Norbert & Odile: Two trips out West for something new

The east Pacific hurricane season was extremely busy. Several intense hurricanes impacted Mexico, particularly portions of the Baja peninsula. The strongest of these impacts was hurricane Odile in mid-September with significant damage taking place in the Cabo San Lucas area.

Once these Pacific hurricanes turned north and eventually northeast, they spread deep tropical moisture across a region that is normally very dry and very hot: The Desert Southwest. The resulting influx of moisture often leads to a period of heavy rain for areas that are not used to such events on a regular basis. In fact, it had been quite a number of years since the last significant intrusion of tropical cyclone threats to the Southwest United States and this is what drove me to head out there not once, but twice, to document and study the impacts in person.

Norbert: September 5-10 Texas, New Mexico, Arizona, Nevada and Utah

Hurricane Norbert forecast track on Friday, September 5

Hurricane Norbert forecast track on Friday, September 5

Hurricane Norbert threatened to send copious amounts of moisture in to the Southwest United States during the first full week of September. The National Hurricane Center had warned in its advisories that a significant flood threat was shaping up for portions of the Desert Southwest.

Few people truly realize the far-reaching effects of tropical cyclones, even long after they make landfall and dissipate. For the Southwest U.S., there is a history of tropical cyclone impacts in places that we are simply not used to hearing about.

East Pacific hurricane season of 1976

East Pacific hurricane season of 1976

Looking back, we can see that years such as 1976 stand out as big impact years for California, Arizona, Nevada and Utah. Several hurricanes turned northeast towards Mexico and brought with them substantial amounts of moisture which resulted in major flooding events for parts of the Southwest.

Flash-forward to 2014. Norbert was forecast to make landfall along the northern Baja peninsula as a weakening depression but its moisture was already being advected around a large high pressure area over parts of Texas and the western Gulf of Mexico.

Adding to the mess were the remnants of tropical storm Dolly in the Gulf of Mexico. The left-over moisture plume was also transported northward across Mexico and in to west Texas, New Mexico and parts of Arizona.

The complex pattern meant that there would be several days of flash flood threats across a large part of the Southwest. I thought that this set up would provide an excellent opportunity to observe and report on the impacts from a tropical cyclone’s effects in an unusual geographic location.

I hopped a plane in Wilmington on Friday, September 5 and joined my friend and HurricaneTrack.com supporter, Kerry Mallory, in Houston that afternoon. From there, we drove west-bound across the vast countryside of west Texas with Las Cruces, New Mexico our destination late that night.

Saturday, September 6 - photo showing deep moisture beginning to build as Norbert and remnants of Dolly combine for major flood threat across Desert Southwest

Saturday, September 6 – photo showing deep moisture beginning to build as Norbert and remnants of Dolly combine for major flood threat across Desert Southwest

After a long drive from Houston to Las Cruces and some much needed rest, the plan was to head in to Arizona to be in position for any potential thunderstorm activity that could set off flash flooding. The moisture plume was steady with the flow coming north from Mexico, setting the stage for an active week ahead.

Saturday’s destination was Phoenix, Arizona and it wasn’t long after crossing the border in to Arizona from New Mexico that things got interesting.

With the the heating of the day and the surge of tropical moisture on the increase, isolated to scattered thunderstorms were popping up. Kerry and I could clearly see the towering thunderheads in the distance, matching nicely what we observed on radar.

One phenomenon that I really wanted to observe and study up close was a flash flood. Obviously you have to be in the right place at the right time, usually along a wash or dry riverbed that suddenly fills with rain water. Putting my geography and weather skills together helped me to better understand the conditions and locations that I would need to seek out in order to catch a flash flood as it happened.

The Desert Southwest is literally lined with dry washes or Arroyos, as they are also termed, that sit dormant for months at a time. When the rains come, these alley-ways for the run off to cascade through become instant raging rivers, filled with all kinds of debris and mud. When a road way crosses a wash or dry riverbed, and a flash flood occurs, the consequences can be deadly for those who are unaware.

