Model Output Discussion

[The PIT]

I think ECM has been re-programmed by GFS formner programmers. Complete flip flop from mild south westerlies to cold weather. probably explains why the evening and morning forecasts have started mentioning it.

Some impressive cold 850's with the ECM as well

Edited March 25, 2010 by The PIT

[mountain shadow]

I think ECM has been re-programmed by GFS formner programmers. Complete flip flop from mild south westerlies to cold weather. probably explains why the evening and morning forecasts have started mentioning it.

Some impressive cold 850's with the ECM as well

Return to winter next week on the models. Crying out for warmth.

[The PIT]

Return to winter next week on the models. Crying out for warmth.

It's been very mild the last few days hence the massive rise in CET.

[frostyjoe]

I think ECM has been re-programmed by GFS formner programmers. Complete flip flop from mild south westerlies to cold weather. probably explains why the evening and morning forecasts have started mentioning it.

Some impressive cold 850's with the ECM as well

so it wont be cold! ive been dying with this weather i want resbite for once at least when its cold its lovely and sunny with some snow on the ground its lovely!

[Eugene]

lol that is a funny comment PIT regarding ECM being re programmed by GFS former programmers, don't think you have a proper understanding of the way model outputs are produced but funny nonetheless, not really a big change though from previous days ECMWF runs so never take one run in isolation

As JMA 12Z is also similar i wont

http://www.wetterzentrale.de/pics/Rjma1921.gif

It's been very mild the last few days hence the massive rise in CET.

He probably means he wants some some proper settled spring weather where you dont need to worry if it rains or not with light winds clear blue skies and temps into the mid to high teens for the week before Easter

[The PIT]

lol that is a funny comment PIT regarding ECM being re programmed by GFS former programmers, don't think you have a proper understanding of the way model outputs are produced but funny nonetheless, not really a big change though from previous days ECMWF runs so never take one run in isolation

As JMA 12Z is also similar i wont

http://www.wetterzentrale.de/pics/Rjma1921.gif

It twas a joke my friend and actually the people behind the ECM model have been helping the GFS people out. However it has been behaving more like the GFS than normal considering it's recent flip flopping. Makes you wonder what data it's been chewing over recently.

Since I've been off work I've been keeping my eye on every run.

Edited March 25, 2010 by The PIT

[damianslaw]

Very much a colder but still unsettled spell as we head through this weekend and into next week thanks to stronger heights ridging south westwards out of Greenland pushing the trough east of the country and allowing low pressure to engage with the colder air to the north, so a very different feel to recent days with some cold winds it is going to feel particularly unpleasant.

BBC very keen on showing heavy snow over northern Pennines, southern uplands and cumbrian fells on Monday as the low pressure to the south west engages the colder air - maxes of 4 degrees in northern england and southern scotland will feel very cold in the sleety heavy rain.

Next week will depend on where the low tracks, signs that we may not quite get the direct northerly thanks to further low replacing Monday low in a similiar fashion, but eventually I see a straight northerly late next week just in time for easter so sunshine and wintry showers, any heavy showers would likely bring snow to lower levels over the north.

In overview turning cold staying unsettled possibly wintry in the run up to easter especially in the north.

Edited March 25, 2010 by damianslaw

[Eugene]

GFS can't make its mind up over sunday and monday, both days now looking cold and wet on 18Z when it was dry on 12Z.

http://www.wetterzentrale.de/pics/Rtavn961.png

Sunday and monday look a nightmare to forecast currently.

GFS 18Z brings a high risk of some potentially disruptive snowfall overnight monday night into tuesday morning almost anywhere but especially midlands and north

http://www.wetterzentrale.de/pics/Rtavn1081.png

http://www.wetterzentrale.de/pics/Rtavn1024.png

http://www.wetterzentrale.de/pics/Rtavn1083.png

http://www.wetterzentrale.de/pics/Rtavn10817.png

[Thundery wintry showers]

It's been very mild the last few days hence the massive rise in CET.

I don't think what's gone before is necessarily relevant- some would like a consistently warm spring like the one we had last year. But Spring 2010 is progressing in a rather more varied- and normal- vein with spring arriving and advancing in fits and bursts. It looks like cold weather of some description is strongly odds-on next week now.

Not sure about all of the comments about ECM and GFS, but all of the models have been performing relatively poorly recently:

http://www.emc.ncep.noaa.gov/gmb/STATS/html/acz5.html

At T+120 we see a fall-off from the GFS in particular.

GFS 18Z is midway between the 06Z and 12Z outputs- dull cold and wet across many areas on Sunday and Monday (again, the fronts move in before the cold air fully establishes, so snow only for high ground) but then the "true" Arctic airmass heads south into Tuesday and Wednesday, giving sunshine and wintry showers. A "white Easter" is looking a possibility because the northerly is likely to be relatively short-lived but there could be another reload behind a depression for the Easter weekend, though still very uncertain at this range.

