Models, teleconnections and nowcasting

[knocker]

TD one

[johnholmes]

2 hours ago, mushymanrob said:

Yep, thanks a lot for that, appreciated.. i thought that was the case... just a bit unsure.

You seem to be doing well mushy, for sure ask questions

[mushymanrob]

8 minutes ago, johnholmes said:

You seem to be doing well mushy, for sure ask questions

itll come to me..... i taught myself how to map read when i was a kid, simply by looking at them and using logic. my heads a bit more cluttered now, lol.

i look up into the sky and see cirrus, and think why?  why have they formed there.

cheers.

[knocker]

Midday sat image

[johnholmes]

1 hour ago, mushymanrob said:

itll come to me..... i taught myself how to map read when i was a kid, simply by looking at them and using logic. my heads a bit more cluttered now, lol.

i look up into the sky and see cirrus, and think why?  why have they formed there.

cheers.

Look at the Met O Fax actual charts and then the satellite piccs that are available, then look at a relevant skew-t diagram. I suspect if you do this regularly you will get a fair idea of what type of cloud is likely to be around a particular area and why. Like I said mushy ask questions, use the pm facility if you prefer. I'm always happy to try and answer anyquestions.

[knocker]

Now TS Arthur

[mushymanrob]

57 minutes ago, johnholmes said:

Look at the Met O Fax actual charts and then the satellite piccs that are available, then look at a relevant skew-t diagram. I suspect if you do this regularly you will get a fair idea of what type of cloud is likely to be around a particular area and why. Like I said mushy ask questions, use the pm facility if you prefer. I'm always happy to try and answer anyquestions.

Appreciate that john, thanks.

[knocker]

An upper low over Iceland never a good sign and with a brisk upper westerly rather portends unsettled but with a marked N/S bias

Edited May 17, 2020 by knocker

[knocker]

Interesting. The ecm has a low developing on the front at the base of the upper trough which seems to link back to TS Arthur and from this point it develops rapidly

Edited May 17, 2020 by knocker

[knocker]

he North Atlantic 500mb and surface analysis for midnight and current sat image

Cloudy in the north at the moment with rain across western Scotland and NW England courtesy of frontal systems associated with the main low pressure area to to the west. And this will remain the case through today although it will clear up over northern Scotland during the afternoon. Meanwhile further south another sunny and warm day (usual caveats re, model max temps)

More frontal developments to the west during tonight thus more cloud and rain in the north, clear in the south

On Tuesday continuing cloudy with patchy rain/drizzle in the north whilst in the south, after the clearance of early mist, becoming quite warm

By Wednesday the high pressure zones are amplifying whist changes get underway in the upper trough that dominates the Atlantic. All resulting in a warm and sunny day, maybe a tad cooler along some coastal areas

The developments in the west continue on Thursday with a deepening low forming in the southern quadrant of the trough whilst things are a little complicated over the UK with some frontal rain in the north and thundery showers in the south courtesy of a trough tracking east

By Friday the aforementioned low is 989mb over western Scotland and heavy rain will effect N. Ireland and Scotland, perhaps northern England as well, through Thursday night/Friday accompanied by strong winds. Some rain elsewhere as the cold front crosses the country and less windy/

Just to note the gfs interpretation of the developing low is much different to the fax chart

Edited May 18, 2020 by knocker

[knocker]

Taking on board the last comment above I'll just settle with looking at the weekend with the gfs

The main feature is another upper trough tracking into the Atlantic from Canada, merging with the old and forming a new trough dominating the Atlantic.This does initiate more amplification of the subtropical high into western Europe with the UK on the western periphery of this.Thus the weekend continuing unsettled and windy in the north with the better weather in the south/south east

[knocker]

And to digress a second. The Indian satellite observing the current cyclone

Edited May 18, 2020 by knocker

[knocker]

To note that the ecm also has the low on Friday further west and deeper than the fax

Thereafter not dissimilar to the gfs over the weekend

Edited May 18, 2020 by knocker

[knocker]

Not quite complete agreement between the ext anomalies this morning with the GEFs being the main culprit

Ridge NW North America into the Arctic adjacent to the tpv which extends south east over Iceland. Below this a relatively benign westerly upper flow across a positively anomalous Atlantic which portends a quiet spell of weather, temps a tad above average with precipitation favoring the NW

But here the GEFs gives much more traction to the ext of the tpv and aligns it into the eastern Atlantic and thus backing the upper flow south west

I think the difference may quite possibly be down to the handling of the deep low next weekend as it tracks north and the subsequent evolution.

Edited May 18, 2020 by knocker

[knocker]

TS Arthur brushing the Carolinas

Edited May 18, 2020 by knocker

[knocker]

The ecm on the possibility of the odd storm on Thursday. For anyone not familiar with the K index it's used to assess the probability of thunderstorms and not to be confused with CAPE  20-40 is in the lower range as expected

Edited May 18, 2020 by knocker

[knocker]

The midday sat image depicts the synoptic features very well and the Lerwick sounding has solid cloud to around 20,000ft which is understandable given it's proximity to the occlusion

Edited May 18, 2020 by knocker

[knocker]

The gfs this evening on possible storms Thursday and strong winds for the NW Friday

[knocker]

By t144 the Atlantic trough has been 'topped' up from the NW and realigned initiating further amplification to the east

Edited May 18, 2020 by knocker

[knocker]

Widespread convection over Scandinavia today

[knocker]

[knocker]

The ecm tends to have a slightly different structure and orientation of the Atlantic trough that facilitates advection of warmer air

[knocker]

The ext anomalies are more in line this evening regarding the NH pattern previously discussed which essentially means the extent and influence of the Iceland trough. Foreby that we are still looking at a suppression of the subtropical high with a relatively benign westerly upper flow. This indicates continuing relatively settled, dry and little precipitation which will be concentrated in the NW

 

Edited May 18, 2020 by knocker

[knocker]

Following on from the above a glance at the middle two weeks of June from the EC weeklies update

09 > 16

Ridge NW North America adjacent to a weak tpv Franz Joseph > northern Canada with a weak trough under the perennial Greenland ridge. South of this a benign westerly upper flow across a positively anomalous Atlantic, with the additional complication of a trough near Iberia,and thus a slack gradient over the UK. Portends quite settled arid dry, with temps above average, perhaps significantly so in some areas.

17 > 24

No significant change, perhaps a tad more changeable, but noted for whole swathes of the relevant areas being positively anomalous.

Edited May 19, 2020 by knocker

[knocker]

Tropical cyclone Amphan is one of the most extreme on record