Alex Boreham
@cyclonicwx.bsky.social
Tropical meteorologist, B.S. FSU, amateur web, Python, & GrADS programmer.
Also known as Not Sparta
Also known as Not Sparta
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!
November 10, 2025 at 3:20 AM
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!
November 8, 2025 at 5:34 AM
#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
November 5, 2025 at 10:22 PM
#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
November 4, 2025 at 4:00 AM
#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!
October 30, 2025 at 9:03 PM
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!
October 30, 2025 at 8:05 PM
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
October 30, 2025 at 3:13 AM
#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
October 28, 2025 at 11:55 PM
#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
October 28, 2025 at 2:15 PM
Insane dropsonde from #Melissa's southern eyewall. Stronger than the one yesterday morning, strongest I can remember seeing. Agrees with 160kt intensity from NHC
#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
October 28, 2025 at 1:30 PM
#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
October 28, 2025 at 4:18 AM
#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
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
October 27, 2025 at 5:35 PM
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!
October 27, 2025 at 4:26 PM
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
October 27, 2025 at 1:19 PM
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
October 27, 2025 at 1:12 PM
#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
October 27, 2025 at 2:58 AM
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
October 26, 2025 at 9:05 PM
#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
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.
October 26, 2025 at 1:32 PM
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
October 25, 2025 at 11:21 PM
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
October 25, 2025 at 9:08 PM
#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
#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
October 25, 2025 at 1:52 PM
#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
October 25, 2025 at 12:05 AM
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
#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.
October 24, 2025 at 5:07 PM
#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
October 24, 2025 at 1:04 PM
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
P.S. you can create GIFs like this now from the TDR data! Sort of like an MRI of the storm
October 24, 2025 at 12:13 AM
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
P.S. you can create GIFs like this now from the TDR data! Sort of like an MRI of the storm