Rainfall/Drought Watch 2020

bazermc · 31-05-2020 7:40pm

I was done by Grand Canal Dock at the weekend to see what if was like with the new Capital Dock building and new green area.

They (dont know who) had a hose hooked up to water the grass outside the Fresh and the playground.

They were taking water from the hydrant thingy. Which was overflowing at the source and completely flooding the footpath area

Clever stuff in a drought.

Oneiric 3 · 31-05-2020 7:41pm

This chart shows the national running 90 day % total since June 2018 and up to yester.

Not quite on the level yet of the Summer 2018 dry spell, at least in terms of percentages, but getting there. I'll work on an actual running 90 day total chart later if I has time to compare later as it must be remembered that low %s in April/May would be more significant than their equivalent in mid Summer as it is a relatively drier part of the year.. on average.

Yes, that data is C/O Met Eireann. Deal with it.

PS, forgot to include year in chart dates, but you'll get the idea.

Oneiric 3 · 31-05-2020 11:14pm

Just looking at some stats here for Dubalin Airport, and regarding the wettest and driest 365 day running totals, both occurred pre 1980s. For example, the highest 365 day total was 1154.5mm occurred in 1966, peaking on October 27th, with the lowest being just 472.2mm which was recorded between Sept 16th 1974 and Sept 15th 1975. The long term running annual average (since 1943) is 755mm at this little dote of a station.

.nnaeriÉ teM morf ataD

Neddyusa · 31-05-2020 11:43pm

Gaoth Laidir wrote: »

It's an interesting report by Maynooth but shows the common problem of choosing an arbitrary time period based purely on calendar months. Weather doesn't work that way.

If the guys were to take the year so far as a whole, or the hydrological cycle (from 1st October) we would see that the situation is not as dire as they make out. Claiming records depends on which exact period you happen to choose. We can get equally impressive dry spells that last from say the second half of one season through the first half of the next, but if both of those seasons are book-ended by wetter conditions the dry spell doesn't make the records.books as.both seasons will turn out around average.

Nearby Casement is bang on average accumulation for 2020 and above average for the hydrological year so far (Dublin Airport and Dunsany are on average).

So while it is a remarkably dry period the whole country is experiencing, I dare say we've seen similar periods before only they didn't exactly match up with a convenient calendar period. Trends all depends on how near or far you want to zoom in or out. Given the very wet winter we've had it's inconceivable that just 3 months later our water system again seems well capable of squandering the excess. This is what should be prioritised as our population grows, not some pointless green GHG tax initiatives.

From an agricultural point of view though the timing of the dry spell is very significant, as almost 50% of the grass that grows in an average year grows in the months of April and May.
Because this is a factor of the reproductive cycle of the grass plant, the current loss of growth will not be compensated for later in the year.

DOCARCH · 01-06-2020 9:09am

Rainfall total here, in Dublin 16, for Spring, just 47.4mm.

March 20.0mm + April 20.6mm + May 6.8mm.

SleetAndSnow · 01-06-2020 11:05am

Cork totals according to the airport : March:64.7 April:72.3 May:68.8 so total rainfall of 205.8mm for spring

Timmaay · 01-06-2020 4:40pm

Neddyusa wrote: »

From an agricultural point of view though the timing of the dry spell is very significant, as almost 50% of the grass that grows in an average year grows in the months of April and May.
Because this is a factor of the reproductive cycle of the grass plant, the current loss of growth will not be compensated for later in the year.

Agreed in terms of grass growth, however hopefully the compensation comes in the form of a mild autumn and winter that results in livestock staying out grazing longer. But if your anyways short on winter fodder now is the time to take action and buy in fodder.

Oneiric 3 · 01-06-2020 7:33pm

Forecast Rainfall totals out to Thursday midnight:

Some showery outbreaks moving down over the country overnight tomorrow night/Weds morning. Not much forecast but might be just enough to settle the dust in more eastern areas. Interestingly, the UK Met are showing some scattered, if potentially heavy showers breaking out tomorrow afternoon and eve over the eastern half of the country, so maybe some hope there of some local soakings, but that model seems to be on its own regarding this. We'll see anyways.

sryanbruen · 01-06-2020 7:36pm

I see Irish Water have now mentioned the words "hosepipe ban". Not going to say anything more than that...

