WxWatcher007

Agree. If the center is really reforming north along the edge of that convection as recon seems to be finding, that could help spur a period of more consistent organization.

Tropical Storm Nicholas Discussion Number 3 NWS National Hurricane Center Miami FL AL142021 1000 PM CDT Sun Sep 12 2021 Nicholas is not yet a well-organized tropical cyclone, with little evidence of convective banding features on satellite imagery. Observations from the Air Force Hurricane Hunter aircraft indicate that the center is still not very well-defined, and appears to have reformed again, this time farther south. Data from the aircraft indicate that the central pressure has not changed much since earlier today, and the maximum winds remain near 35 kt. This is above the latest Dvorak intensity estimates from TAFB and SAB. Nicholas will be traversing very warm waters during the next day or so, and within a moist, unstable atmosphere. These factors would favor strengthening. However, moderate southwesterly shear associated with an upper-level trough over northern Mexico could be an inhibiting factor for strengthening. In spite of the shear, the GFS model forecasts the system to strengthen while it nears the Texas coast. The official intensity forecast is at the upper end of the current model guidance. Given the uncertainties in the future strength of Nicholas, a Hurricane Watch is in effect for a portion of the Texas coast. The current location of Nicholas is quite uncertain since the aircraft-reported center position is within a broad area of light winds and is well south of most of the deep convection. Although the fixes show little motion this evening, based on the model predictions, it appears likely that the center will shift or re-form significantly northward as early as Monday morning. This is at least partially accounted for in the latest NHC track forecast, but some northward adjustments are possible over night. The storm is expected to move toward a weakness in the subtropical ridge during the next 36 hours or so. The track guidance and the model consensus has shifted eastward somewhat since the earlier advisory package. This has necessitated an eastward shift in the official track, and a northeastward extension of the watches and warnings. Key Messages: 1. Periods of heavy rainfall are expected to impact portions of the Texas and Louisiana coasts through the middle of the week. Significant rainfall amounts are possible, potentially resulting in areas of considerable flash and urban flooding, especially in highly urbanized metropolitan areas. Isolated minor to moderate river flooding is also expected. 2. There is the danger of life-threatening storm surge inundation along the coast of Texas from Port Aransas to San Luis Pass. Residents in these areas should follow any advice given by local officials. 3. Nicholas is forecast to approach the middle Texas coast as a strong tropical storm late Monday and early Tuesday, and could be near hurricane intensity if it moves to the right of the forecast track and remains over water longer. Tropical storm conditions are expected along portions of the middle Texas coast beginning Monday afternoon, with hurricane conditions possible from Port Aransas to Freeport late Monday and Monday night. 4. Tropical storm conditions are expected along portions of the northeastern coast of Mexico and the coast of south Texas beginning Monday morning. FORECAST POSITIONS AND MAX WINDS INIT 13/0300Z 22.5N 95.5W 35 KT 40 MPH 12H 13/1200Z 24.7N 96.5W 45 KT 50 MPH 24H 14/0000Z 27.0N 96.5W 50 KT 60 MPH 36H 14/1200Z 28.6N 96.1W 55 KT 65 MPH...NEAR THE COAST 48H 15/0000Z 29.9N 95.4W 45 KT 50 MPH...INLAND 60H 15/1200Z 30.4N 94.8W 40 KT 45 MPH...INLAND 72H 16/0000Z 31.0N 94.0W 30 KT 35 MPH...INLAND 96H 17/0000Z 31.7N 92.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 18/0000Z...DISSIPATED $$ Forecaster Pasch

Steering pattern generally would support a close approach/threat if something could make it to the SW Atlantic in about ten days. Agree this is one to watch should it develop.

LOL

Recon has entered the invest. Looking for evidence of a well defined LLC. Some FL and SFMR readings are already over 34kts.

Agree. At least as it stands right now it looks like it's way too broad to develop quickly, and just meanders up the coastline. Where have we seen that before... Only caveat is that we're still a few days out before something actually develops so we casually watch to see what the trends are, if any. I'm more bullish on 94L. I didn't think that it'd kill more people than in LA, but once the WPC was talking high risk for rainfall, I knew something big was coming. A WPC high risk tends to be reserved for some of the all time precipitation events.

Recon heading toward the system now. They’re not wasting any time with this one.

That looks like a recurve to me but like you said, 10 days away. If that weakness isn’t there that’s trouble.

