Lettucing Gutted
-
Posts
1,109 -
Joined
-
Last visited
Content Type
Forums
Blogs
Gallery
Events
Learn About Weather and Meteorology
Community guides
Posts posted by Lettucing Gutted
-
-
8C February 2009 CET
-
The stability though the atmospheric profile will also be concrete from surface to 10Hpa, we might also see a global temperature inversion.
So could this "global temperature inversion" be a very cold polar troposphere and very warm polar stratosphere combination extending well into the mid latitudes?
-
My favourite weather event of 2008 is the closing cold spell of October 2008. B)
-
I could see Craig Evans coming in with 5.5 at this rate.
Going to hold fire until the 31st here, worked well enough last year.
Hi Roger B) I foresee a very warm second half of January to rival May giving a final CET of 8C.
-
Business as usual for 2009 11C
-
Should be fairly interesting how cold the 1st half of December will come in as. Looks like today - 15th will average somewhere around 2.3c. With the current CET at 2.7c, maybe as low as 2.5c by the 15th with low maxima and so the coldest first half of December since 1991 (which averages 2.1c)
It would be very nice to hear Tamara's thoughts on this remarkable sustained cold spell.
-
-
I suspect as long they don't track this way they won't have much direct influence more a subtle one. Bertha threw up a nice ridge and gave us a bit of summer.
Do hurricanes "throw up" upper level ridges due to latent heat release in the upper troposphere?
-
Its looking like being the warmest on record here. Like the CET figure, the warmest is August 1997 at 14.0C. This month is currently running at 14.3C, which is the warmest minima of any month ever. The current record-holder is July 2006 at 14.2C. It shows how cloudy this month has been though, because at the same time, our average maxima is 20.6C, which is 0.4C below average! Fortunately sleeping hasn't been so bad though, as the lack of sunshine means our bedroom is remaining cool despite being south facing.
It has been a strange old summer though, like last year its been slightly above average as we always seem to miss out on the few colder nights due to cloud cover. There have been times where nearby Bridlington and Leconfield (both Metoffice sites) have remained clear and the temperature dropped as a result, while here it has remained cloudy and mild. In the past the minima were quite similar, but due to those differences the last two summers have seen mean mins around a degree higher on average in some cases.
I think there is more than cloud cover at work there with regards to the high minimas this August. I think those warm SST anomalies in the North Atlantic that never seem to go away have been putting a lot heat back into what could have been an unseasonaly cold maritime polar airmass. So a potentially unseasonaly cold August has been turned into an average one.
Augusts like 1912, 1956 and 1986 managed far cooler CETs despite having a lot of cloud and similar westerly synoptics to this month.
-
It's because of night time minima. It always starts of high then dips down later in the month as Autumn closes in.
Mean maxima as of today stands at 19.7c which is 0.6c below 61-90 average. If minima was the same the mean temperature would stand at 15.2c.
The minima are surprisingly high considering were in cold sectors in the westerly airstream. They must be well modified by the nearby warm SST anomalies.
-
just looking at the Jan 79 chart..if that was a recent winter..i would have expected to see temps 10-12c with a sw flow like tht..not 3-5c...oh how times have changed!
Indeed that is a feature that other winter months like January 1978 and January 1984 use to have known as Cool Zonality.
-
Thanks for those links Reef. The reason I wanted to keep the initial figures so soon after they are released is that I believe that they are subject to numerous revisions. Take 23rd of July for instance. The immediate CET figures released were 19.9ºC (maxima 27.1ºC). The next day these were revised to the provisional values 18.7ºC (maxima 24.6ºC). The final quality controlled values were 18.9ºC (maxima 23.9ºC). I guess in the long run, that it does not matter, as the daily provisional CET figure is adjusted accordingly.
Any way to the here and now, yesterday came in at 18.0ºC (max 21.5ºC, min 14.4ºC) so the monthly CET to the 2nd is 17.5ºC.
c
Another advantage of the early figures is that we can see clearly which factor is driving the August CET upwards. Currently it is the minima since they are well above the 1961-1990 average whilst the maxima are bang on average.
