Here is my 2024 Atlantic hurricane season forecast. As you can see, I (like everyone else) am expecting a very active hurricane season. I’ll detail some of my thoughts and reasoning in the following thread 🧵 (1/12)
A massive, symmetrical CDO. A warming and clearing eye. And now tons of lightning surrounding about 80% of
#Ian
’s eyewall. I’m honestly not sure what to say anymore.
The day 10-15 timeframe (Mid January) has the strongest Eastern US storm signal that we've seen thus far this winter. With ridging/blocking surrounding the Eastern US, this could be one of the best widespread snow opportunities this winter. Definitely worth watching.
It's clear that
#Ian
is going to slow to a crawl as it approaches Tampa .This is because of two opposite steering flows at different levels in the atmosphere. Exactly how close Ian is at this point has huge implications on impacts, and that's something we can't nail down yet.
Still watching for East Coast storm potential on Thanksgiving weekend. There's increasing model support for a trough to dig into the Eastern US in response to a building Western US ridge. We're too far out to resolve any details at this range, but keep watching.
TS Bret (2023) ties TS Bret (2017) for earliest named storm on record. Current Bret is in position to take advantage of a very favorable environment tonight.
AL, 03, 2023061918, , BEST, 0, 112N, 414W, 35, 1008, TS
Long range thread🚨
We began January with a favorable look for snow along the East Coast, but only the Interior Northeast ended up cashing in. Mid Jan brought another favorable period, which resulted in a couple nice storms interlaced with an Arctic airmass. What’s next? (1/7)
Feb 5-6 looks like our first snow window in our upcoming favorable East Coast pattern. A huge Candian ridge and a screaming subtropical jet carrying troughs underneath said ridge is a great way to force favorable storm tracks. If our trough spacing looks good, watch out.
4” of snow on the ground here in Oakton, VA as the main stuff wraps up and some squalls head into the region. Also caught a nice video of a fox running through the yard earlier today
@capitalweather
I don't have much going on today so I thought I'd make a thread on my general thoughts as we approach this upcoming winter.
The El Nino is by far the biggest player this year due to its amplitude, but I think our persistent high-latitude blocking will play a role as well. (1/6)
Two problems this morning:
#93L
is organizing faster than modeled (looks close to TC status), and its center looks a good bit offshore the Yucatan. The upper environment looks pristine today, so we’ll see if it continues to overperform.
After a quiet December, we've entered a very active period of weather which won't be shutting down anytime soon. What will change, however, is who is favored to see snow.
We start with our retracted jet inducing a Pacific ridge and Western US trough. (1/4)
There's decent model support for a Rossby Wave Train to develop in a week, aided by the fact that the MJO is moving into the W Pacific. The downstream propogation of this should force a trough to dig into the Eastern US. East Coast storm potential will be enhanced as this occurs.
Excited to say that I'll be attending
@UWMadison
next year to major in atmospheric sciences. Looking forward to meeting everyone in the department and beginning my formal education in meteorology!
Our potential storm in 7-8 days might set off a cyclonic wave-break, something that would significantly amplify the -NAO. This could cause the pattern to get rather amplified and backed up by the end of November, potentially bringing a prolonged period of interesting weather.
#Ian
’s pressure is absolutely tanking right now. It’s fallen from 961mb to 955mb, a rate of about 4.5mb per hour.
Rapid intensification will likely go uninhibited for much of today barring an EWRC. Shear doesn't really begin to pick up until tomorrow.
September 24th, 2021
Final Hurricane Season Forecast
There will probably be more tropical cyclones in the Atlantic. Or there might not be. They will probably form over water, but some may form over Kansas. Refer to the graphic below to determine if you are at risk.
Some personal news: Thanks to NOAA’s Lapenta program, I’ll be interning with the Hurricane Research Division in Miami this summer! I’m super stoked to work with the HAFS model and it’ll also be interesting to be at AOML during hurricane season.
7 years ago, the GOAT occurred 👑
Pretty wild to think that DC is capable of a 2-3 foot storm like this but is equally capable of going snowless through January lol
It's looking increasingly likely that a TPV lobe dives into the US in about a week and proceeds to cut off from the flow. Not only does this mean a blast of Arctic air is coming, but big storm potential is also increasing. This evolution/setup is about as favorable as it gets.
Over the next several days, a big time ridge will be setting up over the Eastern US. This will do two things: it'll force our potential TC westward towards Florida, and it'll also provide an anomalously low-shear environment for this time of year.