Guidance still doesn’t do a hell of a lot with it and now the GFS tries to kick it before it ever even makes a true landfall. Like Tip said yesterday, until we see something form we bide time.

I still regret not chasing that blizzard. Epic event.

Literally above average to well above average in every single relevant category.

All four areas I referenced last night are now highlighted by the NHC. Happy peak! Tropical Weather Outlook NWS National Hurricane Center Miami FL 200 PM EDT Sat Sep 11 2021 For the North Atlantic...Caribbean Sea and the Gulf of Mexico: The National Hurricane Center has issued the last advisory on Post-Tropical Cyclone Larry, located over the Labrador Sea. A tropical wave and an upper-level trough continue to produce a large area of disorganized showers and thunderstorms over portions of southeastern Mexico and the southern and central Gulf of Mexico. Although upper-level winds are not conducive for development currently, they are expected to become more favorable for the system during the next day or so. A tropical depression is likely to form on Sunday or Monday while the disturbance moves northwestward and then northward near the coast of northeastern Mexico. Further development will be possible through the middle of next week if it remains over water, and interests along the western and northwestern Gulf coast should monitor the progress of this system. An Air Force Hurricane Hunter aircraft is scheduled to investigate the system tomorrow. 1. Regardless of development, this disturbance is expected to produce heavy rain across portions of Central America and the Yucatan Peninsula through today which may lead to flash flooding and mudslides. By late this weekend, heavy rain will likely reach portions of the western Gulf coast, including coastal Texas and Louisiana through the middle of next week. Localized significant rainfall amounts will be possible, potentially resulting in areas of flash and urban flooding. * Formation chance through 48 hours...high...80 percent. * Formation chance through 5 days...high...90 percent. 2. Showers and thunderstorms have not become any better organized in association with a tropical wave located just southeast of the Cabo Verde Islands. Environmental conditions appear generally conducive for gradual development, and a tropical depression is likely to form late this weekend or early next week while the system moves westward over the far eastern Atlantic. Regardless of development, this disturbance is likely to bring gusty winds and locally heavy rain across the Cabo Verde Islands later today and tonight. * Formation chance through 48 hours...medium...50 percent. * Formation chance through 5 days...high...70 percent. 3. Another tropical wave is expected to move off the west coast of Africa in a few days. Some development of this system will be possible through the middle of next week while it moves westward across the eastern tropical Atlantic Ocean. * Formation chance through 48 hours...low...near 0 percent. * Formation chance through 5 days...low...20 percent. 4. An area of low pressure is expected to form near the southeastern Bahamas in a few days. Gradual development of this system is possible thereafter as it moves northwestward across the western Atlantic. * Formation chance through 48 hours...low...near 0 percent. * Formation chance through 5 days...low...20 percent. Forecaster Cangialosi

Tropical Weather Outlook NWS National Hurricane Center Miami FL 200 PM EDT Sat Sep 11 2021 For the North Atlantic...Caribbean Sea and the Gulf of Mexico: The National Hurricane Center has issued the last advisory on Post-Tropical Cyclone Larry, located over the Labrador Sea. A tropical wave and an upper-level trough continue to produce a large area of disorganized showers and thunderstorms over portions of southeastern Mexico and the southern and central Gulf of Mexico. Although upper-level winds are not conducive for development currently, they are expected to become more favorable for the system during the next day or so. A tropical depression is likely to form on Sunday or Monday while the disturbance moves northwestward and then northward near the coast of northeastern Mexico. Further development will be possible through the middle of next week if it remains over water, and interests along the western and northwestern Gulf coast should monitor the progress of this system. An Air Force Hurricane Hunter aircraft is scheduled to investigate the system tomorrow. 1. Regardless of development, this disturbance is expected to produce heavy rain across portions of Central America and the Yucatan Peninsula through today which may lead to flash flooding and mudslides. By late this weekend, heavy rain will likely reach portions of the western Gulf coast, including coastal Texas and Louisiana through the middle of next week. Localized significant rainfall amounts will be possible, potentially resulting in areas of flash and urban flooding. * Formation chance through 48 hours...high...80 percent. * Formation chance through 5 days...high...90 percent.

Don’t know the exact number but it’s somewhere around that.