-
It looks like July 2008 is yet another that promised to finish below the 1961-1990 and yet it has failed to thanks to another insane warm spell.
-
20C. The warmest August on record.
-
It looks like this could be the first "8" July to record a CET above the 1961-1990 average for July.
-
Interestingly, i remember Terminal Moriane (i think) looking into preceding months and the following winters and there were four main conclusions...
1) We should actually be looking for an above average April
2) We should be looking for a cool and wet August
3) We should be looking for October to record a positive NAO
4) We should be looking for a cool and wet November
With wintry weather possible in just over three months, i am going to look for signs of Autumn/winter being upon us by monitoring the model charts for signs of the Polar Cell expanding. What is the Polar Cell you ask and how can you see it on a weather chart??
Simply put, you cannot achieve a true polar feed without a connection to the Polar Cell/Vortex, and for winter, the further south, the better...
At the moment, we are seeing a very bifurcated pattern with displaced lows (standard summer pattern)...
http://www.wetterzentrale.de/pics/Rhavn1801.gif
However, as we look into FI, there are signs of a more Autumn pattern developing with cold cored low pressure systems digging down well into the Atlantic...
That is the type of pattern i will be looking for...
And a bit more east as well. The problem with cold Atlantic troughs is that they build downstream Euro/Bartlett ridges over the continent which actually draws up warm air or shallow inversion cold at best.
A better position for the displaced upper cold low would be over us like so on 13/01/87:-
http://www.wetterzentrale.de/archive/ra/19...00119870113.gif
-
Not sure they have nothing to do with our weather Eugene. I imagine any escaping cooler water into the Atlantic is causing the pattern, ie, where the cooler water meets the warmer Atlantic water low pressure is being spawned, and unfortunately seems to be arrowing over the north of the UK. It probably therefore has some indirect effect.
I think the indirect effect is that the northerly tracking lows build compensating deep warm highs over Europe which enhances warm air advection into the UK (an enhanced Ferrel Cell).
-
Continental winds in summer usually mean heatwaves but here is an example of a freak event... Here is a cold continental flow on 3rd August 1912.
http://www.wetterzentrale.de/archive/slp/1...slp19120803.gif
This brought one of the coldest CET daily means on record for August. The 3rd August 1912 recorded a daily CET mean of only 10.5C.
http://hadobs.metoffice.com/hadcet/cetdl1772on.dat
This was due to a very cool daily CET maximum of 15.7C on the 3rd August 1912
http://hadobs.metoffice.com/hadcet/cetmaxd...8on_urbadj4.dat
offset by a very cool daily CET minimum of 5.2C on the 3rd August 1912
http://hadobs.metoffice.com/hadcet/cetmind...8on_urbadj4.dat
It was very apt indeed that August 1912 was the coldest on record in the CET zone with a CET of only 12.9C.
-
Can't see the min being all that low probably double figures but being close to the max value.
Once again this will be yet another June without any particular cool monthly minima. Infact a lot of Junes since 2000 have been warm due to warm nights.
-
With Arctic Sea Ice once again approaching record lows expect temperatures to go through the roof...
20C
-
It'll be interesting to see the consequences of next week's cool spell on the CET, given that it isn't much above average at the moment (although will rise a bit until Wednesday). A below average June certainly is not outwith the realms of possibility at this stage, and we haven't seen one of those for a while.
I think it is unlikely this June will be below average. For that we need a slow northern jet to allow cool troughs to buckle over us combined with a negative AO and a negative NAO to unleash the cool air from the north.
-
That must be pretty rare. Thundersnow on Spanish mountains in June!
-
Anyhoo, with NOAA being split over a moderate El Nino/return to La Nina and the pole set to melt
Oh not another moderate El Nino...
-
Could your cold but sunny May be down to frequent low level highs combined with upper level cool troughs to allow maximum radiative cooling?
The Curse Of The Modern Winter
in Spring Weather Discussion
Posted
Since the Azores High is a deep warm pool perhaps its unusual persistence near our shores as cold patterns are emerging is due to heat being displaced from lower latitudes in the North Atlantic caused by the deep eastern seaboard cold spells?