Feb 13-15 continues to be the period I'm watching for a higher-end snow threat. This is because a threat during this timeframe would be forced by a "pattern breaker". The persistent ridge sitting off the West Coast gets forced eastward, creating an opportunity for a cutoff low.
My thoughts about the mid/long-range pattern really haven't changed over the past few days. It's still looking like our persistent cold/stormy pattern should return to the East around Feb 10.
It's rather unusual to see this type of pattern repeat itself in a La Niña year.
For the next week,
#95L
will be steered WNW under the subtropical ridge and through an incredibly favorable environment, and should become quite strong as a result. After that, its track entirely depends on the mid-latitude pattern which is unpredictable at this range.
Cat 4
#Fiona
and a strong trough look set to undergo one of the most impressive phases I’ve ever seen so close to the Eastern Seaboard. Hell of a storm incoming for SE Canada.
To my 3 Nova Scotian followers, please prepare as soon as possible.
#Lee
is undergoing about as clear of an EWRC as you’ll ever see on satellite imagery, with microwave confirming that it’s well underway. Looks like Lee is more interested in becoming fatter rather than stronger.
#98L
is entering the Carribbean. Initially, it'll struggle with shear related to
#Fiona
's outflow. Eventually, it'll outrun this shear and move under Fiona's old ULAC. This is expected to turn into a ridiculous outflow pattern which will set the ceiling quite high for 98L.
I've plotted 500mb height anomalies overlaid with the Pacific Jet for each MJO phase in El Niño years. You can see how jet extension (phases 7/8/1) favors split flow and a Rex block-type pattern over the US. It also constructively interferes with El Niño, leading to
We're still 8-9 days out, but the end of January continues to have winter storm potential for the East Coast. Models and their ensembles show a favorable "banana high" look, which indicates that both cold air and blocking should be in place. Just have to get closer to the event.
I'm honestly kinda stumped on why global model support is so weak for
#91L
. It's going to be embedded within an environment of fairly high moisture and divergence. I could see a ULL bringing some shear, though models generally have 91L outrunning it.
After a day of being fairly anemic, deep convection has exploded over
#Idalia
. This is likely forcing steady intensification and is also dragging the center south. Models are tend to be pretty bad at forecasting this (see
#Franklin
) so this may have track implications.
I guess we know what peak season: strong El Niño/record warm Atlantic edition looks like. Whole lotta waves trying to develop and a whole lotta weird, October-like tracks with upper lows all over the place. We’ll see what the next few weeks hold.
Starting to see a mesovortex appearing around
#TD10
's center, denoted by a small region of vigorous rotation. Features like this will try to take over tonight as centralized deep convection returns. This helps to build an inner core and take the TC to the next level.
Here is my snowfall forecast for our Jan 28-30 Nor'easter. I decided to include the entire Northeast, rather than just DC.
Boston will likely see extreme snowfall totals, NYC and Philly are in the highly uncertain gradient zone, and DC and Baltimore should just miss out.
#Lee
is going to continue westward under the subtropical ridge over the next few days, slowing as the ridge breaks down. In 4-5 days, Lee will turn sharply north into a weakness created by a trough moving across the Northeast. What happens next is uncertain. (1/3)
Models have recently begun pointing towards the onset of a -NAO event in a few days. Depending on how intense the initial wave break is, this could end up being a rather strong and long lasting -NAO event that pushes well into December.
Although Mid February saw a couple nice East Coast snowstorms, the period of favorability ended up being much shorter than anticipated. In fact, February looks to end with above average temps and below average snow for many. So what went wrong? (1/4)
#Franklin
is absolutely exploding this morning. Recon has found a Category 4 hurricane with pressure *still* tanking at a rate of 5mb an hour. A sharp temp spike accompanies its impressive eye; it looks like we’re trying to make a Cat 5 run here.
Odds are increasing for significant storm development in 5 days as a Pacific trough crashes into the US. Upstream wave amplification should help to strengthen this feature, and a surface low should develop east of the Rockies. (1/2)
We're closing in on our next multi-day severe weather threat, so it's time to take a closer look at it. The surface low associated with it should get both stronger and further north than the low with our previous threat, which may bring the maximum risk further north. (1/3)
On July 17th, a tropical wave moved off West Africa into the Atlantic (Invest
#95L
). It moved into the Eastern Pacific on July 29th and became
#Dora
.
Dora is now about to cross into the Central Pacific, and perhaps even the Western Pacific after. It truly is Dora the Explorer.
Snow will break out along the I-95 corridor as our northern and southern jet streams phase. An earlier phase (what meso models have trended towards) leads to an earlier onset of snow and a further west storm, allowing for higher snowfall totals.
