Weather briefing chat (6th October at 0800UTC)

Good morning, Maja

Hi Guys, how are you?

Fine here, Sarah - how are you doing_

Hi Sarah, very good and you?

Am well thanks :-), we are the early birds

Hi Vesa

I see more people looking at your slides than present in the chat room...

Hi Philip, welcome to the chat.

Let me try and help them navigate by dropping a message

Good idea :)

good morning M. and Ms.

Good morning!

Good morning from sunny Zagreb-Croatia

hi All

Hi, all

Welcome Lada and Patricia

and Larisa

Hi all

welcome Sara nice to see you again

Nice to see you again Usama

Good to see more people joining :)

I can already see one benefit of using text chatroom... I dont have to wear my headset :)

I came an hour early as we've just changed to daylight saving. I'm OK with the local time but forgot about adjusting UTC.

Hi Ian, I can understand the confusion...I usually use this website to convert time: http://www.timeanddate.com/worldclock/

Do you know it?

Good thing about being in the tropics, no need to convert time :-)

Welcome Vesa

I'm used to working in UTC but just forgot to adjust my local time

Vesa, i see another benefit - i can do another work at the same time and be in discussion too :)

Larissa, is it a benefit? :P

It's great to be part of this text chat mode of weather briefing, can't wait to see what is in store

for me yes, as i have urgent work and want be with all you too :)

I guess Sarah is getting ready with her slides?

already i'm at work now and weather at cairo is fair with 26 degree and sky free of cloud

Yes Maja, I am getting ready with the chats

It's great to see Pat on here, welcome Pat

Hi Sarah. Sorry I joined the chat late. I did not review the instructions well I guess. :)

You are on time Pat, we are still waiting for some more people to join so that we can begin

OK. We are under mostly sunny skies here in Geneva. It has been a nice Fall so far.

hello, nice to see and to meet you again!

Hi Sarah, I think we should start now and not penalise those who arrived on time.

I agree... we do have a quorum and it would be great to know each other

Just to introduce myself again, am Sarah from IMTR, Kenya and we are having sunny conditions today

Hzllo everybody.

Welcome barbara

So to start us off let's move to slide number 2 where we have the world map and just pick and place the stars that are on the side to where you currently are

I seem not to be able to place a start (only View mode), but please place a star in Germany :)

OK. I am on the slide 2. I see some stars ready :)

its on edit mode now, let's see who will succeed :-)

same problem than Vesa

me too...

reloading the page helped !

only view mode too

I guess we have no edit rights, I am in Versoix (Switzerland)

oh yes!

Reloading worked for me too

Re-load the page and it will be all right

Thanks for the tip to reload the page. That worked!

I can see most of us are in Europe and someone in Sydney

And someone in the Canary Islands.

We feel honoured by their presence, maybe they can say hello?

I'm in Melbourne, not Sydney

Am in Nairobi with Sarah, sunny Nairobi

Oh great ...

Usama said its sunny in Cairo ...

Hello from Tenerife (Canary Islands).

So today we shall look at a few slides of near real time satellite and ECMWF products and being from Kenya I will be biased to discuss our current weather

yes Vesa

what should we do at stars ?

we shall begin with slide number 3 where we have IR 10.8 overlaid with MSLP at 12UTC yesterday

Usama, place a star on where you are on the map :-)

Usama, you can draw a star at the Google slide 2 to Cairo to practice annotation . .

ok , it is already placed

In Nairobi with Patricia and sarah

Am sure we have had a look at slide 3 where we see that on the south of Africa (St. Helena) we had strong ridging which pushed the active weather to the east

The ridging is on a SW-NE orientation which favored the region

Anyone who can comment on the SE - NW ridging?

Nobody? :-)

I think the SE-NW ridging of the Mascarene is denying the central and Coastal parts of Kenya rainfall

Patricia, is it the Mascarene hign you mean ?

that is correct Patricia, the high pressures push the active systems further North confining the activities to the North of Kenya

Patricia a talking of Mascarene or St. Helana

Yes that is the one i was refering to

thank you for that

What can we say about the North pressure systems, also consider the IR image as you analyse

Morning every body

Hi Francis, nice to see you here

Sarah, can you show me the North pressure systems on the image?

Azores High is strong ..northerly winds and cold maybe in tenerife

the Azore High pressure it can be seen clearly in the image

am back: internet acting up a little bit

thanks for your comments

I have indicated the pressures with yellow stars....

they are both strong and this helped to maintain the active sytems over our region

let's compare that to slide number 4

Hello everyone.. Roro from Jakarta, just joining. Nice to see you all. Good luck for Sarah..

Is there a difference between the 2 slides, 3 and 4? (Hint; Concetrate on the St. Helena and the Mascarene high

wV and IR?

It is still on IR 10.8

or different time steps?

