Flash Floods Kill 3 in Colorado; Dangerous 93L Developing in Gulf of Mexico

By: Dr. Jeff Masters , 3:06 PM GMT on September 12, 2013

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Devastating flash floods swept though numerous canyons along the Front Range of Colorado's Rocky Mountains Wednesday night and Thursday morning, washing out roads, collapsing houses, and killing at least two people. The floods were triggered by widespread torrential rains of 4 - 6" that fell in less than twelve hours, thanks to a flow of extremely moist air from the southeast that pushed up against the mountains. These sort of upslope rain events are so-named because as the air flows uphill, it expands and cools, forcing the moisture in it to fall as rain. Balloon soundings from Denver last night and this morning recorded the highest levels of September moisture on record for the station. The total precipitable water (PW), which is how much water would fall at the ground if the entire amount of water vapor through the depth of the atmosphere was condensed, was 1.33" at 12Z (8 am EDT) on September 12, and 1.31" at 00Z September 12. The previous September record was 1.23", set on September 10, 1980. Balloon soundings began in 1948. Wednesday night's rainfall was heaviest near Boulder, Colorado, where a flash flood watch continues through Thursday evening. Though rainfall amounts today are not expected to be as great as on Wednesday, the soils are saturated, and additional flash flooding will occur today as an upper-level low centered over the southern Great Basin continues to pull a moist southeasterly surface flow of air across Eastern Colorado. A map of Boulder flood zones and detailed history of previous floods in the area may be found here.


Figure 1. Flooding in Boulder, Colorado on Wednesday evening, September 11, 2013. Photo posted by brandish on Instagram @photogjake.


Figure 2. Radar-estimated rainfall for the Colorado's Front Range from the September 11 - 12 flash flood event. Rainfall amounts of 6 - 8" (dark rad colors) were indicated near Boulder (circle with a "+" symbol), and confirmed by rain gauge measurements.


Video 1. Flooding in Boulder, Colorado at 36th and Colorado Street on Wednesday night, September 11, 2013.

Dangerous 93L developing in the Gulf of Mexico
A low pressure system (Invest 93L) over the Southwestern Gulf of Mexico's Bay of Campeche is generating heavy rains over the Yucatan Peninsula and adjacent waters as it moves west-northwest at about 5 mph. Radar loops from Mexico show that 93L has a pronounced rotation and is developing low-level spiral bands, and there is a strong possibility that the Air Force hurricane hunter plane scheduled to investigate 93L Thursday afternoon will find that a tropical depression has formed. Satellite loops show only a modest area of heavy thunderstorms, but these are steadily growing in intensity and areal coverage. The atmosphere is unusually moist, ocean temperatures are a very warm 29 - 29.5°C (84 - 85°F), and wind shear is a moderate 10 - 15 knots. These favorable conditions for development are expected to continue through Monday, according to the latest SHIPS model forecast. The computer models predict a landfall location along the Mexican coast between Veracruz and a location a few hundred miles south of the Texas/Mexico border by early next week. The storm is expected to maintain a forward speed of about 5 mph during the coming five days, and this slow motion will potentially allow 93L enough time to intensify into a hurricane before landfall. The high levels of moisture and slow motion of 93L make it a very dangerous rainfall threat, and I expect rainfall amounts of 5 - 10 inches will affect portions of the Mexican coast between Veracruz and Brownsville, Texas over the next five days. An added danger is the presence of tropical disturbance 90E in the Eastern Pacific Ocean, on the other side of Mexico. If 93L intensifies sufficiently, it could draw in the moisture from 90E across Southern Mexico, resulting in torrential rains on both the Pacific and Atlantic sides of Southern Mexico. In their 8 am EDT Thursday Tropical Weather Outlook, NHC gave 2-day odds of development of 60% and 5-day odds of 80%.


Figure 3. Latest satellite image of Tropical Depression Ten.

Humberto peaks in intensity
Hurricane Humberto is headed northwards over the far Eastern Atlantic, and has likely peaked in strength, with 85 mph winds. Humberto is listed in NHC's preliminary Best-Track data repository as having achieved hurricane strength at 8 am EDT on September 11, which would tie it with Hurricane Gustav of 2002 for latest appearance of the season's first hurricane since 1941. Satellite loops show that Humberto is well-organized hurricane with a distinct eye, but the storm has moved over waters cooler than 26°C, and wind shear has risen to 20 knots, which will likely cause weakening over the next few days. Humberto is not expected to be a threat to any land areas.

Gabrielle heads towards Canada
Tropical Storm Gabrielle is headed northwards to Canada after bringing 40 mph winds and just over an inch of rain to Bermuda on Tuesday night. Satellite loops show that wind shear has ripped up Gabrielle, leaving the storm with almost no heavy thunderstorms, and exposing the low level circulation to view. Wind shear is expected to rise to an extremely high 45 - 70 knots on Friday as Gabrielle encounters a trough of low pressure, which will likely destroy the storm. Gabrielle's remnants will likely bring heavy rain to the Canadian Maritime Provinces on Friday and Saturday.