Strong thunderstorm just north of I-10 in Arizona during the afternoon of September 6

Strong thunderstorm just north of I-10 in Arizona during the afternoon of September 6

The key for us was to be in the vicinity of a strong thunderstorm that dumped a lot of rain in a short amount of time. Safety was also an obvious element that we placed at the top of the list. We thought we had a shot, the first of many, near Bowie, Arizona, just north of I-10. A group of thunderstorm cells had developed over the mountains and we could clearly see a thick ,well developed rain shaft underneath. I have to admit, it is breathtaking to see something so beautiful take place in the desert. The juxtaposition of dry, desert landscape with a tropical downpour is a sight to behold. The rain literally makes the air come to life around the storm, with outflow wind blowing cool air like the best air conditioning you could ever imagine. We had our first storm of the mission and it was spectacular.

Kerry and I pulled off the Interstate and traveled north along Highway 191 for just a few miles until we had the perfect alignment with the approaching storm. I set up a GoPro on our tripod for a time lapse session. The slow moving storm came right at us but weakened as the heating of the day waned. However, the time lapse that I was able to process was wonderful. It clearly demonstrated the dynamic structure of the storm, the rain falling underneath and the outflow pushed ahead of it by the rain-cooled air. All of this in the desert, mind you, not over Florida or the Great Plains where such events are common place. It was a small but significant victory for us and once we had wrapped things up at that location, it was time to press on towards Phoenix.

As the afternoon wore on, more thunderstorms developed near Phoenix and produced a substantial Haboob or dust storm that was all the rage on Twitter. Kerry and I missed it by about three hours but arrived as the cluster of storms that created the dust storm was still ongoing.

I cannot begin to describe how strange it was to see Saguaro cactus back-lit by brilliant flashes of lightning – which is exactly what we saw as we approached Phoenix along I-10. We arrived an hour or so after dark and settled in for the night, ready for a busy and more active weather day on Sunday.

Sunday, September 7

Norbert was weakening as it turned northeast towards the Baja but the abundant moisture feed was already being pulled north in to the Southwest. The strong high over the western Gulf of Mexico continued to pump moisture from Dolly and the Gulf itself, setting the region up for a wild few days to come.

The plan for Kerry and me for Sunday was simple: literally go storm chasing! We wanted to try and get to a developing cluster of thunderstorms near peak heating in order to witness the elusive but dangerous effects of a flash flood. Keep in mind, most of southeast California, southern Nevada, western Arizona and almost all of New Mexico had been placed under a flash flood watch due to incredible PWAT or precipitable water values being very high considering the geographic location. Some areas were looking at 200% to 300% above the long term average for potential rain fall. This meant an increased risk of flash flooding where thunderstorms developed. Unlike a true hurricane or tropical storm making landfall with organized rain bands, this situation was different. The remnant moisture from dying hurricane Norbert was the culprit, not the tropical cyclone itself. We had to rely on radar via the iPad and of course, luck, to find what we were looking for.

We spent the morning surveying an area not far from Maricopa that had flash flooding during the night Saturday. Once again, I was stunned at the contrast between seeing dust devils dancing playfully across the open desert and standing water where torrential rain had fallen the previous night. It was a weather geek’s dream come true – seeing so many interesting elements all in the same place.

Thunderstorms over the mountains near Prescott, AZ during the afternoon of September 7

Thunderstorms over the mountains near Prescott, AZ during the afternoon of September 7

By early afternoon, the convection began to build over the mountains to the north of Phoenix, near Prescott. The distances from which you can see towering thunderheads out west is staggering. We were south and west of Phoenix watching clouds billow up nearly 100 miles away. We had to get moving if we wanted to get to the storms in time.

After a couple of hours driving towards Prescott, sure enough, the storms had dumped enough rain to warrant a flash flood warning for the area.

One interesting aspect of flash flooding in the Southwest is what are called “burn scars” or areas along mountains that suffered effects from wildfires in recent months or years. The left over barren landscape invites disaster as the ground is like concrete, not allowing rain water to soak in. Instead, you get these mud and ash flows, filled with burned out trees and other debris. In a severe flood situation, burn scars can help to lead to catastrophic flash flooding over quite a distance, even far from where the rains fell.

Kerry and I had studied up on nearby burn scars and there was one fairly close to where we were headed. After passing through Wickenburg, we turned northeast along Highway 89 and in to the mountains.

RadarScope screen shot showing the cluster of thunderstorms to the northwest of Prescott, AZ

RadarScope screen shot showing the cluster of thunderstorms to the northwest of Prescott, AZ

The thunderstorm complex was nearly stationary and seemed to keep building over the area. Creeks were already filling up and the National Weather Service was busy dealing with flash flooding as a result. Our task was to try to get to where this was happening but do so with extreme caution.