The odds for tropical development in the Bay of Campeche and western Gulf of Mexico has continued to increase, and the NHC has designated the disturbance currently over southern Mexico as Invest 94L. This one will need to be watched as it traverses the historically favorable BoC and skirts northward along a ridge toward the western Gulf. Shear and land proximity look like potential limiting factors, but 1) this is likely to be a significant rain maker in TX/LA, and 2) If land interaction is reduced early on it could intensify at a faster rate. Tropical Weather Outlook NWS National Hurricane Center Miami FL 800 AM EDT Sat Sep 11 2021 For the North Atlantic...Caribbean Sea and the Gulf of Mexico: The National Hurricane Center is issuing advisories on Hurricane Larry, located over the Labrador Sea. A tropical wave and an upper-level trough are producing a large area of disorganized showers and thunderstorms over portions of Central America, southeastern Mexico, and the adjacent waters of the northwestern Caribbean Sea and southern Gulf of Mexico. Although upper-level winds are not conducive for development currently, they are expected to become more favorable for the system during the next day or so. A tropical depression is likely to form on Sunday or Monday while the disturbance moves northwestward and then northward near the coast of northeastern Mexico. Further development will be possible through the middle of next week if it remains over water, and interests along the western and northwestern Gulf coast should monitor the progress of this system. 1. Regardless of development, this disturbance is expected to produce heavy rain across portions of Central America and the Yucatan Peninsula through today which may lead to flash flooding and mudslides. By late this weekend, heavy rain will likely reach portions of the western Gulf coast, including coastal Texas and Louisiana through the middle of next week. Localized significant rainfall amounts will be possible, potentially resulting in areas of flash and urban flooding. * Formation chance through 48 hours...high...70 percent. * Formation chance through 5 days...high...80 percent.

So true, and maybe the saddest part is that there are still people dying as a result of what they were exposed to at the WTC site. It's all just heartbreaking and incredible to think two decades have passed.

Larry is just hauling through the area. Landfall has occurred. Hurricane Larry Tropical Cyclone Update NWS National Hurricane Center Miami FL AL122021 1150 PM AST Fri Sep 10 2021 ...LARRY MAKES LANDFALL ON NEWFOUNDLAND... Recent satellite, radar and surface data indicate that Larry has made landfall in Newfoundland near South East Bight at 1145 PM AST (0345 UTC), with maximum sustained winds of 80 mph (130 km/h) and an estimated minimum pressure of 960 mb (28.35 inches). SUMMARY OF 1150 PM AST...0350 UTC...INFORMATION ---------------------------------------------- LOCATION...47.4N 54.5W ABOUT 85 MI...135 KM WSW OF ST JOHNS NEWFOUNDLAND MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H PRESENT MOVEMENT...NNE OR 030 DEGREES AT 47 MPH...76 KM/H MINIMUM CENTRAL PRESSURE...960 MB...28.35 INCHES $$ Forecaster Blake

Congrats to Maritime Canada on getting a hurricane before New England Hurricane Larry Tropical Cyclone Update NWS National Hurricane Center Miami FL AL122021 1150 PM AST Fri Sep 10 2021 ...LARRY MAKES LANDFALL ON NEWFOUNDLAND... Recent satellite, radar and surface data indicate that Larry has made landfall in Newfoundland near South East Bight at 1145 PM AST (0345 UTC), with maximum sustained winds of 80 mph (130 km/h) and an estimated minimum pressure of 960 mb (28.35 inches). SUMMARY OF 1150 PM AST...0350 UTC...INFORMATION ---------------------------------------------- LOCATION...47.4N 54.5W ABOUT 85 MI...135 KM WSW OF ST JOHNS NEWFOUNDLAND MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H PRESENT MOVEMENT...NNE OR 030 DEGREES AT 47 MPH...76 KM/H MINIMUM CENTRAL PRESSURE...960 MB...28.35 INCHES $$ Forecaster Blake

