Ex Katia storm thread - TECHNICAL DISCUSSION, FORECASTS AND OBSERVATIONS ONLY!

nacho libre

fairly good explanations about low pressure and high pressure here:

http://geography.about.com/od/climate/a/highlowpressure.htm

http://www.weatherquestions.com/What_causes_low_pressure.htm

monster1

well lads, the auld lad has to go up to galway for treatment in the hospital monday morning.. will it be ok to travel in the morning or should we organise accommodation sunday nite? thanks in advance, ye doing a good job

sdanseo

Can't see it stopping you driving once you're not on an exposed cliffside road :rolleyes: - but if whoever is going to be driving is not that confident driving when it's a bit windy then maybe best to organise something in advance.

TheMilkyPirate

Katia can suck my hairy balls.

monster1

ah right,as long as there wont be trees and mobile homes in the middle of the road on the way il be grand. was just making sure it wasn't going to be dangerous on the way up.. although I want it to be a proper storm all the same.. cheers

monster1

so its only going to be a bit windy? ah fack it..

M.T. Cranium

The guidance continues to give mixed reviews for Katia but I am leaning towards the stronger winds as well as stressing that overnight (tonight) there may be strong frontal showers and thunderstorms moving very quickly, in this scenario strong gusts can develop rapidly too, not just in the coastal regions but scattered around other regions depending on where the storms are stronger. That part will pretty much have to come from very short-term forecasts and radar interpretation.

My impression was that the two European models have stronger wind potential for the northwest than the various North American models, and also, I have been watching hourly positions for the storm and noticed that after a jog north 21-23z the motion has returned more to ENE and now the centre seems to be close to 50N 28W. This seems to be a bit south of what the models would suggest even in a 6-hour time frame. So now the wait begins to see exactly how strong this storm will become.

I have maintained the alerts in the Boards forecast and added this comment ... a point I would like to stress is that the west and north coast winds are not the only story of this storm, the potential for overnight frontal storms must be watched closely as well. And those could affect more populated areas all over the country.

MiNdGaM3

Looks to me like Monday night will be worse in the north than tonight.

irish1967

1 Hour.... No Posts.... Ah this is what is meant by the Calm Before The Storm !

MiNdGaM3

irish1967 wrote: »

1 Hour.... No Posts.... Ah this is what is meant by the Calm Before The Storm !

Busy watching Ireland fart about against the USA maybe?

nacho libre

MiNdGaM3 wrote: »

Busy watching Ireland fart about against the USA maybe?

I was, anyway. I fear we are going to get hammered next week:(

nacho libre

Parts of Scotland, and the very north west of Ireland gets the worst of the wind on this guidance

MiNdGaM3

nacho libre wrote: »

I was, anyway. I fear we are going to get hammered next week:(

Yeah, don't want to watch the match next week but I know I will in the end!

I wonder how long the storms will keep tracking up towards us? Maria goes on a similar path to Katia but gets rapidly absorbed into a low around Iceland before it arrives.

maquiladora

I think Australia will be hammering Ireland a lot stronger than ex-Katia ever will! :rolleyes:

Anyway, here is the latest warning from Met Eireann. I can't remember the previous one, so not sure what if anything has been added here.

Issued at 11 September 2011 - 07:21

Weather Warning

Later Sunday night and continuing through Monday, southwest winds will increase to mean speeds of 50 to 80km/h, with gusts ranging 90 to 130 km/h. The most sustained and severe winds are expected across Connaught and Ulster.

Exceptionaliy high seas along the western seaboard, in conjunction with high spring tides, may cause coastal flooding in prone locations during Monday also.

Redsunset

Here is the previous warning,

Severe weather warning
Warning Stormy weather is likely to develop late Sunday night and continue much of Monday with coastal counties of Connaught and Ulster most at risk. Connaught and Ulster most at risk Southwest winds could gust between 100 and 130 km/ hr in exposed areas. Very high waves expected on west, northwest and north coasts on Monday with wave heights between 6 and 10 metres

maquiladora

http://www.ssd.noaa.gov/eumet/neatl/flash-wv.html

Looks to be more or less on track up to 06:00 UTC anyway.

Deep Easterly

Satellite animation of Katia between 12.15utc 8th Sept through to 0615utc 11th Sept in 6 hour increments:



Amazing to see how as a hurricane, Katia was slow moving but once she got caught up in the jet, there was no stopping her.

ronnie3585

It's incredible to see how fast she crossed the Atlantic!

maquiladora

The global models still have the pressure wrong for ex-Katia.

Look at the Fax compared to the UKMO.

John.Icy

Seeing the first few slides of that satelite image sequence would make you think katia is going to plough straight through us. Nex time for us Southies

Deep Easterly

maquiladora wrote: »

The global models still have the pressure wrong for ex-Katia.

Look at the Fax compared to the UKMO.

HIRLAM has it at 965mb at the same time frame on the 06 run. I think it is fairly typical for actual LP values in a deepening depression to be slight lower than what is indicated by quality NWP models and I reckon the guys at Exceter are probably taking that into account, but it is a tricky one for sure to try and estimate.

Pangea

Looks iike the storm had lots of potential but will turn out out to be a relativley normal very windy event. High seas should be nice to look at it.

maquiladora

Deep Easterly wrote: »

HIRLAM has it at 965mb at the same time frame on the 06 run. I think it is fairly typical for actual LP values in a deepening depression to be slight lower than what is indicated by quality NWP models and I reckon the guys at Exceter are probably taking that into account, but it is a tricky one for sure to try and estimate.

Yep, the NHC on their last advisory for the storm had it about 20mb lower than the models based on the last buoy it passed near to yesterday. The models corrected a bit but not enough and thats why I think there is still that difference now.

maquiladora

Pangea wrote: »

Looks iike the storm had lots of potential but will turn out out to be a relativley normal very windy event. High seas should be nice to look at it.

The powerful jet has taken its toll on it but it should get in better shape again later.

Discodog

I wonder if it will just appear to be a continuation of what we have now. Very unusual to have three really windy days together.

maquiladora

Slightly further southeast at 24 hours on the 06Z GFS.

Pangea

Ive been hearing Katia has turned back into a hurricane, is this true?

maquiladora

Pangea wrote: »

Ive been hearing Katia has turned back into a hurricane, is this true?

Nope. It's tropical days are over.

fryup

so what time will it hit ireland?

km79

Maquiladora can u give a quick synopsis of how things look now please ? Is it still likely to hit...how hard...where ?