Major flooding in Austin from Hermine

By: Dr. Jeff Masters , 1:24 PM GMT on September 08, 2010

Share this Blog
5
+

Major flooding is occurring in the Austin, Texas region after Tropical Storm Hermine dumped an estimated 10 - 15 inches of rain over the past 24 hours. The flash flood warning for Austin from the National Weather Service at 4am this morning summarized the danger:

"Areas along I-35 and the Balcones Escarpment in and around the Austin Metro area will continue to experience a very dangerous flash flood event over the next few hours. Numerous evacuations and high water rescues have already been reported by the media and law enforcement personnel."

As wunderground's Dr. Rob Carver reports in his blog this morning, hardest hit was the area ten miles north-northwest of Austin, where an NWS cooperative station measured 10.11" of rain yesterday. The rains have swollen the South Fork of the San Gabriel River at Georgetown, Texas to 50-year flood heights.

Hermine has dissipated, but its heavy rains live on, and are now affecting the Dallas/Fort Worth region, where 1 - 3 inch rainfall amounts have been common. Hermine's rains are still lingering over the hard-hit Austin area, but should remain under one inch for the remainder of the morning. However, this afternoon, additional significant rains are possible near Austin as the sun's heat drives thunderstorm development in the very moist airmass over Central Texas.


Figure 1. Radar estimated rainfall for the Austin, Texas area shows that over fifteen inches of rain may have fallen in the region ten miles north-northwest of the city.

Gaston's remains no longer a threat
Dry air has significantly disrupted the remains of Tropical Storm Gaston, which are now over the Dominican Republic. NHC is now giving Gaston a 0% chance of developing, and no models are calling for development. It appears Gaston is finally dead.

Invest 91 off the coast of Africa
A large, well-organized tropical wave (91L) is just off the coast of Africa, near the Cape Verdes Islands, and is bringing sustained winds of 30 mph this morning to Praia in the southeast Cape Verdes. 91L is under a high 20 - 30 knots of wind shear, but this shear will decline to the moderate range, 10 - 20 knots, by Thursday. Water temperatures are warm, 28°C, and 91L has plenty of spin. The Saharan Air Layer (SAL) is well north of 91L, and should not be an impediment to development over the next few days. The models are pretty unanimous about developing 91L into Tropical Storm Igor sometime in the next 1 - 3 days. NHC is giving 91L a 70% chance of developing into a tropical depression by Friday. The GFDL model predicts 91L will be Hurricane Igor five days from now. The storm will track west to west-northwest over the next week, with long range forecasts from the GFS and ECMWF models putting 91L several hundred miles northeast of the Lesser Antilles Islands 7 - 10 days from now. History shows that about 20% of all tropical cyclones that have existed at 91L's current position have gone on to hit the U.S. East Coast; these odds are 10% for the U.S. Gulf Coast, 5% for Puerto Rico, and 10% for Canada. The forecast steering pattern for the coming two weeks from the GFS model shows a continuation of the pattern we've seen all hurricane season, with regular strong troughs of low pressure moving off the U.S. East Coast. This pattern favors a continuation of the sort of tracks we saw for Danielle, Earl, and Fiona, with threats to the northern Lesser Antilles, Bermuda, the U.S. East Coast, and Canada.


Figure 2. Morning satellite image of Invest 91L (Igor?)

Elsewhere in the tropics
The GFS and ECMWF models are predicting the development of a new tropical wave off the coast of Africa 5 - 6 days from now.

Death toll in Guatemala from Tropical Depression 11E rises to 54
In the Eastern Pacific, heavy rains from Tropical Depression 11E have killed at least 54 people in Guatemala, with many more missing and feared dead. The heavy rains triggered nearly 200 landslides and collapses, causing damages near $500 million. Fifteen landslides hit portions of the Inter-American Highway, burying a number of vehicles and a bus. Tropical Depression 11E formed on September 3, moved over Mexico and Guatemala, and dissipated by the next day. Remnants from the depression may have played a role in the formation of Tropical Storm Hermine in the Gulf of Mexico on September 5.

Guatemala is still recovering from the impacts of Tropical Storm Agatha, which killed 287 people in the country and did over $1 billion in damage in May. This September's heavy rains in Guatemala come on the heels of the rainiest August in Guatemala's history, according to preliminary data from the National Institute of Seismology, Volcanology, Meteorology and Hydrology (INSIVUMEH). Rain was more than 100% above average in many parts of the country, and more than 200% above average in some regions. September and October are historically Guatemala's rainiest months, and any additional tropical cyclones which affect the country can be expected to cause more serious flooding.


