[Hurricane Rita.]

btw, I'm stopping signing my posts "Steve M" in case I get confused with someone with consderably more knowledge than me!

Smich

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LOL

I glanced at your post yesterday scrolling down to find a link and thought- I dont remember wrinting that-

ALL posts are welcome whatever the scientific content-

Steve

[Hurricane Rita.]

Morning All-

Latest advisory out from NHC & NOAA say the track continues to change, looking at the Ensemble tracks from GDFL, NOAA, UKMET, GFS etc sees a More Northerly Vector coming into play- the upper level ridge doesnt look like holding long enough to keep the path westerly towards Houston - but more Up towards Louisiana- This means that the lowlying areas slightly further along to the East of the Gulf coast can expect to see the full force of the storm ( Its north-eastern) quadrant-

The outer rand bands are just beginning to effect New-orleans, with the outflow just beginning to become more apparent- Concerns are growing that if Rita should track further North then the levvies over New Orleans will come under further threat-

The current rise in pressure to over 900 Mb could be concentric eye wall development- but this may be bad news as the hurricane 'COULD' come back stronger if when the secondary eye wall develops there still enough latent energy heat from the sea surface- SST's are more condusive to less weakening the further north & east Rita hits-

We will have to see the developments over the next 24 hours to see if this is the case- however there is no more talk of Cat 3 landfall- just cat 4 or cat 5- whatever the case- just looking at the cloud tops- they were at -80C last night- now slightly warmer with dryer air-

All of the risk areas have substantial oil rig populations that are closing down- with the price of crude expecting to rise dramatically- as well as this Louisiana is quite lowlying and the storm surge could well sweep further inland....

Whats got to be also noted with the storm surge is the current circualtion driving the surge is catagory 5, however when the Hurricane begins to weaken to Cat 4 this will NOT be enough time to tranfer that downgrade into the circulation and energy back to the Sea- The MAX storm surge- some 20 feet will NOT diminish before landfall....

Whatever way you look at this its a lose lose situation.....

regards

Steve

[Hurricane Rita.]

just been looking at the temps on land where Hr Rita is located in Florida today it was 85oF but in texas it was 96oF, so taking these temps in mind if Rita is sitting in the coolers seas of the florida coast its will track into slightly warmer water of the coast of texas. So i would imagine that as the Hr approches landfall it will possible maintain its Cat 5 status as the warmer waters will feed the storm system.

a simple observation but is there more to the mechanics than this ????

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steve murr-

As Rita moves in the mid gulf it moves into a zone called the heat loop-

The heat loop basically desribed is-

'The intensification of tropical cyclones involves a combination of

different favorable atmospheric conditions such as atmospheric trough

interactions and vertical shear, which lead to good outflow conditions

aloft. As a result of this, inflow conditions in the near-surface layer are

enhanced. Clearly, as this process continues over the scale of the storm,

the upper ocean provides the heat to the atmospheric boundary layer and the

deepening process. In this scenario, the upper ocean thermal structure has

been thought to be a parameter that only played a marginal role in tropical

cyclone intensification. However, after a series of events where the sudden

intensification of tropical cyclones occurred when their path passed over

oceanic warm features, it is now being speculated that it could be

otherwise. While the investigation of the role of these rings and eddies is

a topic of research in a very early stage, preliminary results have shown

their importance in the intensification of hurricane Opal.Therefore, the

monitoring of the upper ocean thermal structure has

become a key element in the study of hurricane-ocean interaction with

respect to the prediction of sudden tropical cyclone intensification. These

warm features, mainly anticyclonic rings and eddies shed by the Loop

Current, are characterized by a deepening of several tens of meters of the

isotherms towards their centers and with different temperature and salinity

structure than the surrounding waters. '

So far I would say the intensity of Rita has been underestimated, and with

the addition enhancement of the heat loop from the upper ocean heat content

(UOHC) and tropical cyclone heat potential (TCHP) from altimetry then a

storm more powerful than Katrina could be observed in the gulf-

If the storm can intensify to a stage where it retains strength through

Concentric eyewall cycles then record breaking gusts well over 200 MPH

could be observed-

The *very* latest obs show a 11mb drop in 105 mins-

and may outdo- Katrinas 902 MB- even dipping under 900-

Once out of the heat loop Rita will begin to weaken, however she still

could hit land ( track estimates a hit on Port O'Conner and Freeport early

Saturday)

However at this rate even a weak 5 could be on the scale with a storm surge

over 20 feet......

