Hurricane Carlotta made landfall last night along the southern Mexican coastline with winds to near 90 mph, according to the National Hurricane Center. The circulation is now weakening rapidly over the rugged terrain of Mexico but the threat of heavy rains will continue for the next few days. Remember that tropical cyclones release a tremendous amount of heat through rain fall and it takes time for the moisture envelope to totally spin down and dissipate. The mountains of Mexico will also serve as a focusing mechanism to wring out even more moisture and should help to hasten the process. Interests in the region should continue to be aware of the rain threat, especially along the higher elevations where mud slides and flash flooding could occur with little to no warning.
There is another area of interest in the east Pacific but it is farther away from the coast and will likely move in to cooler water before it can develop much.
Now we will turn our attention to the southern and western Gulf of Mexico over the next few days. The pattern is such that there is at leas some potential for a tropical depression to form later next week. Water temps are plenty warm and the current wet phase of the MJO, coupled with the remnants of Carlotta, could trigger a low pressure area to form in the Bay of Campeche. I do not see any indication in the global computer models that anything too strong will come of this but the region will certainly bear watching as we begin the week ahead.
It appears that quite a potent storm is going to take shape over the eastern Gulf of Mexico this weekend as upper level energy digs in from the Great Plains. A surface low is forecast to form over the eastern Gulf and bring the potential for very heavy rain and severe weather to portions of Florida (figure 1).
Figure 1: Coastal Storm - 48 Hour Forecast from GFS
From there, the low is forecast to move up the East Coast, bringing with it wind and rain all the way to New England. For coastal areas, this will be basically a warm (relatively speaking) Nor’easter. If this were January, we would probably be looking at an epic snowstorm for a good deal of the East Coast. As it stand now, a decent rain event looks to be in store for a wide swath of the Florida peninsula all the way up to Maine with coastal areas experiencing rough seas and a stiff onshore flow (figure 2).
The storm is non-tropical in nature but will tap warm Gulf of Mexico water that is itself running well above normal for this time of year. This warm water will add energy and moisture to the storm system and provide the fuel for it to strengthen and dump copious amounts of rain along its track. If you have outdoor plans this weekend in Florida all the way to New England, keep up to date on the latest weather forecast for your area.
Figure 2: Coastal Storm - 60 Hour Forecast from GFS
One excellent tool to understand the impacts better of any storm event is to read the local forecast discussion from your National Weather Service office. You can find this by going to www.weather.gov and typing in your ZIP Code. Then scroll down on the landing page to find “Forecast Discussion”. It will have detailed meteorological information with timing, impacts and projected watch/warning info for any storm event forecast for your area. It’s a great tool, use it.