We managed to get in to the region where the storm was but it had moved on just enough to lessen the impact of flooding in the Prescott area. We found an impressive dry wash out in the desert and I took the opportunity to fly the quad copter around it to get a better look at the structure and general look of these interesting geographic features. The one we had found was as dry as could be but the evidence of past flood events was frozen in time, preserved as if it had happened just days ago, yet it could have been months or even years. Seeing this just made me work harder to try and get to a location where one of these dry washes filled up with water. It is literally like trying to find a needle in a haystack, very tough to do unless you’re in the right place.

We pressed on and left Prescott behind us as more concentrated rain and thunderstorms had developed along I-40 between Flagstaff and points west, including Las Vegas, Nevada. In fact, an especially large cluster of storms was pounding the area around Kingman, just east of the Nevada border in Arizona.

Very heavy was falling over a burn scar area in the mountains near Kingman, AZ during the evening of September 7

Very heavy was falling over a burn scar area in the mountains near Kingman, AZ during the evening of September 7

Night was approaching quickly when we arrived in the Kingman area where very heavy rain had prompted flash flood warnings. A burn scar in the region was noted in the National Weather Service advisory which suggested debris flows could be moving down the mountain towards an RV park not far off the Interstate. Kerry and I did all we could to find it but the event was probably not too severe, great news for the people in the RV park for sure!

After taking a close look at the pattern setting up for Monday, it was clear to me that southwest Utah and southern Nevada should be the place to be for Monday when the tropical moisture from Norbert would get tapped and energized by an approaching upper level trough coming in from the Pacific.

Vast regions of the Southwest were now under flash flood watches. We are talking New Mexico, Arizona, southern California and Nevada, southern to central Utah and now extending in to parts of Colorado. The effects from Norbert’s moisture were going to impact a huge portion of the Southwest, putting lives at risk and disrupting travel at key locations throughout the region. Monday, it seemed, was the biggest day yet. We were going to be ready.

Our destination for Sunday night and through Monday was St. George, Utah. I would have never thought that anytime during my 20 year career tracking and studying hurricanes that I would be in Utah because of one. The situation was rather serious and local National Weather Service offices were doing an excellent job of posting information on their websites about the possible flood threat unfolding.

Kerry and I passed through Las Vegas and headed north via I-15. The night air was muggy – something you don’t experience very often out that way. Low clouds obscured a late-rising moon, foreboding as it tried to illuminate the barren desert landscape.

qMap of St. George, Utah and Snow Canyon State Park

Map of St. George, Utah and Snow Canyon State Park

We arrived in St. George around midnight local time and immediately began scoping out a location along the Virgin River to place an unmanned camera unit – the same one that I had set up during hurricane Arthur along the Outer Banks earlier in the summer. This time, it would keep watch over the river which was likely to rise dramatically due to recent rain and the incoming flow of deep tropical moisture.

It did not take long and we settled on a spot right along the river not far from our hotel, just down from the bike and running trail that snakes around parts of St. George. Kerry had several flood gauges upstream bookmarked for monitoring and we knew that it was only a matter of time, and some added heavy rain Monday, and the Virgin River would spring to life.

I spent another hour or so researching local canyons for possible flash flood potential on Monday. The advisories from the National Weather Service mentioned slot canyons and area washes and dry river beds as being prime targets for fast moving, deadly flash floods. Obviously, there was no way to pinpoint which of the many canyons and dry washes would be impacted. We would have to get lucky but this time, the heavy rain was poised to cover a much wider area and with greater intensity.

I suggested to Kerry that we check out Snow Canyon during the early part of Monday. There was a substantial dry wash that ran through the canyon area which is itself a state park. Of particular interest to me was a point where the road and the wash intersected. I had a feeling that this would be the best spot for us to capture a flash flood, even if it were not especially dangerous or damaging, I just wanted to document the event without having to put Kerry or myself in harm’s way.

Monday, September 8

After rounding up some hardware needed to set out the unmanned camera along the banks of the Virgin River during the mid-morning hours, it was time to get to work.

