@webberweather.bsky.social
Gov't meteorologist. UNCC & NCSU Alum. Specializes in Climate Dynamics & S2S variability. Opinions are my own & not a reflection of my employer.
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Quietly while La Niña persists, the tropical upper troposphere is becoming very El Niño-like
A large build-up of westerly momentum (+U) in the tropics is being supplanted by a West Pac MJO orbit & repeated bouts of positive E Asia Mtn Torque (+EAMT) fluxing/squeezing +U equatorward
A large build-up of westerly momentum (+U) in the tropics is being supplanted by a West Pac MJO orbit & repeated bouts of positive E Asia Mtn Torque (+EAMT) fluxing/squeezing +U equatorward
November 11, 2025 at 11:01 PM
Quietly while La Niña persists, the tropical upper troposphere is becoming very El Niño-like
A large build-up of westerly momentum (+U) in the tropics is being supplanted by a West Pac MJO orbit & repeated bouts of positive E Asia Mtn Torque (+EAMT) fluxing/squeezing +U equatorward
A large build-up of westerly momentum (+U) in the tropics is being supplanted by a West Pac MJO orbit & repeated bouts of positive E Asia Mtn Torque (+EAMT) fluxing/squeezing +U equatorward
The global tropics zonal wind anomalies this year are evolving very similarly to late 1981, which of course preceded a “Super” El Niño event in 1982
Note how this yr & 1981 have a big & slow westerly wind burst over the Indian Ocean & Maritime Continent in Oct-Nov that moved into the Pacific in Dec
Note how this yr & 1981 have a big & slow westerly wind burst over the Indian Ocean & Maritime Continent in Oct-Nov that moved into the Pacific in Dec
November 11, 2025 at 10:07 PM
The global tropics zonal wind anomalies this year are evolving very similarly to late 1981, which of course preceded a “Super” El Niño event in 1982
Note how this yr & 1981 have a big & slow westerly wind burst over the Indian Ocean & Maritime Continent in Oct-Nov that moved into the Pacific in Dec
Note how this yr & 1981 have a big & slow westerly wind burst over the Indian Ocean & Maritime Continent in Oct-Nov that moved into the Pacific in Dec
As you might expect from the very strong -IOD event strengthening La Nina’s footprint globally, this October’s observed pattern has deviated very little from the last 30 years worth of La Ninas over N America
November 7, 2025 at 10:55 PM
As you might expect from the very strong -IOD event strengthening La Nina’s footprint globally, this October’s observed pattern has deviated very little from the last 30 years worth of La Ninas over N America
The latest Euro weekly forecast thru mid-December is almost exactly what you’d expect for typical a La Niña December over the last 30 years:
A faster-than-usual start to winter over the East-Central US with plenty of high-latitude blocking
A faster-than-usual start to winter over the East-Central US with plenty of high-latitude blocking
November 7, 2025 at 1:53 PM
The latest Euro weekly forecast thru mid-December is almost exactly what you’d expect for typical a La Niña December over the last 30 years:
A faster-than-usual start to winter over the East-Central US with plenty of high-latitude blocking
A faster-than-usual start to winter over the East-Central US with plenty of high-latitude blocking
La Niña is living on borrowed time.
The extreme -IOD we're currently seeing (right) is about to collapse because the warm water in the Equatorial Indian Ocean will get flushed into the tropical West Pac at depth over the next month in this MJO event's westerly wind burst (left)
The extreme -IOD we're currently seeing (right) is about to collapse because the warm water in the Equatorial Indian Ocean will get flushed into the tropical West Pac at depth over the next month in this MJO event's westerly wind burst (left)
November 5, 2025 at 9:10 PM
La Niña is living on borrowed time.
The extreme -IOD we're currently seeing (right) is about to collapse because the warm water in the Equatorial Indian Ocean will get flushed into the tropical West Pac at depth over the next month in this MJO event's westerly wind burst (left)
The extreme -IOD we're currently seeing (right) is about to collapse because the warm water in the Equatorial Indian Ocean will get flushed into the tropical West Pac at depth over the next month in this MJO event's westerly wind burst (left)
This winter seems to be intent on following the cool ENSO/East QBO/solar max paradigm of early winter -AO/-NAO
I replicated Gray et al (2004)'s analysis except used SLPa from 20CR & isolated -ENSO (left), which is close to the latest Euro weekly forecast (right) journals.ametsoc.org/view/journal...
