MAweatherboy1's Blog

TD 1-E Forms; Likely to Strengthen But No Threat to Land

By: MAweatherboy1, 11:38 PM GMT on May 22, 2014

Good evening to everyone. We are now one week into the official Eastern Pacific hurricane season, and predictions are for an active season in this basin as El Nino develops. After remaining unorganized for the past few days, the season's third East Pacific invest, 92E, organized significantly today, developing a closed circulation as observed by scatterometer data as well as a clearly vigorous twist in visible satellite loops. It is a new season, so I am going to try a bit of a new format for my blogs. I hope to be able to provide at least semi-regular updates on storms before I leave for college at the very end of August, after which time I likely won't be on the blog as much. One thing hasn't changed, however, and that is the standard warning that my forecast is not official and certainly not representative of the forecast of any official agency.

Current Storm Information (from the National Hurricane Center)-
Location: About 640 miles SSW of Manzanillo, Mexico
Winds: Maximum 1 minute sustained are 30mph.
Pressure: Estimated at 1007mb
Movement: Slowly WNW, at about 3mph

Official NHC forecast:

INIT 22/2100Z 10.3N 107.4W 25 KT 30 MPH
12H 23/0600Z 10.5N 108.0W 35 KT 40 MPH
24H 23/1800Z 10.8N 108.6W 40 KT 45 MPH
36H 24/0600Z 11.1N 109.2W 45 KT 50 MPH
48H 24/1800Z 11.4N 109.7W 50 KT 60 MPH
72H 25/1800Z 11.7N 110.3W 55 KT 65 MPH
96H 26/1800Z 12.0N 111.0W 55 KT 65 MPH
120H 27/1800Z 12.0N 113.0W 50 KT 60 MPH

Model Discussion:
One glaring issue is that models have not forecast the rapid development of 92E very well. In fact, many of the 12z models don't show development for another 2-3 days, so the short term forecast is not going to rely heavily on the models. Beyond 2-3 days, I'm using a blend of models, especially the CMC and ECMWF, as well as the NAVGEM. The 12z GFS appeared to be an outlier in showing little to no development of the storm throughout the next several days. It's 18z run has now come in more reasonably, but because of these inconsistencies I've largely stayed away from it, though the 18z run is probably pretty good. For intensity, I've also considered the SHIPS model. ECMWF seems too aggressive with its prediction of a 971mb hurricane, although both the GFDL and HWRF take 1-E below 970mb, and they naturally have better initialization than the global models.

12z CMC in 5 days.

18z GFS in 5 days.

Forecast Confidence:
Track: Moderate-High
Intensity: Low-Moderate

TD 1-E is currently in an environment of very weak steering currents, as it is being nudged WNW ever so slowly by a ridge to its north and east. Little change is forecast in this steering pattern for the next 2-4 days, so a slow WNW drift seems to be the most likely scenario for 1-E, which is likely to become tropical storm Amanda in the next 24 hours. With such weak steering currents, some erratic motion is also possible, and the NHC notes that the ECMWF is even showing the system going basically stationary for a couple of days. I would expect that it will keep moving, albeit slowly, and I'm thinking the storm will go a bit north of where the NHC has it, partly because I think it will move a bit quicker and thus pick up a bit more latitude, and also because I am expecting a deeper system than the NHC. This brings me to the intensity forecast. The NHC is forecasting 1-E to strengthen steadily for the next 3-4 days before a leveling off and decrease in intensity as the storm encounters higher shear and drier air. Currently, 1-E is in an environment of low shear and warm waters that should fuel intensification. In addition, the SHIPS rapid intensification index is significantly higher than normal for this system, so a period of rapid intensification in the next 2-3 days is possible. All things considered, I have gone somewhat higher than the NHC on my forecast. I would expect 1-E to become a tropical storm by tomorrow afternoon, if not sooner, and continue strengthening for the next 4 days or so, before it starts to weaken as shear and dry air begin to affect it. It should be noted that the ECMWF shows intensification well beyond Day 5, likely due to the extended stall it has the system perform.

My forecast, remember, NOT official:

Background map credit

Land Impacts:
Direct: None
Indirect: Enhanced surf possible for southwest Mexico.

Thank you for reading! I'd appreciate any feedback on how I've structured this blog or any other comments. I hope you all have a great rest of your week and a great Memorial Day weekend!

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.