Its verification time. As of 15z Today Oct 7th, Tropical Storm #Jerry has formed with 40 kt winds. Pretty clear at this point the #ECMWF has struggled with this genesis case, possibly due to the same amped up gravity wave issues that have plagued the model in the tropics for some time.

NHC will initiate advisories on Tropical Storm Jerry (formerly AL95), located over the central tropical Atlantic, at 1100 AM AST (1500 UTC). https://x.com/NHC_Atlantic/status/1975563833306493383

8am EDT Oct 5th -- NHC is monitoring an area of low pressure associated with a tropical wave (#AL95) which now has a high chance (70% 🔴) of formation over the next week. It is forecast to approach the Leeward Islands by late this week. Late... https://x.com/NHC_Atlantic/status/1974805335572693115

There is now an MDR tropical wave in the outlook that has a medium chance 🟠 of TCG in the next 7-days. The 00z Op ECMWF feels like deja vu, gravity waves in wave axis dispersing energy & preventing convective consolidation. Seems unrealistic, but check back in 5 days to see how it performs. 🌀

I'm not sure how I missed when they made the change, but .gifs now seem to upload & automacially be converted into .mp4's on @bsky.app. Finally I don't have to convert them myself! I'm probably the last person to find this out, but hurrah! 👍

Swells and high surf from Imelda are expected to produce dangerous marine conditions and rip currents along much of the East Coast of the United States during the next several days.

And with the 15z advisories -- #Hurricane #Imdelda & #Humberto are just 479 miles apart. This might be the closest two simultaneous hurricanes have ever been in the Atlantic basin in the satellite era (since ~1975). Close enough for their outer sfc circulations to interact as well.

Yes it's pretty darn unusual to see two #hurricanes in the North Atlantic basin this close. #Imelda & #Humberto. It has happened recently w/ weaker TCs (e.g., #Philippe & #Rina in 2023), but unsure the last time both systems involved in binary interaction were both ≥65 kt in the NATL. 🌀🔄🌀

Nice thread by Tomer here. Agree it requires nuance when looking at ensemble means to determine how skillful that dataset is for TC track forecasting. In addition — skill vs spread plots are helpful to see if the ensemble dataset is capturing realistic spread, or if it’s over or under dispersive.

A provocative question: *Why* is activity in the NATL basin now? NATL is under ⬇️ motion via +VP' at 200 mb. Maybe near peak annual instability helps? 🤷 @webberweather.bsky.social @ericblake12.bsky.social @drkimwood.bsky.social @tropicaltidbits.bsky.social @btangywx.bsky.social @bmcnoldy.bsky.social

Zooming out and looking at the GOES-19 Full Disk View, the western hemisphere is finally acting like September for #TC activity. While ET #Gabrielle is existing stage right, #Hurricane #Humberto (Cat 4 125 kt) & #TD9 (30 kt) have taken its place. Also can't forget Hurricane #Narda in the EPAC. 🌀

Tropical depression Nine is expected to strengthen and bring tropical storm conditions to portions of the Bahamas through Sunday night. Tropical storm conditions are also possible along portions of the east coast of central Florida beginning Monday, where a Tropical Storm Watch has been issued.

Advisories on Potential Tropical Cyclone Nine (formerly AL94) will start at 5pm ET, meaning that while it is not a tropical cyclone yet, there is high confidence of it developing and bringing significant wind or storm surge impacts to land within the next 72hrs. Check hurricanes.gov for the latest.

NHC will initiate advisories on Potential Tropical Cyclone Nine (formerly AL94), located near eastern Cuba, at 500 PM EDT (2100 UTC). https://x.com/NHC_Atlantic/status/1971670145887084834

We continue to monitor Hurricane Humberto and AL94 in the Atlantic. Make sure to check hurricanes.gov for the latest forecast.