I replicated Gray et al (2004)'s analysis except used SLPa from 20CR & isolated -ENSO (left), which is close to the latest Euro weekly forecast (right) journals.ametsoc.org/view/journal...
November 3, 2025 at 10:04 PM
This winter seems to be intent on following the cool ENSO/East QBO/solar max paradigm of early winter -AO/-NAO
I replicated Gray et al (2004)'s analysis except used SLPa from 20CR & isolated -ENSO (left), which is close to the latest Euro weekly forecast (right) journals.ametsoc.org/view/journal...
I replicated Gray et al (2004)'s analysis except used SLPa from 20CR & isolated -ENSO (left), which is close to the latest Euro weekly forecast (right) journals.ametsoc.org/view/journal...
Worth mentioning, this year has the 2 main precursors to a -EPO/+TNH ("polar vortex" pattern) dominated winter in place atm as identified by Zhong & Wu (2023).
Namely, a warmer-than-normal Maritime Continent & West Pac as well as a Eurasian Snow Cover Dipole.
journals.ametsoc.org/view/journal...
Namely, a warmer-than-normal Maritime Continent & West Pac as well as a Eurasian Snow Cover Dipole.
journals.ametsoc.org/view/journal...
November 1, 2025 at 2:48 AM
Worth mentioning, this year has the 2 main precursors to a -EPO/+TNH ("polar vortex" pattern) dominated winter in place atm as identified by Zhong & Wu (2023).
Namely, a warmer-than-normal Maritime Continent & West Pac as well as a Eurasian Snow Cover Dipole.
journals.ametsoc.org/view/journal...
Namely, a warmer-than-normal Maritime Continent & West Pac as well as a Eurasian Snow Cover Dipole.
journals.ametsoc.org/view/journal...
Much like last year, the very warm Tropical Indo-Pacific Warm Pool (IPWP) is going to play a major role in this coming winter.
Compare the current global mean SSTa (left) to the Oct-Nov Warm Pool SST [20S-20N, 90-150E] difference for east QBO/cool ENSO winters only (right)
Compare the current global mean SSTa (left) to the Oct-Nov Warm Pool SST [20S-20N, 90-150E] difference for east QBO/cool ENSO winters only (right)
October 31, 2025 at 10:20 PM
Much like last year, the very warm Tropical Indo-Pacific Warm Pool (IPWP) is going to play a major role in this coming winter.
Compare the current global mean SSTa (left) to the Oct-Nov Warm Pool SST [20S-20N, 90-150E] difference for east QBO/cool ENSO winters only (right)
Compare the current global mean SSTa (left) to the Oct-Nov Warm Pool SST [20S-20N, 90-150E] difference for east QBO/cool ENSO winters only (right)
Reposted
Multi-panel view of the last few days of Hurricane Melissa:
↖️ GOES-19 infrared brightness temp
↗️ GOES-19 visible satellite
↙️ Hurricane hunter planes & flight paths
↘️ Recon-derived flight level wind swath
⬇️ Estimated minimum pressure from recon dropsondes
↖️ GOES-19 infrared brightness temp
↗️ GOES-19 visible satellite
↙️ Hurricane hunter planes & flight paths
↘️ Recon-derived flight level wind swath
⬇️ Estimated minimum pressure from recon dropsondes
October 29, 2025 at 10:14 PM
Multi-panel view of the last few days of Hurricane Melissa:
↖️ GOES-19 infrared brightness temp
↗️ GOES-19 visible satellite
↙️ Hurricane hunter planes & flight paths
↘️ Recon-derived flight level wind swath
⬇️ Estimated minimum pressure from recon dropsondes
↖️ GOES-19 infrared brightness temp
↗️ GOES-19 visible satellite
↙️ Hurricane hunter planes & flight paths
↘️ Recon-derived flight level wind swath
⬇️ Estimated minimum pressure from recon dropsondes
One characteristic of Hurricane #Melissa that'll always stick w/ me is its lack of "classic" eyewall replacement cycles.
I honestly can't help but think the environmental +SRH was a factor for that, as this modeling study from earlier this yr showed:
journals.ametsoc.org/view/journal...
I honestly can't help but think the environmental +SRH was a factor for that, as this modeling study from earlier this yr showed:
journals.ametsoc.org/view/journal...
October 29, 2025 at 12:02 AM
One characteristic of Hurricane #Melissa that'll always stick w/ me is its lack of "classic" eyewall replacement cycles.
