ATL: SAM - Remnants - Discussion

[InfernoFlameCat]

Looks like what some posters have suspected is indeed correct. It is not uncommon for storms benefiting from trough interaction but with a weak southern eyewall to find it difficult to mix winds effectively to the surface. Zeta last year has flight-level winds that obviously supporting something above 100kt, but NHC at last goes only with 100kt, adopting a lower-than-usual conversion factor.

The best estimate is 125-130kt based on a blend of flight-level and SFMR data.

The SFMR is experiencing issues with this mission. It glitched on multiple occasions.

[ElectricStorm]

I'd probably go 135kts for now, I'm hesitant to go with anything higher since SFMR is so low. Hopefully we get a good dropsonde in the NE eyewall.

[grapealcoholic]

I think this storm is going to get upgraded in post-analysis anyway with its previous peak

[cheezyWXguy]

Looks like what some posters have suspected is indeed correct. It is not uncommon for storms benefiting from trough interaction but with a weak southern eyewall to find it difficult to mix winds effectively to the surface. Zeta last year has flight-level winds that obviously supporting something above 100kt, but NHC at last goes only with 100kt, adopting a lower-than-usual conversion factor.

The best estimate is 125-130kt based on a blend of flight-level and SFMR data.

The SFMR is experiencing issues with this mission. It glitched on multiple occasions.

Agreed. Trough interaction or not, there is little chance that winds in the SW quad are stronger than in the NE quad

[aspen]

It’s best that the NHC waits until the 2pm intermediate advisory to upgrade Sam to 135 or 140 kt. The NW quadrant could theoretically have higher SFMR readings that better support the 90% FL-to-surface conversion, or maybe more 150-155kt FL winds. If not, Sam should either be kept at 130kt (85% FL-to-surface conversion) or maybe generously raised to 135 kt.

[ElectricStorm]

SW eyewall drop shows some nasty winds just above the surface. Probably gusts, but still pretty solid

[grapealcoholic]

Eye still clearing -- it's approaching the 28c dropoff so very little time left to strengthen

[ElectricStorm]

NE eyewall drop shows the winds mixing down pretty well

[grapealcoholic]

ADT is completely useless half the time. They need to discard that trash

[InfernoFlameCat]

Noooo recon dropped the dropsonde too early! They didn't drop it around peak winds!

[aspen]

ADT is completely useless half the time. They need to discard that trash

It may be performing poorly with Sam, but it’s not trash at all. It was actually spot-on with Ida’s peak intensity (130kt and low-930s as confirmed by recon) and functions well under most circumstances. Storms that give it a hard time are pinholes, annulars, ones that had their eyes collapse from EWRCs, and stuff at high latitudes like this.

[kevin]

Noooo recon dropped the dropsonde too early! They didn't drop it around peak winds!

However, the dropsonde does show a conversion rate of 132/142 = 93% of winds mixing down to the surface, which would give 152*93% = 141 kt for the peak winds. I think the dropsonde does an excellent job at confirming that winds are mixing down very well and that there's just something wrong with SFMR right now.

[aspen]

Hopefully recon goes for a NW-SE pass…it’s a long flight back so there’s a non-zero chance they do just one pass.

[Hypercane_Kyle]

152 knot flight level winds. Be curious to see what the NHC makes of that! 135 knots would be my guess.

Dropsonde was 132 knots too on the surface. Sam is borderline Category 5!

[Iceresistance]

I've seen farther Recon Missions (From Louisiana to Eta & Iota in the Caribbean) before

[InfernoFlameCat]

152 knot flight level winds. Be curious to see what the NHC makes of that! 135 knots would be my guess.

Dropsonde was 132 knots too on the surface. Sam is borderline Category 5!

IMO Sam is Cat 5. They did not drop the dropsonde at peak winds but it did show a 93% conversion rate between fl and srfc winds.

[kevin]

The need to go south anyways to get back home so I think they'll do at least one more NW to SE pass.

[Sciencerocks]

I'd go with cat5.

[ElectricStorm]

152 knot flight level winds. Be curious to see what the NHC makes of that! 135 knots would be my guess.

Dropsonde was 132 knots too on the surface. Sam is borderline Category 5!

IMO Sam is Cat 5. They did not drop the dropsonde at peak winds but it did show a 93% conversion rate between fl and srfc winds.

Dropsonde are usually gusts. They never upgrade based on the drops. Also they're flying at 700 mb so the peak FL winds aren't going to show up in the dropsonde.

[Iceresistance]

I'm predicting 155 mph & 938 MB on Advisory 36A