Figure 3. Satellite image from Friday, September 3, 2010, showing Tropical Depression 11E over Mexico and Guatemala. Image credit: NASA.

Next post
I'll have an update Thursday morning.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1031 - 981

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62Blog Index

Quoting StSimonsIslandGAGuy:
I hope Igor stays out to sea. I noticed one ensemble track that makes Igor a potential threat to the southeast coast. Hope that is wrong. I think Igor has the potential to have the most ACE of any storm since Ivan.




I agree - need to watch this one. Not that anybody looks at the models

GFS at 7.5 days has Igor = Fish Also developes next system off Africa in 3 days.
CMC at 6 days has Igor staying S and may be threat - also develops next system off Africa.
NGPS at 7.5 days has Igor = fish - also develops a system in eastern Carri that may threaten S Fl, also develops next system off Africa (3 named storms next week??)
ECMWF - Igor = possible fish, develops next system off Africa
Member Since: Posts: Comments:
Quoting CybrTeddy:
Tropical Storm Igor..


Since August 22nd, we've gone from 3-1-0 to 9-3-2 and shows no signs of stopping with the models developing a system behind Igor and a Caribbean system.

Impressive increase in tropical activity. Will Igor absorb that low off to it's North-East?
Member Since: Posts: Comments:
1026. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #5
TROPICAL DEPRESSION 13
3:00 AM JST September 9 2010
================================

SUBJECT: Tropical Depression In South China Sea

at 18:00 PM UTC, Tropical Depression (1002 hPa) located at 20.4N 118.9E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The depression is reported as moving north northwest slowly

Dvorak Intensity: T2.0

Forecast and Intensity
========================
24 HRS: 22.6N 117.8E - 35 knots (CAT 1/Tropical Storm)
Member Since: Posts: Comments:
1025. SQUAWK
Quoting RecordSeason:
I think DestinJeff wikipedia searched "Ides" after my response a while back.


No, I think he out foxed all of us.
Member Since: Posts: Comments:
1024. KBH
temperature dropped to 23.7 cel sometime this afternoon, little or no wind at this time, but it is pouring down
Grantley Adams, BR (Airport)
Updated: 26 min 21 sec ago
24 °C
Light Rain
Humidity: 94%
Dew Point: 23 °C
Wind: 20 km/h / 5.7 m/s from the NE

Pressure: 1010 hPa (Falling)
Visibility: 8045.0 kilometers
UV: 2 out of 16
Clouds: Mostly Cloudy 243 m
Scattered Clouds 365 m
Mostly Cloudy 2438 m
(Above Ground Level)

Member Since: Posts: Comments:
1023. jonelu
Quoting earthlydragonfly:


Hey cool picture Jonelu!! I love it!!! WINK

So mystery solved. Now I can give you photo credit. I LOVE it!!! Nice work.
Member Since: Posts: Comments:
If Igor is to reach 40 ACE, and his lifespan is say 12 days, for arguments sake. Slightly longer than Earl and in between the usual length for a Cape Verde-hurricane.

12 days with 4 advisories per day is 48. The average he'd need with each advisory would be roughly a 95kt/110mph Category 2 hurricane. (It'd be 43.32, but 90kts would bring him just under and would be under Ike/Wilma's ACE).

Doable, but it depends how long he'd keep a major status (if he achieves it) to bump up the average. He may last longer, may last shorter, depends how fast he's going.
Member Since: Posts: Comments:
1020. tkeith
Quoting mcluvincane:
Lets see if I can get as many responses as storm when he says "afternoon".. Afternoon everyone!
Afternoon Storm!

:)
Member Since: Posts: Comments:
Lets see if I can get as many responses as storm when he says "afternoon".. Afternoon everyone!
Member Since: Posts: Comments:
Nasty lightning blasting way too close here.
I have retreated to the safety of the iPad to come online to see what is "up".
Member Since: Posts: Comments:
1014. angiest
Quoting DestinJeff:
I can bearly think straight know.


I feel badly for you.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
LinkFor vorticty map won't post
Member Since: Posts: Comments:
1012. tkeith
DestinJeff is it too early to forecast that trough that will turn Igor?
Member Since: Posts: Comments:
Tropical Storm Igor..