Trust me this is a beast.....

Steve

[Sst's And Sea Ice - Trends]

Too much might be read into SST anomalies as they can go up and down due to the presence above it of a single storm, which may be caused by a whole host of other factors, irrespective of a cold or warming trend. I'm not saying SST are not unimportant - if you want cold winter you won't care how the anomaly came about. Great, it's cold! However if you're looking for signs of cold winter i think steve murr indicated our prayers for lower STTs should not be at expense of wanting a more southerly Jet Stream than last year.

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Good post there AFT-

Based on that premise the north atlantic should get a good stir this week....

S

[Sst's And Sea Ice - Trends]

I'm very sceptical about the accuracy of this I'm afraid. Have you used proper feeds from buoys over this period? The SST maps are pretty notorious for inaccuracy, but a cursory glance at the charts suggests SSTs for the northern hemisphere are extremely high this year. What might be interesting is for you to do a comparison of the eastern seaboard, and GIN corridor. Now why, I wonder, would you have plumped for the Faroe Islands as your example ...? 

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Good afternoon All-

I dont wish to put a dampner on this thread that is moving along nice- however-

I think it would be a good idea to put things into Perspective-

I remember ( In a heated arguement) my Mother told me

" The world doesnt revolve around you!! "

and this can be said of the GIN corridoor and SST's to the North of us-

In terms of Anomalies its good to see -VE ones to the north as they have some a(although minimalish) modifications on boundry layer temps in Northerly incursions-

However-

What no-one on here has is enough backgorund information on SST's to provide an account on how they will effect this winter based on the fact that the whole globe is effected by lower Scale regional Anomlies-

The 2 biggest 'hitters' probably in terms of global perspective is the ENSO & PDO-

both having large scale effects on global patterns-

Now this year the ENSO is looking fairly neutral suggesting that is will play little or no major part in proceedings-

However the PDO with lesser background information hasnt really got a seasonal forecast because there hasnt been a full proof way of forecasting the changes of it yet-

The correlation so far though in terms of effecting the uk through teleconnections is-( with limited knowledge) ive clipped a bit from my Ode-

The PDO is described as being in one of two phases: a warm phase and a cool phase. Alternately, the PDO can be described by its index value: warm (cool) phase conditions correspond to positive (negative) index values

The AO/NAO was mostly negative during the cool phase of the PDO and mostly positive during the warm phase. The change to a negative PDO in the middle 90s coincided with the change towards negative of the AO and NAO. This would suggest a predisposition towards a negative AO and NAO any winter preceeded by a negative flip of the PDO.

With SO many anomalies effecting the Northern hemisphere this year its a lttle on thin side to make any forecasts JUST based on whats happening in one staright of water-

I do accept the effects that the GIN corridoor has on Low pressure systems- However there are larger forces at work that mean when the time comes to winter these anomalies WONT be a factor in determining the Local of the jet stream.....

regards

Steve

[Cat 5 Hurricane Katrina]

Waken up, Steve :lol:   Been on all day!

Sorry mate some of us have had a hard day at the beach...

Anyway- lets hope that devestation is as minimal as poss-

S

[Cat 5 Hurricane Katrina]

satanisticly beautiful

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Live TV channel feed as it happens...

