Checking Rainfall Totals Across The Country

[johnholmes]

This will be where I hope to keep a check as promised.

Rainfall checks.doc

to Paul M and admin

If this is felt to be in the wrong place could one of you pm me with your suggestion of where you feel it should go please?

[TonyH]

Will be interesting. Can't see my location getting 36mm though, just drizzle so far this morning.

[spindrift1980]

Machrihanish is some way north and west of where your map places it!

It is on the Kintyre peninsula (see link)

http://maps.google.co.uk/maps?client=firefox-a&rls=org.mozilla:en-US:official&channel=s&hl=en&q=machrihanish&um=1&ie=UTF-8&hq=&hnear=Machrihanish,+Campbeltown,+Argyll&gl=uk&ei=G4gsTNGBH4yjsQb8ncHDAg&sa=X&oi=geocode_result&ct=title&resnum=1&ved=0CB8Q8gEwAA

[johnholmes]

well aware of that-trying to get as near a reporting station as possible-any suggestions you have for that area I am happy to receive as long as it is also close to the spot grid location?

be a pal and drop your nearest town in your avatar and welcome to NW lots to look at and use on this site.

[TonyH]

The rains turned heavier here now and although there's only been 5mm so far, a Davis VP station about 15 miles SW of here is on 21mm so far, so not a bad prediction it looks.

[spindrift1980]

What about RAF West Freugh (Stranraer)

[johnholmes]

thanks for adding your location-very useful when any of us report our weather

as to the weather site-I suspect we are both having a geographical nap!

The spot location is nearer Prestwick in my view than either my or your suggestions, but I stand to be corrected?

[Terminal Moraine]

The GFS 06z run now forecasts around 24mm of rain for this area but the rain is now delayed by about 18 hours, until late afternoon Tuesday into the early hours of Wednesday.

Quite consistent with the 21mm forecast the last time I checked about 4 runs ago.

[Spurry]

Can't say exactly how much rain we have had here recently, but since the hosepipe ban was announced it's hardly stopped falling from the sky , and it hasn't been light rain either ...

[johnholmes]

Just remembered I've put nothing in here, first one in the pdf file is for my location, the 2nd one is for the locations outlined in my first post.

Rainfall checks-1st two posted 26 jul10.pdf

I suspect the 2nd one is the first weekend of June?

Edited July 27, 2010 by johnholmes

[The PIT]

What rainfall figures were there over Wales yesterday and Last Night. Met Office were saying originally 25 - 50 mm which later increased too 80 mm netweather radar shows around 50m in some places but then it shows more rain on our area than actually was recorded.

[TonyH]

Indeed the radar accumulation shows over 70mm near the Brecon Beacons, a good half of that in just 4 hours this morning.

0nly 19mm here past 24 hours and we missed the heavy stuff through this morning, all to our SE,

[johnholmes]

I'm monitoring the usual spots in my checks currently St Athan 30.0mm, Lake Vymwy 33.0mm and Capel Curig 34.0mm to 1100z today <BR><BR>full results will be posted late this evening or over the weekend; the period under check ends 18z Friday.<BR>

Edited August 20, 2010 by johnholmes

[The PIT]

I'm monitoring the usual spots in my checks currently St Athan 30.0mm, Lake Vymwy 33.0mm and Capel Curig 34.0mm to 1100z today <BR><BR>full results will be posted late this evening or over the weekend; the period under check ends 18z Friday.<BR>

Cheers John.

[J10]

Indeed the radar accumulation shows over 70mm near the Brecon Beacons, a good half of that in just 4 hours this morning.

0nly 19mm here past 24 hours and we missed the heavy stuff through this morning, all to our SE,

It really was bad here, some monsoon like rainfall and some flooding damage.

[The PIT]

I'm monitoring the usual spots in my checks currently St Athan 30.0mm, Lake Vymwy 33.0mm and Capel Curig 34.0mm to 1100z today <BR><BR>full results will be posted late this evening or over the weekend; the period under check ends 18z Friday.<BR>

Any news on this John ???

[johnholmes]

Predicted rainfall from the Tuesday/Wednesday system

Well the 12z run using GFS/Extra/NAE all shows a fair amount of rain for this spot, lowest is 16mm and highest is 32-42mm by Tuesday lunch time.

Aviemore=2mm

Prestwick=20-23mm

Capel Curig=19mm

Chivenor=19-21mm

Heathrow=13-17mm

The dash represents a spot with no data on it but either dies of it; N-S or W-E.

The surface pattern as shown on the current T+48 Fax chart has a centre near NW Ireland with the cold front into the SW Midlands to Kent and the flow here well back east of south. GFS also suggests similar.

In these situations the rain shadow effect of the hills to the west if usually much diminished especially if the frontal trough is fairly slow moving.

I’ll keep a check again at 12Z tomorrow.

[johnholmes]

Just looking at the spot location for here and the models show 27mm(NAE) with the GFS version 34-37mm(NMM, Extra,GFS basic)

[Terminal Moraine]

About 27mm shown here too on GFS. The last rainfall event I checked, the GFS got it almost spot on so we shall see.

[johnholmes]

Chivenor was generally predicted to have 19-21mm, its stopped raining and report 25mm, so not bad for that spot.

[johnholmes]

Not done the full check yet, it ends 12z today but I got 20.4mm uncorrected, corrected by 25% due shelter=25.5mm, so pretty close for this location.

[Terminal Moraine]

GFS performed very well once again. The forecast was for 27 mm here and we got 29.3 mm.

[johnholmes]

below is the pdf file on check No 8. I hope it opens okay for anyone interested.

A better performance from most models but not good for Aviemore and prestwick spots.

rain check No 8 tue-wed 6-7 Sept.pdf

[johnholmes]

well, nothing much changes in the rainfall forecast area.

This for the Wednesday rainfall

At T+24 GFS gave a predict of 2(south) of here to 5 (north of here),Extra suggested 4mm, NAE 13mm and NMM wanted 4mm. In fact I recorded 0.4mm, with 25% correction=0.5mm.

So even the closest only gave about 17% of the predicted amount.

I am really at a loss to understand why the various models can be so far out 24 hours away from an event.

Please believe me its not an isolated instance, its more the norm rather than just the odd one being out. All the models from GFS/Extra at T+96 down to NAE at T+48 and the GFS+ Extra, down to T+24 which then also includes NMM are as bad as one another at times.

Thank heaven I'm no longer responsible for issuing Alerts/Watches. I'm sure its not my imagination that things have worsened over the past 12 months or more!

This is NOT a dig at any model just one confused ex senior Met O forecaster.

[The PIT]

well, nothing much changes in the rainfall forecast area.

This for the Wednesday rainfall

At T+24 GFS gave a predict of 2(south) of here to 5 (north of here),Extra suggested 4mm, NAE 13mm and NMM wanted 4mm. In fact I recorded 0.4mm, with 25% correction=0.5mm.

So even the closest only gave about 17% of the predicted amount.

I am really at a loss to understand why the various models can be so far out 24 hours away from an event.

Please believe me its not an isolated instance, its more the norm rather than just the odd one being out. All the models from GFS/Extra at T+96 down to NAE at T+48 and the GFS+ Extra, down to T+24 which then also includes NMM are as bad as one another at times.

Thank heaven I'm no longer responsible for issuing Alerts/Watches. I'm sure its not my imagination that things have worsened over the past 12 months or more!

This is NOT a dig at any model just one confused ex senior Met O forecaster.

Also explains why a lot of met office severe weather warnings are complete dross. Can't blame them if the data is duff although they should update faster than they do...