Rainfall radar

mrtom

While taking my dog for a walk about noon I got drenched! Now I always use the excellent Met rainfall radar for guidance however when I double checked I found an interesting discrepancy! See attch.
Do both sites share the same feed or is one just more sensitive hence a different image?

I live on the coast in Sandycove and judge wind direction both from the flag above the Joyce martello tower and the position of ships anchored in Dublin bay ( front into the wind) which indicated a strong southerly, however the rain cloud came from the NW!
Can you help explain how this happens.

Shane O' Malley

The met.ie one is not using the radar from Dublin Airport that time.

Must have been a glitch as it is working now.

Weatherproof79

Met.ie radar for the North West is completely useless and always has been. If the heaviest rain was over the North West it would be showing as the lightest if at all. It's often lashing here and it's not registering or just showing drizzle on their radar. Even on the weather fc on Rte the radar images are diabolical for here. Better to use a different radar

I contacted them about this five years ago and they conceded it was very poor and they hoped to rectify it in the near future but nothing changed. Netweather, met office, rain today are alternatives that are accurate

pauldry

Weatherproof79 wrote: »

Met.ie radar for the North West is completely useless and always has been. If the heaviest rain was over the North West it would be showing as the lightest if at all. It's often lashing here and it's not registering or just showing drizzle on their radar. Even on the weather fc on Rte the radar images are diabolical for here. Better to use a different radar

I contacted them about this five years ago and they conceded it was very poor and they hoped to rectify it in the near future but nothing changed. Netweather, met office, rain today are alternatives that are accurate

Yes weatherproof. Im in Sligo. Raintoday is the only radar to use if you live in West Mayo Sligo Donegal Leitrim Fermanagh

Theres 3mm of rain in sligo now showing dark orange on raintoday but dry on met eireann

Met Eireann excellent for everything except this

Bsal

Why can't met Eireann use the data from the Belfast radar, surely the uk met office don't charge that much for its data usage.

mrtom

mrtom wrote: »

While taking my dog for a walk about noon I got drenched! Now I always use the excellent Met rainfall radar for guidance however when I double checked I found an interesting discrepancy! See attch.
Do both sites share the same feed or is one just more sensitive hence a different image?

I live on the coast in Sandycove and judge wind direction both from the flag above the Joyce martello tower and the position of ships anchored in Dublin bay ( front into the wind) which indicated a strong southerly, however the rain cloud came from the NW!
Can you help explain how this happens.

My enquiry got the following informative & prompt response from Met.ie :


Thank you for your note and we hope you are none the worse for your drenching earlier today!
The discrepancies in radar images occurred because two of the radars that normally make up the composite image were out of action at the time; the radar at Dublin Airport itself and another weather radar at Crug-Y-Gorllwyn on the west coast of Wales. In these instances the radar processing software packages attempt to “fill the gaps” by applying a correction to imagery from surrounding radars; in the case of Dublin probably to the radar imagery from a weather radar near Belfast. However radar imagery at that distance from the radar “head” is always problematic (and there is high ground between Dublin and Belfast to shield the beam) and the “correction” to imperfect data can sometimes amplify the problems with the radar imagery at distance. I should note that these corrections are not applied by Met Eireann but by those who composite the radars and display them on their websites etc.

I hope that this helps.

With best regards

pauldry

Yeah radars are a thorny subject bur thanks to the internet you dont need to rely on the stuff met eireann have to so just browse

Raintoday
Net Weather
Sat 24

All have very good radars

Oneiric 3

Bsal wrote: »

Why can't met Eireann use the data from the Belfast radar, surely the uk met office don't charge that much for its data usage.

Often wondered that myself. The UK Met, along with other 3rd party sites, seem to have free usage of both Shannon and Dublin radars, yet our own Met seem to be severely restricted in being allowed access to use their radar networks, at least publicly? It doesn't sound like a very fair exchange to me.

FWVT

mrtom wrote: »

While taking my dog for a walk about noon I got drenched! Now I always use the excellent Met rainfall radar for guidance however when I double checked I found an interesting discrepancy! See attch.
Do both sites share the same feed or is one just more sensitive hence a different image?

I live on the coast in Sandycove and judge wind direction both from the flag above the Joyce martello tower and the position of ships anchored in Dublin bay ( front into the wind) which indicated a strong southerly, however the rain cloud came from the NW!
Can you help explain how this happens.

The surface wind ahead of a front will be from a more southerly direction, veering more westerly or northwesterly after the front passes through. Today's front was moving eastwards at around 35 knots (~70 kph) as weather systems are steered by larger-scale patterns and not by the surface wind.

This was the situation at 10 am today. The front lay across the midlands, with southerly winds to its east and westerly winds to its west.

highdef

But if the radar at Dublin and the one Wales were out of order, how did net weather manage to have such accurate info? I know it was accurate as I was looking at the net weather radar during the morning and up to lunchtime as I was monitoring the incoming cold front.

Iancar29

highdef wrote: »

But if the radar at Dublin and the one Wales were out of order, how did net weather manage to have such accurate info? I know it was accurate as I was looking at the net weather radar during the morning and up to lunchtime as I was monitoring the incoming cold front.

It was only not visible for one scan though. If you had played the loop you would've been able to notice the glitch judge what was missing.

Happens every other day on all radar sites,not only Met Eireann.

Discodog

pauldry wrote: »

Yeah radars are a thorny subject bur thanks to the internet you dont need to rely on the stuff met eireann have to so just browse

Raintoday
Net Weather
Sat 24

All have very good radars

But for the Galway area aren't they just the output from Shannon ?

My gripe is the resolution. We have a lot of day where the drizzle is heavy enough to soak you in minutes but it doesn't show on ME radar.

I love the Arcus weather app. It monitors the radar & gives pretty accurate warnings & short range rain forecasts.