Slide number 4 is at 18UTC and slide 3 is at 12UTC

another hint: look at the orientation of the Mascarene high

convective clouds developed

and seems to be clouds streets due to strong wind in upper layers

Hi Raf, welcome, we are looking at slide 4 now

The region developed more convective clouds and the ridging became abit more pronoounced and intensed and pushed the active system (meridional arm of the ITCZ) further west

Izolda that is very correct

So basically we have seen how the ITCZ was by 18UTC yesterday and we have had a look at the MSLP

Now on slide 5 ...

We have the natural colour RGB overlaid with CAPe

I welcome comments for slide 5, this was at 12UTC yesterday

I see the CAPE seems to be in line with the ITCZ especially to the Nort and West of kenya

Correct Patricia.

and the highest CAPE on equator, of course

Yes Izolda. Would you say the model is line with the satellite image? Any other interesting features on slide 5?

Hi Wilfried, welcome to the briefing..

no, not too well CAPE with IR clouds image

Any other interesting features on slide 5?

Slide 6

and the same over Madagascar...

Which slide Izolda?

Slide 6, yes

I see people having fun with airmass RGB....comments?

6

Sorry I wa too late. I did not see the announcement due to other duties. Thank you for inviting, Wilfried.

very cold intrution from upper layersover Madagascar and strong convection there and over Southern atlantic

thank you Izolda...any other contribution?

Thats OK Wilfried, lets join the fun...your comment for the slides is welcome.

welcome back Barbara...

We will have more fun with airmass RGB later in the forum but now we can move to slide 7

These are winds over the region with the bright green signifying stong winds from the Indian ocean

On slide 6: I suppose someone is indicating the areas with high PV (reddish colour) indicating presence of Jet Stream?

at what level are those winds sarah

10 meters above the surface

I have circled our region

Philip, u want to have fun with the winds?

strong convergency

Yes, we have convergence over the lake region

and over Victoria lake (I hope I am right ) also stronger winds than surrounding area

*Claps for Izolda* You are quite right, over Lake Victoria (Lake region)

So lets move on to slide 8, shows today's 06UTC humidity with almost 80%RH over our region

I'm always wary of trying to eyeball regions of convergence. There is strong diffluence but it's hard to tell if the changes in wind speed compensate or not. It would be good to see a divergence fiels or vertical velocity.

we see that most of the country seems to have good moisture except over the coast

Ian that is a very good point, we will have a look at the divergence

Divergence slide 8, currently (refresh)

Combining the winds and the divergence and following Ian's contribution, what can we say?

What level is the divergence?

300

ahaa... so it should show divergence at that level where strong convefction takes place?

if the divergency at 300 and convergency at lower levels-very could conditions covcetion to appera

good conditions :)

The divergence slide shows areas of divergence near The lake region at 300mb level which would most likely indicate convergence at the surface

Awesome... Vesa, Patricia and Izolda seem to be speaking the same language

sorry for errrors in printing:(

The lake region from this we expect active weather

It shows there is no strong synoptic scale upper level forcing (unless it shows better with a lower threshold for contours) . Is there a low level divergence available or a vertical velocity?

Back to slide 9, RH, we saw we had almost over 80% of humidity so again great conditions over the region

I hope that before this session is over, you will also show us a photo of what is happening outside your window. :)

Ian, we will look at the low level divergence too :-)

sure Patrick...:-)

Before we look at the low level divergence just have fun looking at athe animation of dust RGB, clearly shows the moisture boundar over the region

sorry, I have to leave the session. Thank you, Sarah

(Refresh) slide 9...overlay of low level divergence (red) and upper level divergence (blue)

The low level divergence is at 1000hpa

beautiful details .. of topography and coastlines.

It's very detailed....

Shall we have fun coming up with the afternoon forecast for the IR image on slide 12 for the region with the star?

that is the North West of Kenya

Will we have overcast conditions, convective rain, or clear skies?

for the afternoon

I think we will have overcast conditions with convective rain

i think based on all the factors we have looked at, i can asy we might have showers

but not on the coastal regions ?

at NW of Kenya

North west of kenya we are likely to have showers in the afternoon , while a long the coast is clear skies

Thank you Usama and Patricia, we can expect slight showers over few places in the NW Kenya

Ian? :-))

Thanks Philip, over the coast we might have showers in the morning but as for the afternoon looking at the factors discusssed we should expect clear skies

Well, that brings us to the end of the live session of my weather briefing, the session will be left open for a few more hours for more discussions

I'd like to see higher resolution but am wondering about the possibility of thunderstorms in the NW??

Thanks for the session Sarah. Enjoy your day.

It would be great also to have fun with more interesting satellite and ECMWFproducts, so go to the briefing forum and post any interesting phenomena and we shall discuss it it

Ian, thank you for your great contribution. Thunderstorms over NW in the afternoon. I will verify our products tomorrow and we see how was right for all the contributions, fun!

Our current weather: last slide :-)