Tropical cyclone tracking thread

[US 89]

What I don't get is why they didn't retroactively name it Arlene. Usually these things aren't identified until well after the season is over, which means they wind up not getting a name or even a numerical identifier (or getting one out of order? not sure how that works). In this case, since they identified it before any other storms formed, they retroactively assigned it the AL01 identifier - but for whatever reason didn't retroactively assign a name. So now, if this depression gets named, we'll have AL02 Arlene - and if it doesn't, then we'll have AL03 Arlene. It's going to drive me nuts having a number that's off from where we are in the alphabet, isn't it - especially now that I work for a company that quality controls hurricane data and issues analyses for them, so I'll be dealing with these identifiers a lot this summer and fall.

[CtrlAltDel]

Okay, hurricane season has started, and for some very odd reason they will start counting from 2 in the Atlantic. I don't remember any pre-season storms.

There was a subtropical storm in the middle of January.

I detected a hint of sarcasm on CNGL's part (he doesn't consider subtropical cyclones to be worthy of being named)

Ah. I see.

[Dough4872]

We officially have Tropical Storm Arlene, looks very disorganized and doesn't appear it will last very long.

[triplemultiplex]

This is interesting.  Hurricane Hillary is projected to bring a buttload of tropical moisture to SoCal after making landfall in Baja this weekend:


Significant rain in the desert like this means we're looking at substantial flash flooding.  Good chance we're looking at another billion dollar disaster to start next week.

[WillWeaverRVA]

This is interesting.  Hurricane Hillary is projected to bring a buttload of tropical moisture to SoCal after making landfall in Baja this weekend:


Significant rain in the desert like this means we're looking at substantial flash flooding.  Good chance we're looking at another billion dollar disaster to start next week.

Hilary will still be a fully tropical system by that point, and the tropical storm watches in effect for parts of southern California are the first ones ever to be issued for that region.

[Dough4872]

This is interesting.  Hurricane Hillary is projected to bring a buttload of tropical moisture to SoCal after making landfall in Baja this weekend:


Significant rain in the desert like this means we're looking at substantial flash flooding.  Good chance we're looking at another billion dollar disaster to start next week.

Hilary will still be a fully tropical system by that point, and the tropical storm watches in effect for parts of southern California are the first ones ever to be issued for that region.

I never thought I would see the day a tropical storm would impact Southern California.

[PColumbus73]

This is interesting.  Hurricane Hillary is projected to bring a buttload of tropical moisture to SoCal after making landfall in Baja this weekend:


Significant rain in the desert like this means we're looking at substantial flash flooding.  Good chance we're looking at another billion dollar disaster to start next week.

Hilary will still be a fully tropical system by that point, and the tropical storm watches in effect for parts of southern California are the first ones ever to be issued for that region.

I never thought I would see the day a tropical storm would impact Southern California.

Definitely an extremely rare, once-in-a-generation event. The NHC discussion mentioned that this is the first time they've ever issued a tropical storm watch for California

[CtrlAltDel]

Definitely an extremely rare, once-in-a-generation event.

It's much rarer than that, although I suspect it won't be going forward.

[WillWeaverRVA]

Definitely an extremely rare, once-in-a-generation event.

It's much rarer than that, although I suspect it won't be going forward.

Much rarer than once-in-a-generation.

If it moves further west than forecast and makes landfall in California, it would be the first tropical storm landfall there since 1939 (the last tropical cyclone of any kind to make landfall in California was the remnants of Hurricane Hyacinth in 1972). The 1939 storm is also the last (and only known) system of tropical origin to move into California at tropical storm strength, whether tropical or post-tropical.

[Henry]

It'll be interesting to see how much damage Hilary deals to SoCal this weekend; probably will be on par with one of the many earthquakes it usually gets.

[US 89]

Definitely an extremely rare, once-in-a-generation event.

It's much rarer than that, although I suspect it won't be going forward.

Much rarer than once-in-a-generation.

If it moves further west than forecast and makes landfall in California, it would be the first tropical storm landfall there since 1939 (the last tropical cyclone of any kind to make landfall in California was the remnants of Hurricane Hyacinth in 1972). The 1939 storm is also the last (and only known) system of tropical origin to move into California at tropical storm strength, whether tropical or post-tropical.

Nora 1997 produced tropical storm winds in California while still tropical, although its center stayed to the east in Arizona. Kathleen in 1976 also produced tropical storm winds over California and Arizona, though it may not have been fully tropical by the time its center made it to the states. And In 1858, a hurricane stayed offshore but produced hurricane force winds in San Diego. These types of events are extremely rare but not quite unheard of.

At any rate, the wind isn't going to be the biggest story here. The west is relatively used to strong winds, and while there will almost certainly be damage it will be less than what a similar wind magnitude would do in the east. The real story here is the tremendous amount of rainfall forecasted for the desert regions of California and Nevada. These areas in many cases are too far west for even much regular summer monsoon influence, and some of these forecast rainfall amounts are more than what normally falls in an entire year.

[bing101]

City of Los Angeles has a press conference on how they would respond to a rare hurricane in their area.

[WillWeaverRVA]

Definitely an extremely rare, once-in-a-generation event.

