WxWatcher007

It's going to be a couple of ugly days for Fred due to land interaction and shear on the other side. Not much else to say until it at least passes DR/Haiti. Still looks like a favorable environment in the Gulf though. Edit: hours

3G? Were you carrying a flip phone?

FYI

Product: Air Force Vortex Message (URNT12 KNHC)Corrected: This observation corrected a previous observation.Transmitted: 11th day of the month at 1:25ZAgency: United States Air Force Aircraft: Lockheed WC-130J Hercules with reg. number AF96-5302 Potential Tropical Cyclone: Six (flight in the North Atlantic basin)Mission Number: 2Observation Number: 11 ( See all messages of this type for this mission. )A. Time of Center Fix: 11th day of the month at 0:40:40ZB. Center Fix Coordinates: 17.34N 66.30WB. Center Fix Location: 75 statute miles (121 km) to the SSW (192°) from San Juan, Puerto Rico (U.S.).C. Minimum Height at Standard Level: 1,504m (4,934ft) at 850mbD. Minimum Sea Level Pressure: 1009mb (29.80 inHg)E. Dropsonde Surface Wind at Center: From 50° at 6kts (From the NE at 7mph)F. Eye Character: Not AvailableG. Eye Shape: Not AvailableH. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 35kts (40.3mph)I. Location & Time of the Estimated Maximum Surface Wind Inbound: 31 nautical miles (36 statute miles) to the N (6°) of center fix at 0:31:00ZJ. Maximum Flight Level Wind Inbound: From 115° at 40kts (From the ESE at 46.0mph)K. Location & Time of the Maximum Flight Level Wind Inbound: 66 nautical miles (76 statute miles) to the NE (38°) of center fix at 0:20:00ZL. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 25kts (28.8mph)M. Location & Time of the Estimated Maximum Surface Wind Outbound: 8 nautical miles to the W (274°) of center fix at 0:43:00ZN. Maximum Flight Level Wind Outbound: From 43° at 31kts (From the NE at 35.7mph)O. Location & Time of the Maximum Flight Level Wind Outbound: 77 nautical miles (89 statute miles) to the WNW (291°) of center fix at 1:01:00ZP. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 17°C (63°F) at a pressure alt. of 1,532m (5,026ft)Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 19°C (66°F) at a pressure alt. of 1,526m (5,007ft)R. Dewpoint Temp (collected at same location as temp inside eye): 7°C (45°F)R. Sea Surface Temp (collected at same location as temp inside eye): Not AvailableS. Fix Determined By: Penetration, Wind and PressureS. Fix Level: 850mbT. Navigational Fix Accuracy: 0.02 nautical milesT. Meteorological Accuracy: 6.5 nautical milesRemarks Section: Maximum Flight Level Wind: 43kts (~ 49.5mph) which was observed 71 nautical miles (82 statute miles) to the NE (38°) from the flight level center at 0:19:00Z Maximum Flight Level Temp: 19°C (66°F) which was observed 8 nautical miles to the N (352°) from the flight level center

Don’t want to get too far ahead of myself, but 95L has a high ceiling to me. The environment ahead looks good for development and this could be another long range US threat given the steering pattern.

A tradition unlike any other!

It’s having a hard time developing a closed circulation. This is effectively a very sharp wave at the moment. As soon as it closes off it’ll be a named system.

No upgrade at 5pm.

Invest 95L has been designated in the eastern Atlantic. Looks like August

This. Buyer beware. I think the ceiling is certainly higher than 24 hours ago, but land interaction is still a big wildcard IMO. It looks like unlike earlier model runs, the upper level environment in the Gulf is going to be more favorable for organization and/or intensification.

The recon earlier didn't find enough evidence of a closed center, so it wasn't designated. It looks pretty solid on visible satellite right now though. We're not far off from our next named system of the season.

Looks like recon found reliable 40kt surface winds. Close call on whether there’s enough of an LLC to name. Probably just enough IMO.

Definitely ill defined and broad, but I agree, probably worth a name.

