FI Charts ( T120+ onwards) Spring / Summer 2019 **READ MOD NOTE IN FIRST POST**

Plentiful high pressure again on ECM 12z for early July.

So it looks like yan sno may have been right in his prediction.

United road wrote: »

Could you remind me what he said, could not find his comment going back!
Be interested to know, i recall him being very accurate on snow chances last winter!

If i'm not mistaken, he said June would be a cool and unsettled month, overall, but it should begin to settle down going into July. As you mention he was right about winter too, despite all the promising forecasts of prolonged cold.

hatrickpatrick wrote: »

A lot of pessimism and sh!te runs over the last week for sure, but last night's 0z runs of both the GFS and ECM show decent potential, with the FI frames of the ECM 0z showing some proper high pressure and the GFS 0z sort of flirting with it, enough that we would certainly get a good amount of sunny weather if they were to verify. Fingers crossed...

A bit of hope...it's all I need!

eon1208 wrote: »

How does it stop the warm air physically Sryan.

Here's a very simple diagram of three different dry weather scenarios for summer in Ireland.

The first one is of the pattern that gives us cool and dry (an unusual combination that very few summer months have like Summer 1981, July 2011 or June 2015). Why there is no way to pull up warmer air from the south or southeast is due to the alignment of the high pressure system. In the Northern Hemisphere, winds go clockwise around high pressure and anticlockwise around low pressure - it's the opposite way round in the Southern Hemisphere. With the high pressure centred to our west/southwest though ridging in somewhat over Ireland (allowing it to be mainly dry), the wind comes from a northerly to northwesterly direction drawing in polar maritime air from the North Atlantic. This is never a particularly warm direction.

The second one shows very anticyclonic conditions with high pressure centred over top of the country. This scenario is warm and dry usually if there is a warm air mass contained within the high pressure and if it sticks around for a few days, the air will tend to warm up as the sun shines. Sometimes, there can be easterly winds on its southerly flank which will give away to hot conditions in the west whilst relatively cooler in the east affected by sea breezes. This pattern was what we had during much of May to July 2018. Many classic summers like 1947, 1955, 1975, 1976 and 1995 also have such a pattern.

The third one shows high pressure centred a bit further northwards and northeastwards with slacker gradients indicating lower pressure over the Bay of Biscay. This leaves us pulling in a very warm to hot southeasterly wind which will result in tropical continental air filtering into Ireland. A good few of our hot spells or heatwaves also have this pattern, most notably July 1983. However, with the slacker gradients to our southwest and the hot air becoming unstable, there is the possibility of thunderstorms. This is the pattern that models were projecting for late June 2019's warm spell over a week before.

Personally while I love a bit of warm or hot sunny weather as much as anyone, I'll happily take the cool and dry scenario - just don't piss rain all over us

gugsy wrote: »

If memory serve me right I think the gfs picked up the last heat wave first.

That's correct and I found it completely hysterical given how extreme it was (also gave it a 0.00000001% chance of happening). Other models then latched on to the idea although it took a while to catch the signal of an onshore northeasterly wind for a few days first before the winds would go southeasterly.

GEFS have had very warm or hot outliers for several days now in FI.

Gonzo wrote: »

this evenings ensembles still pointing towards a very warm or hot final week of July. I'd love if this continues into August. However this very warm trend is also looking rather unsettled with lots of rainfall spikes.

I could take the rain as long as it remains warm with a bit of sunshine.

It’s so nice to be able to have the heating off, the windows open and walk around in a t-shirt.

You’d think that’s a given in summer but not so after the miserable June we had!

Back to an unsettled scenario again this morning from the ECM 0z... the remnants of Barry must be throwing a wrench into the works. The more unsettled scenario generally holds a higher chance for now.

Had a very brief look at some model output this morning and to me it looks like there could be some trouble brewing for parts of Ireland as several fronts come up against a moisture layered southwesterly flow of air with very warm conditions over England and Wales. There would be the possibility of some really heavy orographic rain which I think is rather unusual for summer and more typical of late autumn or winter.