Model Output Discussion 12z 03/04/13

[Milhouse]

Yes Gavin, It seems like the rise in upper temperatures coincide with a build in pressure over Europe so a decent warm spell might not be too far a away. A fair few rain spikes so probably fair to say that we are goint to be entering a much milder but also wetter period, with just a hint of pulling up something significantly warmer as the month progresses.

[Captain Shortwave]

The only issue with the GFS warm up yet again is it's conflict at the mid range with the ECM/UKMO

Backs UKMO

[Summer Sun]

ECM and UKMO pretty much in agreement at t120

ECM

UKMO

Edited April 3, 2013 by Gavin.

[Panayiotis]

I would assume there would be some thunderstorms from this chart produced by the ECM:

[Summer Sun]

As one LP system clears its possible another will follow on

[Stuie]

12z ensembles continue the rise not many cold members now thankfully

A return to some seasonal temperatures is just days away now the cold is finally on its last legs

Finally Gavin the tables are turning in your favour. Which part of July are you going to start the search for cold, 2nd week?

[Captain Shortwave]

yet again watch to the North East, possibly heights building replicating the last run.

Edited April 3, 2013 by Captain shortwave

[Summer Sun]

Finally Gavin the tables are turning in your favour. Which part of July are you going to start the search for cold, 2nd week?

Me looking for cold?!

Anyway t216 sees the next deep low in the Atlantic

Less cold uppers for all feeling warmer with the winds coming from the south west

Edited April 3, 2013 by Gavin.

[Summer Sun]

Low to the west high to the east the result? warm up getting pumped up from the south to south west

Wet and windy in the north west driest and probably brightest in the east and south east where your closest to the high

Edited April 3, 2013 by Gavin.

[Captain Shortwave]

Gavin and all other mildies will love this

Sceuro high building, warmth invading from north Africa

Edited April 3, 2013 by Captain shortwave

[Milhouse]

T240 would likely see that low in the Atlantic staying put and pressure building to our south east. We'll soon see.

edit: T240 already out on meteoceil and the run ends on an increasingly warm and dry note.

Edited April 3, 2013 by Milhouse

[Milhouse]

How is the BOM model faring currently?

Currently the BOM 12z has high pressure in control until the middle of next week maintaining the dry and fairly cool conditions. Low pressure sliding south east towards day 10 with the UK in a mild southerly flow but a cold easterly not that far away.

[Gibby]

Good evening. Here is the report on the 12z output from GFS, UKMO, GEM and ECM for tonight Wednesday April 3rd 2013.

All models continue to show a change in the weather on the way. The progress will not be a quick one though with temperatures unlikely to reach normal values until the middle of next week. In the meantime the cold NE flow over Southern and Eastern Britain will persist and as an upper disturbance moves slowly SW close to Southern Britain more cloud and wintry flurries are possible over the next 48 hours. frosts will continue at night away from cloudy and windward parts of the SE. Through the weekend a ridge moves SE over the UK with the cold NE wind decaying away to leave the UK under calm conditions with bright, dry days but frost at night still over the weekend.

GFS then shows the start of next week with fronts slowly making inroads into the UK from the Atlantic. The NW will be worst affected with strong winds and some quite heavy rain for a while. Some rain will spread East across other areas too for time though the most important aspect of the weather here will be the rise in temperatures to near average levels. Later in the week a change to brighter and showery conditions will affect most areas with some sunshine in between. Changeable weather does continue through FI with the trend towards more settled and warm weather for England and Wales shown by the end of the run.

The GFS Ensembles show temperatures on the rise over the next 5 days before some pleasantly mild conditions look like being setup with temperatures achieving 14C-15C later in the output in the South. There is some rainfall shown at times too as Atlantic depressions make their presence felt

The Jet Stream continues to show the migration of the flow to more Northern latitudes at around 50-55deg N over the following week which means it should be flowing east over the British Isles as we move through next week.

UKMO tonight shows Low pressure slowly moving into the UK from the West bringing progressively windier, milder and wetter weather into the UK as we move deeper into next week.

GEM tonight also shows Low pressure in the Atlantic pushing troughs forward of it over the UK before midweek with rain moving steadily across the UK falling as sleet or snow for a time in the North as milder air follows into the SW first and other areas later.

