User blog:Hurricane Layten/Eyes on the Tropics: July 3, 2017

It might only be early July, but the tropics ae certainly trying to get their act together. There are currently 5 areas of discussion today. Lets start with the biggest concerns first though, then work our way down.

Out in the western Pacific, Severe Tropical Storm Nanmadol is nearing typhoon intensity, with winds of 70 mph 1-minute sustained, and 65 mph 10-minute sustained. This system has already passed through most of the Ryukyu Islands of Japan, and could also hit the mainland in around a day's time, before turning northeast out to sea and accelerating as it undoes an extratropical transition. Although the official forecasts don't call for an intensification into a typhoon, it may well be possible, considering the systems history of defying forecasts. Looking at the shear graphics, Nanmadol is in an area of favourable shear, and this will remain the case until the system moves on out into the Pacific. Water temperatures are also plenty warm in the vicinity, at around 29*C. The only thing really in Nanmadol's way to prevent it becoming a typhoon is land interaction, which should begin to have more if an impact on Nanmadol within the next several hours.

Now, onto the system that is the topic of conversation in the Atlantic. The tropical wave that is now known as Invest 94L has had it's chances updated within the last two hours, which now indicate a 20% chance of tropical cyclone formation within the next 48 hours, and a 70% chance of doing so within the next five days as it moves towards the west at about 5-10 mph. This system is beginning to be picked up by the forecasting models more over the last day or so, with the most aggressive model being the GFS, which appears to develop a tropical depression about a third of the way between the Cabo Verde Islands and the Lesser Antilles. Now, for those in that region, don't be alarmed at this, but certainly keep an eye on the system though, just in case the system doesn't follow its projected west-northwest to northwest track.

With this storm comes a first as well - the availability of the current HMON runs, the model that has replaced the GFDL this season. The HMON is indicating a track to the north-northwest over the next five days, with a peak intensity of 40kt in 36-48 hours. The other models seem to follow suit on this scenario, with the exception of the European and Canadian models, which don't really show any development of the system for several more days.

Whilst it is unlikely that Invest 94L will still be a tropical cyclone in the western Atlantic (at least at this time, anyway), it still bears watching for those on the eastern coast of the United States, just in case the system does defy the forecasts like so many other systems have around the world so far this year, but I suppose only time will tell on this matter.

Now, onto the eastern Pacific, where there is Invest 94E and another area of interest also marked by the National Hurricane Center. Invest 94E has also had it's development chances raised in the latest update, to 30% within the next 48 hours, and 50% within the next five days. 94E is expected to move out into the open Pacific, and although there is the possibility of a threat to Hawaii, it's far tpp early to say exactly what the system will do so far in advance. The modelling has really begun to back off on this system, with most of the modelling developing the system in 24-48 hours still, but really backing off in terms of the forecasted pea intensity. The GFS has gone from showing a hurricane last night to showing a moderate tropical storm at best on the latest runs, and really doesn't have the system hanging on for long. The HMON also seems to follow this reasoning, developing a tropical cyclone in around 24 hours, before peaking the system at 40kt, and having it as a remnant low by the day five period. Again though, it's only the early stages, and we all know how quickly things can change.

Anyway, I should have an update on this blog around 1800 UTC, and then probably a new blog tomorrow afternoon if conditions warrant.