Average 18 year old weather nerd. Freshman at Plymouth State University, majoring in meteorology, with the goal of becoming a professional forecaster.
By: MAweatherboy1 , 1:27 AM GMT on June 19, 2013
There are currently two active tropical cyclones in the world right now, one in the Atlantic basin and the other in the West Pacific. The Atlantic cyclone is Tropical Depression Two (02L). 02L is currently located near the southeastern corner of the Bay of Campeche. After a trek across parts of Central America, the depression is clearly in poor shape this evening, and the National Hurricane Center (NHC) very nearly issued the last advisory on the storm at 5PM EDT today. Instead, they maintained it as a weak tropical depression with maximum 1 minute sustained winds estimated at a possibly generous 30mph and a minimum central pressure of 1007mb. 02L is moving generally WNW at about 10mph.
Figure 1: Tropical Depression 02L. The center is just now reemerging over water in the Bay of Campeche. Overall, the structure of the storm is quite poor, though a well defined center remains. Most of the deep convection over Central America is simply diurnal thunderstorm activity that is not related to 02L and should dissipate in the coming hours. The weaker convection farther north is in association with 02L.
Forecast for 02L
The reasoning behind the NHC maintaining 02L as a depression in the 5PM advisory is likely at least partially due to the fact that it is now moving back over the more favorable waters of the Bay of Campeche. This will give the system a brief, but non-zero opportunity to regain strength in the next 24 hours or so before it makes a final landfall on the far southern Gulf Coast of Mexico. A steady WNW motion is likely until landfall. The official forecast from the National Hurricane Center shows little change in strength during the system's time over water, as they intensify it slightly to 35mph tropical depression status. This is very much in line with my thinking. While there is some speculation that 02L may strengthen just enough to become Tropical Storm Barry, I find that less likely right now, as I think it probably has too much reorganizing to do in conditions that are only somewhat favorable for development. An aircraft reconnaissance mission is scheduled to investigate 02L tomorrow morning, if necessary. Regardless of development, locally heavy rains, flash flooding, and mudslides will be the main threat for areas impacted by this system.
Figure 2: Official NHC forecast for 02L.
Leepi Disorganized, Poses Minimal Threat
The other active tropical cyclone in the world tonight is Tropical Storm Leepi in the West Pacific basin. According to the latest warning from the Joint Typhoon Warning Center (JTWC), Leepi is currently located about 400 miles south of Kadena Air Force Base, and is moving northward at about 10mph. Maximum 1 minute sustained winds are estimated to be about 35kts or about 40mph, making it a minimal tropical storm equivalent.
Figure 3: TS Leepi, showing a large amount of disorganized deep convection. While it looks quite menacing, looks can be deceiving, as there is very little organization within the storm right now. The very warm waters of the West Pacific make it easy for many storms to fire off extremely deep convection.
Forecast for Leepi
Leepi is currently tracking northward along the western edge of a steering ridge. This should continue for about the next 24-30 hours. After that time, the shallow system will get caught in the strong prevailing westerly winds that so often dominate the northern part of this basin, which will cause it to accelerate, begin extratropical transition, and recurve east. This will bring it on a track that takes it fairly close to the south coast of Japan. The official forecast from the JTWC keeps Leepi offshore throughout its track. Meanwhile, the JTWC forecasts slight intensification to a peak of about 45kts between 24-36 hours out. This seems reasonable to me, as despite fairly favorable conditions Leepi will likely struggle to consolidate itself. I wanted to make my own track forecast but unfortunately ran a bit short on time tonight. However, I will say that looking at the models I think Leepi will have a tough time staying off of southwestern Japan, as it will likely not get caught in the westerlies until it is around that areas latitude. Therefore, I would expect a minimal Tropical Storm Leepi to likely come very close to making an official landfall or actually make a landfall in far southwest Japan in a little under two days. Impacts will be very minimal, with just some squally weather likely, along with enhanced surf and a rip current risk, which is likely the biggest threat.
Figure 4: Official JTWC forecast track for Leepi. As mentioned, I would favor a slightly more northerly track that brings a weak Leepi into or just offshore of southwest Japan late Thursday eastern time.
That is all for tonight. I thought about adding my thoughts on what to expect for the next couple weeks, but figured that can probably wait for a day or two. I am now on summer vacation (finally!!) so will have some extra time to blog and keep up on the tropics. Thank you as always for reading, and enjoy the rest of your week.
Comments will take a few seconds to appear.