Model Output Discussion 06Z, 13 Sep. 2013 ---->

[lorenzo]

Here is some more information on the broken Buoy reporting a very high SST. 

See WTMP on this link   73.4F  http://www.ndbc.noaa.gov/station_page.php?station=42099

 

This was the source on Twitter who posted about it last night. Got a lot of time for Dr Ryan, his site is superb and has some good data sources.

 

Related chart output as a result.

 

Certainly looks to me like some kind of error with the EPS mean chart above? Am in no way fuelling the missing data mythology, one could argue the GFS 06z does that on it's own every day !

 

 

 

 

[Summer Sun]

GEM also builds pressure next weekend and into the following

 

[Frosty.]

Latest met office update briefly brings a more anticyclonic spell to the southeastern half of the uk just in time for next weekend with light winds, sunny spells and gentle warmth but with chillier nights and fog, however, it only looks like 2-3 days respite before it turns unsettled and cooler nationwide, the nw of the uk continuing unsettled and breezy throughout. This fine spell is clearly shown on the ecm ens mean which were posted here earlier this morning, most of next week looks unsettled with occasional strong but mild s'ly to se'ly winds which will eventually moderate and veer sw'ly, some of the rain will be heavy and thundery.

Further ahead through october remains unsettled with near average temps but with drier, brighter and relatively warmer spells, chiefly across the south of the uk but a more westerly upper flow beyond next week currently looks likely, especially for the north of the uk with the PFJ sustained further south than at any stage of the autumn so far.

Edited September 28, 2013 by Frosty.

[johnholmes]

Here is some more information on the broken Buoy reporting a very high SST. 

See WTMP on this link   73.4F  http://www.ndbc.noaa.gov/station_page.php?station=42099

 

This was the source on Twitter who posted about it last night. Got a lot of time for Dr Ryan, his site is superb and has some good data sources.

Capture.PNG

 

Related chart output as a result.

Capture2.PNGCapture3.PNG

 

Certainly looks to me like some kind of error with the EPS mean chart above? Am in no way fuelling the missing data mythology, one could argue the GFS 06z does that on it's own every day !

 

I don't doubt this occurred but when the 'actual' data is being processed the analyst/forecaster will check for any 'odd' readings within any area. That would be flagged immediately and like I said before adjusted and remain adjusted until they were satisfied the data was acceptable alongside what the initialisation showed.

[Berty73]

I don't doubt this occurred but when the 'actual' data is being processed the analyst/forecaster will check for any 'odd' readings within any area. That would be flagged immediately and like I said before adjusted and remain adjusted until they were satisfied the data was acceptable alongside what the initialisation showed.

[Berty73]

Hi John

Would this error lead to a false reading in the raw model output, hence causing initial un-modified data to be look worse on the verification stats? Fairly new to this so a genuine question

[johnholmes]

Hi JohnWould this error lead to a false reading in the raw model output, hence causing initial un-modified data to be look worse on the verification stats? Fairly new to this so a genuine question

 

I have to say that I honestly do not know. All I could suggest is that you approach NOAA, quote the posted fault, and ask if it had any effects? Or the Met O you never know they might give a reply from the Ops room?

sorry can't be any more help.

[Berty73]

I have to say that I honestly do not know. All I could suggest is that you approach NOAA, quote the posted fault, and ask if it had any effects? Or the Met O you never know they might give a reply from the Ops room?sorry can't be any more help.

Thanks anyway John, I will try e-mailing as you suggested. I will post any response i get on here for everyone's benefit.

[Frosty.]

The GFS 12z operational run shows a mild, windy and unsettled spell for most of next week but high pressure builds in across the southeast next weekend with a fine and pleasantly warm few days but with chilly nights and fog patches, further north & west it looks more average with more cloud, breeze and a risk of rain further northwest. Beyond next weekend the pattern becomes flatter and more zonal with atlantic lows racing towards the uk on an increasingly southerly tracking jet, the uk actually ends up on the cold side of the PFJ later in the run with temperatures struggling to reach average and a lot of unsettled weather. This run sums up what the met office update said today, briefly settled and pleasant towards the southeast next weekend then becoming cooler and unsettled.

Edited September 28, 2013 by Frosty.

[Paul]

Comparing the 'big 4' models tonight, at 120 hours at least we've decent agreement in terms of the overall picture. They're all happy with the scandi block, but there are differences in terms of the low pressure trying to make it's move from the atlantic, with the met office going currently showing the weakest low pressure option, along with the slowest progress east.

 

[Summer Sun]

Once again we have a settled picture developing later next week and into the following from ECM

 

 

A cooler flow at t240 but still settled for most the further north and east you are could leave your prone to some showers but those in the west have no problems

Edited September 28, 2013 by Summer Sun

[Summer Sun]

Latest from Gibby

 

Good evening folks. Here is tonight's look at the midday outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Saturday September 28th 2013.