Our unmanned camera location along the left bank of the Virgin River in St. George, Utah

Our unmanned camera location along the left bank of the Virgin River in St. George, Utah

We set up the camera system in less than 15 minutes and it was streaming live video not far from the river bed itself. The view was great and it allowed us to continuously monitor the river throughout the day. Nothing much was happening just yet but the unit was functioning as designed, now we just had to wait.

I set up the GoPro along the bike bath just up from where we had the live cam feed along the river. Deep moisture was gathering from the south and it wouldn’t take much to set off large clusters of very heavy showers and thunderstorms.

By mid to late afternoon, the storms initiated in Nevada and began to track north. They were slow moving, probably less than 10 miles per hour. It did not take long for the first flash flood warnings to go up. One of them was near Moapa, along I-15 just southwest of Mesquite and the Arizona border. We could see the tops of the thunderstorms, resembling a large cluster that you might see over the Everglades in Florida on a steamy August day.

Within the same hour that the storms fired off in Nevada, more took shape in southwest Utah, including around the St. George area. The intensity of the rain was just like what I would expect in a tropical storm. Storm water run off was a big problem from the get go and people had to slow down or face perilous driving conditions for the rest of the day.

We learned via Twitter that Moapa Valley and vicinity were facing a flash flood emergency. A wall of water was apparently cascading down I-15, sweeping away vehicles and people. This news was chilling, knowing that we drove that exact stretch of Interstate just the night before. There was no way to get to the location safely and it was, in fact, very dangerous in and around the Moapa area. Kerry and I kept a close watch on Twitter for any reports coming from the highway patrol or local news media. The deluge had begun and the first significant impact to people and commerce was unfolding less than an hour from our location.

As the day wore on towards dusk, the rain kept falling. We drove out to Snow Canyon to see if flash flooding had taken place yet along that intersection that I was suspect of. Nothing yet. There were, however, spectacular waterfalls pouring out of the sides of the canyon walls. So far, there was nothing noteworthy happening in and around the St. George area.

By evening time, we learned that I-15 was literally torn up and washed out in places near Moapa. People were stuck and some had to be rescued during the flash flood. Fortunately, despite the ferocity of the flood waters, no one was killed. However, the major north-south Interstate that connects Las Vegas with Arizona and Utah was, for the time being, closed.

Hundreds of people were stranded along I-15 between Mesquite and Las Vegas. This casino was the only facility that had power, a literal beacon of light for those trapped by the flooded out highway

Hundreds of people were stranded along I-15 between Mesquite and Las Vegas. This casino was the only facility that had power, a literal beacon of light for those trapped by the flooded out highway

Kerry and I made our way south to Mesquite by going around via secondary roads and through the mountains. Most of the town was without power and in fact, several hundred people were stranded in the dark, many along the Interstate. It was quite an eerie scene. I wonder how many people really knew what the cause was and that it had everything to do with a Pacific hurricane? Even Las Vegas had to deal with some flash flooding, filling up my Twitter feed with incredible, dramatic photos of water rushing through casino garages.

After a long day, it was time to head back to St. George and keep an eye on the river gauges along the Virgin River. There was a noticeable rise but nothing dramatic just yet. The skies had all but cleared but the moisture remained in place, ushering in yet another very humid night in southwest Utah.

We returned to St. George and I used the last hour or so of my waking moments to check the forecast for Tuesday. Our time was running out as I had a plane to catch back in Houston, some 1,800 miles away, in less than 36 hours.

It seemed that one more piece of upper level energy was forecast to move through California, across Nevada and in to Utah overnight. This would likely set off one more round of thunderstorms over the same areas that were pounded during the day Monday. I turned in for the night and figured we would just wait and see how things were Tuesday morning.

Tuesday, September 9

The sun had barely risen when Kerry woke me up, urging me to check the live camera that we had set up along the banks of the Virgin River. He had stayed up all night monitoring river gauges upstream from St. George.

As forecast, more heavy rain was falling across the region and once again, flash flood warnings were plentiful.

The rain from Monday had finally done its work, forcing a substantial and dramatic rise in the Virgin River. The flow had increased significantly as well with the live camera feed showing all sorts of debris moving swiftly along in the muddy water.

As more thunderstorms lined up like box cars on a long track to the northwest of our location, practically over Snow Canyon, I made the call to head out there immediately. We jumped in to Kerry’s truck and took off for Snow Canyon.

