Self development and 'hurricanes making their own weather.

[Ed Lizard]

That trough apparently went negative to capture the 1938 storm.

Did 1938 'make its own weather', ie, influence the trough.

Who doesn't keep the Uccellini/Koscin book in their private reading room? Developing storms in Winter can release enough latent heat to cause the 500 mb pattern to change, in what is sort of a positive feedback loop, the subsiding air closest to the mean trough would be North of the hurricane, slowing the Northern part of the trough and building a ridge, perhaps, and leading to a negative tilt.

I got to thinking about this yesterday, comments are welcome

[bronxx]

That trough apparently went negative to capture the 1938 storm.

Did 1938 'make its own weather', ie, influence the trough.

Who doesn't keep the Uccellini/Koscin book in their private reading room? Developing storms in Winter can release enough latent heat to cause the 500 mb pattern to change, in what is sort of a positive feedback loop, the subsiding air closest to the mean trough would be North of the hurricane, slowing the Northern part of the trough and building a ridge, perhaps, and leading to a negative tilt.

I got to thinking about this yesterday, comments are welcome

My observation has been that:

On a couple of occasions when a large, westward moving hurricane has approached a trough that is about to re-curve it, the westward motion has continued for a period of 6-12 hrs longer than was forecast. The forecast was even substantiated by excellent data in front of the hurricane at mid and high levels; and the confidence that re-curvature was about to occur, and when, was quite high.

I do believe in those few circumstances (large, intense hurricane) the outflow from the hurricane eroded the southern extremity of that trough it was approaching, a LITTLE. IE: the hurricane's outflow was extending the ridge it was riding under a tad further west; but certainly did not extend that influence great distances as to re-configure the deep trough it was approaching.

I believe it is much more likely that the analysis and drawing of the contours at and near the bottom of the trough you posted (and others at the time) was incorrect. It might have been more accurate that the southernmost contour of the trough on the map should really have been analyzed as the outer contour around the hurricane--- meaning the trough was weaker than and/ or did not extent quite as far south as depicted, or was going to go negative shortly, anyway. Or more simply, that 209 contour around the trough should have run across central Georgia and central SC, not across N. Florida and out into the Atlantic.

I doubt very seriously a hurricane's outflow can change a major trough from top to bottom, more than a thousand miles north. Many, many, many hurricanes, intense ones included, have not initiated that influence that you question might have been the case with the Long Island Express.

It is also possible that the hurricane came westward concurrently with a westward moving mid level ridge (which is often the case with landfalling hurricanes.) That mid-level ridge north of the hurricane was plunging westward, and that ridge's western-most point poked into the trough enough to influence its configuration.

As most hurricane watchers have observed, the most intense hurricane can be quickly disfigured when it runs into even a small pocket of shear. The westerlies reign. It is only in the basic absence of westerlies that a hurricane can even exist..