2012 Atlantic Hurricane Season Birdseye Discussion #15A (Special Update)

By: NCHurricane2009 , 4:13 AM GMT on May 23, 2012

Share this Blog
2
+

...MAY 23 2012...
Early tropical activity persists in the Atlantic basin! The Naval Reasearch Laboratory (NRL) of the United States Navy has upgraded an area of disturbed weather in the western Caribbean Sea to Invest 94-L.

This disturbance has been several days in the making as a browse through previous discussions shows:
Second special feature section of discussion #12
Paragraph P6 of discussion #13
Paragraphs P7 and P8 of discussion #14
Paragraph P7 of discussion #15

The prognosis for this disturbance had been that it would not develop due to exposure under westerly vertical shear on the north side of Caribbean upper ridging. The upper ridge was expected to remain suppressed to the south (and maintain the shearing) due to (a) the upper vorticity near Tropical Storm Alberto and (b) the next upstream frontal upper trough behind this upper vorticity.

Shortly after full discussion #15 was written...the lowest surface pressures in the western Caribbean were able to collocate with the Caribbean upper ridge axis...and the system became a little better organized with T-storm banding features E of the low surface pressures. T-storm activity west of the low surface pressures remains absent due to the persistence of aforementioned westerly vertical shear.

The upper vorticity near what was once Alberto has been absorbed by the next upstream frontal upper trough...as this frontal system moves into the eastern US. The first challenge this system faces is surviving the impulse of westerly vertical shear on the south side of this frontal upper trough.

The second challenge is adjacent dry air that has been persisting in the Gulf of Mexico and northern Florida over the last several days (for example see discussion #15...paragraph P5 for the source of this dry air). If the low surface pressures spin up into a cyclone...the cyclonic circulation could easily ingest this dry air source.

Prognosis this early morning is to watch this system carefully...and see how well it fares against the above two challenges. If I see signs of tropical cyclone formation...I will once again be resuming pre-season full birdseye discussions. If not...this will be the last until June 1 2012. Regardless...the presence of this disturbance will continue rains in the western Caribbean (Honduras...Nicaragua...Cayman Islands...Jamaica...Cuba) and Bahamas over the next days. Some of these areas have been saturated by the persistent rainfall with this sytem...so flooding is another possibility.

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 7 - 1

Page: 1 — Blog Index

7. nigel20
3:59 PM GMT on May 25, 2012
Quoting NCHurricane2009:

You're welcome. Technically I wrote this about 24 hrs ago....but this update seems to still be relevant with 94L struggling....


No problem. Have 94L's rains reach you?

We had mostly light to moderate showers...nothing significant
Member Since: November 6, 2010 Posts: 11 Comments: 8226
6. NCHurricane2009
3:58 AM GMT on May 24, 2012
Quoting ilovehurricanes12:
thanks for the update on invest 94L

You're welcome. Technically I wrote this about 24 hrs ago....but this update seems to still be relevant with 94L struggling....

Quoting nigel20:
Thanks much NC

No problem. Have 94L's rains reach you?
Member Since: September 15, 2009 Posts: 503 Comments: 3688
5. nigel20
3:50 AM GMT on May 24, 2012
Thanks much NC
Member Since: November 6, 2010 Posts: 11 Comments: 8226
3. NCHurricane2009
2:45 PM GMT on May 23, 2012
Quoting KoritheMan:
It has been rather active, hasn't it?

Yeah...I am really impressed with the amount of pre-season activity. Until Alberto formed...I was thinking it felt like 2011...but we are now a bit ahead of 2011....
Member Since: September 15, 2009 Posts: 503 Comments: 3688
2. KoritheMan
6:35 AM GMT on May 23, 2012
It has been rather active, hasn't it?
Member Since: March 7, 2007 Posts: 587 Comments: 20877

Viewing: 7 - 1

Page: 1 — Blog Index

Top of Page

About NCHurricane2009

NCHurricane2009 doesn't have a bio yet.