Dude, I hadn't even looked until you said something. Looks like I won't be sleeping for a while

Reposting this here because it's a great find. Thank you! It's good to know my lack of sleep is actually creating something of value for people. Also, for folks reading, here's the 06z EPS. Remember it only goes out 6 days, but note that now we're starting to see stronger ensemble members show up. Far from a lock, but that's definitely something to watch.

Oh yeah, I appreciate the tweet thread. Always good to throw out ideas. Totally agree on the Gulf hit. I know some of you got fringed in Elsa, but that was impactful up here in my neck of the woods. That's part of the reason why I am discounting the GFS solution for inland impacts for now. Tallahassee to Detroit Express doesn't really fit climo

Recon en route now to see if this has actually become a tropical cyclone. Still looks like it's trying to get its act together, but certainly wouldn't be surprised if they found a closed circulation.

Interesting thread. I agree that it's possible for this to slide further west into the Gulf, but I don't think it's likely. The operational guidance (for those that are lurking, I mean the GFS, Euro, etc.) in general has been consistent and more important--has stayed within the range of track possibilities outlined by both the ensembles (GEFS, EPS). The huge caveat here though is we're tracking a Potential Tropical Cyclone. TC genesis has not officially occurred yet, though recon is en route right now to confirm. Once we have more data and a well-defined center, we can have greater confidence in eventual track. We've seen situations before where you get a center a little further north or south and it can make a difference in intensity which can make a difference in track. I think one thing for this region to watch, is the sharpness of the curve. I think there's a pretty high chance this ridge pushes this into the Gulf, but there's a split in what happens after that. Does this end up being a sharper recurve that brings remnants to the region or does the GFS have the right idea and the ridge actually pushes this almost due north and washes it out quickly. I think that's entirely up in the air at this point. GEFS EPS While we're at it, once again I want to note the signal on both ensembles for a follow up wave right after this one...

Surprised nobody posted the GFS. It might be a blip, but it really intensifies the system in the Gulf. Looks like a hurricane landfall in the Big Bend area verbatim. Looks like the potential shear vector is further west in the Gulf and that’s enough for this to quickly organize. Just one run, but interesting..

Caveats galore for the HWRF when there isn't a well-defined center.

Wasn’t it Isaias that split the Mona pass last year and became a hurricane while doing it?

I love me some HWRF, I just don't like looking at it before something is well-defined and closed off. I do think it has a higher ceiling than this time yesterday, but as you said, a lot of moving pieces with this one. These Caribbean crossers always seem to be a challenge. Totally agree about having a stronger vortex. I think we'll get one of modest strength before PR, so then it becomes a question (to me at least) of 1) how damaged, if at all, it becomes crossing land and 2) does the shear actually pan out? We've seen cases where shear isn't quite what we thought (in both directions) and it has had a significant impact on the eventual evolution of a tropical system. Finally, what will happen with this ridge? It seems like there's agreement that this ridge holds until the Bahamas, but then there's divergence on the guidance in when a more pronounced turn occurs. I think the 12z EPS does a good job with individual members highlighting a fairly wide variety of possible track outcomes. A lot of interesting pieces to watch.

I think it would survive (barely), but it'd be hard pressed to recover, especially if it gets sheared after passing the area.