A legitimate East Coast snow threat is coming into view for next weekend (Jan 7th). We set the stage for it as the preceding shortwave (Jan 4th) treks through the Mid-Atlantic, perhaps bringing snow showers with it. It becomes of importance once exiting the coast, phasing...
Snow has quickly tapered off in Oakton, VA, and my expectations were most definitely exceeded.
10” of snow fell (okay maybe 9.9” but I refuse to say that) over a span of 9.5 hours. Highest daily snowfall total since the great Blizzard of 2016!
Cold air damming (CAD) is going to play a big role in this weekend’s winter storm. As our storm approaches from the south, cold air will be entrenched at the surface. This will allow snow to hold on for longer in the DC area, but could force a serious ice threat in the Carolinas.
Keep in mind that this current TC outbreak is occurring in what’s frankly a terrible shear pattern basinwide. This shear should flip as we approach September, when intraseasonal forcing moves over Africa. We’re just at the foothills of a big peak season imo
Regardless of what happens Feb 6 (looks lame, bad trough spacing), the favorable pattern which we've been waiting for all winter has indeed appeared on ensembles for mid February. We finally look to settle into a nice Pacific jet extension and a -NAO favoring Atlantic.
After being torn apart by strong wind shear and undergoing major sturctural reorganization (including an EWRC),
#Lee
is on the upswing again. Very deep convection is wrapping around the new eyewall and recon is finding strengthening winds. We'll see how strong Lee gets.
The mid-latitude jet is waking up after its summer slumber. A Western US Rex block is going to put us in an amplified pattern through mid October, with an Eastern US trough and a blocking ridge over Greenland. This should lead to some seasonable big time mid-latitude storms.
Troughing will be favored in the Western US through the beginning of December, forcing the dreaded Southeast ridge to make an appearance. This favors a storm track cutting through the Midwest, enhancing storm chances there while the East Coast stays on the warm side of things.
I'm obviously going to be tracking this potentially historic snowstorm, but god it sucks that DC is going to be just barely missing out on it lol. Just ridiculous dynamics on the latest NAM.
Looks like
#90L
is overperforming the models this morning which is pretty unsurprising considering its convective activity and favorable environment. Looks like we're dealing with a sharp trough axis, not a closed low just yet, but this isn't far off from TC status.
The reason our Jan 28-30 storm has such a high ceiling it thanks to the fact that it will be located near the favorable quadrants of intense polar/subtropical jet streaks. This will lead to massive amounts of upper divergence, allowing for rapid surface deepening.
A CCKW is currently traversing the Pacific and should reach the Americas in a week. This should lead to the formation of a CAG, which could spark our first West Hem tropical activity. The EPAC is generally favored at this time of year, but we can't fully rule out the Atlantic.
All systems are go as Hurricane
#Hilary
bombs out in the Eastern Pacific. The fairly small core (despite Hilary itself being huge) implies a high intensity ceiling, barring the onset of an EWRC. Beautiful outflow is indicative of the pristine environment.
Models have perked up today regarding the development of
#94L
(low riding wave behind
#Sean
). Unfortunately, a poorly timed and unusually strong ridge for October looks to force 94L towards the Antilles. Hopefully, the westerly shear that 94L *should* face keeps it in check.
The CAG potential that we've highlighted is indeed materializing on the medium-range models in 7-10 days. There's a decent chance we get a TC out of this assuming the signal persists. Whether that development is in the Atlantic or EPAC (or both) is still very much TBD.
At least a couple inches of snow from our Jan 19th threat looks like a pretty safe bet for the Mid-Atlantic (DC to NYC) as our shortwave of interest will slide directly through the region. For those north of NYC, you're reliant on coastal low amplification which looks very iffy.
Here's my snowfall forecast for our Jan 19th snowfall event. Snow will break out across the Mid-Atlantic ahead of our shortwave swinging through. The maximum over NYC/Philly comes from an inverted trough feature, allowing snow to hang on while our coastal low pulls away.
Our North Pacific ridge will build into the Arctic over the next several days. This will open the floodgates for Arctic air to pour into a large chunk of the US. A strong baroclinic zone should set up ahead of this Arctic air, which could support a big storm in 8-10 days.
A couple weeks ago, the MJO was expected to move into the Western Pacific. This probably would've led to the death of our La Niña. Instead, the MJO is moving back into the Indian Ocean, which will actually reinforce our La Niña.
We may be in for a 3rd year of La Niña conditions.
As some have mentioned, a rare preseason tropical wave is expected to arrive in the S Caribbean as our CAG forms. The coincidental interaction between these two features could actually spark TCG. For once, the GFS may not be *completely* fantasy (though it's still overboard).
