Masters student in tropical meteorology at FSU. Raised in Alaskan blizzards, but drawn toward tropical cyclones by their superior PGF.
By: Levi32 , 5:28 PM GMT on June 29, 2009
Tropical Tidbit from 12:00pm EDT Monday, June 29, 2009:
No video today. There's nothing going on in the tropics.
The system that looked like it had a great chance at becoming our first named storm in the Atlantic is dead and is not a threat to develop anymore, although the surface trough should not be ignored while it's still in the gulf. The reason this didn't develop was the energy didn't get consolidated. Energy was taken to the NE out of the system and the upper low to the west finished it off. The energy is now bundling in the east Pacific again. You can see though how this pattern that I stressed so much since the beginning of June has brought the moisture north from the east Pacific into the western Caribbean and the Bay of Campeche, where a disturbance formed in each of those areas that I lined out.
Elsewhere....there are currently no imminent threats of tropical development in the Atlantic Basin. A tropical wave south of the Cape Verde Islands continues to show cyclonic turning but has no convection and is not likely to develop, but will have an eye kept on it.
A quiet June:
It's been a very quiet June in the tropics. We managed to eek out 3 named storms worldwide, with 2 in the west Pacific and 1 in the east Pacific. El Nino is continuing to do its thing and getting the MJO locked down in this pattern of upward motion in the central and eastern Pacific with downward motion in the west Pacific and north Indian Ocean.
This pattern completely shut down the Indian Monsoon during the month of June, which although expected to recover in July, will likely remain below normal. The Indian Meteorological Department reports that the cumulative seasonal rainfall for the country of India as a whole during this year’s monsoon has so far been 54% below the long period average (LPA), with 30 out of 36 meteorological sub-divisions receiving scanty precipitation.
Tropical Outlook for the next 2 weeks:
In the month of July average tropical cyclone tracks shift a little farther to the east, with storms more likely to form and travel through the eastern Caribbean and western Atlantic. A little over half of all hurricane seasons see their first named storm by July 10th.
The tropical Atlantic is forecast to be in a mostly downward phase of the MJO for the first 2 weeks of July, which suppresses upward motion and usually puts a damper on tropical activity. El Nino tends to disrupt the MJO, which means this isn't going to be a very strong pulse of downward motion like the one in the Indian Ocean that crippled the Indian monsoon. We will probably see a lot of this sort of thing throughout the of the hurricane season, with the MJO in the tropical Atlantic staying near neutral or in the negative (downward motion). One should keep in mind that the MJO, just like ENSO, is not a magic wand that kills storms or makes them form. A tropical cyclone can still form during a downward MJO pulse, it just makes it a bit harder to do.
The TUTT is forecast to be dipping into central and eastern Caribbean quite a bit during the first half of July, causing unfavorable high wind shear in these areas and the SW Atlantic during most of this time. Higher than normal trade winds through the central/east Caribbean will also be unfavorable for development.
There are 2 areas I am watching for tropical trouble during the next 2 weeks. The first one is off the Carolinas and SE US coast during the 2nd week of July between the 6th and the 13th.
The sub-tropical ridge over Texas is pretty much staying put for the next 2 weeks thanks to the El Nino pattern, but it does go through cycles of oscillating west and east. It's currently going west which is why the upper trough currently coming in will be digging so far west over the SE states. Later this week the ridge is forecasted to start pushing east again, forcing the trough back near the eastern seaboard.
The long-wave upper pattern over North America has been becoming more zonal (flatter) and that trend is expected to continue into next week. This less-amplified pattern does not produce as many trough-splits over the Gulf of Mexico. However, this sets up a pattern where fronts associated with low pressure systems off the US east coast like to hang back near the Carolinas or down near Florida and be slow to drag out. Mischief between the SW side of the upper trough and the upper ridge to the west can occur in this situation with cyclogenesis at the tail-end of those fronts. This type of situation may occur sometime in the next 7-14 days.
The 2nd area that I think has the greatest chance of seeing a tropical disturbance during the next 2 weeks is the western Caribbean. This is basically for the same reasons I called on it to see a tropical disturbance in June. The pattern we have right now with the MJO and El Nino supports periodic advection of moisture north out of the eastern Pacific and into the western Caribbean and Bay of Campeche. We are currently seeing a retreat of the moisture after a surge northward that produced a tropical disturbance in the Bay of Campeche and 93L in the western Caribbean. Moisture will again be trying to invade these areas during the next 2 weeks, predominantly the western Caribbean. Timing of these bursts will be crucial in determining whether we get tropical disturbances, as upper-level conditions will be alternating from unfavorable to marginally favorable in the western Caribbean. Although we are much more likely to see development in the east Pacific than the Caribbean, it is still in my opinion the 2nd best area to watch for the next 2 weeks.
So overall things are expected to be pretty quiet in the Atlantic, but may be a couple areas to watch during the next 2 weeks. The 2nd half of July, as you might expect due to the time of year, probably has a greater chance of seeing a named storm than the first half of the month. The eastern Pacific may also see a shot at another named storm in 3-8 days from the area of bundling energy south of central America that will be creeping NW.
The heart of the hurricane season is fast approaching. I hope everyone is prepared.
We shall see what happens!
Caribbean Visible Satellite: (click image for loop)
The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.