Heavy Rain Risk Sunday Night/Monday

Deep Easterly · 04-09-2010 8:28pm #1

Well discussed on other threads so worthy of a thread of its own I think.

Some heavy rain is forceast to move in over many parts of Ireland tomorrow evening as a frontal zone, currently developing to the west of Ireland, gets caught up in a strengthen jet and makes its merry towards Ireland.

ECMWF forecast chart for noon monday:

Heavy pulses of rain are forecast to pump up over Ireland through sunday night into a good part of monday, with the eastern half of the country most at risk of the heaviest bursts with more showery conditions (which could be still heavy) forecast to develop further west during monday afternoon.

My advice is to enjoy it!

Su Campu · 04-09-2010 8:45pm

The Spanish HIRLAM has crazy rain rates Mondy morning, from 30-50mms/6 hrs in the east. That would appear to be a bit over the top to me, but one to watch alright

fishmahboi · 04-09-2010 8:58pm

1:00 am sunday night

kindredspirit · 04-09-2010 9:35pm

Senor Balor always seems to be on the money.

delw · 04-09-2010 9:54pm

Is it the scraps left from huricane Danielle?

Su Campu · 04-09-2010 10:11pm

delw wrote: »

Is it the scraps left from huricane Danielle?

Not really. Satellite loops of the last 6 days shows Danielle dissipating to our west a few days ago, with a bit of remaining high cloud passing over us on Thursday, and the rest of the fragments heading north towards Iceland. It may have injected a bit of oomph to the Atlantic low, but that's about it.

Click here and choose Meteosat 9. Set the date from Aug 28th, and you'll see Danielle coming up the left side of the shot, past New Foundland. Follow it from there

Redsunset · 04-09-2010 10:19pm

Yes certainly worthy of its own thread.

Heavy rainfall rates possibly coming from the front stalling over at least two thirds of the country but all areas getting a good soaking.

Crazy stuff from the NAE

ECM

GFS

So we could be in for some flooding folks and with the ground fairly hard in places after the warm spell,water might run off it and create some problems. This is all subject to change of course but for now im issuing my warning sign.:D

fishmahboi · 04-09-2010 10:25pm

Hmm.. YR.no seems to dissagree with the rainfall being that big although it could be wrong :pac:

dexter647 · 04-09-2010 10:28pm

Could we get a few sparks with this heavy rain?

Su Campu · 04-09-2010 10:31pm

dexter647 wrote: »

Could we get a few sparks with this heavy rain?

We sure could!

Redsunset · 04-09-2010 10:32pm

Well this i feel will be slow moving and create some significant totals in a few spots,especially if there's any embedded thundery downpours which i think there will.

Redsunset · 04-09-2010 11:36pm

Weather Warning
Met Eireann
Issued at 04 September 2010 - 11:00
Weather Advisory of Heavy Rain
Heavy rain expected Sunday afternoon and evening in parts of the southwest and west and in all areas on Sunday night. Further heavy rain or thundery showers on Monday. Rainfall totals of 25 to 40mm, highest in eastern counties. Valid from 1500 Hours 5/9/2010 to 2400 Hours 6/9/2010

fishmahboi · 04-09-2010 11:43pm

This is actually really scary :eek:

Takeshi_Kovacs · 05-09-2010 12:02am

What time ye expect first of the heavy rain to come in over Kerry/Southwest in general tomorrow?

delw · 05-09-2010 12:16am

Su Campu wrote: »

Not really. Satellite loops of the last 6 days shows Danielle dissipating to our west a few days ago, with a bit of remaining high cloud passing over us on Thursday, and the rest of the fragments heading north towards Iceland. It may have injected a bit of oomph to the Atlantic low, but that's about it.

Click here and choose Meteosat 9. Set the date from Aug 28th, and you'll see Danielle coming up the left side of the shot, past New Foundland. Follow it from there

cheers Su Campu,great view of storms coming off west africa to cape verde,anyway east in for a wet spell&hopefully a rumble of thunder

fishmahboi · 05-09-2010 12:21am

delw wrote: »

cheers Su Campu,great view of storms coming off west africa to cape verde,anyway east in for a wet spell&hopefully a rumble of thunder

Can you say when the extreme part of the heavy rain will start and end?

delw · 05-09-2010 12:40am

fishmahboi wrote: »

Can you say when the extreme part of the heavy rain will start and end?

sorry fishmohboi i wouldnt no where to start,i am reading&trying to learn from the knowledgable people(experters in this forum)&from what ME are saying that the east are in for the heaviest of the rain

Redsunset · 05-09-2010 12:47am

fishmahboi wrote: »

Can you say when the extreme part of the heavy rain will start and end?

Difficult question to answer as rainfall intensity time period changes in model runs.

Latest GFS for example.

Add to that any imbedded thunder storms would give large rainfall rates for short periods.

fishmahboi · 05-09-2010 1:32am

Just checked the charts and it looks like most of the rain is heaviest in the midlands and it looks slightly more moderate in the east

Redsunset · 05-09-2010 8:43am

From what i can see,parts of the north ,midlands and east and south east that will bear the brunt of the most prolonged and heaviest rain.
But everyone can expect a good drenching.

Because of the blocking high pressure around scandinavia the system will be slow moving and stall for a time and re energising in pulses of thundery downpours.

Deep Easterly · 05-09-2010 10:56am

EMHI HIRLAM cloud forecast for 1200 UTC tomorrow, giving a rough idea of where the frontal zone will be parked this time tomorrow approx:

Latest prognosis is for persistant rain over the northeastern half of Ireland for much of tomorrow afternoon with showers developing elsewhere as a slack area of low pressure develops on the back edge of the front.

