Alex Boreham

With this system pulling to the east, the northerly flow behind is producing a lot of lake effect snow off Lakes Michigan and Huron. Getting to that time of year!

#FungWong has turned out to be a very large typhoon with quite the broad core. This means previous guidance suggestions of a very strong storm did not come to pass, but it also means a larger region impacted as it comes ashore. Stay safe if you are in the path!

#TD32W has become a large, sprawling tropical cyclone with lower shear and impressive upper divergence. Will be interesting to see the size of the inner core that forms from this. If on the smaller side, will lean towards stronger solutions. Something to keep an eye on this weekend in Luzon

#90W is trying to get itself together with an LLC in a broader area of rotation. Some decent upper divergence right now, but it is sheared. The environment will get even more divergent and shear should drop tomorrow. Some guidance has been quite aggressive, we'll see how it fares

As it was when it developed, #Melissa is once again sheared. Its MLC is becoming displaced from its LLC, and if you get far enough up, it's much harder to see a TC signature and it turns into a trough in the middle of the jet stream flow. Lots of neat stuff on TDR data!

I've added radar data from Taiwan to the lineup. Between this and JMA radar, there's nice coverage in this part of West Pacific to see typhoon structures!

#Melissa continues NE tonight, weakened again from land interaction with Cuba. There is some upper divergence which could cause some strengthening as it approaches Bermuda, but the disrupted structure means it won't be significant before shear increases and SST drops below 26C

#Melissa is much weaker as expected coming off of Jamaica. However, with some time over water and the improved satellite presentation, there will likely be increased winds from what recon is finding. Luckily for Cuba, Melissa will not be able to intensify as strongly as before due to the disruption

Insane dropsonde from #Melissa's southern eyewall. Stronger than the one yesterday morning, strongest I can remember seeing. Agrees with 160kt intensity from NHC

There are some data sources that give you the center location on a relatively frequent basis. It's good enough to tell me generally where a storm's center is, then I take a 50km radius around that point and look for the warmest value there is

#Melissa has managed to continue strengthening over the night, and has gotten wind speeds up to 155kt and pressure of 892mb. About as low as it gets. Seems it will strengthen into landfall as well. I just pray everyone in the path has somewhere safe to be right now

#Melissa has impressive outflow and upper divergence beginning as it interacts with the oncoming upper trough. This may allow for another unfortunate burst of intensification (barring an EWRC) as it approaches Jamaica

I use 0.84 for the 150m, and 0.80 for the 500m. That is what I believe is correct, hopefully I'm not mistaken. It's easy to run away with those raw mean wind values so I feel like it's important to have the reduction in there

And there we have it. #Melissa's WV eye temperature has broken -5°C, making it warmer than any other eye observed through geostationary water vapor imagery. Takes an upper echelon warm core for this

Also crazy subsidence inversion in #Melissa's eye. At 907mb, you get weird stuff like 30C at 775mb!

Also worth noting #Melissa's very warm eye on water vapor imagery. -7.5°C is even warmer than Erin from this August and reflects extreme subsidence (drying+warming) in the eye. About as strong as warm cores get in the Atlantic basin

#Melissa has continued strengthening overnight, to a pressure around 913-914mb, with winds having risen to about 145-150kt based on obs from this morning's recon. Surprisingly no sign of an ERC yet. Can only hope there is some weakening on the way soon, awful situation for Jamaica

As recon leaves, #Melissa's satellite presentation once again improves. Lots of new bursting around the eyewall and another cooling of the CDO. Look at those gravity waves going outwards! Suggests a strengthening storm but satellite trends haven't totally agreed with recon obs lately

#Melissa's satellite presentation has become quite impressive this afternoon, with a more symmetric, cold CDO, and a warming, drying eye. Suggests continued strengthening is occurring. Will be interesting to see just how much it's deepening from recon soon

Still, landfall is not expected for another couple days so it is not time to let your guard down. This will still be a very dangerous storm as it is and does still have time to strengthen

So far it seems despite the eye clearing out #Melissa's intensification hasn't been explosive as thought. Could be some of the shear that has still not gone away is subtly disrupting it for now.

Recon is finding #Melissa notably stronger, at about 85kt with pressure having dropped all the way to 971mb. The wind field is much more coherent and symmetric, and there are double hot towers trying to surround the eye. Could see some impressive intensification rates from recon this evening

#Melissa has had several vortical hot towers appear wrap around its eyewall, with another active right now. Likely heralds the beginning of RI when these wrap more. Will certainly be interesting to see what recon finds. Seems tonight will be the long-predicted quick strengthening phase

Thank you! It's a new feature I added the other day. Don't know how I didn't have it earlier honestly

#Melissa looks like it has managed to stack this morning and looks fairly healthy on satellite. Wind field is a little interesting though. Was west weighted earlier and now east weighted. Doesn't look like a RI phase right now but the structure is no longer in the way like yesterday

While #Melissa has begun to strengthen and has a well-defined LLC, its MLC is still quite far off to the ESE. Sign of the shear that hasn't quite let up. Will not see more rapid intensification until the tilt reduces

Once again worth keeping a close eye on in Jamaica, as it is very much in the crosshairs of Melissa. Some more agreement on a track that could be very impactful for the island

#Melissa may finally be getting itself together this afternoon. It has begun to produce higher winds and deepen, and the center is well embedded within the convection. Shear is decreasing so this may herald the anticipated strengthening.

Looking at this morning's recon, #Melissa looks to have moved or reformed further east. A little fly in the ointment is the dropsondes suggest a surface center quite a bit further south. Could still be quite tilted. Melissa has a lot of work to do when shear comes down

Recon found #Melissa has reformed north, but is still misaligned. The LLC is to the west, but the winds reverse as you ascend through the levels, showing the tilt quite well.

P.S. you can create GIFs like this now from the TDR data! Sort of like an MRI of the storm