Alex Boreham
@cyclonicwx.bsky.social
📤 2254
📥 74
📝 317
Tropical meteorologist, B.S. FSU, amateur web, Python, & GrADS programmer. 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!
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about 9 hours ago
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#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!
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2 days ago
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#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
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5 days ago
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#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
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6 days ago
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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!
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11 days ago
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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!
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11 days ago
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#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
11 days ago
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#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
13 days ago
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Insane dropsonde from
#Melissa's
southern eyewall. Stronger than the one yesterday morning, strongest I can remember seeing. Agrees with 160kt intensity from NHC
13 days ago
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#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
13 days ago
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#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
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13 days ago
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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
14 days ago
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Also crazy subsidence inversion in
#Melissa's
eye. At 907mb, you get weird stuff like 30C at 775mb!
14 days ago
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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
14 days ago
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#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
14 days ago
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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
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14 days ago
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#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
15 days ago
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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.
15 days ago
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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
16 days ago
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#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
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16 days ago
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#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
16 days ago
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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
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17 days ago
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#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.
17 days ago
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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
17 days ago
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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
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18 days ago
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#Melissa
isn't looking so good once again this afternoon as the LLC shears off. Hard to say what it looks like near the new convection. Luckily, TDR recon is on its way, and we'll get a good look at the structure and just how tilted it is.
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18 days ago
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I've added an extra feature in the recon page, data for an entire storm! Now every time recon goes into a (named) storm, all its data will be viewable, plus estimated minimum pressure from center dropsondes. Looks cool with stronger storms! Here's what it looks like for
#Melissa
:
18 days ago
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The TDR from
#Melissa
shows just how decoupled it is. An area where the low-levels have solid southerlies (LLC to the west) has W/NW winds (MLC to the NE). The two centers are impressively far apart! Implies one may dissipate
18 days ago
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#Melissa
is presently being sheared by an incoming trough. This trough is why we are expecting a north drift, and is partly to blame for the high track uncertainty (this setup means very different steering with different intensities!)
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19 days ago
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Every year, people hype up NW Caribbean OHC. Sometimes there's even a nice anticyclone there! But usually no storm is around to take advantage of it. However, after
#Melissa's
continual shifts west, this time may be different.
19 days ago
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#Melissa's
LLC so far has not been seriously disrupted by the convection east of it. As the convection grows closer to it, it seems less likely we would see the more dramatic center relocations some of the models have had. Part of the reason we have been seeing west shifts
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19 days ago
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Recon found
#Melissa's
MLC in the blob of convection as expected, very far east of the decoupled LLC. If we see a center reformation this is where it would try to set up
20 days ago
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#Melissa's
short-term intensity will be unusually influential in its eventual track. A quicker intensification right now means a higher chance of interaction with Hispaniola and recurvature. Slower means it misses an incoming trough and would stall and move into the NW Caribbean.
20 days ago
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Weak flow aloft + Caribbean trades = a sheared
#98L
. LLC now running ahead of the MLC. Shear looks to remain high until it gets further west, which may align closer to western solutions if it remains weak. Can tell water is very warm here though given convection sprouting from outflow boundaries
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21 days ago
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#95S
is interesting. Due to the WWB, despite being very close to the equator, it has a circulation! Won't be able to do much though with very little Coriolis force. Needs to move south soon (which it is expected to do)
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22 days ago
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#98L
is entering the Caribbean. It is a sharp wave, still moving a little too fast to close off. It will slow down in the Caribbean and contend with some shear. If it is in good shape later conditions improve and it may be something to watch. Eventual impacts uncertain given large variance of tracks
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22 days ago
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Sure, you've heard of twin TCs. But have you ever seen quadruplet TCs? Strong Indian Ocean WWB will make it possible next week
23 days ago
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Nice -IOD signature forming. Will encourage strengthening of warm pool in WPAC in coming months and suggests possible flip to +ENSO in 2026
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23 days ago
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Watching for development on both sides of this large cold front. Up north, some convective activity may allow for a brief subtropical storm in the next few days before it moves off to the NE.
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24 days ago
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We have
#Jerry
today in the MDR. There is some shear affecting it, pushing the LLC towards the western end of most of the convection despite an upper anticyclone. It turns out the fast easterly flow near the surface is canceling this out.
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about 1 month ago
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Seems the Atlantic has read a new book today...
#Humberto
#Imelda
about 1 month ago
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#Imelda
has quite the broad wind field, despite the satellite presentation today. Weird storm. Not going to do anything fast with this sort of structure, except maybe become extratropical when it interacts with the next trough
about 1 month ago
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Seeing some of those higher winds near
#Imelda's
center for the first time. May be first signs of a core beginning to form
about 1 month ago
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I've just redesigned the recon page, so now you can see all the data in one page! I have also added a few shiny new plots. One consolidates the observations the plane makes all in one image, and the other plots wind for various levels reported by dropsondes. Will be useful with upper level flights!
about 1 month ago
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Recon found
#Humberto
weaker and in the late stages of an ERC. The moat showing up on IR and outer eyewall winds dominant over the inner suggests the inner eyewall is not long for this world. We'll see if it can finish before shear starts to rise tomorrow
about 1 month ago
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#Humberto's
eye is warming rapidly on water vapor imagery, signifying extreme subsidence in the eye and an upper echelon tropical cyclone. This warmth in the eye is something hard to come by even for Category 4s!
about 1 month ago
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The upper trough originally expected to reel
#TD9
in is weaker today, making it less likely to landfall in the Carolinas. However, with more ridging around and slower movement, it has inched closer to Florida. There are now tropical storm watches up for some of its east coast
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about 1 month ago
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#Humberto
has a meso sector on it now. As a strong Category 4, it has a nice, cleared out stadium effect eye. You can even see the low level clouds spinning around in the eye! Always love the views like this
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about 1 month ago
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Either way,
#94L's
main hazard will be flooding. The upper low in the area bringing some moisture in combined with 94L's approach will set off a possible predecessor rain event. If it slows down/stalls in the area this issue could be compounded. Will need to keep a close eye on steering/track
add a skeleton here at some point
about 1 month ago
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#94L
has an interesting strength forecast. While moving NNW it will be hit by southerly shear ahead of an upper trough, with some dry air working its way upshear. However, it will traverse very warm waters near the Gulf Stream along with very strong upper divergence.
about 1 month ago
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