Gonzo · 01-06-2020 8:11pm

If the GFS is to be believed this dry spell looks like it's coming to and end. Not much in the way of heavy rain over the next week but from the second week of June we have lots of rainfall spikes coming back along with an increase in temperatures.

Oneiric 3 · 01-06-2020 11:09pm

Looking at stats from the 2018 spell, and going by the a 90 day running total (on a national level) the lowest value bottomed out at 103.7mm on July 25th of that year. The current national 90 day mean total so far stands 141.0mm, which would mean that to achieve a similar depth of dryness to that of 2018, we would need to have zero rainfall between now and June 9th.

Danzy · 01-06-2020 11:09pm

sryanbruen wrote: »

I see Irish Water have now mentioned the words "hosepipe ban". Not going to say anything more than that...

Dykes here that were strongly flowing in late June 18 are near bone dry now.

Danzy · 01-06-2020 11:58pm

Gonzo wrote: »

If the GFS is to be believed this dry spell looks like it's coming to and end. Not much in the way of heavy rain over the next week but from the second week of June we have lots of rainfall spikes coming back along with an increase in temperatures.

Still looks like a very hot summer, thankfully not continuous,

nacho libre · 02-06-2020 10:44am

Gonzo wrote: »

If the GFS is to be believed this dry spell looks like it's coming to and end. Not much in the way of heavy rain over the next week but from the second week of June we have lots of rainfall spikes coming back along with an increase in temperatures.

The GFS has a tendency to herald the end of blocking highs only to backtrack later. It maybe right this time, but i would not be surprised to see it show a less unsettled scenario in subsequent runs.

pauldry · 02-06-2020 11:06am

Yes. There is only one thing that can end this drought.....

August

Gonzo · 02-06-2020 1:35pm

pauldry wrote: »

Yes. There is only one thing that can end this drought.....

August

hopefully this year will be different. We are well overdue a decent warm and sunny August for the past 17 years!

KingdomRushed · 02-06-2020 2:21pm

Little more certainty on a slow breakdown of the months long dry spell in June. Met Eireann 7 day forecasts showing rain most days now from tomorrow morning right through to next Monday.

Gonzo · 02-06-2020 4:08pm

KingdomRushed wrote: »

Little more certainty on a slow breakdown of the months long dry spell in June. Met Eireann 7 day forecasts showing rain most days now from tomorrow morning right through to next Monday.

BBC showing rain for here every day from the 8th of the June to the 14th and I think they are right, looking at the models this period becomes quite unsettled with several low pressures near us or above us. The real unsettled period takes place once we lose the northerlies and temperatures start to recover. I am hoping that the models will change before then and we see the azores high trying to come back into play for the 2nd week of June but at the moment that is looking unlikely.

Gonzo · 02-06-2020 4:18pm

latest GFS going for a very wet week between the 10th and 16th of June. This is probably the wettest ensemble I've seen since February, possibility of deluges even. It's over a week away and could get pushed back all the way to August.

ens_image.php?geoid=64981&var=201&run=6&date=2020-06-02&model=gfs&member=ENS&bw=1

ens_image.php?geoid=64981&var=201&run=6&date=2020-06-02&model=gfs&member=ENS&bw=1

compsys · 02-06-2020 4:28pm

Gonzo wrote: »

latest GFS going for a very wet week between the 10th and 16th of June. This is probably the wettest ensemble I've seen since February, possibility of deluges even. It's over a week away and could get pushed back all the way to August.

The pavements everywhere are filthy and the land is scorched. There is now talk of water restrictions.

Still being under quarantine and having to also contend with water rationing would do most people's head in.