>>>>>>> Link-

S

[Cat 5 Hurricane Katrina]

weather2,depends on how strong its sustained winds are by the time it makes landfall,but I suspect that wind gusts of 200-210mph is likely at its current strength.I think we may see some slight weakening but probably only down to 170-165mph I suspect and will still cause massive amount of damage,its stil Annular and still has a cracking satilite representation...this is going to be,as they say,the big one for Nw Orleans,and with damage estimates already of 2 billion from just Florida alone,add another 30-40 billion to that on the next landfall making it the most costiliest hurricane ever even past Andrew I believe.

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New Orleans Weather Forum-

>>>>>>Forum

you will be able to read and browse as things develop- info through 'our' channels will never be as quick as some wort of 'live' feed-

S

[Cat 5 Hurricane Katrina]

So the pressure dropped a good bit, but the winds also dropped?!  When the pressure drops isn't the wind force supposed to pick up?

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SOME VERY worrying hours lay ahead for the strike zone area- the outer rain bands beginning to affect coastal areas-

Courtesy of NHC-

click this link >>>> ( set the animation speed as fast as poss changing the tool bar- what an amazing site-)

AWSOME run loop of Vis sat

NHC predicted track-

Accuweather Update-

Real time update

Regards

Steve

[Synoptic Patterns]

Soon to be broken this coming Winter by the developing 1090mB Greenland High.... :lol:

heres hoping.....

S

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I see the 18z is keen to start developing this.....

Steve

[Synoptic Patterns]

The highest air pressure recorded was 1085.7mb at Tonsontsengel, Mongolia on the 19th December 2001. Our good old friend the Siberian high, shame it never moves west

Imagine the headache under that one then.

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Soon to be broken this coming Winter by the developing 1090mB Greenland High....

heres hoping.....

S

[Synoptic Patterns]

-Well the good points for now are to the north of us we have -SST's - I'm not sure why this is beneficial - but apparently it is...

-The NAO looks like being negative for the forseeable future

- High pressure looks like it will create a certain amount of cold pooling over and around Greenland.

I just hope southern Greenland cools down, it's had a very very warm summer so far.

Steve, is there any information on any melting ice in the Arctic regions at all? - this may also enhance high pressure ridging from the north.

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No-

Grey Grey area that one.....( I doubt anyones conducted a survey of how Ice levels/melt effects the BI)

I messaged Atmos a few times and we had discussed it- only to the level of if there is a decline then it has usually recovered by the next year-

If i remember the rightly ice coverage has had a greater decline against the Norm over the western side of the Artic as opposed to the Eastern Side-

'Perhaps' Its all to do with the intense WAA pumped up the South and western side all summer Long-

Im guessing/Hoping that this winter will continue the theme of very Low MSLP averages over the western side (against the norm) to assist in the displacement through CAA to the South & South-west-

You never know-

Regards

Steve

[Synoptic Patterns]

Actually having read the post you send a link to, it physically makes sense, because the ITCZ is further North so in essence these hurricanes are forming in slightly cooler air, and this in turn is going to cause a conveyer belt of low pressure (due to the warmer than average water (strange really), and then this leads onto cooling the atmosphere. it does fit together i'll give it that.

The Greenland High would cool water, but this may only produce more anticyclonic development - of course we know a polar low develops better in warm water, but of course warm water can modify the 2m airsource to slightly warmer (I think that may be what people are worrying about) but if it's cold enough, it may not matter.

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Agreed- It will be interesting if we get any Polar Low scenarios this winter- I will be looking for a 500 HPA temp of about -35C over the shelf and that long drag of northerlies across the Country-

With a High frequency of Strong Driving Troughs Cutting through Scandi recently I would say we have a good chance of seeing at least one this Winter-

Eastern Ireland, The North west and Sometimes the Home Counties do well out of those-

Regards

Steve

[Synoptic Patterns]

I would agree that this winter is half setup, but the SST anomalies need to take a massive dive first. However having said that, the anomalies above the UK would give us snow on a low in winter as opposed to rain we may have seen in the past (the borderline issue), first we have to hope the NAO stayed negative - which it should do as I saw an interesting little charts earlier today which showed the NAO in decline since the new millenium. However whether we get the right setup come winter is the real question, until then all we can do is speculate unfortunately (and trust me I wouldn't mind finding out that winter would be a corker right now)

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Hi Steve-

In JB's post he ( I think once I translated his post into English) mentions that the Neutral Signal in the pacific & the +VE signals across the atlantic will ASSIST the prospect of a negative NAO- A Little confusing for those that thought that colder SST's would assist the development of the Greenland high.....

