Question for Met--On Motion of Recent Longwave Troughs

[Berwick Bay]

I'm posting this WV overview of the continent to illustrate the westward or what appears to me "retrograde" motion of the longwave trough over the Eastern U.S. (Backing back to the west). Am I mistaken or didn't this just happen a couple of weeks ago with another air mass. I know that very infrequently, here in La. during the winter months, we will get a frontal boundary come in from the NE instead of the NW. This seems to be basically the same thing except no real change in temps, just evidence of the motion of upper air masses. I'm used to seeing independent minded upper level lows retrograding in the tropical Carribean and Gulf during the hurricane season. But normally the movement of these longwave troughs is a pretty consistent W to E. What about this, and what about the implications for tropical development? (Would seem to work against it.) Here's the loop.

[Berwick Bay]

Forgot the loop. Here it is.

http://weather.unisys.com/satellite/sat ... op-12.html

[JonathanBelles]

I was beginning to think that my self. Everything down here seems to be going west or south, which in florida is normal, but in the rest of the US, this isnt normal. Isnt the Jet still over florida? If so than why is everything going against it?

[Aric Dunn]

I'm posting this WV overview of the continent to illustrate the westward or what appears to me "retrograde" motion of the longwave trough over the Eastern U.S. (Backing back to the west). Am I mistaken or didn't this just happen a couple of weeks ago with another air mass. I know that very infrequently, here in La. during the winter months, we will get a frontal boundary come in from the NE instead of the NW. This seems to be basically the same thing except no real change in temps, just evidence of the motion of upper air masses. I'm used to seeing independent minded upper level lows retrograding in the tropical Carribean and Gulf during the hurricane season. But normally the movement of these longwave troughs is a pretty consistent W to E. What about this, and what about the implications for tropical development? (Would seem to work against it.) Here's the loop.

first and for most! that vertically stacked system is over cool water second the long-wave trough/ upper low that is on top of it would have to dissipate or move away as in the case with Andrea or ana a few years ago. now there is a very well defined surface low that would have the potential to possible turn sub tropical or trop if !! it were to lose the upper low and the important thing is move much farther south ! south of say 35 to 30 north. with that said the chances are never zero but very low do to the fact that the surface low is imbeded within the long-wave trough, which by the way is a large and well established complex area of multiple ULL within it. it would take quite a bit to break that down and or move out and leave the surface feature behind but i have seen stranger things i guess, but very unlikely. but everything is always worth watching because there is something to learn.

[MGC]

Looks like an classic omega block pattern to me. Don't look like anything is going anywere anytime soon. Hope the shear stayes like it is all season......MGC

[Berwick Bay]

Yes I agree. And this is the second time since the latter part of May that I've seen the air mass over the East Coast work its way "backwards" or retrograde. You would think that it has to be negative for development. But you know me, its my nature to "reach out" and see if I can find anything at all. My thinking now(strictly wishcasting--okay by me!) is that the retrograde air mass can't continue to much further west (Remember the High still over Mexico). Yet that High and its attendant shear in the central Gulf might be weakened as it eases back a little west toward the West Gulf Coastal Waters of Texas and Mexico. Now the ULL in Bay of Campeche is moving SW toward the Vera Cruz area of Mexico. There may be a "niche" (love that word) between all three of these systems. That niche would be NW of the Yucatan Penninsula at about 24N and 92W (those numbers again). It is possible however that I am simply trying to relive my heroics of June 1st, when Barry came to be in a "niche" that I foresaw between three air masses.

[HouTXmetro]

Yes I agree. And this is the second time since the latter part of May that I've seen the air mass over the East Coast work its way "backwards" or retrograde. You would think that it has to be negative for development. But you know me, its my nature to "reach out" and see if I can find anything at all. My thinking now(strictly wishcasting--okay by me!) is that the retrograde air mass can't continue to much further west (Remember the High still over Mexico). Yet that High and its attendant shear in the central Gulf might be weakened as it eases back a little west toward the West Gulf Coastal Waters of Texas and Mexico. Now the ULL in Bay of Campeche is moving SW toward the Vera Cruz area of Mexico. There may be a "niche" (love that word) between all three of these systems. That niche would be NW of the Yucatan Penninsula at about 24N and 92W (those numbers again). It is possible however that I am simply trying to relive my heroics of June 1st, when Barry came to be in a "niche" that I foresaw between three air masses.

lol, we will see. but the 16th is approaching rapidly...Time is running out BB !!!!

[Berwick Bay]

Oh yeah, Houston. The timeframe is a loser now. The "forecast" therefore a bust. But there's not much else going on, and considering everything (at least for a few days more), I'll continue to watch this area. But regardless of what happens now, my "forecast" was a bust, because it is dependent not just on place, but on time.

[tailgater]

BB here's what is supposed to happen with the ULL in the BOC.

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
218 PM EDT WED JUN 13 2007

DISCUSSION FROM JUN 13/0000 UTC. A MID/UPPER TROUGH OVER THE
WESTERN USA EXTENDS SOUTH TO THE MEXICAN BORDER...MEANDERING OVER
NORTHERN SONORA-CHIHUAHUA. THE TROUGH WILL BE SLOW TO
EVOLVE/MIGRATE...BLOCKED BY A RIDGE ACROSS MID WEST USA. AN UPPER
LEVEL RIDGE IS TO MEANDER ACROSS NORTHERN MEXICO... WITH GRADUAL
INTENSIFICATION OF THIS AXIS AS THE CYCLE PROGRESSES. AS THE
PATTERN EVOLVES...EXPECT A GRADUAL DECREASE IN CONVECTION ALONG
THE SIERRA MADRE OCCIDENTAL OF MEXICO...WITH MAXIMA OF 20-40MM
ACROSS SINALOA DURANGO EXPECTED THROUGH 36 HRS...AND 15-30MM/DAY
AT 36-84 HRS.

AT 250 HPA...THE SUBTROPICAL RIDGE INITIALLY CONSISTS OF TWO
CELLS...THE AFOREMENTIONED OVER NORTHERN MEXICO/WESTERN GULF AND
ANOTHER ACROSS THE CARIBBEAN BASIN. THE LATTER IS TO CENTER ON A
CLOSED HIGH OVER SOUTHERN GUATEMALA/EL SALVADOR EARLY THIS
CYCLE....SUPPORTING A RIDGE OVER THE CARIBBEAN/ CENTRAL AMERICA.
THROUGH 72 HRS THE HIGH WILL MOVE TO SOUTHERN MEXICO...WHERE THE
CARIBBEAN-MEXICAN RIDGES WILL MERGE INTO A BROAD RIDGE PATTERN. AS
THE RIDGE PATTERN EVOLVES...A WANING TUTT OVER THE CENTRAL
GULF/CAMPECHE SOUND...WILL MOVE OVER YUCATAN PENINSULA BY 24
HRS...WITH WEAK VORTEX OVER THE YUCATAN CHANNEL BY 48 HRS. AT
60-72 HRS IT WILL LIFT ACROSS WESTERN CUBA AS IT MERGES INTO THE
BASE OF A BROAD TROUGH OVER THE BAHAMAS/EASTERN USA.