Since August 22nd, we've gone from 3-1-0 to 9-3-2 and shows no signs of stopping with the models developing a system behind Igor and a Caribbean system.
Member Since: Posts: Comments:
1009. KBH
as seemed to be happening of recent there is not a lot of circulation in that SE system in the c'bean but fair amount of rainfall
Member Since: Posts: Comments:
1008. angiest
Quoting DestinJeff:


Education is dead.

My post about the Is of September and the subsequent responses solidified it.


Yep.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
1007. tkeith
Quoting DestinJeff:


I think that should be "than did I."

Pretentious Flag: ON
see... :)
Member Since: Posts: Comments:
Quoting MississippiWx:


Damn sure has plenty of fuel to support its formation...gotta be careful with these sneaky types...
Considering the favorable upper (wind shear) to mid level (dry air) environment I wouldn't be surprised to see it do something similar to Hermine when it developed quite rapidly. It may want to distance itself some from south America before any true organization takes place, but it definitely has a decent chance to become the next tropical cyclone.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
1003. KBH
Quoting Jeff9641:
I know the focus right now is on IGOR but this system in the SE Caribbean could be a major player somewhere along the gulf coast.

Jeff
we had major flooding in Barbados after three hours of continuous rains from that system this afternoon, also a fair amount of lightning in that system
Member Since: Posts: Comments:
Member Since: Posts: Comments:
1001. A4Guy
the latest model runs for Igor all shifted considerably north of the NHC track...and basically show the storm starting to move WNW...with the xtrap position still showing a WSW movement. Wonder if the NHC will adjust track at 5:00, or wait for the next set of runs. Not much difference in the shift, as the NHC track and model tracks still end at just about the same latitude, more or less.
Member Since: Posts: Comments:
Quoting StSimonsIslandGAGuy:
I hope Igor stays out to sea. I noticed one ensemble track that makes Igor a potential threat to the southeast coast. Hope that is wrong. I think Igor has the potential to have the most ACE of any storm since Ivan.


He'd need to beat Ike/Wilma for that to occur (both 39.0).

It's possible, but he'd need to hit the ground running. Category 4 would probably be needed (1.3225-1.8225 [per 6/h]) at some point to do it. Being quite slow and/or a loop would help to that end also.

Initial feelings are that he'll fall short, but will end up being the highest ACE storm of the year.
Member Since: Posts: Comments:
It appears a COC is forming at 16.8N 72.8W.

Any comments?
Member Since: Posts: Comments:
Look at 850 mb vorticity on Igor quite impressive I am hearing the theme music for Jaws when you put the vorticity in motion. Just when you thought it was safe to go back in the water.
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
It has acquired a good amount of 850mb mainly to the SE of the convective cluster. May be the start of a low pressure area.


Damn sure has plenty of fuel to support its formation...gotta be careful with these sneaky types...
Member Since: Posts: Comments:
Quoting DestinJeff:
Ok everyone... a bit late here, but please know that my post

"Beware the Is of September!"

was a reference both to the I storm (Igor), as well as the Brutus' warning to Ceasar..."Beware the Ides of March".

I know it is "ides" not "Is"... and that my "Is" looks like the word "is".

Please bare with me.



What you do on your own time is your own business, but please don't bring it to the blog! I don't think anyone in here wants to get bare with you!
Member Since: Posts: Comments:
Quoting presslord:
you mean "bear" with you...not "bare"...hopefully...


Dawgs and Hawgs in two more weeks Press...
Member Since: Posts: Comments:
Quoting Hurricanes101:


thats the system the ECMWF was developing a couple of days ago

some thought it was redeveloping Ex-Gaston, but it was this system

I just noticed you can start to see the circulation...
Member Since: Posts: Comments:
looks like a duplicate of the last few storms
Member Since: Posts: Comments:
Quoting DestinJeff:
Ok everyone... a bit late here, but please know that my post

"Beware the Is of September!"

was a reference both to the I storm (Igor), as well as the Brutus' warning to Ceasar..."Beware the Ides of March".

I know it is "ides" not "Is"... and that my "Is" looks like the word "is".

Please bare with me.

a little more in depth explaination please...lol

maybe try... I's ?
Member Since: Posts: Comments:
983. Vero1
Quoting tatoprweather:
SST's around the system in the SE Caribbean are at about 31°C. Can somebody please confirm? How about shear...dry air in the area??


Member Since: Posts: Comments:
you mean "bear" with you...not "bare"...hopefully...
Member Since: Posts: Comments:

Viewing: 1031 - 981

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.