PTC#9, AKA ISAIAS, LIKELY TO REMAIN EAST OF LOCAL AREA… The large tropical wave we’ve been tracking over the last several days that was in the Atlantic Ocean has now crossed into the eastern Caribbean Sea. This system has taken the designation of Potential Tropical Cyclone #9, but for the sake of simplicity, it is helpful to think of this system as basically a tropical depression. This system has clearly struggled to organize over the last few days and a low-level center of circulation has yet to form. That is officially why the system is not a tropical storm (or a classified tropical depression) just yet. The system IS producing tropical storm force winds near the U.S and British Virgin Islands and Puerto Rico. While there are still plenty of questions that we just don’t know the answer to just yet, confidence is now much higher that impacts from PTC#9 (aka what will likely be Tropical Storm Isaias soon) will likely never happen in Alabama or northwest Florida. There is also high confidence that this system will be some type of issue (magnitude unknown) for the East Coast of the United States. Let’s look at what we know on this Wednesday evening…
LOCAL IMPACTS IN SOUTH ALABAMA & NW FLORIDA ARE UNLIKELY… First things first, let me be clear that there is good confidence this evening that whatever becomes of this system, big impacts for south Alabama and northwest Florida are now unlikely. This is not a complete all clear just yet, but this is a “breathe easier tonight as confidence is pretty high that this system will never bring impacts to our local area.” Why is this? A few reasons… 1) The overall trend (and I don’t mean the microscale trends, I mean the overarching ideas here) have been that this system would likely be an issue for the East Coast of the United States. That has been a consistent theme of this system since it emerged off the African coast several days ago. 2) The upper air pattern over Alabama and northwest Florida don’t exactly suggest we would have impacts EVEN IF the system makes it into the eastern Gulf. A large trough in the jet stream will be moving into our area this weekend. This trough (and a big ridge of high pressure over the southwestern Atlantic) will act to steer PTC#9/Isaias to the north and ultimately northeast early next week. 3) Let’s hypothetically say the system moves into the Gulf this weekend and skirts northward along the current eastern side of the cone of uncertainty. In that scenario, most (if not all) of the impacts of the system would be over the Florida Peninsula (not the Panhandle) and on the eastern side of the system. Our area, in that scenario, would be on the west side of the system with an offshore flow. Big takeaway here is that confidence is high (and growing) that local impacts in Alabama and northwest Florida are now unlikely.
UNCERTAINTY PERSISTS, BUT GOOD CONFIDENCE IN GENERAL MOTION… Once Potential Tropcial Cyclone #9 forms a low-level center of circulation, models will be able to have a better grasp of future motion. Keep in mind, there absolutely IS still a possibility that PTC#9/Isaias is ripped apart by the high terrain of Haiti and the Dominican Republic (Hispaniola) and perhaps Cuba if the system takes a more southerly track. Most models today have trended toward the idea of potentially forming a low-level center north of Hispaniola with a stronger system moving into The Bahamas and ultimately moving near or east of the Florida Peninsula and south Florida. There is high confidence in the general motion of the system moving WNW or NW for the next day or so. Interests in Hispaniola, The Bahamas, the Turks & Caicos, Cuba, and the Florida Peninsula should closely monitor the progress of this developing system. I would suggest too that interests in the Carolinas and the entire Eastern Seaboard of the U.S. closely watch this system as there is a growing degree of confidence of potential East Coast impacts.
REST OF THE TROPICS ARE QUIET… The Gulf of Mexico and the remainder of the tropical Atlantic basin are quiet with no new tropical storms expected to develop (outside of PTC#9/Isaias). Tropical waves emerging from Africa are in a hostile, unfavorable environment for intensification over the next several days. Good news!
LESS IN THE WAY OF STORMS ON THURSDAY… Unrelated to the tropics, we’ll have isolated showers and thunderstorms around south Alabama and northwest Florida on Thursday, BUT I do expect storms to be more isolated in nature meaning more of us should have sunshine throughout the day. High temperatures will be in the upper-80s.
APP ALERTS… Be sure to download our free RedZone Weather app if you haven’t done so already. redzoneweather.com/app is the link where you can download the app for your iOS or Android device. Once you have the app downloaded, be sure to visit the Alerts tab in the lower right corner of the app to select the specific notifications you would like to receive straight from me.
My next detailed forecast video will be posted by 7:15AM on Thursday morning. I’ll have the latest information on PTC#9/Isaias and a look at what you can expect this weekend locally. See you then!