It's much rarer than that, although I suspect it won't be going forward.

Much rarer than once-in-a-generation.

If it moves further west than forecast and makes landfall in California, it would be the first tropical storm landfall there since 1939 (the last tropical cyclone of any kind to make landfall in California was the remnants of Hurricane Hyacinth in 1972). The 1939 storm is also the last (and only known) system of tropical origin to move into California at tropical storm strength, whether tropical or post-tropical.

Nora 1997 produced tropical storm winds in California while still tropical, although its center stayed to the east in Arizona. Kathleen in 1976 also produced tropical storm winds over California and Arizona, though it may not have been fully tropical by the time its center made it to the states. And In 1858, a hurricane stayed offshore but produced hurricane force winds in San Diego. These types of events are extremely rare but not quite unheard of.

At any rate, the wind isn't going to be the biggest story here. The west is relatively used to strong winds, and while there will almost certainly be damage it will be less than what a similar wind magnitude would do in the east. The real story here is the tremendous amount of rainfall forecasted for the desert regions of California and Nevada. These areas in many cases are too far west for even much regular summer monsoon influence, and some of these forecast rainfall amounts are more than what normally falls in an entire year.

Yeah, the rainfall is by far the bigger story. There could be catastrophic flooding in the valleys, and the ground is already saturated from above-normal rainfall this year, plus the monsoon rains moving through ahead of Hilary.

[Scott5114]

Any chance the storm might track further east and funnel some of that rain into the Colorado basin?

[gonealookin]

Any chance the storm might track further east and funnel some of that rain into the Colorado basin?

Southern Nevada should get plenty and that generally funnels down into Lake Mead, but much east of there, I don't think so.  Generously using Page, AZ as a proxy for "the Colorado basin", forecast rain amounts there for the next few days are trivial. 

[The Ghostbuster]

Has anyone needed to evacuate from Hillary? If so, I wish you all the best of luck.

[PColumbus73]

It looks like California issued a State of Emergency for Hilary, I wouldn't be surprised if Arizona did too within the next couple days, as well as the other western states.

The way Hilary looks on the satellite, she almost looks like a nor'easter with the way the rain bands are spreads up into California ahead of the eye. Thankfully it would be weakening once it reaches land, but it will be interesting to see how the tropical storm interacts with the terrain there. NHC information is indicating that Hilary will be particularly dangerous for flooding.

[Scott5114]

Any chance the storm might track further east and funnel some of that rain into the Colorado basin?

Southern Nevada should get plenty and that generally funnels down into Lake Mead, but much east of there, I don't think so.  Generously using Page, AZ as a proxy for "the Colorado basin", forecast rain amounts there for the next few days are trivial. 

The Colorado watershed doesn't extend much further west than the Las Vegas Valley, so if the heaviest rain bands go over Death Valley and end up in Nye County, that runoff will unfortunately not make it to Lake Mead.

NWS Las Vegas has flood watches out for the Las Vegas Valley as well as southern Nye County, so it seems like there is still some uncertainty here (or the storm may impact both basins).

[bing101]

City of Los Angeles releases an update on the Tropical Storm Hilary response.

https://www.nbclosangeles.com/weather-news/storm-hilary-who-to-call-in-case-of-emergency-in-la/3209442/

[bing101]

https://www.nbclosangeles.com/news/national-international/hilary-becomes-a-tropical-storm-moving-very-near-to-mexicos-baja-coast-packing-deadly-rainfall/3209470/

https://abc7.com/earthquake-ojai-usgs-ventura-county/13676973/

Apparently a 5.0 quake hit Ventura County while Tropical Storm Hilary takes place.

[keithvh]

https://www.nbclosangeles.com/news/national-international/hilary-becomes-a-tropical-storm-moving-very-near-to-mexicos-baja-coast-packing-deadly-rainfall/3209470/

https://abc7.com/earthquake-ojai-usgs-ventura-county/13676973/

Apparently a 5.0 quake hit Ventura County while Tropical Storm Hilary takes place.

I live in the San Fernando Valley ..... replace "apparently" with "definitely."  :-)

Not the big one, but still a good one.

[Scott5114]

The sequel to Oklahoma's quakenado...California's quakeicane.

[US 89]

Salt Lake had the quakeronavirus, that first week after the world shut down.

[cl94]

Crossing over into the roads side, this storm has gotten fuuuuuuuuun with road impacts. As far as road closures, segments of I-10, US 395, CA 14, CA 58, CA 1, CA 178, CA 18, CA 38, CA 138, CA 78, CA 98, CA 62, CA 177, CA 247, and CA 127 are closed, as is everything in/around Death Valley.

As of 7 PM, several desert towns were reporting 3+ inches of rain. Many locations shattered daily rainfall records, sometimes by well over an inch. Some mountain locations were reporting 7 inches this evening.

The storm made a weird turn west, with the center hanging out over the LA Basin as of the last update. This has pushed some of the impacts west, but the desert is still getting slammed pretty badly. It's going to be a long night and Monday here in CA and NV.

[Quillz]

Are most of those highways closed as precaution, or due to actual damage? I noticed Google Maps is showing most will be open again later today, but I don't know how they determine that.