Deelan Jariwala

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Deelan Jariwala

Deelan Jariwala

@WxTca

Just another weather enthusiast that obsessively tracks the tropics and impulsively codes. UM ‘26

Katılım Eylül 2018
551 Takip Edilen4.1K Takipçiler
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Deelan Jariwala
Deelan Jariwala@WxTca·
With significant external threats to NOAA, I figured it may be pertinent to discuss what TC forecasting looked like a mere half century ago. All images used in this thread come from the NHC — I will be focusing on 1974’s Hurricane Fifi, at 00z on September 19th.
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Paul Roundy
Paul Roundy@PaulRoundy1·
@EricBlake12 @BigJoeBastardi I don't think there's a good analog to this scenario, it's driven by extratropical wave breaking, if that map verifies, it will likely become the biggest El Niño advancement signal in a century.
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Paul Roundy
Paul Roundy@PaulRoundy1·
Fascinating westerly wind burst structure over the northwest tropical Pacific basin, consisting of a trough that covers the entire western basin from the equator to 50N. This pattern will move massive warm water volume from the Pacific tropics toward the equator. In contrast, I also show the westerly wind event of March 1997. The structures couldn't be more different.
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Andy Hazelton
Andy Hazelton@AndyHazelton·
This looks like a newspaper headline that'll be shown during the opening scenes of a documentary on the next big Miami hurricane, whenever it happens. I'm reading a book about the 1926 hurricane now, and it's amazing how many similarities there were back then (rapid growth, tons of people moving down, lots of wealth pouring in). I don't think people are ever gonna stop flocking here, but something like 1926 nowadays would probably be the costliest natural disaster in world history.
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Deelan Jariwala retweetledi
Backpirch Weather
Backpirch Weather@BackpirchCrew·
Spliced together an 81-hour radar loop of the Alaskan Snowicane and my goodness it is insane. A tropical-looking storm made entirely of freezing rain and snow.
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Deelan Jariwala
Deelan Jariwala@WxTca·
@backinblack_wx @oldscarf1stweek @simbasad2 Maybe I'm misunderstanding here, but isn't that a little inconsistent with this thread? The SPC unilaterally(?) deciding against issuing high risks for wind events feels more impact-driven than plain forecast verification. x.com/evan_bentley/s…
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Evan Bentley@evan_bentley

Let’s talk about the SPC High Risk. This is my opinion, but I am confident most SPC forecasters would agree. Everyone wants to know if the SPC will go High and the weather community goes wild when we do. And that is exactly how we like it.

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Brandon Black
Brandon Black@backinblack_wx·
@oldscarf1stweek @simbasad2 Spc isn’t in the game of impacts real they are in the game of forecasting WMO defined severe weather and that definition is built on a standardized impact. WFOs and their warnings can be a little more tuned to local impacts. It’s a hate the game not the players situation
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WeatherFront
WeatherFront@WxFront·
Easily a top 5 radar loop in WF history. The atmosphere is incredible.
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Deelan Jariwala
Deelan Jariwala@WxTca·
@EthanKerr2003 Certainly looks like it! Vorticity does what vorticity does I guess. Sea level pressures at a nearby station have dropped below 990mb, so it's not like the disturbance is weak (although environmental pressures are probably pretty low too)
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Ethan Kerr
Ethan Kerr@EthanKerr2003·
@WxTca Is there also some mesovortex action going on in the core of this low?
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Deelan Jariwala
Deelan Jariwala@WxTca·
A lot of people (including myself!) tend to scoff at the notion that these Mediterranean storms can be something other than (sub)tropical. However, from time to time, the atmosphere reminds us that classifying convective lows is hard! Take a look at this polar low near Alaska:
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Deelan Jariwala@WxTca

Interesting disturbance in the Mediterranean Sea drifting towards Libya's Gulf of Sidra. It doesn't look particularly frontal, and there's some persistent convection near the center, although not particularly deep. It probably isn't too far off from being a subtropical storm.

