MAweatherboy1's Blog

Tropical Depression 3-E Forms

By: MAweatherboy1, 10:41 PM GMT on June 09, 2014

Good evening. For the third time this year, we are tracking a tropical cyclone in the East Pacific basin. The Atlantic is currently quiet with no development expected for the next week or so, at least. Our newest system in the East Pacific is Tropical Depression 3-E, which has formed from an area of low pressure, invest 94E, that has been tracked for the past few days. I will format this blog in the same new format that I used for my previous entry. Enjoy!
Current Storm Information (From the National Hurricane Center)
Location: Approximately 160 miles S of Zihuatanejo, Mexico, or 15.4N/102.0W
Wind: Estimated at 35mph, based on a compromise of satellite measurements
Pressure: Estimated at 1006mb
Movement: Due west, at about 5mph


Figure 1: Tropical Depression 3-E.

Official National Hurricane Center Forecast:


Figure 2: Official NHC forecast.

INIT 09/2100Z 15.4N 102.0W 30 KT 35 MPH
12H 10/0600Z 15.5N 102.8W 40 KT 45 MPH
24H 10/1800Z 15.6N 103.8W 50 KT 60 MPH
36H 11/0600Z 15.7N 105.1W 60 KT 70 MPH
48H 11/1800Z 15.9N 106.6W 70 KT 80 MPH
72H 12/1800Z 16.6N 109.1W 70 KT 80 MPH
96H 13/1800Z 17.6N 112.1W 60 KT 70 MPH
120H 14/1800Z 18.7N 114.3W 40 KT 45 MPH

Model Discussion:

As noted by the NHC discussions, global models are in generally great agreement on a WNW movement for 3-E for the next five days. In terms of intensity, there is a bit of discrepancy. The ECMWF and GFS are in fairly close agreement on their intensity forecasts, with the ECMWF perhaps a bit more aggressive, but both suggest a high end tropical storm or low end hurricane. The SHIPS intensity model as well as the HWRF, which has performed well in the East Pacific this year, are also similar to these forecasts. The GFDL model, as usual, is much more aggressive and shows 3-E becoming a strong hurricane. The CMC model is uncharacteristically unenthusiastic about 3-E’s future, showing limited strengthening.


Figure 3: HWRF forecast for 3-E in 66 hours, bringing it to minimal hurricane strength.

My Discussion/Forecast

As is sometimes the case with East Pacific cyclones, where steering currents are often more simple than Atlantic steering currents, 3-E’s future track should be fairly easy to forecast, at least for the next five days. 3-E will track west and soon WNW along the southern periphery of a strong ridge to its north. With time the motion may bend closer to NW than WNW, but an average heading of about 290 degrees should prevail for the next five days. As you will see, my forecast is quite close to the forecast of the NHC, and in good agreement with most of the global models. Inherently, the intensity forecast is a bit trickier. Currently, 3-E is in an environment of low shear and warm waters, with some hindrance from dry air. This will likely be the story of 3-E’s existence for the next 4 days or so. Shear will remain low and waters will remain plenty warm for that period. Beyond four days water temperatures will drop off and weakening will begin. The SHIPS rapid intensification index is quite high for 3-E. However, while this is a possibility, I do not anticipate rapid strengthening of 3-E due largely to a significant amount of dry air it will have to contend with. Currently, despite a seemingly healthy satellite appearance, 3-E has several problems, including a slightly elongated circulation, as shown by ASCAT, and a lack of vertical alignment between its low and mid level circulations. In addition, it has ingested a significant amount of dry air from the mountains of Mexico, as evidenced by the pronounced dry slot on its western side. While 3-E will move away from Mexico, the source of its current dry air problems, there is plenty of dry, stable air ahead of it over the open ocean, so this will act to inhibit significant strengthening. Because I think it will likely take much of the next 24 hours to resolve its current early stage problems, and because of the dry air in its path, my intensity forecast is a bit below that of the NHC, peaking 3-E just below hurricane status at 70mph, though a slight increase to hurricane strength is certainly a distinct possibility.


Figure 4: My forecast for 3-E. This is NOT an official forecast of any forecasting agency, it is only my personal forecast. For the official forecast refer to the NHC forecast. On my graphic, the lines go in 24 hour increments, where I give my predicted intensity for the system at that time, the strength of the system on the Saffir Simpson Scale (in this case it is all tropical storm), and in parentheses at the end I give the NHC intensity forecast for the same time.

Overall Forecast Confidence:
Track: High
Intensity: Moderate

Land Impacts:
* Rainfall for the area of the Mexican coast currently being affected for the next 24 hours or so. Tropical storm watches and warnings are not anticipated.
* Enhanced surf and rip currents along the Mexican coast for the next several days.

Thank you as always for reading! I hope you all enjoy the rest of our week!

-MAweatherboy1


The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

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About MAweatherboy1

Average 20 year old weather nerd. Plymouth State University Meteorology, Class of 2018. NOAA Hollings scholar. Summer 2016 intern at NWS Boston.