Jeff Masters

After the Rain (mtnwoman67)
Lots of rain in Colorado for weeks. Last evening's setting sun gave us a great show east of us.
After the Rain

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Quoting 1057. VAbeachhurricanes:


I don't think "luck" is a term scientists should be using.


Some discoveries are just luck, the scientist part is figuring out the meaning of the discovery.
Member Since: June 25, 2011 Posts: 2 Comments: 3733
1098. Patrap
Become a politician
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Quoting 1091. beell:


Pay attention.

I'm too poor to pay attention, is there a gov program that will pay attention for me.
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1096. barbamz
Quoting 1087. zicoille:


Please, wish that for us in the northern leewad islands


Zicoille and Caribboy, don't stay on this flooded blog for a while or you're constantly suffering the pains of Tantalos:

Tantalus was a Greek mythological figure, most famous for his eternal punishment in Tartarus. He was made to stand in a pool of water beneath a fruit tree with low branches, with the fruit ever eluding his grasp, and the water always receding before he could take a drink.
(From Wiki)
Member Since: October 25, 2008 Posts: 58 Comments: 6245
Member Since: March 12, 2013 Posts: 48 Comments: 79464
1094. Pallis
Quoting 981. centex:
While some will get too much, I'm afraid the Texas totals are over blown. We've seen this too many times, we need a more direct hit. But I keep my hopes up.
I am not a Christian, but I do believe in the power of prayer, so pray to the one true God and your wish may be granted,or not.God bless Texas!
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Quoting 1071. Neapolitan:
The Big Thompson River (Drake Station) is experiencing a major flood now that it's crossed the 8' mark. It's currently predicted to crest at 8.8' tomorrow morning. FWIW, the record level there was just a few inches higher at 9.3 feet during 1976's Big Thompson Canyon Flood, which killed 143 people.

BT

Heavy, training rain is falling on and around Boulder at the moment...

Getting really picky here, but with KDP values generally between zero and one, it would be incorrect to call it heavy rain at this point. However, what it is is persistent and unwelcome at this point, and any little bit more is going to aggravate the flooding concerns that already exist. With the moist orographic upslope continuing, it's a pretty bad situation along the Front Range right now.

*EDIT to correct Specific Differential Phase acronym.
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Quoting 1073. MrMixon:


I've started collecting animals in pairs, just in case. Anyone know how to tell a male miller moth from a female?


Well, usually the female moth is telling the male that . . .

Then again, nevermind ;)
Member Since: June 25, 2011 Posts: 2 Comments: 3733
1091. beell
Quoting 1084. VAbeachhurricanes:


How do I know its not a different butterfly?


Pay attention.
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Quoting 1079. Patrap:
Thats a lil stale Joe, as most of us are Seniors..and not in your Freshman class, so.........


Good Evening Rest Home!
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Quoting 1081. beell:
If you see it once and never again, it was a female.

That applies to more than just butterflies. I learned that in my teen years. :(
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1088. Patrap
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Quoting 1071. Neapolitan:
The Big Thompson River (Drake Station) is experiencing a major flood now that it's crossed the 8' mark. It's currently predicted to crest at 8.8' tomorrow morning. FWIW, the record level there was just a few inches higher at 9.3 feet during 1976's Big Thompson Canyon Flood, which killed 143 people.

BT

Heavy, training rain is falling on and around Boulder at the moment...


Please, wish that for us in the northern leewad islands
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Quoting 1063. 1900hurricane:

I don't think Humberto is faring as well as you think he is.



I haven't looked at Humberto in days.. he could be in Madagascar for all I know. I'm glued to pre-Ingrid. Naturally.
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Quoting 1081. beell:


The males continually circle around their territory, which is typically 100 metres across, whereas the females just wander across the land haphazardly. So if you see the butterfly or moth come past regularly say every 15 minutes, it is a male. If you see it once and never again, it was a female.


How do I know its not a different butterfly?
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1083. Patrap
If you see it once and never again, it was a female.

Why that mystery in my life is now solved.

Thanx!
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1082. MrMixon
Member Since: March 26, 2006 Posts: 44 Comments: 1520
1081. beell
Quoting 1073. MrMixon:


I've started collecting animals in pairs, just in case. Anyone know how to tell a male miller moth from a female?


The males continually circle around their territory, which is typically 100 meters across, whereas the females just wander across the land haphazardly. So if you see the butterfly or moth come past regularly say every 15 minutes, it is a male. If you see it once and never again, it was a female.