Not a definate though.

looksee · 05-09-2010 11:05am

So guess when we are having our staff development day, doing outdoors-type dashing about the countryside! Better go and pack some more clothes.:eek:

Su Campu · 05-09-2010 12:20pm

Some decent convection taking place to our southwest, with cloudtops around -55°C. Some sferics showing up in it too.

Personally though I think the models have gone a little crazy with the rainfall totals on this, and I'd say we might get the odd location registering 30mms by this time tomorrow, but for most it will be 10-20mms.

mickger844posts · 05-09-2010 1:39pm

Su Campu wrote: »

Some decent convection taking place to our southwest, with cloudtops around -55°C. Some sferics showing up in it too.

Personally though I think the models have gone a little crazy with the rainfall totals on this, and I'd say we might get the odd location registering 30mms by this time tomorrow, but for most it will be 10-20mms.

I agree with this, even looking at what's on the Radar at present there is nothing that heavy there. Looks like just normal amounts of rain nothing that heavy.

Su Campu · 05-09-2010 2:19pm

mickger844posts wrote: »

I agree with this, even looking at what's on the Radar at present there is nothing that heavy there. Looks like just normal amounts of rain nothing that heavy.

I wouldn't go on what you see on the radar at the moment, the heaviest rain will be moving up from the south later tonight.

Deep Easterly · 05-09-2010 2:45pm

Su Campu wrote: »

I think the models have gone a little crazy with the rainfall totals on this, and I'd say we might get the odd location registering 30mms by this time tomorrow, but for most it will be 10-20mms.

I have noticed that myself, seemingly very unrealistic totals forecast on some models alright. The latest NAE rainfall accumulation for the 36hr period up to 18hrs GMT has up to 80mm falling in some areas up the spine of the country (image attached).

I think it will be more a case of persistant light to moderate rain (which can still result in fairly reasonable totals) but with some heavy pulses moving through at times which is fairly typical of this type of set up, and what is more or less being forecast by the DMI model:

(late tomorrow morning chart)

Whether the models are onto something regarding the actual totals I do not know. From a weather enthusiast's point of view though it will be interesting to monitor this event to see if the most reliable models have called this well or not.

Anyway, all eyes on the skies!

fishmahboi · 05-09-2010 5:21pm

Hmm.. After looking at this it looks like the coming rain is likely to weaken

North Cork · 05-09-2010 5:29pm

Forecasters Warning Heavy And Persistent Rain

Areas Affected: Highest risk for Northern Ireland and the Republic of Ireland, but Wales and southwest England also at risk.

Valid: 03:00 Monday 06th September - 06:00 Tuesday 07th September 2010

This is a Weather Watch issued by Metcheck at 09:14 on Sunday 05th September 2010.

An Atlantic weather system bringing outbreaks of heavy rain will move in across the Republic of Ireland, Northern Ireland, parts of Wales and southwest England during Sunday night and Monday. This system is expected to become slow moving over these areas during Monday, with heavy and persistent rainfall expected to continue for much of the day, particularly across Ireland.

Rainfall totals of between 25mm and 50mm (1 to 2 inches) are expected to fall quite widely, and over parts of Ireland totals of over 75mm (3 inches) in some localised spots may result in some localised flooding and hazardous travelling conditions.

This Weather Watch will be updated later today, Sunday 05th September 2010, where it may be upgraded into a Severe Weather Warning depending on developments.

Issued by: Paul Barber for Metcheck

fishmahboi · 05-09-2010 5:53pm

North Cork wrote: »

Forecasters Warning Heavy And Persistent Rain

Areas Affected: Highest risk for Northern Ireland and the Republic of Ireland, but Wales and southwest England also at risk.

Valid: 03:00 Monday 06th September - 06:00 Tuesday 07th September 2010

This is a Weather Watch issued by Metcheck at 09:14 on Sunday 05th September 2010.

An Atlantic weather system bringing outbreaks of heavy rain will move in across the Republic of Ireland, Northern Ireland, parts of Wales and southwest England during Sunday night and Monday. This system is expected to become slow moving over these areas during Monday, with heavy and persistent rainfall expected to continue for much of the day, particularly across Ireland.

Rainfall totals of between 25mm and 50mm (1 to 2 inches) are expected to fall quite widely, and over parts of Ireland totals of over 75mm (3 inches) in some localised spots may result in some localised flooding and hazardous travelling conditions.

This Weather Watch will be updated later today, Sunday 05th September 2010, where it may be upgraded into a Severe Weather Warning depending on developments.

Issued by: Paul Barber for Metcheck

I think this forecast is a little exaggerated and far feteched too since it was issued at 9:14

Deep Easterly · 05-09-2010 5:55pm

Latest Met Eireann forecast very encouraging:

met eireann update 05 September 2010 15:54 wrote:

Today
Persistent and heavy rain in the southwest and west will spread countrywide this evening and early tonight, along with strengthening southeast winds.

Tonight
Wet and windy overnight with widespread rain, low cloud and mist. Some heavy falls of rain will occur with the risk of thunderstorms leading to localised flooding. Mild. Temperatures no lower than 12 to 15 degrees.

http://www.met.ie/forecasts/#

Mention of possible thunderstorms. I am not convinced but I will be more than happy to be proven wrong!

gbee · 05-09-2010 7:46pm

Cork: 17mm rain past hour by my WS.

28mm So far today!

Heavy Rain Risk Sunday Night/Monday

Comments