The park ranger we met at the gate alerted us that flash flooding was taking place along the wash and for us to be careful. I told her that hew news was music to my ears and that I was there to document just such an event. To my surprise, she was very understanding and encouraged us to go for it, wishing us to be careful of course.

Within a mile or so in to the park, we found it. Water was streaming across the two land road like a small stream. The flow was not very substantial at the moment but the rain all around us was coming down heavy with more lined up back behind us.

I contacted The Weather Channel and set up a live video feed right from our location. All of a sudden, the flow increased and within seconds, the small stream became a full-own flash flood. I grabbed the GoPro and began recording from as many angles as I could. It was the moment I had been hoping for and the good news was that the flood was not affecting anyone directly since it was contained within the state park of Snow Canyon.

Kerry positioned his truck so as to alert anyone else venturing in to turn around or just park and take in the awesome spectacle. Several people stopped and witnessed it along with us, thunder rolling against the canyon walls.

I was utterly fascinated and intrigued by the rapid changes in flow as the minutes ticked by. I could hear more water coming down the wash as the roar would increase. Seconds later, the intersection of the road and wash would swell, rocks banging in to each other underneath the swift current. I was like a kid on Christmas Day because to me, this was what it was all about. Seeing the effects of a hurricane in an environment that was alien to me made it all worth the effort. The fact that no one was harmed by the flooding was even better. I could just observe and record via GoPro what was happening. The Weather Channel took the stream live during their evening broadcast, amazing considering the fact that I was in a canyon out in the middle of desert countryside in Utah. Technology sure has come a long way!

Meanwhile, our Virgin River cam was doing its thing, recording and streaming live as the river sent tons of upstream debris towards the south and east. The Weather Channel also took this feed live, showing the audience a unique perspective of the effects from Norbert. I was very proud of our success even though the bulk of it came on the last day that we were out there.

Photo of rain-swollen Virgin River as seen from our quad copter

Photo of rain-swollen Virgin River as seen from our quad copter

The rain let up as the afternoon progressed and it was time to pull up the live cam from the river and begin the long trip back to Texas. I captured my moment and had satisfied my urge to witness the impacts from a Pacific hurricane on an area that rarely has to deal with such events.

Norbert faded in to a remnant low pressure area over the cool waters of the east Pacific, not too far off the Baja peninsula. Its reach was far and wide, affecting millions of people from southern California to west Texas. Even as Kerry and I made our way back to Texas for me to fly home, the left over, nearly depleted moisture continued to produce scattered thunderstorms along our route. If I hadn’t documented the incredible journey, I might not have believed it happened. While the Norbert field mission was not in the same category as something like Ivan or Katrina, it was very much worth the time, expense and effort it took to hang in there for five days as the event took place.

I am a geographer at heart and with that comes a deep passion for weather. Hurricanes are such an important part of shaping the landscape, both natural and man-made. Norbert was an opportunity for me to learn about something that I had always wanted to experience. I was glad to have made the trip and felt that I had contributed to the story, even if only a little bit. After all, every little bit helps, right? Turns out, I would be back sooner rather than later. Another powerful east Pacific hurricane was brewing and already it looked like a track very similar to Norbert’s was possible. It was 1976 all over again for the Southwest United States.

Next up in my recap blog series: a very challenging hurricane Odile threatened to surpass Norbert’s flood threat, putting Arizona, New Mexico and west Texas in the cross hairs.

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Odile leaves trail of destruction along Baja, heavy rain poised to inundate parts of Southwest

Tropical storm Odile continues to churn away over the Baja peninsula and the Gulf of California

Tropical storm Odile continues to churn away over the Baja peninsula and the Gulf of California

Even though the Atlantic hurricane season is certainly not very busy, the impacts from tropical cyclones on people and places within the United States cannot be ignored. We are about to see once again how tropical moisture from an east Pacific system gets pulled northward in to the Desert Southwest and causes all kinds of issues.

In this case, it’s the remnant circulation of once powerful hurricane Odile. So far, we are seeing quite a bit of evidence of damage to parts of the southern Baja peninsula where Odile made landfall as a strong category three hurricane just a couple of nights ago. There are a lot of people who are without fresh water and other basic needs due to the hurricane and its unlikely path right in to Cabo San Lucas. That story will continue to play out over the coming days as rescue and recovery efforts unfold.

