L to grow and maintain deep convection and develop some spiral banding. Land interaction won't kill a developed storm, if it were to go over Cuba especially central Cuba where the topography is flatter compare to Hispaniola. As for the specific track after the Caribbean its too early to call. A very dangerous situation could unfold if things go as forecasted by the models for the islands.
RECON is now airborne

The fun begins
At 1200 UTC, 27 September 2016, LOW INVEST (AL97) was located in the North Atlantic basin at 11.3N and 52.5W. The current intensity was 30 kt and the center was moving at 16 kt at a bearing of 285 degrees. The minimum central pressure was 1008 mb.





12z Int:

Quoting 598. ProPoly:



Yeah, that would not be good.


Jamaica and the Caymans more in the zone on each run.
Quoting 607. Grothar:




Too close to me for comfort. I never like it when the models keep inching to the West :-)
Quoting 589. WxLogic:

4 min to departure.


Where are you going?
Quoting 603. Ricki13th:


Shear will improve by day 3 as an upper level anticyclone establishes itself over top the system. As it slowly gains latitude due to the trough. Trade winds from the Eastern Caribbean will cause air to pile upward and allow 97L to grow and maintain deep convection and develop some spiral banding. Land interaction won't kill a developed storm, if it were to go over Cuba especially central Cuba where the topography is flatter compare to Hispaniola. As for the specific track after the Caribbean its too early to call. A very dangerous situation could unfold if things go as forecasted by the models for the islands.


I am 100% with you on all that also yes it will not affect the circulation if it did take the path over Cuba, I mentioned that earlier as well which could make it even more of a dangerous storm to the gulf or east coast. Much to watch over the next week.
Quoting 527. RitaEvac:

Looks like folks watching invests huh, y'all hold the fort down. Not watching anything till there's a named storm out there. lol ;)


I live in Dominica, where even the slightest drift north in track could have devastating effects on our little island.

You bet I'm watching this "invest", for me Iowa is far, far away but Matthew is closing fast.
Possible COC developing near 13.5N 52W

Link


Quoting 612. Grothar:



Where are you going?


I was going to drive down to your house to eat some shrimp but you know NHC called me up and so I gotta go. LOL!!!
24 hours:

Note to grothar,


I successfully mowed my VA glasses into dust




what would give us that would really help track forecasts?
Quoting 604. wunderkidcayman:

RECON is now airborne

The fun begins


Unstable
Quoting 611. kmanislander:



Too close to me for comfort. I never like it when the models keep inching to the West :-)



U betcha...counselor


Quoting 615. CaribBoy:

Possible COC developing near 13.5N 52W

Link



The
Quoting 615. CaribBoy:

Possible COC developing near 13.5N 52W

Link



SAY WHAT!?
lets hope it turns north soon......I think the shear and general lack of ideal atmospheric conditions during our current "quiet" period will keep this from becoming the monster it would have 10 years ago
Quoting 611. kmanislander:



Too close to me for comfort. I never like it when the models keep inching to the West :-)
1.25" in 24 hours seems awfully low for a soil absorption maximum rate in a state
with soils as good as Iowa's are. I thought field capacities (amount of water in the
saturated soil profile) were about three inches in these soils. Our soils in Maryland absorb more than 1.25" when
dry.

The number of separate serious flood events this late spring through early Autumn (so far) in widely separated areas with different systems, is amazing. Likely fallout from unusually high PWATS in both extreme events and averaged over the whole season which also suggests why nighttime minima have been more extremely warm
this summer east of the Rockies, than daytime maxima. New Orleans has smashed a record for the number of 80 nights, 43! Previous record was only 13.

https://www.washingtonpost.com/news/capital-weath er-gang/wp/2016/09/26/the-mind-boggling-new-orlean s-heat-record-that-no-one-is-talking-about/

DC metro has had an extreme number of these, seven. This ties the 2011 record. The first fourteen years I lived here 1964-1977 there were NONE. First one in my time was in mid July 1978 (and of course I had a night job as an outdoor laborer after my day job outdoors.. at 20 you can do this stuff!
Quoting 615. CaribBoy:

Possible COC developing near 13.5N 52W

Link




Looks more like the mid-level center. The system is not as stacked as it was before due to shear.
Quoting 610. Grothar:


Jamaica and the Caymans more in the zone on each run.

So we are back to where we started to watch the models some days ago ;-)

48 Hours

Into the storm

the GFS seems a little excited:)
GFS weaker through 42 hours, minimum tropical storm will likely trend slightly west this run maybe through the windward passage.
Quoting 628. VAbeachhurricanes:

48 Hours



Expecting a shift west more inline with the Euro this time around.
GFS through 60hrs...
12Z GFS further west and a bit weaker so far - looks like it'll trend towards the Euro
3 days, dipping south

Heavy rain and very windy!! here in Miami.
I don't know if my eyes are playing tricks on me,but I can see some cloud rotation in the lower keys?.
Any comments on this,not that this is a Tropical System but maybe a low trying to form??.
Getting near

Quoting 615. CaribBoy:

Possible COC developing near 13.5N 52W

Link





carib boy your correct it seems like its moving more north of west you should be happy because the more north it comes the closer to us
Quoting 592. SELAliveforthetropic:

Ok, so basically stronger storm...GFS and weaker storm Euro....

I think I will go with the Euro only because the way these storms been going this year.
I really doesn't matter the strength of the storm, I would never go with the GFS model, the physics in this U.S. model su*k, and when they are finally fixed, then maybe I will start to watch it. They need to rebuild this model from the ground up.
Quoting 637. Hurricane1956:

Heavy rain and very windy!! here in Miami.
I don't know if my eyes are playing tricks on me,but I can see some cloud rotation in the lower keys?.
Any comments on this,not that this is a Tropical System but maybe a low trying to form??.

Let's see if the turn to the north happens soon.
Models should have recon data at 18z but actually more likely the 00z overnight runs.
Moving WNW slightly further west than the previous run...
JeffMasters has created a new entry.
Area Forecast Discussion...UPDATED
National Weather Service Miami FL
944 AM EDT Tue Sep 27 2016

...STRONG TO A FEW SEVERE STORMS POSSIBLE EAST COAST METRO AREAS
THIS AFTERNOON...

.UPDATE...
An upper level trough of low pressure over the eastern Gulf of
Mexico will move east through the Florida Peninsula today allowing
the steering flow to be from the southwest but light over South
Florida. This will keep the east coast sea breeze over the east
coast metro areas with the west coast sea breeze pushing across
South Florida. The CAPE was around 3000 J/KG this morning with the
potential of getting up to around 4200 J/KG this afternoon.
Therefore, the pops will be raised to likely CAT over the east
coast metro areas for the afternoon hours. The light steering flow
will also lead to some minor street flooding over the metro areas
of South Florida this afternoon due to the slow movement and
possible training of showers and thunderstorms.

The 500MB temperature this morning was also around -8.1C on the
12Z MIA sounding. This will allow for some of the thunderstorms
to become strong with even a few storms possibly becoming severe
over the eastern areas of South Florida this afternoon. The
primary impacts from the strong or severe storms will be frequent
lightning strikes, gusty winds, and hail. Therefore, the morning
HWO will be updated to add these threats.





Quoting 631. WeatherkidJoe2323:

GFS weaker through 42 hours, minimum tropical storm will likely trend slightly west this run maybe through the windward passage.


:)


651. ackee
So the 12z Gfs shift even further west Gfs takeing it sweet time going further west again the Cmc staying west south of Jamaica as 108 hours
Ok from what I can see GFS and CMC both shifted W on new 12Z run however they still move W then N at an almost 90° angle still not buyin it