AL94 is likely to become a tropical depression in a day or two near the Bahamas and interests there should monitor the progress of this system. Heavy rainfall is likely across portions of the Virgin Islands, Puerto Rico, the Dominican Republic, Haiti, the Turks and Caicos, & the southern Bahamas. 👇

Now that #Humberto is a #TC, want to discuss an issue ECMWF exhibits in tropics, unrealistically strong gravity wave dispersion affecting convection/vorticity. A d(prog)/dt analysis of EC shows #TCG may have been poorly forecasted by dispersion. Graphics: @burgwx.bsky.social @ polarwx.com/models/

8 am EDT - In addition to #Humberto and #Gabrielle, NHC continues to monitor #94L located near the Dominican Republic. This system has a chance of becoming a tropical depression in the vicinity of the central and northwest Bahamas during the next couple of days. hurricanes.gov

2 PM Thursday Sep 25 Update: Here are Key Messages associated with the disturbance (#AL94) located over the western Atlantic. The system is likely to become a tropical depression in a day or two near the Bahamas. Interests in the Bahamas and a... https://x.com/NHC_Atlantic/status/1971267883520098788

Tropical Storm #Humberto Advisory 1: Tropical Storm Humberto Forms in Central Tropical Atlantic. http://hurricanes.gov https://x.com/NHC_Atlantic/status/1970950374438658248

@NHC_Atlantic: 8p EDT Tues 9/23- We are monitoring 2 disturbances that are likely to become tropical depressions this week. The western one #AL94 could form near the Bahamas in a few days, with a heavy rain threat for the Lesser Antilles, Puer... https://x.com/NHC_Atlantic/status/1970638241247187073

@NHC_Atlantic: Here are the Key Messages for Hurricane Gabrielle for Tuesday evening- a Hurricane Watch is up for the Azores. Catch the latest at https://x.com/NHC_Atlantic/status/1970638800998003139

8 am EDT - There is high chance of a tropical depression forming over the central Atlantic later this week #93L and a medium chance of a tropical depression forming over the southwestern Atlantic in a few days #94L. For more information, visit https://x.com/NHC_Atlantic/status/1970454851197849794

Pretty neat radar evolution w/ #Gabrielle which rapidly intensified into a Cat 4 #hurricane today. An eyewall replacement cycle occurred, but instead of the typical cycle of the inner replacing the outer eyewall, it appears the two eyewalls merged & did not interrupt continued intensification.

Just a reminder that the application deadline for positions in the Hurricane Specialist Unit (HSU) & Technology and Science Branch (TSB) at the National Hurricane Center is *Tomorrow* So get those applications in!

8 am EDT - NHC is monitoring two tropical waves. The western one has a medium chance of development late in the week over the southwestern Atlantic. The eastern one has a high chance of development over the central Atlantic in a few days. Visit https://t.co/Wq6ZtKfHp9 for updates.

The Fall/Autumnal Equinox is TODAY at 2:19 PM EDT. That's the time at which our Sun is directly over the Earth's equator, signaling the start of Northern Hemisphere astronomical fall. The Earth’s northern hemisphere will continue to tilt further from the sun through the Winter Solstice on Dec 21.

The 2025 WPAC season finally has TCs >100 kt: Super #Typhoon #Ragasa (145 kt) 🌀 & Typhoon #Neoguri (125 kt) 🌀forming this past week. Contrasting genesis pathways. Ragasa was a classic genesis case in the monsoon trough, but Neoguri formed from an upper-level low (tropical-transition). Deep-dive ⤵️

Wrapping up this post from a week ago: Here is event verification as of 12 UTC Friday 12 Sep 2025. All quiet in the N Leeward Islands today. A tropical wave is nearing the islands, but it's not the same system as ex #91L which dissipated long ago. Be careful when choosing your weather info source.

Want to come work for the National Hurricane Center, #NHC? There are two new job postings that were just announced yesterday. The 1st opportunity is a position within the #Hurricane Specialist Unit, #HSU: GS-13 Hurricane Specialist Position -- www.usajobs.gov/job/845559000

🌍 The MMM lab at @ncar-ucar.bsky.social is running experimental realtime forecasts with a global 3.75-km MPAS model. Goal: Highlight the power of global km-scale models for weather prediction from local to planetary scales, incl. tropical cyclones. 👉 project.mmm.ucar.edu/real-time-fo...

I think it is time to re-up my thread again from last month. Posts like these on #91L do not help with public messaging. Please do not name a system before it occurs & it is not helpful to issue a track/intensity forecast if that pre-genesis system is not a short-term land threat. Just my 2 🪙s.

