ATL: FIONA - Post-Tropical - Discussion

[Hurricane Mike]

11:30pm Video Update on Tropical Storm Fiona for those interested
https://www.youtube.com/watch?v=W1ZWIPo2vOY

[galaxy401]

Pressure dropping with each Recon pass. Winds likely at 55 kts now. Fiona is gradually ramping up.

[ElectricStorm]

Certainly looking better now. Hopefully the PR folks aren't too affected by this. Stay safe y'all

[Landy]

VDM just came in putting Fiona at 994mb. Last VDM 2 hours ago had it at 999.

[skyline385]

VDM just came in putting Fiona at 994mb. Last VDM 2 hours ago had it at 999.

Think its safe to ignore the previous drop, it had 999mb with 23 kts wind and also showed an anomalous increase in pressure from the drops before it.

Also, fwiw, the 994mb is higher than both the HWRF and HMON forecasts which had it at 989mb and 984mb at 0600 Zulu time respectively.

[Hammy]

VDM just came in putting Fiona at 994mb. Last VDM 2 hours ago had it at 999.

Think its safe to ignore the previous drop, it had 999mb with 23 kts wind and also showed an anomalous increase in pressure from the drops before it.

Also, fwiw, the 994mb is higher than both the HWRF and HMON forecasts which had it at 989mb and 984mb at 0600 Zulu time respectively.

https://i.imgur.com/MrcsBnv.png

65/994 on the 2am advisory, almost 24 hours ahead of the latest Euro run

[skyline385]

VDM just came in putting Fiona at 994mb. Last VDM 2 hours ago had it at 999.

Think its safe to ignore the previous drop, it had 999mb with 23 kts wind and also showed an anomalous increase in pressure from the drops before it.

Also, fwiw, the 994mb is higher than both the HWRF and HMON forecasts which had it at 989mb and 984mb at 0600 Zulu time respectively.

https://i.imgur.com/MrcsBnv.png

65/994 on the 2am advisory, almost 24 hours ahead of the latest Euro run

Yep, but personally I wouldn't use the Euro for intensity estimates. Asides from being a global model, it was the worst performing model intensity wise in last year's (or 2020) post-season verification. I always prefer to use the global models for track and hurricane models for intensity estimates.

[skyline385]

Looking much better on radar now, even the centers seem to be aligned




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[Hurricane Mike]

Fiona is looking on her way to becoming a hurricane.

[Chris_in_Tampa]

Low-bandwidth imagery options that don't use as much data to load. (such as to use on a phone with little connectivity)



Short range Puerto Rico radar:

Single image, the latest image available (45kb - kilobytes):
https://radar.weather.gov/ridge/standard/TJUA_0.gif

Single animated GIF image of last 10 images, you can't pause it. (425kb)
https://radar.weather.gov/ridge/standard/TJUA_loop.gif



Puerto Rico satellite:


600 pixel wide single images:

IR - Color (80kb):
https://cdn.star.nesdis.noaa.gov/GOES16 ... 00x600.jpg

Geocolor (60kb):
https://cdn.star.nesdis.noaa.gov/GOES16 ... 00x600.jpg

Visible (During day; Size should be less than color):
https://cdn.star.nesdis.noaa.gov/GOES16 ... 00x600.jpg



1200 pixel wide single images:

IR - Color (230kb):
https://cdn.star.nesdis.noaa.gov/GOES16 ... 0x1200.jpg

Geocolor (160kb):
https://cdn.star.nesdis.noaa.gov/GOES16 ... 0x1200.jpg

Visible (During day; Size should be less than color):
https://cdn.star.nesdis.noaa.gov/GOES16 ... 0x1200.jpg



2400 pixel wide single images:

IR - Color (600kb):
https://cdn.star.nesdis.noaa.gov/GOES16 ... 0x2400.jpg

Geocolor (450kb):
https://cdn.star.nesdis.noaa.gov/GOES16 ... 0x2400.jpg

Visible (During day; Size should be less than color):
https://cdn.star.nesdis.noaa.gov/GOES16 ... 0x2400.jpg

[Hammy]

Think its safe to ignore the previous drop, it had 999mb with 23 kts wind and also showed an anomalous increase in pressure from the drops before it.

