WxWatcher007

I wouldn’t be biting on any longer range intensity or track solution right now. Ensemble guidance is still very wide 4-5 days out. Also current intensity matters a lot less here than it’s inner organization. The more organized it becomes before the Lesser Antilles, the more likely it is to survive the Caribbean IMO, even if that doesn’t translate into wind speed early on.

Tropical Depression Five Discussion Number 2 NWS National Hurricane Center Miami FL AL052021 1100 PM AST Wed Jun 30 2021 The satellite presentation of the system over the last 6-12 hours has continued to gradually improve, with a prominent banding feature to the west of the estimated center. An ASCAT-A pass received at 2323 UTC revealed that the low-level circulation has become a bit better defined compared to earlier today, though still somewhat elongated to the south and west. The peak wind retrievals from this instrument were 30-32 kt. While subjective satellite estimates from TAFB and SAB were a bit higher, the latest estimated intensity was held at 30 kt for this advisory in agreement with the slightly lower scatterometer data. The initial motion has accelerated a bit tonight at 280/20 kt. A strong subtropical ridge is situated poleward of the tropical depression and this feature should steer the system quickly to the west-northwest over the next several days. After 72 hours, the tropical cyclone will reach the westward extent of the ridge and begin to move more poleward and slow down as the ridge also becomes eroded by a mid-latitude trough to over the eastern US. The track guidance in the latter portion of the forecast continues to exhibit large spread, with the GFS and HWRF/HMON models along the left side of the guidance envelop, while the ECMWF and its ensemble mean on the right side. The latest NHC track forecast is a shade right of the previous one, and also slightly faster, but given the spread in the models, the latter portion of the track is more uncertain than usual. While the depression is currently in a favorable environment of low vertical wind shear, warm sea-surface temperatures, and high mid-level relative humidity, the expected acceleration in forward motion could cause the system to outrun the favorable upper-level easterlies currently overhead, after 36 hours. In addition, the system could be near or over some of the Greater Antilles in the latter portions of the forecast. For these reasons, the intensity remained capped at 50 kt after 36 hours, and is still on the lower end of the intensity guidance suite, though this forecast could be somewhat conservative. Key Messages: 1. The tropical depression is expected to become a tropical storm before reaching the Lesser Antilles and tropical storm conditions are expected beginning late Thursday night in portions of the Windward and southern Leeward Islands. 2. Heavy rainfall will move quickly across the Windward and southern Leeward Islands, including Barbados, on Friday. Isolated flash flooding and mudslides are possible. 3. There is a risk of wind and rainfall impacts in portions of the Virgin Islands, Puerto Rico, Hispaniola, Cuba, the Turks and Caicos and the southeastern Bahamas through early next week. Interests in these areas should monitor the system's progress and updates to the forecast. 4. Interests in Florida should monitor updates to the forecast for this system, but it is too soon to determine what if any impacts could occur there next week given the uncertainty in the long-range forecast. FORECAST POSITIONS AND MAX WINDS INIT 01/0300Z 9.6N 46.3W 30 KT 35 MPH 12H 01/1200Z 10.5N 49.6W 40 KT 45 MPH 24H 02/0000Z 11.7N 54.4W 45 KT 50 MPH 36H 02/1200Z 13.0N 59.6W 50 KT 60 MPH 48H 03/0000Z 14.7N 65.0W 50 KT 60 MPH 60H 03/1200Z 16.5N 69.8W 50 KT 60 MPH 72H 04/0000Z 18.3N 73.8W 50 KT 60 MPH...NEAR THE COAST 96H 05/0000Z 20.9N 78.6W 50 KT 60 MPH...NEAR THE COAST 120H 06/0000Z 24.5N 82.0W 50 KT 60 MPH...OVER WATER $$ Forecaster Papin/Brown

The next few days will be telling, as other guidance keeps PTC 5 intact heading into the Gulf while the Euro/EPS kill it and keep whatever destroyed vorticity east of the US. NHC chose the non-euro camp but it can’t be understated how uncertain the longer term future is for this system. If it gets to the western Caribbean it may very well find another favorable window before being turned by the trough.

Should be a depression at 11.

Two more from today

Here’s the time lapse.

Did you report the wall cloud I see on the spotter network?

Caught this as that fell in northern CT was exploding to 58k ft. Should have a time lapse as well. About as good a view as you can get.