S

[Synoptic Patterns]

i cant find that steve. can you point me in the right direction? cheers LS

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Autumn thread

S

[Synoptic Patterns]

Those '68 charts, with 1045mbs over to the North and West illustrate the achilles heal of the even larger teapot - how not having a stable, strong Greenland High leaves us with little more than SW'ly and W'ly zonality.

Anyone remember those pesky little 'Channel Lows' or an equivalent say across the Midlands - introducing an artic or E'ly blast behind as they move off into the Low Countries?

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Interesting you mention that Shuggs... If you look at my post in the Autumn thread you MAY not have much longer to wait to see those artic winds digging in bring Cold snowy weather...

S

[Weather Abbreviations]

Glad it's not just me.  Sometimes I actually know what it stands for but my brain insist on using the "wrong" wording when I read the intial. 

What about FI?  I cannot search the forum because of the tem length limit.  I know what it means (I think) but not what it stands for?

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EVo-

FI refers to ' Fantasy Island-' The often referred to part of the charts between the hours of T180- T384- always over the rainbow...... and far far away-

S

[Weather Abbreviations]

A quickie on the abbreviations...

WZ- Wetterzentrale ( German website for viewing charts)

NAO- North atlantic oscillation

PNA- Pacific North american

SOI./ENSO- El-Nino Southern oscillation

WAA- Warm air advection

CAA- Cold air advection

528 DAM- is the line drawn on the maps that equated to the temperature ( MAX) that snow can be often observed at

GFS- Global forecasting sytem

METO- Met office model

UKMO- United kingdom Met office

ECM( Or ECMWF) European centre of medium range weather forecasts..

ASL- Above sea level-

PPN- Precipitation

Ensembles- 10 GFS model runs- Control run is the one seen on the models

SST'S sea surface temperatures

PM- Polar maritime air

MT- Maritime Tropical air

PC- Polar Continental air

LRF's - Long range forecasts

MRF's- meduim range forecasts

Trough- Upper level equivalent to a surface Low pressure

Ridge- Upper level equivalent to a surface High pressure

Blocking- The jet stream being moved AROUND CLOCKWISE a large area of high pressure.

Regards

Steve

[Our younger days - Winter memories......]

What a great post TM- Im glad I started this thread now as obviously I wasnt the only one looking out of the window on those winter nights when everyone else was asleep.....

The more I think about the more I miss those wintry nights.......

regards

Steve

[Our younger days - Winter memories......]

Evening all- Thought Id pop a little message on here to evoke memories of what we used to do as children when we thought it was going to snow-

Heres my memories-

I was always fanatical about snow,my parents used to stand bemused at this scruffy 8 year old standing looking out of the window on the landing waiting for it to snow......

It was an obsession- every day at 12pm I would have the European weather forecast recorded onto video for me ( Usually forecast by Bill giles) so I could view the impending pressure charts.

I had all sorts of second hand temperature guages in the garden giving me that vital information-

Then sometimes the news that id been waiting for- " A blast from the East was coming"

The excitement was amazing.-

Finally the day came where the showers would come....

If it was dark I used to look to the east over shooters hill to see if the ' BLUR' level was getting worse- The blur level being the more shooters hill was blurred from sight the heavier the snow was!!!!!!

1987 was the best- Sent home from school and the heavy snow continued to fall- it lay 1ft deep on the dustbin outside- and the temp that day peaked at -5C- all in all some great memories.....

Has anyone else got any funny memories of what they used to