Finally, here's the discussion. As @Windspeed was mentioning, those towers going up in PTC 6 right now could have an impact on the track, as a center positioned a little further north could allow for the vortex to miss some land masses. It does look like the environment in the western Atlantic could keep things in check if that were to happen, but we'll need to see what the trends are with projected shear in the next few days. Of course, this could also hit everything given the ridge to the north steering it WNW. Potential Tropical Cyclone Six Discussion Number 1 NWS National Hurricane Center Miami FL AL062021 500 PM AST Mon Aug 09 2021 Deep convection associated with the area of low pressure located northeast of Barbados has continued to consolidate this afternoon, with several bands noted in both satellite and radar data from Barbados and Martinique. ASCAT data from this morning revealed a sharp trough axis, but the system lacked a well-defined circulation. However, recent visible satellite imagery hints that a better defined center may be forming just southwest of the primary convective mass. These trends suggest the system is likely to become a tropical depression or storm tonight or Tuesday when it moves near the Lesser Antilles and into the eastern Caribbean. Therefore, advisories are being initiated on the system in order to issue Tropical Storm Watches for portions of the Lesser Antilles, the U.S. Virgin Islands, Puerto Rico and parts of the Dominican Republic. Since the system is still in its formative stage the initial motion estimate is a somewhat uncertain 290/13 kt. A mid-tropospheric ridge anchored over the western Atlantic should steer the system west-northwestward through the forecast period. Although there is high confidence in the overall steering pattern over the next several days, there is lower than normal confidence in the details of the track forecast, especially in the short-range due to the lack of a well-defined center. Exactly where the center forms will have some downstream implications on the exact forecast track, especially across the eastern Caribbean. Regardless of the exact track, locally heavy rainfall and gusty winds are expected to spread across portions of the Leeward Islands, the Virgin Islands, Puerto Rico, and the Dominican Republic over the next day or two, hence the need for Tropical Storm Watches for portions of those areas. The disturbance is embedded within an area of low vertical wind shear and SSTs of around 28C. These conditions favor additional development, but the occasional entrainment of dry mid-level air located just west of the system is likely to prevent more rapid organization. By Wednesday, the system is likely to be near Hispaniola, where subtle differences in the forecast track could have large implications on the intensity of the storm later this week. A track directly over Hispaniola would likely significantly disrupt the circulation, while a track more poleward of the island could allow the system to stay more intact. An additional caveat beyond 48 hours is that vertical wind shear out of the southwest may also increase, which could limit the intensity after the system moves past Hispaniola, although uncertainty exists in how much the shear will increase given differences between the more favorable ECMWF and less favorable GFS model solutions. The NHC intensity forecast brings the system up to a 45 kt tropical storm before potential land interaction with Hispaniola and afterwards is conservative given the possibility of additional land interaction and less favorable environmental conditions towards the end of the forecast period. KEY MESSAGES: 1. The system is forecast to become a tropical storm as it moves through the Lesser Antilles tonight. Tropical storm conditions are possible in portions of the southern Leeward Islands tonight and Tuesday and in the Virgin Islands and Puerto Rico beginning Tuesday afternoon, and in the Dominican Republic by Wednesday. 2. Heavy rainfall could lead to flash, urban, and small stream flooding and potential mudslides across the U.S. Virgin Islands and Puerto Rico. The greatest threat for flooding impacts will be across the eastern and southeastern portions of Puerto Rico. 3. There is a risk of wind and rainfall impacts in portions of Hispaniola, the Turks and Caicos, the southeastern Bahamas, and Cuba later this week, although the forecast is more uncertain than usual since the system is still in its formative stage. Interests in these areas should monitor the system's progress and updates to the forecast. 4. Interests in the remainder of the Bahamas and Florida should monitor updates to the forecast for this system, but it is too soon to determine what if any impacts could occur there by late this week or this weekend given the uncertainty in the long-range forecast. FORECAST POSITIONS AND MAX WINDS INIT 09/2100Z 14.2N 59.2W 30 KT 35 MPH...POTENTIAL TROP CYCLONE 12H 10/0600Z 15.4N 61.4W 35 KT 40 MPH...TROPICAL CYCLONE 24H 10/1800Z 16.8N 64.5W 40 KT 45 MPH 36H 11/0600Z 17.9N 67.3W 45 KT 50 MPH 48H 11/1800Z 19.2N 70.2W 35 KT 40 MPH...INLAND 60H 12/0600Z 20.3N 72.8W 35 KT 40 MPH...OVER WATER 72H 12/1800Z 21.1N 75.0W 35 KT 40 MPH 96H 13/1800Z 22.8N 78.8W 40 KT 45 MPH 120H 14/1800Z 24.5N 82.0W 40 KT 45 MPH $$ Forecaster Brown/Papin