Potential Tropical Cyclone Five Discussion Number 1 NWS National Hurricane Center Miami FL AL052021 500 PM AST Wed Jun 30 2021 Satellite imagery indicates that the convection associated with the low pressure area over the central tropical Atlantic is becoming better organized. However, earlier scatterometer data showed that the circulation was elongated and not well defined. Since the system is about 48 h away from the Lesser Antilles and is expected to become a tropical storm before reaching the islands, advisories are being initiated at this time on Potential Tropical Cyclone Five. The initial intensity is set to 30 kt based on the scatterometer data and satellite intensity estimates from TAFB and SAB. The initial motion is 285/18. The disturbance is currently on the south side of a strong subtropical ridge, and for the next 72 h the system should move rapidly west-northwestward. Indeed, the forward speed may exceed 25 kt as the system moves through the Lesser Antilles. There is excellent agreement in the guidance on this part of the forecast track. After 72 h, the system is expected to approach a weakness in the ridge caused by a mid-latitude trough over the eastern United States. The should cause the system to slow its forward speed and turn more northwestward. The track guidance become more diverse during this time in regards to how far north the system will turn, and this part of the NHC forecast track is most similar to the GFS and UKMET forecasts. Note that the track forecast is more uncertain than usual since the system does not yet have a well-defined center. The disturbance is currently in a favorable upper-level wind pattern. However, most Atlantic systems in this area moving near 25 kt have trouble strengthening, and there are indications that the fast forward speed may produce some westerly shear. Thus, the NHC intensity forecast for the first 72 h is near the lower edge of the intensity guidance. After 72 h, the intensity forecast becomes highly uncertain due to possible land interaction and differences in the model forecasts of the upper-level winds. This portion of the NHC intensity forecast maintains a constant 50-kt intensity due to the level of uncertainty. Key Messages: 1. The system is expected to become a tropical storm before reaching the Lesser Antilles and tropical storm conditions are possible beginning Friday in portions of the Windward and southern Leeward Islands. 2. Heavy rainfall will move quickly across the Windward and southern Leeward Islands, including Barbados, on Friday. Isolated flash flooding and mudslides are possible. 3. There is a risk of wind and rainfall impacts in portions of the Virgin Islands, Puerto Rico, Hispaniola, Cuba, the Turks and Caicos and the southeastern Bahamas through early next week, although the forecast is more uncertain than usual since the system does not have a well-defined center. Interests in these areas should monitor the system's progress and updates to the forecast. 4. Interests in Florida should monitor updates to the forecast for this system, but it is too soon to determine what if any impacts could occur there next week given the uncertainty in the long-range forecast. FORECAST POSITIONS AND MAX WINDS INIT 30/2100Z 9.6N 43.7W 30 KT 35 MPH...POTENTIAL TROP CYCLONE 12H 01/0600Z 10.2N 46.6W 35 KT 40 MPH...TROPICAL CYCLONE 24H 01/1800Z 11.1N 51.0W 40 KT 45 MPH 36H 02/0600Z 12.4N 56.0W 45 KT 50 MPH 48H 02/1800Z 13.8N 61.2W 45 KT 50 MPH 60H 03/0600Z 15.4N 66.3W 50 KT 60 MPH 72H 03/1800Z 17.0N 70.9W 50 KT 60 MPH 96H 04/1800Z 20.0N 77.0W 50 KT 60 MPH...INLAND 120H 05/1800Z 22.5N 81.5W 50 KT 60 MPH...INLAND $$ Forecaster Beven

Cell near Pittsfield looks nice. Went up quickly and got a warning. 51k ft top per RadarScope.

Bingo. The eastern Caribbean called the graveyard for a reason. Those trades are tough to deal with. That said, if it gets to the western Caribbean watch out.

Nice cell to the NE of Rutland.

Recon scheduled to investigate Friday.

If I get time maybe I’ll do a post on track guidance. In the meantime, bookmark this thread:

97L this morning

No rest for the weary, as the end of June looks more reminiscent of mid August with 97L on track to become our fifth named storm of the season. With four already named, 2021 is in rarefied air with regard to the pace of TC genesis. Although the NHC provides 60% two day odds, the trend over the last 24 hours suggests that 97L may already be on its way to TD status. Tropical Weather Outlook NWS National Hurricane Center Miami FL 800 AM EDT Wed Jun 30 2021 For the North Atlantic...Caribbean Sea and the Gulf of Mexico: 1. A broad area of low pressure, associated with a tropical wave, is located about midway between the west coast of Africa and the Windward Islands. This system is producing a large area of showers and thunderstorms that continues to show some signs of organization. Environmental conditions appear generally favorable for development, and a tropical depression is likely to form during the next few days while the system moves west-northwestward at about 20 mph. Interests in the Windward and Leeward Islands should closely monitor this system as it will likely be moving through that region on Friday. * Formation chance through 48 hours...medium...60 percent. * Formation chance through 5 days...high...80 percent. 97L has a few things in its favor that 95L, the other once vigorous wave to its west, did not. First, it is developing further south, in a much more favorable environment with regard to instability and moisture. As you can see, it is south enough to stay (mostly) away from the influence of the SAL, which isn't terribly strong to begin with relative to what we've seen in past years at this time. That said, the northern envelope of the wave borders the drier environment and as a result things are a little less convectively active on the northern side (though still fairly robust as you'll see below). The second thing is the lack of wind shear. This has allowed for gradual convective organization. The path ahead toward the Lesser Antilles looks pretty clear. In fact, it's quite amazing that we don't see more TUTT influence but that's probably too deep a dive to go into right now. Now, all that said, look at the potential environment ahead. As Windspeed noted yesterday, TC genesis is one thing, it's another thing getting through the Caribbean "Graveyard" this time of year. Trades are strong in the Caribbean this time of year and that's a significant factor in why some of the guidance although bullish in the short term, are not as bullish once 97L reaches the Caribbean. There's also the potential for land interaction, but that's for another post. Overall, the environment in this part of the MDR is unusually conducive for development, and aided by a gradually warming SST environment to the west, low wind shear, and a potential CCKW to enhance convection, 97L is likely to develop over the next few days if current trends hold. From there, we will see if there's a path for survival in the Caribbean and potential long range threat to the US in the next 7--10 days.

Good luck out there today. I'm thinking of getting up into MA later but hopefully things hold together so I don't have to go far lol.

At this point, I think it’s less of a question whether 97L develops, it’s whether it can survive the graveyard. This’ll be another TC genesis miss by the Euro and ensembles at short range IMO. 97L still needs more organized convection.

Get ready for E. 97L looks like it’s trying to get it going.

Just catching up. Nice disco, @weatherwiz. Tomorrow looks active. Did you see some of the 3km NAM DCAPE numbers around here? The BOX discussion was pretty good, albeit short. Potential for a higher end day if things line up. I would not be surprised at all to see the ENH pushed a little further south into northern CT. Let's see what the landscape looks like tomorrow...

Nice storms out here. I caught some decent wind too earlier.

Nice. Looks like I’ll fall short of 100 unless I get another late spike.

Euro meanwhile, is nowhere near the GFS depiction. Model battle underway.

Nice. My station is up to 98.5.