Be careful what you wish for Gonzo. Hate to say it but the rain is badly needed.

pauldry · 02-06-2020 5:03pm

Drops of rain falling in Co Sligo now and 14c.

The drops are very few though

riclad · 02-06-2020 7:01pm

I crossed the liffey today. There's just a stream of water,
I have never seen it so low. I hope we get heavy rain soon
It looks to be about 2ft deep in most places.

nacho libre · 02-06-2020 9:20pm

KingdomRushed wrote: »

Little more certainty on a slow breakdown of the months long dry spell in June. Met Eireann 7 day forecasts showing rain most days now from tomorrow morning right through to next Monday.

There isn't much rain forecast away from the north west between now and Monday- certainly not enough to satisfy farmers. Talk of a breakdown is premature- there is a temporary blip, but a breakdown lasting weeks is not a certainty at this stage by any means.

FVP3 · 02-06-2020 9:48pm

The UK met is predicting, as far as I can see, that the unsettled weather from mid June is more common to their east and not the west. So maybe Ireland is dry.

Which is unusual, maybe thunder storms pushing up from Europe.

Anyway, I was surprised by all this as I am sure they were predicting a dry June just a few weeks ago.

We do need rain though.

FVP3 · 02-06-2020 9:52pm

Here is the mid June forecast. 7th to 16th.

To start the period, there will be a mixture of sunny spells and showers across many parts. The showers will be most frequent in the north and east, along with some longer spells of rain. The best of the drier conditions should be seen in the south and west, with plenty of bright or sunny spells. Into the second half of the period, the changeable conditions should continue with further showers and perhaps longer spells of rain, mostly confined to the north and east. Generally, rather cool at the start of the period, particularly in the north and east. Temperatures could start to recover to average in the south and west towards the end of the period.

We are of course to the west of all of this.

That doesnt seem like atlantic fronts barreling in, either, as the west of Ireland and Britain take the brunt of that.

Gonzo · 02-06-2020 9:55pm

FVP3 wrote: »

Here is the mid June forecast. 7th to 16th.

To start the period, there will be a mixture of sunny spells and showers across many parts. The showers will be most frequent in the north and east, along with some longer spells of rain. The best of the drier conditions should be seen in the south and west, with plenty of bright or sunny spells. Into the second half of the period, the changeable conditions should continue with further showers and perhaps longer spells of rain, mostly confined to the north and east. Generally, rather cool at the start of the period, particularly in the north and east. Temperatures could start to recover to average in the south and west towards the end of the period.

We are of course to the west of all of this.

That doesnt seem like atlantic fronts barreling in, either, as the west of Ireland and Britain take the brunt of that.

yep most if not all of our weather will be from Europe over the next 2 to 3 weeks, not the Atlantic.

Our traditional conveyer belt of low pressures in off the Atlantic are off the table in the near to medium term. We can still get a decent drop of rain from the east but it's usually showery in nature.

fleet_admiral · 02-06-2020 9:56pm

Starting to rain in Terenure, south Dublin

Gaoth Laidir · 02-06-2020 9:57pm

The first time I've looked at my Rainalarm app in ages and it really does give a misleading impression. All the activity showing up in my area is from virga. Not a drop reaching the ground. I wonder does this get accounted for when rainfall totals are being calculated from radar returns.

sryanbruen · 02-06-2020 11:21pm

Well here is a stat I would have never figured out... 19 March to 1 June was the driest 75-day period on record for Dublin Airport and 2018 was 2nd before this.

https://twitter.com/IrishDataViz/status/1267907049343668225?s=20

Rougies · 02-06-2020 11:42pm

Gaoth Laidir wrote: »

The first time I've looked at my Rainalarm app in ages and it really does give a misleading impression. All the activity showing up in my area is from virga. Not a drop reaching the ground. I wonder does this get accounted for when rainfall totals are being calculated from radar returns.

When are rainfall totals calculated from radar returns? Not familiar with the app, maybe that's what you mean. Surely not in any professional meteorological setting anyway.

Rainfall/Drought Watch 2020

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