Ivan and the cold front connection...

[Johnny]

I've read a few extended forecasts and have looked over a few models. I don't see any cold fronts coming down to pick Ivan up. Does anyone else see a cold front coming down in the extended? If not then what would pick Ivan up and turn to the Northwest? Thanks.

Johnny

[BayouVenteux]

I've read a few extended forecasts and have looked over a few models. I don't see any cold fronts coming down to pick Ivan up. Does anyone else see a cold front coming down in the extended? If not then what would pick Ivan up and turn to the Northwest? Thanks.

Johnny

1.) Check out the GOES East water vapor loop at the RAMSDIS site:

http://www.cira.colostate.edu/ramm/rmsdsol/RSOMAIN.HTML

By my admittedly non-professional met eyes, I think the trough to our west that is associated with a weak cold front progged to move into the central Gulf Coast region today and tomorrow as Frances moves NEward is cited as one influence that might weaken the ridge Ivan is riding underneath at present.

According to the NHC:

IVAN IS MOVING TOWARD THE WEST OR 280 DEGREES AT 16 KNOTS. THE HURRICANE IS SOUTH A RATHER STRONG SUBTROPICAL RIDGE WHICH IS STEERING THE HURRICANE WESTWARD. IN TIME...A LARGE MID TO UPPER LEVEL TROUGH IS EXPECTED TO DEVELOP OVER THE CENTRAL UNITED STATES AND THE GULF OF MEXICO. THIS TROUGH IS FORECAST TO ERODE THE RIDGE ALLOWING THE HURRICANE TO MOVE MORE TOWARD THE WEST-NORTHWEST AND NORTHWEST WITH A DECREASE IN FORWARD SPEED BY THE END OF THE FORECAST PERIOD. HOW FAR NORTH THE HURRICANE WILL MOVE DEPENDS ON THE INTENSITY OF TROUGH OVER THE GULF OF MEXICO...AND THIS VARIES WITH MODELS.

After that, it's a question of where the ridges build in, their strength...and...the timing and amplitude of the next eastward advancing trough in the 7 to 10 day period. As of this morning the 5a.m. discussion was citing the models almost unanimously developing a NE to SW ridge that will block any movement into the central and western Gulf...so at the moment...AT THE MOMENT...I would say anywhere from the MS/AL border and up to the Carolinas appears to be a possibility with regard to the progged synoptic leanings.

FWIW, That's my interpretation. Now to find my buck-fifty for the cup of coffee to go with it.