Convective/Thunderstorm Discussion: Spring/Summer 15

maquiladora

Wednesday and especially Thursday are the days to keep an eye on.

Storm 10

Hi Maq looking at that chart what are the chances of storms in the West.

maquiladora

Storm 10 wrote: »

Hi Maq looking at that chart what are the chances of storms in the West.

Just too soon to say really. Airmass storms can pop up almost anywhere if the conditions are right. It's too early to look out for anything more organised than that.

RobertKK

The charts show precipitation moving up from the south on those days mentioned above.
Spanish plume possibility: high.

WheatenBriar

RobertKK wrote: »

The charts show precipitation moving up from the south on those days mentioned above.
Spanish plume possibility: high.

One to watch certainly but the tendency is for the heat to track north east so the end result might have hottest uppers well east of Wales
Still if I could reach above 25c last Saturday, This airmass could give high 20's at least
Not in Arklow though as a southerly will cool us as the sea is due south
Inland Dublin could get very hot
Need rain badly, got none last night bar a slight dampening, land is parched

jimmynokia

Fingers crossed for an EVENT next week.

Kermit.de.frog

This is a storm factory.

Elmer Blooker

Kermit.de.frog wrote: »

This is a storm factory.
YES
http://www.meteociel.fr/ukmo/fax/fax120s.gif?2

Rikand

Elmer Blooker wrote: »

Kermit.de.frog wrote: »

This is a storm factory.

YES
http://www.meteociel.fr/ukmo/fax/fax120s.gif?2

Question about charts for a second if you dont mind.

If that's a lower pressure pushing into the south east of england, how is it going to be so warm ? Wouldnt it normally be high pressure pushing in there to generate such high temperatures, but the chart has the figure L1008 on there

WheatenBriar

At this stage it's a guess at where a shallow low could form possibly along a convergence zone which requires heat energy conflicting with cooler sea breezes which there could be in abundance
The upper air is above 20c,so in Sun that's low to mid 30s at sea level

Regarding Ireland, Lets see,it's thunder I'm looking for
Of course now I've said it that won't happen in abundance.

maquiladora

Pretty disappointing output from the 06Z GFS for storm potential. A moderate risk of a few thundershowers on Wednesday and probably nothing at all for Thursday if that verified. Still several days away so this can change but right now things looking less interesting than a few days ago.

FWVT

At first glance the 850 hPa theta-e charts look almost identical (or even warmer) to those of July 25th 1985, but there is not the same upper forcing in place (digging trough). Shame, as it could have been something special, but we still could see a few elevated storms.

maquiladora

Looking at the 12Z GFS, the most interesting period on that model looks like being early Wednesday morning with a line of thundery cells stretching from northwest France up through southwest England, Wales, the Irish Sea and reaching the east coast. Too far away to look at in any kind of detail but just an idea of something that might happen.

Oneiric 3

Looking at various reanalysis charts for the July 1985 storm, there seems to be nothing of note regarding the actual synoptic pattern or the 500 hPa/850 hPa temp profiles. 850 temps for example, merely based on these reanalysis charts, were no more that about 13c over the east of Ireland as the storm kicked in. Guess it was just a freak combination of all the above factors and more that led to this particularly severe event.



Image from Vedur.is/ERA-40

FWVT

Oneiric 3 wrote: »

Looking at various reanalysis charts for the July 1985 storm, there seems to be nothing of note regarding the actual synoptic pattern or the 500 hPa/850 hPa temp profiles. 850 temps for example, merely based on these reanalysis charts, were no more that about 13c over the east of Ireland as the storm kicked in. Guess it was just a freak combination of all the above factors and more that led to this particularly severe event.



Image from Vedur.is/ERA-40

Theta-e charts are more useful in this situation as they show where the temperature AND moisture are greatest.Look also at the 500 hPa chart, with its sharp negatively-tilted trough overriding the tongue of highest theta-e.

WheatenBriar

Oneiric 3 wrote: »

Looking at various reanalysis charts for the July 1985 storm, there seems to be nothing of note regarding the actual synoptic pattern or the 500 hPa/850 hPa temp profiles. 850 temps for example, merely based on these reanalysis charts, were no more that about 13c over the east of Ireland as the storm kicked in. Guess it was just a freak combination of all the above factors and more that led to this particularly severe event.



Image from Vedur.is/ERA-40

can you look at June 28th 1986,the night of the Simple minds concert at Croker
That was some thunder after a very hot day
The World Cup final was the next day
Some amount of rain that Saturday night and Sunday and some amount of lightning,I remember we weren't able to get a taxi and walking out by Rte,the forks were massive alongside the donnybrook mast
Power was off all over the place,the noise terrific and it went on so long
One of the many memorable 80's summer storms

maquiladora

Oneiric 3 wrote: »

Looking at various reanalysis charts for the July 1985 storm, there seems to be nothing of note regarding the actual synoptic pattern or the 500 hPa/850 hPa temp profiles. 850 temps for example, merely based on these reanalysis charts, were no more that about 13c over the east of Ireland as the storm kicked in. Guess it was just a freak combination of all the above factors and more that led to this particularly severe event.