Also, fwiw, the 994mb is higher than both the HWRF and HMON forecasts which had it at 989mb and 984mb at 0600 Zulu time respectively.

https://i.imgur.com/MrcsBnv.png

65/994 on the 2am advisory, almost 24 hours ahead of the latest Euro run

Yep, but personally I wouldn't use the Euro for intensity estimates. Asides from being a global model, it was the worst performing model intensity wise in last year's (or 2020) post-season verification. I always prefer to use the global models for track and hurricane models for intensity estimates.

I ignore the hurricane models entirely, they always vastly over-intensify everything

[ChrisH-UK]

Fiona is starting to look good on radar but on IR still looks a bit sheared and disorganised. Should be better once the sun rises.

[Hurricane Mike]

[Chris_in_Tampa]

5am NHC public advisory headline:

...FIONA FORECAST TO BECOME A HURRICANE LATER TODAY... ...LIFE-THREATENING FLOODING AND MUDSLIDES EXPECTED ACROSS PUERTO RICO AND THE DOMINICAN REPUBLIC...

Rainfall is now forecast to be up to 25 inches in Puerto Rico. Previous forecast was for up to 20 inches. That brings an important wording update. Rather than previously saying "These rains are likely to produce life-threatening flash flooding and urban flooding" it now says "These rains will produce life-threatening flash flooding and urban flooding".

Most important section from public advisory:

RAINFALL: Fiona is forecast to produce the following rainfall:

Leeward Islands: Additional 2 inches or less.

British and U.S. Virgin Islands: 4 to 6 inches, maximum of 10 inches
on St. Croix.

Puerto Rico: 12 to 16 inches with local maximum of 25 inches,
particularly across eastern and southern Puerto Rico.

Northern and Eastern Dominican Republic: 4 to 8 inches with local
maximum 12 inches, particularly near the far east coast.

Rest of Dominican Republic and Haiti: 1 to 3 inches.

Turks and Caicos: 3 to 6 inches.

These rains will produce life-threatening flash flooding and urban
flooding across Puerto Rico and the eastern Dominican Republic,
along with mudslides and landslides in areas of higher terrain.

MRMS radar:
https://mrms.nssl.noaa.gov/qvs/product_ ... oduct=CREF

72-hour rainfall accumulation in MRMS display:
https://mrms.nssl.noaa.gov/qvs/product_ ... pacity=0.5

River observations in Puerto Rico:
https://water.weather.gov/ahps/region.php?state=pr

[Iceresistance]

NOAA2 Eye Dropsonde has 992 MB with 7 knots of wind.

[Iceresistance]

We now have 2 recons active in Fiona, AF303's first pass has the lowest extrapolated pressure at 989.5 MB.

[kevin]

Pressure falling, second plane just measured an extrapolated 988.9 mbar. But SFMR so far is only up to 50 kt. Even with max. 10% undersampling that barely supports the current 55 kt intensity. Might be that Fiona is still busy organizing itself. Or the wind field is quite tricky so it's difficult to find the peak winds.

[skyline385]

65/994 on the 2am advisory, almost 24 hours ahead of the latest Euro run

Yep, but personally I wouldn't use the Euro for intensity estimates. Asides from being a global model, it was the worst performing model intensity wise in last year's (or 2020) post-season verification. I always prefer to use the global models for track and hurricane models for intensity estimates.

I ignore the hurricane models entirely, they always vastly over-intensify everything

In the 2021 NHC verification, both hurricane models actually come out as the best models intensity wise with the GFS and Euro as the worst, HWRF even beat the FSU super ensemble. Yea they have a tendency to sometimes blow up but with proper recon data fed into them they have been very good. The HAFS model being touted as the next generation model by NOAA will be basically an extension of the hurricane models as well.

Anyways, think we have gone a bit off topic so going to stop here. If you prefer we can continue the discussion in the model thread

[skyline385]

Pressure falling, second plane just measured an extrapolated 988.9 mbar. But SFMR so far is only up to 50 kt. Even with max. 10% undersampling that barely supports the current 55 kt intensity. Might be that Fiona is still busy organizing itself. Or the wind field is quite tricky so it's difficult to find the peak winds.

Just got two unflagged 60 kts SFMR with 65 kts FL. NHC will probably upgrade because of proximity to land.

[kevin]

Both planes just measured higher winds, 64 kt FL winds with 59 kt SFMR. Could be enough to support 60 kt.