Meanwhile, the moisture from what is still tropical storm Odile will continue to move northward towards Arizona and New Mexico. As a result, flash flood watches have been posted for most of Arizona, parts of southeast California and southern Nevada and a good deal of southwest New Mexico. The threat of excessive rainfall across the region is high over the next few days and this could lead to major issues for areas not used to this much rain.

It looks as though the heaviest rain will come tomorrow and in to Thursday when the bulk of the moisture from Odile arrives. The possibility of seeing 3 to 5 inches of rain raises the odds that significant flooding will occur but the exact location of this is impossible to know right now. Being alert for rapidly changing conditions and being ready to move to high ground will be essential to keeping safe. Anyone traveling across the region is advised to keep a close watch on the local weather conditions and do not try to cross any flooded roads, no matter what you’re driving. Swift moving water can overpower your vehicle in a matter of seconds, we saw this during last week’s flash flood along I-15 northeast of Las Vegas. This is a serious flood threat for the region and people need to take it as such.

I am currently in Tuscon working to document and report on the situation over the next few days. My team and I will will make use of some of the same equipment we use in hurricane storm surge with the idea being that we try to capture video of a dangerous flooding situation without having to be there ourselves. There are numerous low spots, washes, dry stream beds, etc that we can place an unmanned camera close enough to capture video of a flash flood. With the amount of heavy rain forecast for the area, I don’t think we will have too much trouble and in fact, will have to make sure we are well away from those areas when the flooding begins.

I will post updates from time to time using Instagram – follow along @hurricanetrack. These posts automatically hit our Twitter feed as well. In addition, I will have longer duration video blogs posted to our app, Hurricane Impact, throughout the next few days. If you know people in the region, let them know that this is a very serious situation. We may think of rain as being a necessary element of survival, especially in the desert, but too much in too short a period of time can bring havoc. I’ll keep you updated from the ground from the Tuscon area up to Phoenix and over towards New Mexico over the next few days.

As for the Atlantic – no worries anytime soon, Edouard will continue to move on out over open water and no other developments are seen within the global models for the time being.

I’ll post more here later tonight from southern Arizona.

M. Sudduth 10:19 AM ET Sept 16

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Dangerous hurricane Odile heading closer to the Baja peninsula, likely to spread more flooding rain in to Southwest U.S.

Powerful hurricane Odile off the Baja peninsula

Powerful hurricane Odile off the Baja peninsula

Hurricane Odile in the east Pacific has strengthened significantly over the past 24 hours and is now a solid category four. This is an extremely dangerous hurricane capable of inflicting serious wind damage as well as accompanying heavy rain, storm surge and enormous waves. People along the southern Baja peninsula should be ready by now, if not, time is running out quickly.

The forecast track keeps the core of the hurricane just off the extreme southern part of the Baja, sparing Cabo San Lucas the worst of the category four winds. However, hurricane force winds are likely to occur and any deviation to the east would bring the eyewall that much closer to the coast. Indeed, it will be an interesting and potentially frightening night along the southern Baja peninsula.

Further up the coast, conditions should be less intense as the hurricane begins to weaken over cooler water, partly due to being disturbed by category three hurricane Norbert just last week. Never the less, the entire southern region of the Baja is at risk from this hurricane and preparedness measures need to be taken. From what I am seeing, a category four hurricane has never passed this close to the area – it needs to be taken very seriously.

Seven day total precip for Southwest U.S. showing large area of 1-2 inches of rain

Seven day total precip for Southwest U.S. showing large area of 1-2 inches of rain

Once Odile moves northward over the coming days, its circulation will begin to push deep tropical moisture in to the Southwest U.S. setting the stage for another possible high-impact flood event next week.

After dealing with the rains from Norbert, coupled with Gulf of Mexico moisture being funneled in around a large high pressure area, this part of the country is vulnerable to serious flooding issues throughout the week ahead.

It is important for people living in or traveling to the area to monitor local National Weather Service information. If you have a Smartphone, use it to stay up to date on the latest information. It won’t be long now before flash flood watches are posted for the region. We could be looking at several days of heavy rain setting up and the problem is, it is impossible to know precisely which locations will get hit the hardest with rain.