Go figure.
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Quoting 1068. MrMixon:
Sad news out of Jamestown...



Jamestown residents say they are worried about the welfare of a man who has been missing since early Thursday after a roaring mudslide crushed his home.

Joey Howlett, 72, the former owner of the Jamestown Mercantile Cafe, is missing and his bedroom is buried under 12 feet of rock, mud and debris, according to a half-dozen friends, neighbors and city officials.

"We lost a good friend here last night," said Richard Jenkins, who has known Howlett for 30 years. "He was like the town patriarch. He was everybody's friend."

Officials have said a man was killed in a collapsed house in Jamestown, but they have not identified the man. Acquaintances identified the owner of the home as Howlett.

Jenkins said it is far too dangerous yet to try to dig through the mud to look for any possible remains, Jenkins said.

"It's still raining up here and the ground is too unsettled," he said.

Source: The Daily Camera

----------

Note - this is not an additional death, just more information on one of three deaths I've heard of in Colorado today. I didn't know him well, but I've met Mr. Howlett. Sorry to read this news.

May he Rest In Peace
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1079. Patrap
Thats a lil stale Joe, as most of us are Seniors..and not in your Freshman class, so.........
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Quoting 1069. PalmBeachWeather:


It's not luck, that is statistics.
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The mesovortex recon went through earlier was also visible on radar.

Member Since: July 6, 2010 Posts: 113 Comments: 32520
Good Evening Class!
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Quoting 1068. MrMixon:
Sad news out of Jamestown...



Note - this is not an additional death, just more information on one of three deaths I've heard of in Colorado today. I didn't know him well, but I've met Mr. Howlett. Sorry to read this news.


Sorry to hear that, had heard that earlier.
Member Since: June 25, 2011 Posts: 2 Comments: 3733
Quoting 1030. Stoopid1:


Tone of your post aside, I guess I should have said more. Looking at the way Humberto's structure is evolving and how he's still maintaining good convection, and the conditions it is going into, I was thinking that an annular storm could be a possibility. Small chance all things considered, I know.
Wow. I am glad I plussed that post for the correct reason. LOL.... that is exactly what I thought as I looked at it. You mean it wasn't obvious???

[heh heh]

Though I'd like to see it clear out the eye more.
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1073. MrMixon
Quoting 1056. daddyjames:


I want you to build an ark.




I've started collecting animals in pairs, just in case. Anyone know how to tell a male miller moth from a female?
Member Since: March 26, 2006 Posts: 44 Comments: 1520
NOAH.....

How Long can you tred water?
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The Big Thompson River (Drake Station) is experiencing a major flood now that it's crossed the 8' mark. It's currently predicted to crest at 8.8' tomorrow morning. FWIW, the record level there was just a few inches higher at 9.3 feet during 1976's Big Thompson Canyon Flood, which killed 143 people.

BT

Heavy, training rain is falling on and around Boulder at the moment...
Member Since: Posts: Comments:
1070. beell
.
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Quoting 1065. VAbeachhurricanes:


Hahaha, I hear that, but there is a reason for everything, and IAnd the "Lottery"?
Member Since: October 3, 2008 Posts: 0 Comments: 5928
1068. MrMixon
Sad news out of Jamestown...



Jamestown residents say they are worried about the welfare of a man who has been missing since early Thursday after a roaring mudslide crushed his home.

Joey Howlett, 72, the former owner of the Jamestown Mercantile Cafe, is missing and his bedroom is buried under 12 feet of rock, mud and debris, according to a half-dozen friends, neighbors and city officials.

"We lost a good friend here last night," said Richard Jenkins, who has known Howlett for 30 years. "He was like the town patriarch. He was everybody's friend."

Officials have said a man was killed in a collapsed house in Jamestown, but they have not identified the man. Acquaintances identified the owner of the home as Howlett.

Jenkins said it is far too dangerous yet to try to dig through the mud to look for any possible remains, Jenkins said.

"It's still raining up here and the ground is too unsettled," he said.

Source: The Daily Camera

----------

Note - this is not an additional death, just more information on one of three deaths I've heard of in Colorado today. I didn't know him well, but I've met Mr. Howlett. Sorry to read this news.
Member Since: March 26, 2006 Posts: 44 Comments: 1520
1067. Patrap

946
WGUS55 KPUB 122326
FFWPUB
COC041-130230-
/O.NEW.KPUB.FF.W.0042.130912T2326Z-130913T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000 Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PUEBLO CO
526 PM MDT THU SEP 12 2013

THE NATIONAL WEATHER SERVICE IN PUEBLO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
WEST CENTRAL EL PASO COUNTY IN EAST CENTRAL COLORADO...

