Small town USA guy. Politics nerd. Soccer fan. Interested in eyewalls, deformation zones, and hook echos.
By: TropicalAnalystwx13 , 1:27 AM GMT on July 15, 2012
It's been a while since my last blog entry. Since that time, Daniel has dissipated and is crossing the Central Pacific as a remnant low, Emilia has reached its peak with 140 mph winds and is now weakening, and Fabio has formed and become a hurricane. With Fabio being the most intense at the current time, we'll start with it. As of the latest special public advisory from the National Hurricane Center, Hurricane Fabio was located at 16.4 °N 115.4 °W (position accurate within 10 nm), or about 575 miles southwest of the southern tip of Baja California. Maximum sustained winds are up to 105 mph and the minimum barometric pressure is down to 972 millibars. The system is moving towards the west-northwest at 9 mph. Visible satellite loops reveal that Fabio has organized quite considerably over the past few hours. The eye has become much more circular and warm on geostationary imagery, with cooling cloud tops in the eyewall. Satellite intensity estimates from SAB and TAFB were T5.0/105 mph at 00 UTC, with UW-CIMSS showing a final CI# of T5.8/125 mph. While this is likely overdone some, Fabio has strengthened since the 5PM PDT special advisory and is likely nearing major hurricane intensity.
Figure 1. Evening visible satellite imagery of Hurricane Fabio.
The forecast for Fabio
Fabio is likely nearing its peak intensity. Sea Surface Temperatures have cooled to 26-27 °C, and are expected to cool even more, and an increasingly stable environment lies to the north and west of the hurricane. Gradual weakening should begin tomorrow morning, followed by more rapid weakening after 36 hours out as Fabio enters waters cooler than 26 °C. My forecast lies slightly above the National Hurricane Center's over the next 36 hours, but below it thereafter. The system should weaken to a tropical storm by Monday night and may become a remnant low as early as Tuesday.
Contrary to Daniel and Emilia, Fabio is expected to take a more northerly route. A shortwave trough is located over the Northwest USA, with the subtropical ridge north of the storm extending below that. Over the next 24 hours, this shortwave trough is expected to deepen and help erode the western edge of the subtropical ridge. This should allow Fabio to gradually turn northwest by tomorrow, north by Tuesday, and northeast by Wednesday. All of the model guidance continues to indicate that this motion will continue through the forecast period, and many of the models' 120 hour forecast point show Fabio--or the remnants of--located over California. While it is unlikely the system will be a tropical cyclone by then, increased moisture will likely impact the Southwest USA by late this week.
...FORECAST POSITIONS AND MAX WINDS...
INIT 15/0000Z 16.4N 115.4W 90 KT 105 MPH
06H 15/0300Z 16.5N 115.9W 100 KT 115 MPH
12H 15/0600Z 16.6N 116.3W 90 KT 105 MPH
24H 15/1800Z 17.2N 117.9W 80 KT 90 MPH
36H 16/0600Z 17.9N 119.1W 70 KT 80 MPH
48H 16/1800Z 19.0N 119.9W 50 KT 60 MPH
72H 17/1800Z 21.4N 120.4W 30 KT 30 MPH...POST-TROP/REMNT LOW
96H 18/1800Z 24.1N 120.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 19/1800Z 25.2N 120.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
Tropical Storm Emilia weakening
After peaking as a mid-grade Category 4 hurricane with 140 mph winds the other night, Emilia has met the same fate as Daniel and is now well on its way to dissipating. As of the latest public advisory from the National Hurricane Center, Emilia was located at 15.5 °N 132.9 °W (position accurate within 20 nm), or about 1585 miles west-southwest of the southern tip of Baja California. Maximum sustained winds were down to 50 mph and the minimum barometric pressure was up to 997 millibars. The system was moving towards the west at 15 mph. Visible satellite loops reveal that Emilia is not well-developed at all with cloud tops warmer than -60 °C covering only the southeastern side of the center of circulation. Satellite intensity estimates from SAB and TAFB at 00 UTC were T2.0/35 mph-T3.0/50 mph, with the Final CI# from UW-CIMSS at T2.9/50 mph. A blend of these values gives 45 mph, although given the satellite appearance, 40 mph would be a good value to use as well. Emilia will not survive as a tropical storm much longer.
Figure 2. Evening visible satellite imagery of Tropical Storm Emilia.
The forecast for Emilia
There's not much to be said concerning the forecast intensity of Emilia. The tropical cyclone is located over sub-26 °C waters and is surrounded in all four quadrants by very dry air. Vertical wind shear remains in the moderate range, 10 to 20 knots, which is definitely not helping Emilia's chances of entering the Central Pacific Hurricane Center as Hurricane Daniel did. The National Hurricane Center forecast shows the system becoming a remnant low by 36 hours out; I agree with this and it's possible that Emilia could become post-tropical even sooner than that.
Emilia is a very shallow system and is now embedded within the low-level tropical trade winds that move from east to west. For this reason, a motion in that direction is expected over the next few days, as indicated by the model guidance. Emilia is no threat to the island of Hawaii and should stay well away from any landmasses.
...FORECAST POSITIONS AND MAX WINDS...
INIT 15/0000Z 15.5N 132.9W 45 KT 50 MPH
12H 15/0600Z 15.4N 135.1W 40 KT 45 MPH
24H 15/1800Z 15.3N 137.9W 30 KT 35 MPH
36H 16/0600Z 15.2N 140.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 16/1800Z 15.0N 143.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 17/1800Z 14.9N 148.8W 20 KT 25 MPH...POST-TROP/REMNT LOW
For a change this evening, there are no areas of interest in the Atlantic or the East Pacific. While both basins are expected to remain quiet over the next week, the East Pacific may produce another two named storms before July is over as indicated by some of the global models. As for the Atlantic...the downward phase of the MJO is expected to remain in place through the rest of the month, and our next named storm (Ernesto) will likely not form until August unless we get a weak, sheared frontal storm now and that time. My forecast for the season remains 14 named storms, 7 hurricanes, and 4 major hurricanes, as we should see a significant spike in activity between August and September, along with 1-2 named storms in October and November. The mean position of the Subtropical ridge across the Central Atlantic so far is worrying, and it needs to be known that even in El Niño years, such as what this will be, it only takes one hurricane to make it a bad year for the USA, or one storm to make it a bad year for you.
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