Only moving 4 mph making forecast tricky!

[caneman]

This will keep the forecast even trickier. This will give her plenty of time over very hot Gulf waters to bomb and I think the next model runs will change again. I'm not sure that the model runs have this slower speed factored in.

[krysof]

If it's moving very slowly, the trough could approach it and the high will break down well before it would move westward.

[BamaMan]

I agre krysof, or it could maintain a low latitude, and strengthen, create its own environment in a way, and not even be picked up by the trough. Looks like a bunch of 2K'ers are going to start feelin even more bug-eyed the next few days.

[caneman]

If it's moving very slowly, the trough could approach it and the high will break down well before it would move westward.

Exactly what I'm thinking but not ready to go out on a limb just yet. I do think we will continue to see changes though.

[Mac]

The slower forward speed may be an indication she is preparing to turn. The key thing to watch out for now is a flashing turn signal on her right rear quarter panel.

[krysof]

The question about whether or not the trough will pick it up is also unclear. It's quite far south than it was supposed to be, and the trough doesn't seem to be digging south.

[HollynLA]

Kind of reminding me of Georges. The NHC was insisting it was going to turn towards Florida but the turn happen much later. I sure hope that doesn't happen again as it will take a place by surprise.

[HurricaneGirl]

It wasn't expected it to dip South either. You never know what it's going to do until it does it.

[CFL]

That's exactly what keeps us glued to these boards. Tropical forecasts have so many variables. I wonder what caused that southwest motion over the peninsula.

[HurricaneGirl]

Good question CFL. Now we have to wait and see how strong she will get and who's going to be in her path next.

[wjs3]

The 5 Pm Discussion explained what induced the SW motion:

12Z AND 18Z UPPER-AIR DATA
INDICATE THE SUBTROPICAL RIDGE TO THE NORTH OF KATRINA HAS CHANGED
LITTLE WHILE AN INVERTED MID- TO UPPER-LEVEL TROUGH HAS DEVELOPED
NORTHWARD FROM THE CARIBBEAN SEA TO KATRINA. THE TROUGH IS EXPECTED
TO INDUCE A SLIGHT SOUTH OF DUE WEST MOTION FOR THE NEXT 12 HOURS
OR SO.

We're all used to seeing troughs to the north of storms, turning them north. They pop up to the south too.

[HurricaneGirl]

Thanks for pointing that out wjs3. That's what I love about these boards. People are always helping eachother to learn.

[wjs3]

Sure.

I just Read Derek's latest forecast too...he discusses this issue much better. It looks like the ridge to the north of the storm was a lot stronger than expected too. Take a read of that too. He'll refer to the 500 MB heights--and when you hear high heights (as he refers to) that means high pressures.

[tronbunny]

The slower forward speed may be an indication she is preparing to turn. The key thing to watch out for now is a flashing turn signal on her right rear quarter panel.

You've made my morning!!

[Steve H.]

This ridge may have the opposite effect since it is retrograding. Remember in this case the trough will poke in due to the high re-positioning westward, causing a weakness to the north and east.

[dcuevas]

This might not be the right place to ask this question but here I go. Does anyone think Katrina could impact Tampa? I saw one Model that puts it through the mouth of Tampa Bay. All Mets here say we won't get anything but wind and rain. However.... I think some Mets in Miami didn't think it was anything to worry about down there either and now look at the situation. Correct me if I'm wrong please.

[johngaltfla]

THIS IS NOT AN OFFICIAL FORECAST NOR ANY TYPE OF FORECAST, JUST MY OBSERVATION...

I'm wondering if now that it's only cruising along at 3-5 mph if that means it has escaped the ridge and is just going to drift for the next 12-24 hours until something picks it up.

If everyone remembers Charley, it stalled also briefly before the low picked it up and slammed the coast just south of us. The bad part about a stall here is the 88-91 degree SSTs.

[wjs3]

Of course it's possible to affect Tampa...

Look at it this way. Overnight, Katrina was on the extreme left edge of the NHC cone...and she was stronger than their forecast. No reason the same kind of thing couldn't happen and happen toward Tampa...

And, things go funny with the models--like Derek's forecast points out, they are guidance, not truth--and models predicts ridges that are too strong, troughs that are too weak (or vice versa), and as they change, so can the forecast and the actual path and intensity of the storm.

But nothing we can do but watch and wait now!

[dcuevas]

Thanks wjs3! My mothers name is Kathleen (KAT) so she said this storm would be a mean lady like her. ( I mean that with respect to mom - just incase she is online)

[BamaMan]

Well spoken wjs3