Atlantic Basin Overview 9/10/21 The peak is here! It has been a very active season so far, with 7 US landfalls including the historic Category 4 landfall by Ida. There were also two additional hurricane strikes, with Grace making landfall as a Category 3 and Larry making a landfall as I type in Maritime Canada. These won't be the last landfalls of the season... Overview I don't really need to go into the environment. It's peak season lol and we have a cool neutral ENSO state, slightly above normal SSTs in the MDR, and while not as expansive as the extraordinary 2020 season, TCHP/OHC and D26 is very strong, especially close to home where I anticipate significant activity in the coming weeks as climo shifts from the MDR to Caribbean, Gulf, and SW Atlantic. Steering Pattern After an extraordinarily busy late August and early September in the US, as expected, the pattern reshuffled, partially driven by climo IMO, to bring less risk to the US. We saw more frequent troughs and a weaker WAR, causing some quick recurves out in the MDR. The exception was Mindy, which developed quickly close to the northern Gulf coast a few days ago. That pattern is coming to an end. As I stated in my last outlook, I expected the pattern to return to a ridge dominant Atlantic toward the end of September. We're about a third through the month of September and we're starting to see the ensemble guidance bring back ridging in SE Canada and over the central Atlantic. It's unclear how long that holds, but it opens the door to a return to the active landfall pattern we had just a few weeks ago if systems can track under the ridge. Let's go to the threats. Atlantic Areas of Interest 1) Invest 93L/Eastern MDR Wave--The wave coming off the coast of Africa has 70% development odds from the NHC. This one is not going to impact the US, but its evolution could have significant implications on another area of interest. 2) Bay of Campeche--It's a little baffling to me that this isn't an invest yet, but the NHC has odds of development at 80% within 5 days. The signal for this one continues to be a little complicated, chiefly because of proximity to land. It looks clear to me that there will be a level of development as the disturbance takes advantage of a favorable environment, including the concave nature of the BoC that should help focus vorticity. As I said in my last update, this is a great space for disturbances to develop and I think the environment brings potential for significant intensification should development happen further east, away from the western Gulf coast. The 18z GFS showed this well and to a lesser extent the 12z Euro. This is one to watch closely, as it could be a US landfall along the TX/LA coast as the disturbance slides around the edge of a ridge. The rain signal for the region looks substantial. 3) Bahamas/SE US--The signal here is growing too IMO. A broad disturbance from either a weak wave or upper low may find itself in an marginally favorable environment for development next week. The changing steering pattern continues to favor the disturbance being pushed into the SE or pulled up the coast. This is worth watching as things come into better focus. 4) Trailing Eastern MDR Wave--This is a new one. There's a strong signal, especially on the EPS, that the wave after 93L rolls off of Africa and becomes a potential long track system. What happens here is closely tied to what 93L ends up doing. Some guidance has 93L hook north quickly, while other guidance, like the Euro is a bit slower with the turn. The delay in the turn allows for 93L to moisten the environment ahead of this wave, which makes it more likely it can find a favorable environment early. In addition, this wave looks to come off of Africa much lower in latitude than 93L and travel westward as the central Atlantic ridge rebuilds, further pushing the wave west. This is the one I'm watching least, as it is still far out, but it could be something worth paying more attention to in the long term. Overall, there's no sign of the basin slowing down. After a bit of a break due to the reshuffling of the steering pattern, a combination of homebrew () focused development and a return to the ridge dominant upper level pattern increases the chances of US impacts for the foreseeable future.

Still really impressive on IR and radar.

Totally agree. The environment looks pretty favorable for some significant development IMO *if* it can avoid too much land interaction. Wouldn't be surprised at all if we saw an even more robust solution if it weren't scraping the TX coast. I'd be watching closely if I were along the TX/LA coastline.

GFS (and the guidance more broadly) shows nicely what I was talking about when I highlighted those three areas of interest. For the BoC/Gulf disturbance, the GFS keeps it further east as it rounds the periphery of a ridge and that gives it just enough space to develop pretty quickly into a hurricane that threatens the TX/LA coast in a few days. Still an outlier for now but can't be discounted at all. GFS and the 12z Euro also continues the signal for some sort of broad mess to develop off the SE US at the end of next week that would be drawn into the SE US as a ridge flexes or up the coastline as a trough advances from the midwest. Right now I'd favor some weak tropical or subtropical system, but a more focused area of vorticity would be able (I think) to modestly develop if shear continues to back off. With today being the official peak of the season I plan to write up a basin overview tonight.

That’s pretty nice organization for that latitude. This was a good long tracker. Hopefully the folks over there do alright damage wise in this storm.

Soooo…I lost?

No, nothing that far out geographically, though the wave behind the current cherry could come off Africa much lower in latitude with a more westward steering pattern at the end of September. The operational guidance has been signaling some sort of weak wave or upper low that could serve as a focal point for tropical or subtropical development in the Bahamas or just off the SE coast about a week from now. It’s subtle, but I wouldn’t expect a particularly aggressive signal given the potential of a PV streamer being nearby.