 

All models are very similar to this morning in their first week of output so those who read my report this morning will know the most likely sequence of events are as follows. The next few days see a lot of fine and dry weather across the UK in an Easterly breeze which feeds off a warm continent. In comparison there is a Low to the South spawning showers and thunderstorms over Northern France and the Channel Islands which move NW across SW England and SW Wales before decaying as they move further inland. Tomorrow will see less of these before a renewed attack from the SW on a slowly veering wind towards the SE and South takes place early next week as the parent Low near Iberia moves North across the Western approaches to arrive near NW Britain by the end of the working week. through the week the showery and unsettled weather in the SW throughout will extend further North and East to all areas by midweek with some heavy and thundery downpours in the mix too. After a warm start to the period cooler air will slowly take over through the week as the winds turn to a more maritime influence.

 

GFS then shows the end of the week with Westerly winds and showers but improvements move up from the SW to affect most of England and Wales for a time where a fine and dry spell coincides with next weekend before a deterioration moves across from the West in the shape of  SW winds and troughs and eventual cool Low pressure when temperatures fall well down on recent levels. There would be showers and outbreaks of rain for all through the rest of the run with some snow possible on the Scottish high ground later on.

 

UKMO shows a showery WSW flow late next week though anticipated pressure rises are looking hard to achieve on the Day 6 frame when looking toward not to expect next weekend. It will become cooler in the more Atlantic based airflow.

 

GEM shows limited improvements late next week and the weekend  affecting mostly Southern and Eastern areas while northern and Western areas stay cloudy and breezy with troughs crossing NE delivering outbreaks of rain and drizzle at times.

 

NAVGEM shows pressure rising next weekend though Northern and western areas remain changeable with further fronts carrying rain and a stiff SW breeze NE next weekend while the South and East become much drier but not overly sunny or warm under a rather cloudy ridge.

 

ECM still shows an improvement next weekend as High pressure builds North across the British Isles giving a change to fine and dry weather with fog at night and maybe a touch of frost in places too. Towards the end of the run Low pressure fills in the Atlantic and drifts South as High pressure replaces it to bring a cooler NW flow across the UK late in the run with a lot of dry weather but with the chance of some showers in the North and East.

 

The GFS Ensembles tonight show a trend towards more average levels of temperature though with the likelihood that temperatures will not likely fall below average but stay slightly above. The second trend is for a spell of wet weather likely for all for a time next week with things trending drier in the South and East latterly.

 

The Jet Stream shows the flow to the South of the UK maintained for quite a while before the flow undulates further North over the UK. In the second part of the run the flow is indeterminate and hard to decipher as there is quite a scope of options from the members.

 

In Summary the weather looks like being rather changeable beyond the fairly agreed sequence of weather for next week. Temperatures will fall back to some degree as we move through next week but there doesn't appear to be any notably chilly weather on the immediate horizon yet.

 

http://www.norton-radstockweather.co.uk/Model-Analysis%282859336%29.htm

 

[Frosty.]

If proof was needed that a Northerly in early october could deliver a cold blast, the Ecm 12z proves it with very cold uppers not far to the north of the uk, if we do get the correct alignment which unlocks a N'ly blast, we will sure know about it. 

[phil nw.]

After quite a decent week for many of us it looks like the blocking high to our east will give way through the next few days as that Atlantic trough edges ever closer bringing increasingly unsettled conditions from the south west. 

The fax for Tuesday for example shows associated fonts becoming slow moving across the centre of the UK.

 

so next week looks more cloudy with some rain/showers spreading across as the system slowly eases through.

 

Current ens means then show us going into a more westerly pattern at the start of the week 2 with some drier/brighter weather more especially the further south and east as pressure builds across from the Azores.

 

 

so the relatively subdued start to Autumn looks like continuing into the start of October.

 

 

[Frosty.]

If you want an anticyclonic outlook, look no further than tonight's Ecm 12z operational run, a more stable sustainable spell of high pressure after the more unsettled midweek period as atlantic low pressure does battle with the scandi high, it then becomes fine with pleasant spells of sunshine but with a risk of slight frosts and fog, it's a much better outcome for the north and west too.

[draztik]

ECM becoming isolated, and i sense we will see a moderation to its output in the days to come, for this HP period it is suggesting towards the end of its run. Certainly, it would throw the MetO long range forecast to bed/shame. GEM has altered somewhat, and the GFS has autumn lows moving in well into FI.

Edited September 28, 2013 by draztik

[Frosty.]

Tonight's GEFS 12z mean highlights the level of uncertainty about the outlook, the weather becomes more benign with dry and fine weather becoming more widespread but night's would be rather cold with a risk of ground frosts and fog would be the biggest hazard, only the northwest corner of the uk would be generally unsettled and the PFJ remains to the northwest of the BI throughout, the Gfs 12z op run begins to look very extreme compared to this.

[Captain Shortwave]

So it's the ECM anticyclonic spell versus the flattened jet and the bartlett(esque) ridge of the other models. Our answer to the differing outputs in across the pond in the central states. The ECM develops a deep low which has the consequence of amplifying the downstream pattern essentially slowly and sharpening the sine wave pattern over the Atlantic and us and hence allows heights to build more strongly.