Image from Vedur.is/ERA-40

And the satellite image to go with that.

maquiladora

Thunderstorms Wednesday night on the ECM?

maquiladora

Looking at the 06Z GFS, first real opportunity for some thundery weather still looks like being in the early hours of Wednesday morning starting down on the coast of northwest France extending through Wales then the Irish Sea and then reaching the east coast here. The model has shown this for the past few runs, will be interesting to see if it happens.

Kermit.de.frog

Tuesday night/early hours of Wednesday looks the target for thunderstorms at this stage. Cells could developed in the eastern half of the country moving up from the south. Something to watch.

Iancar29

Looks like we all have the same thoughts as per target area for storms to fire, but for surface based storms i think its gonna be a cap bust im afraid Its a shame with the ample shear in place.

Best place to be would be along the SE coast to catch any imported elevated storms running up the Irish sea.

maquiladora

German hi-res model is showing thunderstorms pushing up northwards from the south coast from around 6pm Wednesday to around midnight. The same model wasn't making much of the early morning chances for the east coast though and the GFS has backed off a bit on that too. As always it will be a case of nowcasting.
I agree that elevated storms could be a feature.

maquiladora

Looking at the 12Z GFS, there's a chance of some storms sparking off in the northwest tomorrow evening.
The chance of thundery showers reaching the east coast early Wednesday has been reduced due to a eastward shift that looks like keeping things mostly on the other side of the Irish Sea.
Then in the late afternoon into the evening Wednesday there is a general risk of thundershowers popping up.
Whatever happens though it looks like the greatest chance of storms will be over the UK and not here.

Edit: Worth remembering though that the models can get thunderstorms horribly wrong. Only recently there was a setup where it looked like southwest England and Wales were due to see some humdingers. CAPE looked great, Estofex issued a Level 2 for the area and then on the day....zilch, nadda. The storms instead sparked up further east.

FWVT

maquiladora wrote: »

Looking at the 12Z GFS, there's a chance of some storms sparking off in the northwest tomorrow evening.
The chance of thundery showers reaching the east coast early Wednesday has been reduced due to a eastward shift that looks like keeping things mostly on the other side of the Irish Sea.
Then in the late afternoon into the evening Wednesday there is a general risk of thundershowers popping up.
Whatever happens though it looks like the greatest chance of storms will be over the UK and not here.

I'm north of London for today and tomorrow so hoping for some fireworks tomorrow (though not enough to affect my flight home). A very pleasant 24 degrees here at the moment, but signs of upper instability are already evident.

Iancar29

NMM 12z going for a cap bust into Wednesday morning ... Lets hope things will look differently for Wednesday night.

Oneiric 3

ECM showing a convergence line of sorts developing over the southeast and east on Wednesday afternoon/evening, yet not showing anything in the way of precipitation? Surprising giving the sharp temp gradient between west and east, so it would not be surprising if some convective activity did spring up in that region on Wed after/eve.

maquiladora

Oneiric 3 wrote: »

ECM showing a convergence line of sorts developing over the southeast and east on Wednesday afternoon/evening, yet not showing anything in the way of precipitation? Surprising giving the sharp temp gradient between west and east, so it would not be surprising if some convective activity did spring up in that region on Wed after/eve.

Just checked the HIRLAM and that model does show precip developing over the southeast and east early in the afternoon and then a burst of precip over the midlands later in the evening at the end of the run.

Oneiric 3

WheatenBriar wrote: »

can you look at June 28th 1986,the night of the Simple minds concert at Croker
That was some thunder after a very hot day
The World Cup final was the next day
Some amount of rain that Saturday night and Sunday and some amount of lightning,I remember we weren't able to get a taxi and walking out by Rte,the forks were massive alongside the donnybrook mast
Power was off all over the place,the noise terrific and it went on so long
One of the many memorable 80's summer storms

And that was just one of the many memorable storms which occurred in that 6 day spell. The night before, the highest hourly total on record occurred in Co. Wexford (over 50 mm I think). Extraordinary spell of weather that set for me too high a precedent.



From ERA-40/Vedur.

maquiladora wrote: »

Just checked the HIRLAM and that model does show precip developing over the southeast and east early in the afternoon and then a burst of precip over the midlands later in the evening at the end of the run.

Cool cool cool. I'll be looking on in envy - if I can see through the low cloud and drizzle...:rolleyes:

WheatenBriar

Aye,a line from west Wicklow down to mount Leinster often see's convergence activity
I usually miss those being near the coast but can see them afar
There's a lot of things working against something special happening this week,not least of which is the briefness of the flirt with hot and humid/disturbed air up against the flood of the bland and ordinary flooding in from the west which is the very stuff tilting the most potent of energy more northeast than North


Last time we had a weaker effort,I remained hopefull
Not jinxing it this time by saying there's any hope

dubscottie

What happened to give us the 2 days of thunder in 2003 or 2004? I remember it started on the Wed night and didn't stop till the Friday morning.