Tropical Storm Don
So far, Tropical Storm Don has been rather well behaved. Don is looking better organized this morning with max sustained winds of 50mph as of 8am and a pressure of 1000mb. Recon is currently in the storm and finding the pressure remains around 1000mb with some SFMR readings of 45-55 knots. Don is about to run out of real estate as it is aimed at the southern Texas coast and is moving NW towards the Corpus Christi area.
Don will likely make landfall late this evening or towards midnight as a moderate and perhaps strong tropical storm. It wouldn’t be shocking if winds ramped up to 60-65mph before landfall but I doubt Don will reach hurricane status. Don will likely bring with it a swath of 3-6 inches of rain along its path which will offer some relief to drought conditions across south Texas.
Elsewhere, the NHC has designated a tropical wave out around 10N/40W as a code orange area with a 30% chance of development in the next 48 hours. The wave is just now trying to detach from the ITCZ and it has a large cyclonic envelope. It is the time of year that these waves develop and this has a great chance to be our first Cape Verde cyclone.
The system is not well organized yet as deep convection is limited somewhat and disorganized, but I think as it separates from the ITCZ in the next day or so it could develop into a depression over the next 36-48 hours. The NHC intensity guidance shows steady intensification through the next 48-60 hours and then some rapid intensification in the 72-120 hour time range. The intensity models have the system at depression strength by tonight and tropical storm strength by tomorrow morning. With the current look of the system that is likely too soon. The LGEM/SHIPS models show the system reaching hurricane strength in 72 hours with the GFDL and HWRF taking the system to category 2 and even 3 status in about 4-5 days. The SHIPS guidance shows very low shear through the next 96 hours with an increase in shear beyond that. The GFS and Canadian global models show the system developing into a legitimate cyclone, while the ECMWF keeps a rather weak reflection of the storm.
I think this will become a depression sometime this weekend and likely be Emily over the weekend as well. A strong upper ridge centered over the north-central Atlantic will steer future Emily on a W to WNW track the next 3 days and the storm could affect the Islands as early as Sunday night or Monday. It could be a hurricane by this time. Beyond that the global models unanimously show a trough moving off the east coast of the US early next week weakening the western flank of this ridge. What will be important is at what latitude the system is at when this occurs. If the storm is around say 15N the trough could miss the storm and it will move through the Caribbean. If the storm is closer to 20N, this trough will likely tug future Emily NW. This trough may not be enough to re-curve the storm though as a ridge over the southern Plains may rebuild and link up with the western Atlantic ridge turning the storm to the WNW again. After that most global models do show a 500mb low in southeast Canada and a trough axis near the east coast. Depending on where the storm is and how deep this trough is will determine if she is an eventual US east coast threat or a re-curve. It is simply t0o early to feel confident one way or the other.
I will update later today on Don and over the weekend on Invest91.