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

Iancar29

nacho libre wrote: »

hmm... at 945hpa, that's lower than the storms in December 1998 and January 1991

oops. that was the chart for 1974, not this weekend's storm:o

hahaahahahaahahaaha!!!

cherryghost

nacho libre wrote: »

oops. that was the chart for 1974, not this weekend's storm:o

If only

Can't wait to see the next 2 days development on the charts

Redsunset

Guess which model i want to unfold,:D

M.T. Cranium

For any readers unfamiliar with model names, CMC = GEM.

As of 0330z have seen NHC guidance and RGEM output to 00z Sunday.

No real changes and continued signs of a close encounter.

Awaiting the main model runs now.

Katia has accelerated noticeably since 00z. Heading more northeast than previously (north).

M.T. Cranium

GFS slightly faster now, intense ... major storm potential.

This is a scenario with very few analogues in historical terms. A hurricane-force storm with part of its tropical structure still evident Sunday just west of Ireland, then occludes very rapidly. This is a pattern more familiar to severe storm analysis in the Great Lakes region of North America. I am concerned that if the GFS scenario verifies at this reliable time frame, the storm will be historic and produce widespread damage. It will also set in before daylight on Monday on this schedule and last well into Monday.

The rapid rate of occlusion (for those with technical background, the 570 dm thickness maintains a presence in the frontal zone to 0300h then rapidly disintegrates over Ireland) is a sure-fire signature for a very severe windstorm event. There could be tornadic wind streaks briefly present along the extremely fast-moving frontal feature. Then hurricane force winds could strike behind the front. There are structural similarities to the Oct 1987 storm and if we see other models showing this solution from now to T-24h, then I believe the country needs to be prepared for a major storm event.

GEM analysis ... same as GFS now ... timing of strongest winds has moved forward again on this model. Track across Donegal Bay.

For both models, can't totally trust central pressure, potential for this to be quite intense and closer to 950 mbs rather than depicted 960-965. Very rapid occlusion on both models.

ECM also looks intense ... the depiction on meteociel is easier to find the intensity, than the wetterzentrale version. It is perhaps 3 hours slower than the GFS-GEM consensus.

NHC track forecast at 03z also shifted south slightly. GME, a 72h model, now in line with others out to Sunday night.

We seem to be seeing a convergence on the intense storm solution with 60-72h lead time.

The storm has that look of a fast mover now that it has rounded the turn southwest of Nova Scotia. Current position (06z) about 37N 68W.

gally74

Goin to France on the ferry on say afternoon, could it be cancelled

maquiladora

You don't often see something like this in the forecast discussion from the National Hurricane Center :

ALTHOUGH KATIA IS FORECAST TO EVENTUALLY LOSE ITS TROPICAL
CHARACTERISTICS...THIS CYCLONE IS EXPECTED TO REMAIN A VERY
POWERFUL EXTRATROPICAL LOW PRESSURE SYSTEM THAT COULD BRING VERY
STRONG WINDS TO THE BRITISH ISLES BY MONDAY.

http://www.nhc.noaa.gov/text/refresh/MIATCDAT2+shtml/090244.shtml

inabina

ME continue to be cautious!!

"Later on Sunday night and early on Monday it will become very windy throughout the country as strong and gusty southerly winds develop and rain moves in across the country. There will be some very strong gusts in particular along south and west coasts. The strong winds will continue on Monday "

tfitzgerald

These graphs about the weather could be very addictive very quick

maquiladora

inabina wrote: »

ME continue to be cautious!!

"Later on Sunday night and early on Monday it will become very windy throughout the country as strong and gusty southerly winds develop and rain moves in across the country. There will be some very strong gusts in particular along south and west coasts. The strong winds will continue on Monday "

I think thats fair enough considering the uncertainty in the exact track and intensity, which will make a big difference between this being a stormy or just windy event.

Bigcheeze

tfitzgerald wrote: »

These graphs about the weather could be very addictive very quick

You should have seen what it was like here last December!

DOCARCH

inabina wrote: »

ME continue to be cautious!!

3 days is a long time in meteorology!

Joe Public

How do you pronounce Katia so I can talk about it?

Is it

cat ee ah
or
kay tee ah
or
????

M.T. Cranium

I've been hearing "cat-ee-ya" on our media today.

Just go with whirling vortex of doom. :eek:

leahyl

M.T. Cranium wrote: »

I've been hearing "cat-ee-ya" on our media today.