6-year anniversary of Hurricane Dorian stalling over the Bahamas. The result was category 1+ winds for over a day and a half, and category 3+ winds for 12 hours straight! The product attached here was derived from recon observations, and one of the first collaborations with @burgwx.bsky.social

🌎 Fresh data just in from space: the first results from the Microwave Sounder and Radio Occultation Sounder onboard @eumetsat.int’s MetOp-SG-A1 satellite are here, after less than a month in orbit: esa.int/Applications... 📸Eumetsat

I wrote about how Hurricane Katrina helped spur pretty remarkable improvements in hurricane forecasts since 20 years ago and how current and planned budget cuts by the Trump administration to research could set us back.

Impressive view of #Hurricane #Erin yesterday as its large sprawling structure moves roughly in between the Outer Banks of North Carolina & Bermuda. Both are under TS watches/warnings since Erin is so large! #NCwx

My flight actually just flew right over the #wildfire in West Broward County near Alligator Alley! Producing a thick smoke plume moving into #Miami metro & you can even see some PyroCu clouds at the fire source.🔥☁️ Paging @drdavepeterson.bsky.social @miamiherald.com @wsvn.bsky.social @nbcmiami.com

As expected #Erin has become a very large #hurricane. However, it has lost the very tight inner core it possessed over the weekend. A quick peak at a recent F18 SSMIS microwave image shows large outer rain bands are just as dominant as the core. 700mb FL wind max is also in the outer bands.

That tracks with the GFS forecast for significant wave heights with #Erin. In fact, the peak value is exceeding the colorbar on @tropicaltidbits.bsky.social maps, >48 ft in 24 hours! Very dangerous seas for ships & beachgoers alike. Please don’t go out into the water this week in the Eastern US.

Looks like a significant fire in the Everglades is bringing quite a bit of smoke into metro #Miami this morning. A little unusual to see this occurrence in late August but it’s been an unusually dry summer here in South #Florida. 🔥💨

Storm surge flooding and tropical storm conditions are expected in the NC Outer Banks beginning late Wed/Wed night, where Tropical Storm & Storm Surge Warnings are in effect. The storm surge will be accompanied by large waves, leading to beach erosion & overwash, making some roads impassible.

A tale of two very different types of TC #Erin, 18 years apart. Plenty of sustained TS winds with the 2007 event over Oklahoma with significant rainfall totals. Unfortunately led to 13 fatalities total, mostly due to flooding rain in TX/OK/MO. TCR: www.nhc.noaa.gov/data/tcr/AL0...

#Erin continues to grow, aided by an 📈 in NW shear in the past 24h. Another factor that may affect the #hurricane is cool upwelling under the large & slow system. A ocean glider found a > -2C drop in SSTs nearby. These in-situ obs help as sat-based SST data can't see the ocean till Erin moves out.

A large portion of the Atlantic coastline will see the risk for high surf and rip currents this week due to #Erin. 🟥Risk of Rip Currents is High🟥 Life-threatening rip currents are likely. Swimming conditions are unsafe for all levels of swimmers. Stay out of the water. nhc.noaa.gov/refresh/grap...

RT by @nhc_atlantic: The National Hurricane Center Director Michael Brennan will provide a LIVE update on Major Hurricane #Erin around 11:15 AM EDT today August 18, 2025. Please join us on Facebook Live and the NHC YouTube Page at: youtube.com/user/... https://x.com/NWSNHC/status/1957454684718834038

Hurricane Erin's maximum wind speed may have decreased from its peak as a category 5 hurricane, but the storm is getting larger! Here's the evolution of Hurricane Erin's size according to NHC's estimates of 34-knot (tropical storm force) wind extent from the 15 UTC advisories during 11-17 August:

8/17 evening: In addition to #Erin, the tropical wave in the eastern Atlantic now has a medium🟠chance of tropical cyclone formation within the next 7 days. The system should approach the NE Caribbean or SW Atlantic by the end of this week. ... https://x.com/NHC_Atlantic/status/1957219724087218328

The NWS' radar in San Juan PR is capturing a beautiful eyewall replacement cycle! bmcnoldy.earth.miami.edu/tropics/radar/

Unbelievable footage from NOAA’s Hurricane Hunters inside the eye of Hurricane Erin. Simply incredible.

📸August 16: Images from the NOAA Hurricane Hunter and our NOAA Satellites Ocean Winds team show an intense eyewall in Hurricane #Erin This photo shows the ocean surface calm in the eye and roaring in the eyewall. For the latest forecast visit hurricanes.gov