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Deelan Jariwala
Deelan Jariwala@WxTca·
This system possesses a very shallow warm core in the low levels, which is evident based on the structure on both satellite and radar. Lapse rates are extremely steep locally given its position beneath troughing aloft, which allows for barotropic growth of convection.
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Deelan Jariwala
Deelan Jariwala@WxTca·
It was just pointed out to me that this system is actually within range of Alaskan radar! Much like a TC, there is well-defined spiral banding with the strongest winds in a relatively tight RMW. Unlike a TC though, the precipitation here is…snow.
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Deelan Jariwala
Deelan Jariwala@WxTca·
Interesting to see the westerlies continue to rage on and even intensify with time, spreading towards the equator and dateline. Their persistence in the NWPAC and average CPAC trades may suggest ENSO growth from the E —> W via KWs rather than local warming in the near term.
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Deelan Jariwala
Deelan Jariwala@WxTca·
Interesting disturbance in the Mediterranean Sea drifting towards Libya's Gulf of Sidra. It doesn't look particularly frontal, and there's some persistent convection near the center, although not particularly deep. It probably isn't too far off from being a subtropical storm.
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Deelan Jariwala
Deelan Jariwala@WxTca·
@PlaysSaheb I prefer not to speak in absolute terms when a situation calls for ambiguity as this one does.
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Michael (Aisosa) Igbinoba
Michael (Aisosa) Igbinoba@MichaelIgbino10·
Hello again - With AMS Tropical coming up, I’d like to announce a talk I’ll be giving on April 1st at 8:45 AM PST surrounding my most recent work in internal sheared tropical cyclone dynamics. I’d be extremely grateful if people were able to attend ! #AMSHurr37
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Deelan Jariwala
Deelan Jariwala@WxTca·
@evan_bentley What is the reasonable max intensity of mostly weak tornadoes then? Is it a function of population density (given observation likelihood and construction standards)?
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Evan Bentley
Evan Bentley@evan_bentley·
@WxTca Baseline is for when mostly weak tornadoes are expected. This is when there are severe weather probabilities but no greater intensity forecast. CIG1 is a reasonable max intensity of strong (EF2) tornadoes.
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Evan Bentley
Evan Bentley@evan_bentley·
First guess for CIG1 is anywhere with a STP>1 Nov-May. And EF2 tornadoes w/ STP<1 are HSLC. So yes, most every tornado probability will also have CIG1 this spring Tornado intensity is strongly influenced by shear. And shear is almost always moderate to strong this time of year.
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Deelan Jariwala
Deelan Jariwala@WxTca·
@evan_bentley Adopting a conservative definition makes enough sense for meteorological + climatological purposes to me, but is the consensus at the SPC that this would simplify operations or discourse around these storms? Derecho is a pretty concise word to describe these wind events.
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Evan Bentley
Evan Bentley@evan_bentley·
For those who haven’t seen it yet, might be a good time to review the modified Derecho definition. We are working on an updated webpage, but in the meantime this is the most comprehensive article explaining the changes. BLUF: Serial no longer counts. spc.noaa.gov/publications/s…
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Deelan Jariwala
Deelan Jariwala@WxTca·
@ACarl8610 Personally, I'm not sure I fully agree with the idea of a single basin wide statistic being used for the average errors, but that's probably the simplest way to do it. It'd be cool to have a dynamic measure of uncertainty that is representative of each individual TC.
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Deelan Jariwala
Deelan Jariwala@WxTca·
@ACarl8610 Honestly, I'm far from a public communications expert so it's not really my place to comment on that. As far as my personal opinion goes, I'd guess part of that is a consequence of just how the cone is defined (i.e. using the circle, or now the oval of the average error).
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Deelan Jariwala
Deelan Jariwala@WxTca·
@weatheraub Weirdly enough, I can't find it anymore in the directory. I'm not too sure why -- the information was public and accessible via the WMO website, but I promise it was there last night.
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Aubrey
Aubrey@weatheraub·
@WxTca What presentation are these from? I cannot find it in the folders
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Keşfet

@PaulRoundy1 @EricBlake12 @BigJoeBastardi @AndyHazelton @backinblack_wx @oldscarf1stweek @simbasad2 @EthanKerr2003