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For this elevation (beam height from KLCH is around 16,000ft which is ~550-hPa), these radial velocities seen in the E eyewall of #Laura are incredible. Yes that is an inbound 160-mph velocity... at 550-hPa!

This is a very powerful and deep vertical circulation.
And if you go pixel hunting for the maximum velocity pixel, there are values that are larger than that too. The latest scan for example has a 169-mph pixel!

The @53rdWRS normally samples strong hurricanes at 700-hPa as winds decrease w/ height. This is well above that level!
I’m just gonna continue sharing incredible #Laura velocities in this thread. Now up to 173mph in the NE quad.
Not sure if this is valid, but caught a 187mph pixel in the NE quad of #Laura value surrounded by >175mph pixels. Just ridiculous.
Okay last one for this #Laura radar thread since I don’t see how it can be topped. There were *6* surrounding bins that were >200mph so I don’t think this outbound velocity was an error despite the value, 223mph!

Basically KLCH may have sampled an intense NW eyewall mesovort!
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Philippe Papin
@pppapin
It's been a hard week for CA w/ major wildfires (#GettyFire, #KincaidFire) affecting the state.

Synoptic weather context is key: Fires were aided by repeated mountain & gap winds via ridge building over the Great Basin. This ridge building enhances the pressure gradient over CA.
The synoptic weather sets the stage, but the mountain interaction enhances the winds further.

Let's illustrate the mesoscale details w/ a cross-section across the coastal CA mountain ranges. Hurricane force (#SantaAna) winds form as cold easterly flow tries to cross the barrier.
The record-breaking cold pool intensity associated w/ a 1045-hPa ridge is one reason why this last mountain wind event for southern California may be the worst.

Inland, 850-hPa temps are at record lows, but adiabatic compression modifies the air to near climo on the coast.
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Philippe Papin
@pppapin
Here is the sequel to my steering flow animated explanations. I'm covering 2 periods.

1st period is when #Dorian is expected to stall.

3 Features Cancel out:
1) Ridge over the NATL
2) Ridge over the Midwest
3) Trough that creates a weakness between the two ridges.
So naturally the next question is, what causes the #Dorian to start moving again?

Essentially one ridge becomes stronger (NATL ridge), while the other one weakens (Midwest US), with progressive troughs making sure the weakness stays open. Breakdown below⬇️
So in retrospect, it's not the trough picking up the storm, but rather the transient troughs provide a weakness that then gives #Dorian a path to then be directed around the clockwise circulation of the NATL ridge.
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Philippe Papin
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Okay so while all attention is on #Dorian, let's do a quick tour of the rest of the NATL tropics currently, because there are some other systems to talk about.

There is a weak llvl circ. n/ Cuba W of Dorian. It should move into the GoM where it has a chance to organize further.
Next up is an African Easterly Wave that just emerged off the coast. The model guidance has been somewhat optimistic on this wave developing over the next 5-7 days, so worth keeping an eye on it. Aside from the Cape Verde islands, no threat to land.
Let's continue. There is yet another wave out in the middle of the NATL basin. Its battling some fairly strong westerly shear currently, but some models suggest it will get into a more favorable environment as it moves off to the northwest. #Bermuda should keep an eye on it.
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