I honestly can't help but think the environmental +SRH was a factor for that, as this modeling study from earlier this yr showed:
journals.ametsoc.org/view/journal...
I honestly can't help but think the environmental +SRH was a factor for that, as this modeling study from earlier this yr showed:
journals.ametsoc.org/view/journal...
Wow. This is easily the most ridiculous dropsonde I’ve ever seen.
188 knot mean winds in the low-levels with gusts over 250 mph
Absolutely scary and historic hurricane headed into SW Jamaica this morning
188 knot mean winds in the low-levels with gusts over 250 mph
Absolutely scary and historic hurricane headed into SW Jamaica this morning
October 28, 2025 at 2:21 PM
Wow. This is easily the most ridiculous dropsonde I’ve ever seen.
188 knot mean winds in the low-levels with gusts over 250 mph
Absolutely scary and historic hurricane headed into SW Jamaica this morning
188 knot mean winds in the low-levels with gusts over 250 mph
Absolutely scary and historic hurricane headed into SW Jamaica this morning
After the conclusion of this hurricane season, we need to have a real, serious discussion about the utility and validity of sticking with standard reduction techniques for estimating sustained surface winds from flight level in really intense hurricanes.
October 27, 2025 at 4:25 PM
After the conclusion of this hurricane season, we need to have a real, serious discussion about the utility and validity of sticking with standard reduction techniques for estimating sustained surface winds from flight level in really intense hurricanes.
This latest dropsonde in Hurricane Melissa is mind boggling.
185 knot mean winds in the lowest 150m!!!
This reduces to about 155 knots at the surface, a good bit higher than the current NHC estimate of 145 kt and actually very much in line with satellite consensus (SATCON)
185 knot mean winds in the lowest 150m!!!
This reduces to about 155 knots at the surface, a good bit higher than the current NHC estimate of 145 kt and actually very much in line with satellite consensus (SATCON)
October 27, 2025 at 4:19 PM
This latest dropsonde in Hurricane Melissa is mind boggling.
185 knot mean winds in the lowest 150m!!!
This reduces to about 155 knots at the surface, a good bit higher than the current NHC estimate of 145 kt and actually very much in line with satellite consensus (SATCON)
185 knot mean winds in the lowest 150m!!!
This reduces to about 155 knots at the surface, a good bit higher than the current NHC estimate of 145 kt and actually very much in line with satellite consensus (SATCON)
Even with all of the structural, intensity, and SST/OHC changes underneath Hurricane #Melissa the last few days, the diurnal cycle still remains undefeated and inevitable
October 27, 2025 at 1:57 PM
Even with all of the structural, intensity, and SST/OHC changes underneath Hurricane #Melissa the last few days, the diurnal cycle still remains undefeated and inevitable
Holy mackerel, what a dropsonde….
This explicitly supports Melissa being a 145-150 knot hurricane 😳
This explicitly supports Melissa being a 145-150 knot hurricane 😳
October 27, 2025 at 1:09 PM
Holy mackerel, what a dropsonde….
This explicitly supports Melissa being a 145-150 knot hurricane 😳
This explicitly supports Melissa being a 145-150 knot hurricane 😳
Melissa strengthened into a cat 5 hurricane overnight, w/ winds of ~160 mph & central pressure of 913mb.
Even more strengthening is likely later today, which may put this storm in pretty rarified air historically for Atlantic hurricanes.
Awful situation unfolding for much of Jamaica
Even more strengthening is likely later today, which may put this storm in pretty rarified air historically for Atlantic hurricanes.
Awful situation unfolding for much of Jamaica
October 27, 2025 at 12:56 PM
Melissa strengthened into a cat 5 hurricane overnight, w/ winds of ~160 mph & central pressure of 913mb.
Even more strengthening is likely later today, which may put this storm in pretty rarified air historically for Atlantic hurricanes.
Awful situation unfolding for much of Jamaica
Even more strengthening is likely later today, which may put this storm in pretty rarified air historically for Atlantic hurricanes.
Awful situation unfolding for much of Jamaica
Reposted
This is probably the most tone deaf take I've seen from a professional on wxtwitter and social media more broadly speaking during a natural disaster. Not a good look.
October 27, 2025 at 7:06 AM
This is probably the most tone deaf take I've seen from a professional on wxtwitter and social media more broadly speaking during a natural disaster. Not a good look.
