MAweatherboy1's Blog

Posted by: MAweatherboy1, 12:35 AM GMT on June 04, 2013 +7
With the 2013 Atlantic hurricane season now officially under way, the Atlantic is getting down to business, as there is already an invest knocking on the door of the United States. This disturbance, dubbed invest 91L, is currently located in the south central Gulf of Mexico. It is producing a very large but disorganized area of showers and thunderstorms, which are displaced well to the east of what would be considered the "center" of the system. This is indicative of wind shear, and indeed, 91L is currently in an environment of less than ideal atmospheric conditions for the formation of a tropical cyclone. According to the most recent ATCF update on 91L, it currently has winds of about 25kts and a pressure of about 1007mb. The National Hurricane Center is giving the system a 30% chance of development in the next 48 hours while it moves slowly northward.


Figure 1: Invest 91L, showing the disorganized area of convection well east of the center.

Forecast for 91L
As previously mentioned, Invest 91L is not in a particularly favorable environment for strengthening. The SHIPS intensity model is indicating 17-25kts of shear over the system for the next 24 hours, which will make organization slow at best. However, a window of opportunity may exist after this time for some development of the system. Multiple models are showing 91L developing at least a little, but the only major model to show significant strengthening is the CMC, which I have discarded from the development/intensity forecast due to its bias to overstrengthen tropical cyclones. Overall, I would give 91L a 30% chance of development within 48 hours, with a 50% chance of it ever developing, slightly higher than the 40% I have been thinking for the past 2 days or so. Models are in decent agreement on a general N/NNE track in the next few days. This should cause the system in whatever form it ultimately takes to come ashore at some point later this week. My thinking on track is shown in Figure 2. This is fairly high confidence and in good agreement with the models.


Figure 2: My thoughts on 91L.

Regardless of development, potential impacts from 91L will be the same. Heavy rainfall for the Yucatan, western Cuba, and Florida is likely in the next several days, along with some gusty winds. Development beyond a 45-50mph tropical storm is unlikely. Should this become a tropical storm, it would be named Andrea. Beyond its time in the Gulf, remnants of 91L may be drawn northward and affect the rest of the East Coast with rain and wind, though this is too far out to get into.

Elsewhere, the tropics are quiet throughout the world right now, with no imminent threats for development in any basin and none likely for at least the next 5 days. I hope to provide updates on 91L if necessary in the next few days. That is all for tonight; thank you for reading, and enjoy the rest of your week!
Updated: 12:57 AM GMT on June 04, 2013   Permalink | A A A
Posted by: MAweatherboy1, 2:18 PM GMT on June 01, 2013 +2
Today is June 1, meaning it is the first official day of the 2013 North Atlantic Hurricane Season. Our wait in finally over! With the tropics fairly quiet this morning, however, I thought I would instead blog on another June 1 related topic that has become a matter of importance for me. Today is the two year anniversary of an EF3 tornado that touched down near Springfield, MA, killing three people, injuring about 200 others, and causing well over 100 million doll...
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Posted by: MAweatherboy1, 12:18 AM GMT on May 29, 2013 +3
For the second time in about 2 weeks, a tropical cyclone has formed in the East Pacific basin, as it is off to a fast start so far this year. This cyclone, which has been upgraded from Tropical Depression 2E to Tropical Storm Barbara, was formed from the disturbance invest 92E that has been tracked off the coast of Central America for a few days. The storm is currently located about 145 miles SSW of Salina Cruz, Mexico, and is barely moving, perhaps drifting north...
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Posted by: MAweatherboy1, 11:26 PM GMT on May 21, 2013 +5
All is quiet right now in the global tropics, with no active tropical cyclones anywhere and no areas of interest being watched for development, and no development likely for the next few days at least. The next area to watch for tropical development will likely be the Eastern North Pacific basin, which has already seen one tropical storm this year, short lived Tropical Storm Alvin. Models, particularly the GFS and CMC, are hinting at the possibility of low pressur...
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Posted by: MAweatherboy1, 11:35 PM GMT on May 14, 2013 +6
Happy East Pacific Hurricane Season! Indeed, in just hours, the first official tropical weather outlook for the Eastern North Pacific basin will be issued by the National Hurricane Center, officially beginning the season which runs from May 15-Nov 30. The East Pacific couldn't quite wait for the start of its season, however, as yesterday the first invest of the season, 90E, formed. This is certainly an exciting moment, as it is a strong sign that Atlantic Hurrica...
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About MAweatherboy1
Just an average 17 year old weather nerd. I work as an observer at the Blue Hill Meteorological Observatory in Milton, MA.