Once again, I am heading out West to cover the event. I spent several days out there last week and learned a lot about how the desert interacts with tropical cyclone moisture. It is not something to mess around with. We saw instances where I-15 was washed out northeast of Las Vegas, almost taking the lives of several people who were caught up in the flash flood. Phoenix set its all time rain fall record during this past event with numerous flooding issues and a dust storm. Areas from southern California through southern Nevada, southwest Utah and most of Arizona could be impacted by slow moving, torrential downpours as the week progresses. Flooding is a major concern and I will be in the region to provide live coverage via our Ustream channel and for The Weather Channel. I cannot emphasize enough how important it is for people to realize that tropical cyclones are not just about wind or storm surge. They have several weapons that they can hit you with and rain is most certainly one of them. Be aware and keep up to date on the very latest. I will post frequent updates to our app, Hurricane Impact, which include video blogs in the video section. I never thought I would be covering more hurricane related activity out West than I am along the East Coast or Gulf Coast but here we are – it’s that type of year.

In the Atlantic, hurricane Edouard is forecast to become the season’s first major hurricane but it will remain well out in the open Atlantic, bothering only shipping interests. One weather geek factoid about it – we’re likely to see quite a few ACE points pile up with Edouard as it looks to remain on the map for several days to come. ACE or Accumulated Cyclone Energy is the measure of how much energy a hurricane season outputs based on each individual tropical storm or hurricane. The typical ACE number for the Atlantic is around 100-103 in any given season. Right now, we are in the low 20s but are climbing now due to Edouard. We ended last season around 36 I believe and it’s possible that Edouard will allow this season to eclipse last year, especially if Edouard becomes a major hurricane and stronger than forecast. It’s just something I like to keep track of as it tells me much more about the quality of the season instead of the numbers of named storms, etc.

Elsewhere in the Atlantic, nothing to be concerned with for the time being though I cannot imagine that we will go the entire month of September without something forming in the Western Caribbean or Gulf of Mexico. Long range models are sketchy at best but some do indicate activity brewing within about 10 days in the Western Caribbean or Gulf. No matter how quiet a season is, you never turn your back on it.

I’ll post more here in the morning including details about the field work coming up for the Desert Southwest this week.

M. Sudduth 2:32 PM ET Sept 14

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Round two for Southwest? Possible as Odile tracks close to Baja

NHC track of hurricane Odile in the east Pacific

NHC track of hurricane Odile in the east Pacific

First of all, the Atlantic is a non-issue right now. We are tracking TS Edouard but it will remain far out in the open Atlantic and be of issue only to shipping interests.

Elsewhere in the Atlantic, only minor disturbances are scattered from the Gulf of Mexico to the tropical Atlantic. None of them are forecast to develop much at all in the coming days, keeping the very quiet Atlantic season in check.

The bigger issue appears to be hurricane Odile. Right now it is gaining strength off the coast of Mexico with winds of 85 mph. The NHC is forecasting Odile to strengthen further, perhaps rapidly in the coming days.

Interests along the Baja need to monitor the track closely which shows Odile far enough offshore to keep hurricane conditions away but that could change. The ECMWF model actually gets the hurricane quite close to the peninsula over the next few days and we could see a slight westward adjustment in the track from the NHC as a result.

Beyond the Baja, there is now a growing concern for more flooding issues in the Southwest U.S. around mid-week next week.

The pattern is eerily similar to the one that just produced record rainfall for Phoenix and the wash-out of parts of I-15 northeast of Las Vegas this past Monday afternoon.

Basically we’re looking at a squeeze play between moisture coming in from the Gulf of Mexico coupled with even deeper tropical moisture being pulled in from the Pacific due to the circulation of Odile. Unfortunately, California and Arizona are caught in the middle. Reading the NWS forecast discussion from Phoenix, it looks as though very high precip values will be present in the atmosphere once again next week. The risk of flash flooding looks to increase by Wednesday and through the end of the week ahead.

Sadly, the computer models cannot pinpoint where the heaviest rains will fall. This means people across the region, from SE California and Nevada and in to W Arizona need to be aware of this potentially disruptive and dangerous weather situation. We saw what happened this past week with numerous flood events taking place across the Desert Southwest. There is increasing potential for it to happen again this week so be alert if you live in or are planning to travel to the area.

I will be watching the situation closely and might decide to head out to the Southwest once again. I spent the better part of a week out there for the Norbert-induced flood event and saw first-hand what can happen. I think this time the focus will be more on SE CA and W AZ. We’ll see as each day unfolds and I will plan from there. Mark my words, this has the potential of being a high-impact flood event once again related to the effects of a Pacific hurricane.