[J10]

Chance of a few wintry showers for southern areas for Tuesday and Wednesday, (too mild with the fronts before then.) The showers may give some snow, and in these set-ups in late March and Early April it an be 8c and sunny one minute, and snowing the next.

At this time of years, showers in these set-ups are far more likely than in midwinter.

[mushymanrob]

yep its looking pretty messy and cool into next week with wind and rain (wet snow over high ground)... interestingly the east midland predictions (bbc) to tuesday have double figure maxs and temps above freezing (range 11c - 2c).

[frostyjoe]

Well from monday we have maxes of 4c here and snow on Monday too

[cooling climate]

yep its looking pretty messy and cool into next week with wind and rain (wet snow over high ground)... interestingly the east midland predictions (bbc) to tuesday have double figure maxs and temps above freezing (range 11c - 2c).

According to the GFS 00z run any precipitation Tuesday night would be of snow even in the

south and on low ground. There would be a very high likelyhood of further snow during

the rest of the week especially at night.

Edited March 26, 2010 by cooling climate

[Duane S.]

The amplification in the pattern has been threatening to throw up some fun and games for a while now and however you look at it, the coming next week or so is certainly going to be 'interesting' from a weather perspective.

[snowmadchrisuk]

According to the GFS 00z run any precipitation Tuesday night would be of snow even in the

south and on low ground. There would be a very high likelyhood of further snow during

the rest of the week especially at night.

The 6z carries on that theme of Snow at least at night from Tuesday .

[Thundery wintry showers]

Models continuing to "firm up" on the prospects- I think Mushy's assessment is an accurate one regarding Monday's weather in central areas and Tuesday's in the south and east, but there's increasing agreement that the low will slowly drift away eastwards. This promotes chances of a rain to snow event for many as the band clears away to the south and east with cold air digging in on its western flank. Wednesday onwards looks like having a mix of sunny spells and wintry showers.

[cooling climate]

Models continuing to "firm up" on the prospects- I think Mushy's assessment is an accurate one regarding Monday's weather in central areas and Tuesday's in the south and east, but there's increasing agreement that the low will slowly drift away eastwards. This promotes chances of a rain to snow event for many as the band clears away to the south and east with cold air digging in on its western flank. Wednesday onwards looks like having a mix of sunny spells and wintry showers.

Not according to the GFS 06z. Whether it turns out that way remains to be seen but if it does

verify then there will be snow for more southern areas as well as up north and not just on high

ground either.

[Thundery wintry showers]

I don't disagree with you, I thought "a rain to snow event for many" would in itself imply snow for more than just northern hills? I see the bulk of the "frontal" weather being cloudy and wet, but there's certainly a real chance of rain turning to snow in the north and west during Tuesday and in the south and east during the following night. It all depends on the track and shape of the low.

[frostyjoe]

I don't disagree with you, I thought "a rain to snow event for many" would in itself imply snow for more than just northern hills? I see the bulk of the "frontal" weather being cloudy and wet, but there's certainly a real chance of rain turning to snow in the north and west during Tuesday and in the south and east during the following night. It all depends on the track and shape of the low.

Erm the met office are already forecasting snow for us from Monday they say rain-snow from Monday

[Thundery wintry showers]

I think Northern Ireland won't be cold enough for snow on Monday except high ground- perhaps some sleet/wet snow at low levels late on, but Monday night into Tuesday certainly looks cold enough.

[Weather-history]

This chart for me is significant, at least for GFS as regards to whether there is snow and that is the mean preciptation chart. If you look, you can see the white hatching which means there are a fair few ensembles going for wintry preciptation.

http://91.121.94.83/modeles/gens/run/gens-21-2-108.png?6

[frostyjoe]

I think Northern Ireland won't be cold enough for snow on Monday except high ground- perhaps some sleet/wet snow at low levels late on, but Monday night into Tuesday certainly looks cold enough.

ya it shows sleet for day and snow at night and temp around 4c id say if it was to lower to 2-3c it would show snow..

[kold weather]

Exactly, the pattern the GFS shows is once we get the frontal system out of the way its cold but with lots of convective showers and a whole host of precip from rain, sleet, snow and hail all in there dependng on where you are...it is more interesting then mild, wet and dull, which would be the case if the low went further north.

There is certainly a risk if the GFS is right for a rain-snow event however its a little far out yet to make a call on it.

[reef]

Ive just had to move a shedload of posts. This is the Model Output Discussion thread, not the 'I hate cold and snow in spring' thread. People are entitled to their opinions whether they want homogenous warmth, cold snaps, or whatever and should not be made to feel 'wrong' or guilty for doing so.

Thanks.

[SP1986]

Will the GFS be showing these types of charts in July and August - I wouldn't bet against it, in fact I imagine it could be quite a good bet

http://www.wetterzentrale.de/pics/Rmgfs1684.gif