ATL: LAURA - Post-Tropical - Discussion

[Patrick99]

Currently HWRF has Laura putting key west in the eye as a 943mb storm

https://www.tropicaltidbits.com/analysis/models/hwrf/2020082112/hwrf_ref_13L_28.png


I can’t imagine this playing out currently but who knows at this point

IR

https://www.tropicaltidbits.com/analysis/models/hwrf/2020082112/hwrf_satIR_13L_15.png

Woof. That is a re-run of 1919. 101 years after the fact.

[Aric Dunn]

HWRF and HMON continue to handle it by far the best and having the HWRF/HMON mixture verifying is quite possible. especially through first 72 hours.

[wxman57]

I think that the HWRF has as much chance of verifying as I do in having this weekend off. Meanwhile, Laura is roaring into the islands of the northeast Caribbean, producing northerly winds of 50 kts! Oh, I mean 5 kts. Decimal in the wrong place.

http://wxman57.com/images/Laura3.JPG

.. a center relocation could put SFL back in the cone. A track middle/upper keys is possible

Again, the cone is meaningless. It says nothing about the extent of impacts, which are often well outside the cone. Ignore the cone.

[Blown Away]

IMO the 5pm position will be very close to being centered on St. John’s island. That COC appears to be out running that convection blob to its east.

[wxman57]

NHC expected a Category 1 hurricane in the eastern Caribbean in the first advisory, which at the time I was very skeptical of since only the statistical guidance and HWRF showed that happening.

That's not verifying well. It would be a challenge to find any sustained wind of tropical storm strength in Laura. HWRF predicts everything to be a Cat 3+ hurricane.

[USVIKimmie]

IMO the 5pm position will be very close to being centered on St. John’s island. That COC appears to be out running that convection blob to its east.

*pedant* St John, USVI? Is that where you mean? There’s others around... asking for a friend

I’m next door on St Thomas, been blustery, maybe 20-30kts and very little rain. Too soon.

[psyclone]

If one looks carefully, a discussion that tilts toward historical storms or analogs tend to indicate not much is happening in real time.

[SFLcane]

 https://twitter.com/AndyHazelton/status/1296898566514933760

[Blown Away]

IMO the 5pm position will be very close to being centered on St. John’s island. That COC appears to be out running that convection blob to its east.

*pedant* St John, USVI? Is that where you mean? There’s others around... asking for a friend

I’m next door on St Thomas, been blustery, maybe 20-30kts and very little rain. Too soon.

The one between Barbuda & Guadalupe... Sorry

[HurricaneEdouard]

It is absolutely amazing how identical the current IR presentation is to the HWRF IR forecast for this time. Really impressive forecasting

HWRF does pretty darn well with simulating storm structure. Here's what it had for Dorian last year:
https://pbs.twimg.com/media/EDQxJoJWsAAAelH?format=png&name=small

To be honest it shows this type of IR simulation for almost every hurricane that becomes a major hurricane.

I wouldn't say that; it's showing a very different type of IR simulation for Laura as a major hurricane in the Gulf, ditto for Irma.

[Shell Mound]

NHC expected a Category 1 hurricane in the eastern Caribbean in the first advisory, which at the time I was very skeptical of since only the statistical guidance and HWRF showed that happening.

That's not verifying well. It would be a challenge to find any sustained wind of tropical storm strength in Laura. HWRF predicts everything to be a Cat 3+ hurricane.

Question one: in your view how many marginal tropical storms have been overestimated or wrongly classified since the early 2000s?

Question two: why did the ECMWF bust so dramatically in regard to Hanna? I still haven’t found a good meteorological explanation.

[Cataegis96]

Very persistent convection to the east. This has a really good shot at forcing a new LLC underneath that deeper convection. You can almost see some of the southerlies try to become more westerly before being obscured by higher cloud tops between 59 and 60W. Still a very fine line situation.

[Kingarabian]

NHC expected a Category 1 hurricane in the eastern Caribbean in the first advisory, which at the time I was very skeptical of since only the statistical guidance and HWRF showed that happening.

That's not verifying well. It would be a challenge to find any sustained wind of tropical storm strength in Laura. HWRF predicts everything to be a Cat 3+ hurricane.

Question one: in your view how many marginal tropical storms have been overestimated or wrongly classified since the early 2000s?

Question two: why did the ECMWF bust so dramatically in regard to Hanna? I still haven’t found a good meteorological explanation.

Significant reduction of airline flights has to be playing a huge role.

[Nuno]

NHC expected a Category 1 hurricane in the eastern Caribbean in the first advisory, which at the time I was very skeptical of since only the statistical guidance and HWRF showed that happening.

That's not verifying well. It would be a challenge to find any sustained wind of tropical storm strength in Laura. HWRF predicts everything to be a Cat 3+ hurricane.

Question one: in your view how many marginal tropical storms have been overestimated or wrongly classified since the early 2000s?

Question two: why did the ECMWF bust so dramatically in regard to Hanna? I still haven’t found a good meteorological explanation.

Honestly I cannot imagine there are many tbh. The NHC don't classify storms for funsies, especially as conservative as the NHC are.

[Shell Mound]

Based on visible loops, there appear to be two or even three LLCs: one near St. Martin, another east of Antigua, and maybe a third farther ESE.

All three LLCs appear to be part of one sprawling surface trough: essentially eddies within a broader circulation heading generally westward.

 https://twitter.com/AnthonyMweather/status/1296907337018609664

[Nuno]

That's not verifying well. It would be a challenge to find any sustained wind of tropical storm strength in Laura. HWRF predicts everything to be a Cat 3+ hurricane.

Question one: in your view how many marginal tropical storms have been overestimated or wrongly classified since the early 2000s?

Question two: why did the ECMWF bust so dramatically in regard to Hanna? I still haven’t found a good meteorological explanation.

Significant reduction of airline flights has to be playing a huge role.

I keep seeing this mentioned but it isn't as if planes worldwide are grounded. There are still tons of flights circling around. The lack of GIV flights on the other hand seems to be a major factor.

[tolakram]

[Kingarabian]

Question one: in your view how many marginal tropical storms have been overestimated or wrongly classified since the early 2000s?

Question two: why did the ECMWF bust so dramatically in regard to Hanna? I still haven’t found a good meteorological explanation.

Significant reduction of airline flights has to be playing a huge role.

I keep seeing this mentioned but it isn't as if planes worldwide are grounded. There are still tons of flights circling around. The lack of GIV flights on the other hand seems to be a major factor.

G-IV are usually flown for threatening systems. Worldwide, even though there is some air travel returning, airline flights have been significantly reduced due to COVID. If it's not that, then maybe satellite assimilation errors? We won't know until after this season is over and the ECMWF/NWS release more information.

[hohnywx]

NHC expected a Category 1 hurricane in the eastern Caribbean in the first advisory, which at the time I was very skeptical of since only the statistical guidance and HWRF showed that happening.

That's not verifying well. It would be a challenge to find any sustained wind of tropical storm strength in Laura. HWRF predicts everything to be a Cat 3+ hurricane.

Question one: in your view how many marginal tropical storms have been overestimated or wrongly classified since the early 2000s?

Question two: why did the ECMWF bust so dramatically in regard to Hanna? I still haven’t found a good meteorological explanation.

Good questions Shell Mound.

[AutoPenalti]

https://imgur.com/VhlEPo3

If this were the first time seeing Laura after waking up before Sundown, were would you approximate the center?