Katia Weakens to Category 1 Hurricane

Katia has weakened to a Category 1 hurricane and will continue to go out to sea.

Katia will go out to sea; Unreliable CMC model hits New England

The NHC is predicting Katia to go out to sea, as it appears will happen. The East Coast will likely be safe this time, but there is another wave going off the coast of Africa. That's a different story. Katia will likely strengthen and become a major hurricane soon. As that happens, a trough will break into the western portion of the Azores High, allowing Katia to slip through the cracks.

This is a spaghetti model of the models tracking Katia. See the light blue line that scrapes New England? That's the CMC model. It is considered a very unreliable model and will be discounted at this time. Every other model lets Katia go out to sea, and I believe that is the best solution at this time.

Katia Rapidly Strengthens to Category 2 Hurricane; Track Out to Sea

Katia has strengthened rapidly overnight to a category 2 hurricane as it progresses along its way. The image you see above displays the eye and surrounding convection of Katia. Notice how defined the eye is, but how much stronger the northern side of the storm appears to be than the southern flank of Katia. This is microwave imagery.
I'm thinking that Katia will probably continue to strengthen and reach Category 3 at maximum. After that, Katia will likely curve out to sea as the Azores High breaks in the western portion asa trough moves through. As Katia gains strength, this solution becomes more likely.
Check out these ensemble models- they tell the story.

Disregard the two tracks going towards the US.
The NHC track goes along nicely with this solution.

Custom Katia Forecast

This is my custom forecast for Katia's track. I am leaving a small window, but nonetheless a window, for Katia to scrape North Carolina and OBX. I do let the option of a sharp curve out to sea for Katia, which appears to be the preferred track at this time.

East Coast Hurricane Katia Threat Being Realized

The threat of something happening on the East Coast is being realized by the models and us forecasters as we watch Katia trudge her way WNW. The reason is say the threat of 'something' happening is because I don't want to make predictions of a landfall.
Here's the NHC forecast as of this evening.

What I find interesting is that the NHC is curving more WNW after going NW with Katia. That could, emphasize 'could', play an important role in how the East Coast will be affected by Katia. I guess that the main thing is: If Katia reaches 70W-75W without going above 30N, the chances of an East Coast landfall probably increase. By how much is yet to be seen, but that is what we have right now.

Use the coordinates of 70W-75W and below 30W to see for yourself if the chances of an East Coast landfall supposedly increase. Below, you will find a description of the past couple frames in this model run of these 4 models.

GFS- NW track and also farthest north of the 4 models.
HWRF- Slightly more NW track in last couple frames of this model. Speed is also erratic.
CMC (GEM)- Really hugs the islands on this run. An East Coast landfall could be in the cards if the CMC solution verified.
GFDL- A tad south of the GFS, but close enough to the US that the East Coast could be hit as described in the GEM solution.

Katia a toss-up; Lee forms in Gulf

This is probably the shortest discussion I will issue for weeks to come. I'm exhausted.
Anyway, here's Katia's computer models and NHC track,

As well as Lee's track and rainfall forecast.

Models Think Again- Katia turns eye on East Coast

The models have shifted far west over the day as Katia weakens below tropical storm strength. Katia is once again a tropical storm after briefly reaching minimal Category 1 hurricane strength. The models have al devised a similar plan. They are now projecting Katia to come menacingly close to the East Coast. Below we have the majority of computer models as of 1:00 PM CDT excluding the ECMWF.

We believe we know maybe some of the reason of why Katia may not curve northward as quickly as previously thought. One person had stated that if Katia remains 'weak' after passing the 50W degree point in the Atlantic Ocean (see the map above), then the chances of an East Coast hit would rise. Here's a basic explanation of the more in depth stuff. There is a permanent high stationed over the Azores area. So that high pressure system is there nonstop. However, when troughs, or low pressure areas come through, they can disrupt a portion of that continuous high pressure, mainly on the west sides of the high pressure. When that happens, a gap is created that a tropical system can move into. That happens more often when the system is stronger. Seeing as how Katia is generally weak, we believe this may be occurring and that Katia may be moving more west than thought.
So let's turn to the storm's history.

The storm has been taking on a more west northwest turn over the past several days when it was expected to go more NW. That said, the chances do increase that there is an East Coast threat. If this trend continues in a WNW direction, I do believe the East Coast should begin checking their evacuation plans again. But let's not get ahead of ourselves.

Here's the NHC's forecast. The NHC is expecting Katia to go NW sooner rather than later, in the manner that, by the time I wake up tomorrow, we should see if the NHC was wrong. You really can't blame them in this case- Katia is quite a tricky one to forecast at this time. That's why we are reviewing all aspects. The NHC takes Katia back into hurricane stage and eventually into a major hurricane status, something that would indeed compel Katia to go northwest.

Here we have the ensemble members for track and intensity. Check out how the models in the track are having a fairly tough time, with some of them going haywire. It reminds me of a jumbled stack of wires, and you're trying to find the one that works. There does appear to be a NW consensus over the next few days. But again, if that does not happen, there will be some big changes in store. Intensity forecasts are interesting. This is a more crucial part of the forecasting. Look at the red line at the bottom of the intensity forecast 144 hours out. That is the GFS line. Basically, if it stays in Category 1 strength, it will likely meander along the East Coast like Irene did, but maybe not hit New York. We aren't sure at this time.
Here's the thing you've been waiting for: the ECMWF model.

The ECMWF does take Katia to a fairly strong strength and low pressure. The only reason I say fairly is because resolution is low and we aren't able to zoom in enough to get an accurate reading for our standards. Anyway, the ECMWF does threaten the East Coast, but other than increasing dangerous rip currents and heightening waves, there aren't any huge side effects as Katia should then go out to sea. But as we've learned over the years, do not trust one single model. Trust the consensus.  Of course, even consensus' change time after time in each model run suite. But a band of models is still better than a single model.

Because this is so long range, we are opting not to rely on any models or consensus' right now, but we are  thinking that the GFS may be a contender to be the storm track winner later on.

Katia a hurricane, looking out to sea with latest model runs

It does appear that the East Coast will likely be safe from Katia, but not for sure. Ensembles show Katia strengthening to a major hurricane as it moves NW. One model has Katia in Category 5 strength. Here's the NHC's track.

And here is historical tracks for storms located within 2 degrees of Katia at this moment.