Teenager. Weather aficionado. Soccer fan. Realist. Posts subject to sarcasm. Goal: National Hurricane Center.
By: TropicalAnalystwx13 , 3:14 AM GMT on June 24, 2013
The broad area of low pressure well south of the coastline of Mexico finally acquired enough organization this morning to be considered a tropical cyclone. As of the latest National Hurricane Center advisory, the system was located within 50 nautical miles of 12.6N 104.4W. It had sustained winds of 35 mph and a minimum barometric pressure of 1005 millibars. Three-E was moving towards the northwest at 7 mph after being nearly stationary all day. Visible satellite loops reveal the cyclone is still very much in its formative stages, with generally disorganized shower and thunderstorm activity located south of the broad low-level circulation. However, other than moderate wind shear of 10-15 knots, atmospheric conditions are favorable for steady intensification. The NHC predicts Three-E will intensify into a tropical storm over the next 12 hours, and further to a Category 1 hurricane by 48 hours. Overall, the main impediment for more substantial strengthening is the depression's very large size. The winds in a broad storm typically are forced to cover a larger area and usually take a longer amount of time to intensify.
Figure 1. Tropical Depression Three-E at the time of classification.
Forecast for Three-E
As aforementioned, the depression is situated within a favorable environment for continued development. Maps courtesy of the University of Wisconsin-Madison indicate an anticyclone in the upper 250 millibars of the atmosphere, though it is displaced slightly to the northwest. This is imparting moderate...not detrimental...northerly wind shear on Three-E. Sea surface temperatures lie above 29°C, and 700-500mb relative humidity values are in the upper 80s (%). Ocean heat content values are at or above 50 kJ/cm^2. These conditions are favorable for rapid intensification if the storm develops a well-defined inner core, and in fact, the SHIPS is giving the storm a slightly greater than 5-in-10 chance of undergoing a 30 mph increase in winds over the next 24 hours. The broad nature of Three-E may deter this, however. A majority of the statistical model guidance do not show intensification into a hurricane; however, based on the forecast from the DSHIPS and several global models, my own forecast is unchanged from yesterday in showing a peak intensity equivalent to a Category 1 hurricane in 48 hours. After that time, the storm is expected to enter a region of cooler sea surface temperatures and more stable air, inducing steady weakening. The storm may degenerate at the end of the period.
After remaining stationary for nearly 18 hours, the depression has begun to move northwestward in response to a weakness to the cyclone's northwest. This general northwest motion is expected to continue for the next day or so. Beyond that time, a now-weak area of high pressure across north-central Mexico is expected to build in intensity and force the storm on a more west-northwest trajectory while gradually accelerating. By 96 hours, the weakening storm is expected to turn due west as it becomes embedded within the east-west low-level flow. All statistical, dynamical, and global models remain in agreement for this solution. While Three-E is not expected to make landfall, outer bands may impact the coastline and produce locally heavy rainfall and gusty winds. Increased wave heights are expected, and there is a heightened risk of rip currents.
INIT 24/0300Z 12.6N 104.4W 30 KT 35 MPH
12H 24/1200Z 13.5N 105.0W 35 KT 40 MPH
24H 25/0000Z 15.1N 106.8W 45 KT 50 MPH
36H 25/1200Z 16.2N 108.9W 55 KT 65 MPH
48H 26/0000Z 17.2N 111.3W 70 KT 80 MPH
72H 27/0000Z 18.5N 116.2W 55 KT 65 MPH
96H 28/0000Z 19.4N 121.2W 40 KT 45 MPH
120H 29/0000Z 19.7N 126.3W 30 KT 35 MPH
Invest 95E no concern
After nearly becoming a tropical cyclone last evening, Invest 95E has faltered and is no longer a threat to develop. The well-defined low-level circulation has fallen apart into a weak area of cyclonic turning, and the little convection the storm possessed is being blown away by easterly wind shear produced by Three-E's outflow. Wind shear is expected to increase to over 40 knots by this time tomorrow, and the remnants and energy of the storm should begin to be absorbed into the depression farther east before then. The National Hurricane Center is currently giving this area a 10% chance of developing into a tropical cyclone over the next 48 hours; I put these odds lower, at Near 0%.
I will have a new blog on Three-E tomorrow evening,
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