Just go with whirling vortex of doom. :eek:

Love it!:D

Pangea

Ok on the latest advisory from NHC it shows the yellow area covering the W and N-W coast.
Just to clarify does this mean stronger winds than the green area? I know it was said the eye won't be as windy so it has me confused.

maquiladora

Pangea wrote: »

Ok on the latest advisory from NHC it shows the yellow area covering the W and N-W coast.
Just to clarify does this mean stronger winds than the green area? I know it was said the eye won't be as windy so it has me confused.
[/IMG]

Look at the bar at the bottom. From green to purple indicates the probablity of sustained tropical storm force winds.

irish1967

I would imagine if the eye was superimposed on that chart Pangea it wouldn't be at the center of the colored area. As the chart indicates only wind speed wouldn't the eye be north of center ?

Pangea

irish1967 wrote: »

I would imagine if the eye was superimposed on that chart Pangea it wouldn't be at the center of the colored area. As the chart indicates only wind speed wouldn't the eye be north of center ?

Thanks Irish, naturally I thought the eye would be in the centre orange colour but that would be contradictory to what they were saying about the eye being less windy.

200motels

This from the Met Office, it will be a major storm.

ninebeanrows

Well morning models have move the centre abit to the northwest which may be down to a more intense storm forecast.

Current imagery of Katia on IR would suggest it has intensified and it appears to be developing a decent eye.

Will be interesting to see what it looks like on the visible satellite in a few hours.

Whatever the case, it is magnificent to think that a storm which was a tropical hurricane will smash into the region just 24-36 hours after losing that status.

I await 6z and the visible satellite presentation of Katia with great interest.

Pangea

http://www.highlandradio.com/2011/09/09/hurricane-katia-likley-bring-storm-force-winds-donegal/

irish1967

Been holding off but I think it's time to go get the food supplies in, the batteries, candles, put garden furniture away and take a few 'before' photos of the garden and the 100 year old chestnut tree outside my front door.

One thing that worries me most is that I work in a building on the quay here. 20 feet from waters edge and with a large basement area below the waterline. Given the current charts how high would any storm surge be. Don't wanna tell owners something and then look like an eejit if water levels are normal. High tide at 6.30am Monday morning. With full moon it would be a high high tide even without Ms Katia on the prowl.

Pangea

I was browsing over on Net Weather and one poster said that Northern Ireland looks like it will be hit the hardest.
Since the storm is heading for Scotland, will the storm be less intense once it reaches there?

maquiladora

I could be wrong, but I really don't think this event will be as severe as the 'Carmen' storm from last year. Still time for the models to change and bring it closer to Ireland but I think it will pass too far to our north for us to feel any real severe winds apart from exposed northwest and northern coastal regions that get gales most years anyway.

maquiladora

Pangea wrote: »

I was browsing over on Net Weather and one poster said that Northern Ireland looks like it will be hit the hardest.
Since the storm is heading for Scotland, will the storm be less intense once it reaches there?

It's not like a hurricane that has strong winds in the eyewall, with a storm like this the strong winds are south of the center.

Aiel

I'll be on Salthill Promenade Monday morning with my camera hoping to see decent wave action.Im not stupid so wont be taking too many risks to get "the shot":).

maquiladora

National Hurricane Center latest track has shifted ex-Katia a bit closer to us.

Previous track :



Latest track :



Let's see what the 06Z GFS has.

force eleven

NOAA Hurricane discussion latest update

'THE HURICANE IS MOVING TOWARD THE NORTHEAST OR 050 DEGREES AT 21
KNOTS. SINCE THE HURRICANE IS ALREADY EMBEDDED WITHIN THE
MID-LATITUDE WESTERLIES....IT SHOULD CONTINUE ON THIS GENERAL TRACK
WITH AN INCREASE IN FORWARD SPEED FOR THE NEXT FEW DAYS.

NO 96-HOUR POINT IS BEING GIVEN BECAUSE FORECAST POINTS IN THE
EASTERN HEMISPHERE BREAK A LOT OF SOFTWARE. '

I lol'd at the last 2 lines. Ex Katia is going to continue past 0 Longitude...

munsterlegend

maquiladora wrote: »

I could be wrong, but I really don't think this event will be as severe as the 'Carmen' storm from last year. Still time for the models to change and bring it closer to Ireland but I think it will pass too far to our north for us to feel any real severe winds apart from exposed northwest and northern coastal regions that get gales most years anyway.

MT seems to think it could have a major impact on its current path which i know can change. obviously there is no guarantee - even in america last week with irene the exact track was subject to change. I have my doubts down where i am that it will have any major impact but coastal areas given the timing may have difficulties.