I will have more here tomorrow.

M. Sudduth 3:13 PM ET Sept 13

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Norbert’s influence on Southwest U.S. to be felt over large area

Very high moisture content for the Desert Southwest over the next three days

Very high moisture content for the Desert Southwest over the next three days

It is rare for a tropical storm or hurricane to impact the weather for the Southwest U.S. but it does happen. Going back to 1939 and then again in 1976 and 1997, there have been infamous storm events that brought flooding rains to areas that are not used to such high precip events. It looks as though Norbert will be added to that list.

First of all, let me say that I am in Phoenix, AZ this morning after having traveled here from Houston where I flew in on Friday.

I am working with Amateur Radio operator and friend to HurricaneTrack.com, Kerry Mallory. He has been my wheels, so to speak and we have covered some serious ground since Friday afternoon.

We are out here because of the serious threat of flooding as a result of monsoonal flow and the influx of moisture from what was once category three hurricane Norbert. This situation is unique and is quite different for us than any other hurricane related field mission we have undertaken.

Tropical cyclones have the ability to drop a tremendous amount of rain. Inland flooding from excessive rain fall is often overlooked by the public as being a potential threat. Wind and storm surge grab the headlines until the rains begin to fall and add up – by then, it’s usually too late to react.

In the case of the Desert Southwest, it’s not a matter of seeing ten to twenty inches of rain. In this case, just a few inches is all it will take to cause incredible flash floods to occur which puts property and lives at risk.

The main culprit will be the flow of moisture from Norbert as we get later in to today and through the next few days. Areas from southern California to Arizona, New Mexico, Nevada and in to Utah are under the threat of flooding rains and serious flooding.

One of the more difficult tasks of the NWS out here is to know which areas could be most impacted. The geography of the region makes it tough to predict precisely where heavy rains could fall. Heating of the day, mountain ranges and other factors make it a challenge to convey to the public who is most at risk. As such, the NWS has done a great job in putting out public information statements and even YouTube videos explaining the threat from this flood event.

As I have read the area forecast discussions, it is remarkable to note how much water is available in the atmosphere compared to normal. In some cases, as much as 300% the normal water available in the air column is forecast to be present – giving ample fuel for potentially very heavy rain.

The most vulnerable areas appear to be the mountains and hill sides that have what are called burn scars on them. These are left over scar areas from recent (or not so recent) forest fires. The soil is like pavement with ash and other debris compacted in with little to no vegetation left behind. It only takes moderate rain for a little while to send water down these burn scars, filled with debris as it flows in to streams and otherwise dry washes. The result can be deadly and people caught unaware can be buried by these debris flows.

As I mentioned, Kerry and I are in Phoenix today. We will be on the lookout for developing thunderstorms throughout the day and will try to get to areas where heavy rain is likely to fall. Our goal is to document the event using some of the same technology we utilize during storm surge along the coast. We don’t want to be caught in a flash flood ourselves, so using remote, unmanned cameras will help to keep us safe while we capture video of flooding.

We can also post information to social media to help people in the region keep up with what’s going on in near real time. Video clips can be posted to our Instagram feed in no time at all, it’s amazing what we can do these days, even in the middle of the desert! We’ll also post pics and information on conditions as we encounter the storms later today and tonight.

Believe it or not, the rain threat extends up in to Utah and that is where we plan to be by later tonight. Reading the discussions for the southwest part of the state, it looks serious. We’re talking about widespread flooding a distinct possibility in parts of Utah tonight and tomorrow. This presents us with a unique situation to both try and observe and research the event while remaining safe. I am no stranger to rain but flash floods in canyon lands is totally alien to me. Again, the use of unmanned cameras will be paramount to documenting the effects from incredible viewpoints.

We plan to stream our field work live on our Ustream channel throughout the day today. Follow along at ustream.tv/hurricanetrack

If you live in the region that is forecast to be affected by this unusual event, keep aware of rapidly changing weather. It’s going to be an interesting and potentially dangerous few days out here and we hope to document it and learn from it for future preparedness when the inevitable happens again.

Oh yeah, the Atlantic Basin is of no concern right now, so at least there’s that.

I’ll post another blog tonight from St. George, Utah.

M. Sudduth 11:51 AM ET Sept 7

 

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