The Euro and GFS are now forecasting the strongest West Hem MJO event in March since the March 2015 event that kicked off the Super Nino.
If it verifies, its amplitude should almost certainly kill off our La Nina. I'm feeling pretty bullish on the onset of a legit El Nino event.
Not only is the North Atlantic just warm; a massive chunk of it is record warm (since 1985). This includes a huge chunk of the Far North Atlantic, parts of the Canary Current, and the majority of the Tropical Atlantic.
The only thing today’s model runs tell me is that we’re gonna be hearing a lot of “it’s so over” and “we’re so back” over the next few days. Also, I think the synoptic setup will lock in earlier than usual given that we’re only dealing with one shortwave (no phasing event).
The final 24 hours prior to
#Idalia
's landfall in Florida will be characterized by incredibly diffluent upper levels. If we don't have a core by that time, I'd expect the forecast for a low-end major hurricane to verify. If we do have a core, the ceiling is a lot higher.
With
#Ian
's center still poorly defined, track uncertainty remains pretty high. This is important not only for who gets impacted, but how strong Ian is. The longer Ian spends in the Gulf, the more time it'll have to weaken as shear will get quite high.
The Atlantic looks to remain quiet this week despite favorable intraseasonal forcing. High background pressures are likely part of this issue, as this discourages surface convergence and enhances stability. This looks to flip in about a week, however. (1/4)
Here is my snowfall forecast for our January 3rd snowstorm. Our storm will be moisture loaded but confluence will suppress the snow shield, leading to a sharp gradient but fairly high totals.
Regardless, this storm should bring a period of heavy snow to much of the DC area.
Models generally agree that
#91L
should make it to the Antilles without fully decaying. Its track forecast is going to be interesting, as the mid-latitude pattern will get pretty amped. A longwave trough will try to take 91L out to sea, though it's TBD if it'll succeed.
The pattern for Jan 31-Feb 2 is nearly perfect for a classic nor'easter. Almost every important feature exists; building Western US ridge, 50/50 low, and blocking throughout Canada.
We're still 5 days out from onset, but this is the best look for snow we've had in a long time.
For the first time this season, there's a lot to talk about in the Atlantic.
#Fiona
is undergoing an EWRC as it heads towards Bermuda and SE Canada.
#TD8
has been designated and will traverse the subtropics. Finally,
#98L
looks to become a problem as it cruises the Caribbean.
Here’s our general setup for our favorable timeframe (Mid Jan). A longwave trough will be parked over Eastern Canada, with multiple shortwaves rounding it. Whether or not a snowstorm develops depends on if one of these shortwaves can favorably interact with the subtropical jet.
For the past 2 years, the IOD has been the one thing that hasn't cooperated with our La Niña. This year, we've finally entered a -IOD. We now have a classic La Niña VP config across the globe, one that is very similar to the Spring VP configs of our most active hurricane seasons.
As much as I'd love this to be an East Coast snowstorm, the dynamics behind our Dec 23 storm are going to be ridiculous. You're forcing a trough originating from the Arctic circle to cut off in an already amplified mid-latitude pattern. The intense temp gradient does the rest.
The shortwaves that could force a storm on Feb 13-14 are already interacting with each other, as they're located within the same gyre. Gyres are difficult features to forecast, making this setup highly volatile. We should get more clarity in 2 days as our gyre breaks apart.
Our CAG is finally dying out and the associated atmospheric forcing over the Americas is fading with it. This forcing is progressing eastward over Africa which has sparked our wave train. Models have begun hinting at some tropical wave-induced TC activity as a result. (1/3)
The tropical wave emerging off Africa tomorrow has the potential to be a long-track MDR storm. I've laid out future assets and obstacles that will affect it as it traverses the MDR. I got pretty far out in the future, but used the ensemble mean to show basic features.
Ah yes, this is *exactly* what I'd expect a TC to look like after traversing 25-26C waters for the past 48 hours. Hurricane
#Sam
is one of the coolest TCs I've tracked, and thankfully it's remained far from any landmasses!
#Lee
‘s high-end intensity/longevity will generate a huge -PV bubble, meaning that *it* is the biggest driver of its environment for the coming days rather then external factors. This is pretty unusual but means that shear should remain fairly low over the foreseeable future.
We’ve reached that time of year when people decide that a Category 5 strike is inevitable because the Gulf is warm. It's probably worth noting that SSTs in the Gulf/subtropics are extremely volatile in the Spring, and have little correlation to seasonal ACE.