Man tropical weenies are getting trolled hard tonight
October 27, 2025 at 5:19 AM
Man tropical weenies are getting trolled hard tonight
A renewed bout of intensification is likely ongoing with Melissa as the central dense overcast continues to appreciably cool after sunset.
Also noticing the development of an enveloped eyewall lightning (EEL) signature here, often a signature of a high end category 4 or 5 hurricane
Also noticing the development of an enveloped eyewall lightning (EEL) signature here, often a signature of a high end category 4 or 5 hurricane
October 27, 2025 at 3:47 AM
A renewed bout of intensification is likely ongoing with Melissa as the central dense overcast continues to appreciably cool after sunset.
Also noticing the development of an enveloped eyewall lightning (EEL) signature here, often a signature of a high end category 4 or 5 hurricane
Also noticing the development of an enveloped eyewall lightning (EEL) signature here, often a signature of a high end category 4 or 5 hurricane
Imho, the structural & intensity changes we‘re currently seeing w/ #Melissa are largely tied to the diurnal cycle.
Namely, a radially outward propagating gravity wave causes cloud tops to cool at large radii by the early morning, while the inner core warms.
This is precisely what’s happening atm
Namely, a radially outward propagating gravity wave causes cloud tops to cool at large radii by the early morning, while the inner core warms.
This is precisely what’s happening atm
October 26, 2025 at 3:35 PM
Imho, the structural & intensity changes we‘re currently seeing w/ #Melissa are largely tied to the diurnal cycle.
Namely, a radially outward propagating gravity wave causes cloud tops to cool at large radii by the early morning, while the inner core warms.
This is precisely what’s happening atm
Namely, a radially outward propagating gravity wave causes cloud tops to cool at large radii by the early morning, while the inner core warms.
This is precisely what’s happening atm
Tail Doppler Radar (TDR) data from the current recon mission into Melissa shows that the vortex is vertically stacked up to 15 km w/ the upshear/NW quad being the strongest.
This is about as favorable of a vortex structure as you’ll see for rapid intensification
Plots from @cyclonicwx.bsky.social
This is about as favorable of a vortex structure as you’ll see for rapid intensification
Plots from @cyclonicwx.bsky.social
October 26, 2025 at 12:43 AM
Tail Doppler Radar (TDR) data from the current recon mission into Melissa shows that the vortex is vertically stacked up to 15 km w/ the upshear/NW quad being the strongest.
This is about as favorable of a vortex structure as you’ll see for rapid intensification
Plots from @cyclonicwx.bsky.social
This is about as favorable of a vortex structure as you’ll see for rapid intensification
Plots from @cyclonicwx.bsky.social
While Hurricane Melissa's environment at first glance doesn't seem too favorable for rapid intensification w/ 20-25+ knots of mid-level shear, there's lots of little subtleties here that argue otherwise.
Namely: the northerly wind shear vector, deep-layer +SRH, weak inertial stability, & high SSTs.
Namely: the northerly wind shear vector, deep-layer +SRH, weak inertial stability, & high SSTs.
October 26, 2025 at 12:08 AM
While Hurricane Melissa's environment at first glance doesn't seem too favorable for rapid intensification w/ 20-25+ knots of mid-level shear, there's lots of little subtleties here that argue otherwise.
Namely: the northerly wind shear vector, deep-layer +SRH, weak inertial stability, & high SSTs.
Namely: the northerly wind shear vector, deep-layer +SRH, weak inertial stability, & high SSTs.
If #Melissa finds its way south-southwest of Jamaica in several days, this environment has the highest ceiling for any Atlantic tropical cyclone I can remember.
Big, strong, slow-moving hurricanes like what #Melissa may become are when things like Oceanic Heat Content will start to matter a lot.
Big, strong, slow-moving hurricanes like what #Melissa may become are when things like Oceanic Heat Content will start to matter a lot.
October 22, 2025 at 12:21 PM
#Melissa has struggled w/ wind shear today & the vortex remains very tilted
It's common for weak TCs like #Melissa to struggle in the Central Caribbean, an area of the Atlantic known as the Caribbean "Graveyard"
Here's a mini-🧵 on what the Caribbean "Graveyard" is & why it matters here:
It's common for weak TCs like #Melissa to struggle in the Central Caribbean, an area of the Atlantic known as the Caribbean "Graveyard"
Here's a mini-🧵 on what the Caribbean "Graveyard" is & why it matters here:
October 22, 2025 at 1:40 AM