* UNTIL 830 PM MDT

* AT 524 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
VERY HEAVY RAINFALL MOVING INTO THE WALDO CANYON BURN SCAR. RADAR
AND OBSERVATIONS INDICATE RAINFALL RATES ABOVE 1 INCH AN HOUR WITH
THIS AREA OF RAIN WHICH WILL FALL ON ALREADY SATURATED GROUND.
WATER WILL RUN OFF QUICKLY...PRODUCING FLASH FLOODING IN AND
AROUND THE WALDO CANYON BURN SCAR...ESPECIALLY ON THE SOUTHERN AND
EASTERN PORTIONS.

* THIS IS VERY DANGEROUS LIFE THREATENING SITUATION. RUNOFF FROM THIS
EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO OCCUR. SOME
LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...COLORADO
SPRINGS...AIR FORCE ACADEMY...CASCADE...CHIPITA PARK AND MANITOU
SPRINGS.

JUST A SMALL AMOUNT OF RAINFALL ON A BURN SCAR CAN LEAD TO FLASH
FLOODING. WATER THAT IS NORMALLY ABSORBED BY THE SOILS AND
VEGETATION...RUNS OFF ALMOST INSTANTLY. THIS CAUSES CREEKS AND
DRAINAGE AREAS TO FLOOD AT A MUCH FASTER RATE THAN NORMAL. IN
ADDITION...THE SOILS IN A BURN SCAR BECOME UNSTABLE WHEN IT RAINS...
SOMETIMES RESULTING IN DEBRIS AND FALLING ROCK. ROADS CAN BE WASHED
OUT BY THE FORCE OF THE RUSHING WATER AND DEBRIS.

LAT...LON 3898 10482 3878 10487 3890 10503 3900 10499
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Quoting 1062. Birthmark:

Riiiiight!

What's an ark?


Right? What's a cubit?
Member Since: June 25, 2011 Posts: 2 Comments: 3733
Quoting 1061. PalmBeachWeather:
I'll take "luck" anytime here in south Florida....


Hahaha, I hear that, but there is a reason for everything, and I don't think luck is the reason :p
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Remember next week we will look in the Caribbean again for possible development.
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Quoting 1052. redwagon:


A characteristic of annular is extreme persistence in the face of obstacles that destroy other storms.

I don't think Humberto is faring as well as you think he is.

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Quoting 1056. daddyjames:


I want you to build an ark.



Riiiiight!

What's an ark?
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Quoting 1057. VAbeachhurricanes:


I don't think "luck" is a term scientists should be using.
I'll take "luck" anytime here in south Florida....
Member Since: October 3, 2008 Posts: 0 Comments: 5928
Quoting 1059. daddyjames:


I wish I knew how to embed videos - Bill Cosby routine
Ah... one of my faves.... lol...

Riiiighhhtttt..... lol
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Quoting 1058. PalmBeachWeather:
Home Depot or Sears would be your first stop


I wish I knew how to embed videos - Bill Cosby routine
Member Since: June 25, 2011 Posts: 2 Comments: 3733
Quoting 1056. daddyjames:


I want you to build an ark.


Home Depot or Sears would be your first stop
Member Since: October 3, 2008 Posts: 0 Comments: 5928
Quoting 1045. nrtiwlnvragn:
Why Has It Been So Long Since a Major Hurricane Hit the US?

Excerpt:

Luck

Luck probably plays the biggest role in the lack of major hurricane hits, said Chris Landsea, the science and operations officer at the National Hurricane Center (NHC).


I don't think "luck" is a term scientists should be using.
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Quoting 1049. MrMixon:




I'm really kicking myself for procrastinating on buying that canoe...


I want you to build an ark.


Member Since: June 25, 2011 Posts: 2 Comments: 3733
SUMMARY OF 700 PM CDT...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...19.7N 93.7W
ABOUT 165 MI...270 KM ENE OF VERACRUZ MEXICO
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 5 MPH...7 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES
Member Since: April 29, 2009 Posts: 75 Comments: 14556
big time lightning here in east haven,conn winds gusting to 85 mph in severe weather over here.
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1053. MrMixon
Member Since: March 26, 2006 Posts: 44 Comments: 1520
Quoting 1030. Stoopid1:


Tone of your post aside, I guess I should have said more. Looking at the way Humberto's structure is evolving and how he's still maintaining good convection, and the conditions it is going into, I was thinking that an annular storm could be a possibility. Small chance all things considered, I know.


A characteristic of annular is extreme persistence in the face of obstacles that destroy other storms.
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Is TD10 even moving?
Member Since: September 6, 2012 Posts: 0 Comments: 304
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1049. MrMixon
Quoting 1047. daddyjames:
Mr. Mixon,

Good news, only 2-3 inches forecast for the next 24 hours.

sarcasm flag on.




I'm really kicking myself for procrastinating on buying that canoe...
Member Since: March 26, 2006 Posts: 44 Comments: 1520

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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.