ECM shows rain well into the SW by Monday and as it moves slowly North and East it may begin as snow over the higher ground where a cold SE wind develops. In the SW milder air would arrive later on Monday and march slowly and steadily North and East over Britain on Tuesday. The Low pressure then drifts over the UK and fills in situ later in the week. Several days of outbreaks of rain and showers seem likely before a new deep Low pressure in the Atlantic brings renewed SW winds late in the run with a rise of pressure to the SE some rather warm and dry weather is possible in the South and East towards the end of the run.

In Summary the change in the weather is still on course for early next week as Low pressure edges in from the West early in the week. Temperatures will recover across the UK with time and some indications are shown tonight which could bring rather warm conditions across the South towards mid month.

[phil nw.]

Finally it does look if some Spring warmth is on the way next week.Nothing dramatic to start with as the pattern reverts to a westerly type with rain or showers moving through the UK.

However later outputs from the GFS mean and ECM Op show promise of something more settled and warmer for the south and south east

http://modeles.meteo...21-1-240.png?12

http://www.meteociel...M1-240.GIF?03-0

Pressure continuing to ridge north -perhaps a NW-SE split with a mean Atlantic trough to our NW keeping things rather more changeable up there.

Whatever the later detail there`s every indication of the set-up reverting to a +NAO type with the mean position of the jet easing further north in the next week or 2.

[Guest pjl20101]

Certainly is Phil and tonight the CPC 8-14 day output is still indicative of this:

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

Looking pretty good I'd say and pleased it hasn't changed since yesterday.

[Yarmy]

Now this is exactly what I'm looking for:

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=204&code=0&mode=1

Uppers aren't spectacular, but settled clear skies are perfect conditions for a bouncy castle in the garden on young Niamh's 2nd birthday.

[ANYWEATHER]

To be honest, Im not really convinced at all from the the model output, from the post weekend onwards, we all want a warm up, which is likely, but I think there will be some dramatic changes in the next few days from the models, cant see from experiance and history that such a long period of cold ,the weather will warm up dramatically, I expect some unsettled conditions with rain perhaps a lot of it.... then colder drier conditions from the east...

Edited April 3, 2013 by ANYWEATHER

[Stuie]

Me looking for cold?!

Anyway t216 sees the next deep low in the Atlantic

Less cold uppers for all feeling warmer with the winds coming from the south west

Gavin, searching for warmth in mid-winter, you may as well keep up the fight

I know this is FI but a polar opposite of the current/recent past situation. The (warm) block is now keeping cold from the Atlantic away.

EDIT: for stupid smiley.

Edited April 3, 2013 by StuieW

[johnholmes]

Pressure continuing to ridge north -perhaps a NW-SE split with a mean Atlantic trough to our NW keeping things rather more changeable up there.

Whatever the later detail there`s every indication of the set-up reverting to a +NAO type with the mean position of the jet easing further north in the next week or 2.

The nw-se split is exactly what NOAA 500mb anomaly has suggested for the past two days, the ECMWF-GFS is less inclined to that.

My own view is that the NOAA version is likely to be nearer the mark in the 7-15 day time slot.

[Methuselah]

A warm-up is, I think the most important...If the models/NOAA predictions do come to fruition, at least things will get a wee bit greener...

[Stuie]

To be honest, Im not really convinced at all from the the model output, from the post weekend onwards, we all want a warm up, which is likely, but I think there will be some dramatic changes in the next few days from the models, cant see from expeirience and history that such a long period of cold ,the weather will warm up dramatically, I expect some unsettled conditions with rain perhaps a lot of it then colder drier conditions from the east...

Pretty much why I said the ECM a couple of days ago probably showed the real progression out of this spell, a gradual one. Out of all the models it has been pretty decent in reliable time frames, pretty much since Dec.

Edited April 3, 2013 by StuieW

[phil nw.]

The nw-se split is exactly what NOAA 500mb anomaly has suggested for the past two days, the ECMWF-GFS is less inclined to that.

My own view is that the NOAA version is likely to be nearer the mark in the 7-15 day time slot.

Yes the GFS/ECM 8-10 day outputs often look slightly different John as they represent the Op runs average upper pattern over that period rather than ens.means.We can see that on the 12z charts here.

http://www.meteo.psu...2z/hgtcomp.html

I agree though the NOAA along with 00z NAEFs and ECM 500hPa anomals all point to something like a NW-SE split with rising pressure to the south.

[Summer Sun]

ECM at t240 has ensemble support for milder south to south westerly winds around mid month

Op

Edited April 3, 2013 by Gavin.

[Milhouse]

18z looks promising at T192

[Milhouse]

On into FI the warmth builds