GFS below doesn't want to develop the low as much and hence the flatter jet coming out of the States

 

This is representative of the GEM and NAVGEM solutions too.

UKMO at day 6 is quite similar to the GFS/GEM/NAVGEM solutions with no real low pressure development across the mid-west

The disagreement here starts at T144 really with the ECM veering off. At this point I'm on the fence to any future output.

 

On my thoughts for the future output, a few days back I said I thought we would head into a NW/SE split with the jet going somewhere through the country and to be honest my thoughts haven't changed really. I think the closest to the correct solution is probably the ECM ensemble mean

Edited September 28, 2013 by Captain shortwave

[Summer Sun]

ECM ensemble still building pressure later next week it eases away at t240 but the northerly the op hints at is no where to be seen

 

[draztik]

We'd all feel this, if it verifies

t240

gfs, (as persistent as the ecm is showing hp at this timeframe), continues to shows LP into FI.

Edited September 28, 2013 by draztik

[Frosty.]

I think a clearer picture is emerging on where we go from here and deeper into autumn, I reckon the north and west of the uk will become generally unsettled and stay that way, in contrast, the south and east will become briefly unsettled through next week before joining most of mainland europe in a return to benign and pleasantly warm weather which has already been a significant feature so far this autumn but I expect fog to become more of a problem as time goes on. This doesn't mean the south and east would miss all the unsettled weather but it would be least affected overall.

[Summer Sun]

So this morning ECM has backed away from its pressure rise later this week with it becoming unsettled but remaining relatively mild

 

 

GEM does still go for this pressure rise for a few days later this week and into next week before it eases away on the 8th

 

 

UKMO looks inline with ECM at t144

 

 

 

[Summer Sun]

Latest from Gibby

 

Good morning folks. Here is this mornings look at the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Sunday September 29th 2013.

 

The General Situation. The UK is currently covered by a ESE flow between Low pressure to the SW and High to the NE. The effects of the Low to the SW will be limited today with most areas having a fine, breezy and rather warm day with some sunshine at times. Through the next 24 hours a new push of unstable air will move up to affect the South and west with thundery showers tomorrow while other areas continue the breezy and bright weather with some warm sunshine. By Tuesday and Wednesday Low pressure will be edging further North and East up the Western flank of the British Isles pulling winds round to a more Southerly point as well as bringing all of the UK at risk of showers or longer spells of rain with only short drier spells. By the latter stages of the week the Low will be to the NW of Britain and all areas will see winds swing into a cooler SW direction with a much more maritime influence but still carrying rain and showers East to all areas at times right up to the weekend before a slow change to drier and brighter conditions begin to affect the South and East as a brief High pressure ridge looks like grazing Southern Britain as it moves NE.

 

GFS then maintains a very changeable second week but never too cold anywhere. Further low pressure moves across the North of the UK at times sufficiently far enough South to put the whole of the UK at risk of rain at times with some brighter and drier spells in between. Temperatures would be relatively close to the seasonal average and it would probably be rather windy at times especially towards the North and West.

 

UKMO shows it's final day chart with the UK under a showery Westerly or WSW flow with sunshine mixed with showers passing through in the breeze. Average temperatures would be likely next weekend so it probably wouldn't feel too cold in any sunshine and away from the cloud and showers which would be heaviest by then in the North and West.

 

GEM shows a more meaningful push of high pressure up across the South of the UK next weekend from the SW while the North stays a little more changeable with some further rain at times. After a dry and fine few days in the South the High is shown to give way to renewed Low pressure from off the Atlantic with rain and showers in average temperatures extending to all areas by the middle of Week 2.

 

NAVGEM has High pressure having built over France next weekend but probably insufficiently close to put the whole of the UK under fine weather. Instead a rather cloudy SW flow would likely to have developed with mostly dry conditions in the South and SE while all Northern and Western areas would most likely become cloudy and breezy with rain and drizzle at times. It would be relatively mild though.

 

ECM also shows a short improvement for the South next weekend before all areas join in again with a strong Low pressure influence to the West and NW of Britain with mostly mild South or SW winds carrying bands of potentially quite heavy rain and showers North and East across all areas at times with the North and West seeing the worst conditions.

 

The GFS Ensembles paint a slowly cooling picture through this coming week to average temperatures which are then largely maintained through Week 2. After the potentially thundery rain at times through the coming week a reduction in rainfall is likely through Week 2 especially in the South at least for a time.

 

The Jet Stream's main arm is currently blowing to the South of the UK at the moment in association with the Low to the SW. As that moves North through the coming week so does the Jet flow. Although it's position varies between the members it's most favoured option appears to be a Easterly moving flow close to the British Isles through week 2.

 

In Summary Week 1 looks fairly agreed upon by most members from all models that the gradual transformation of Low to the SW to Low to the NW will take all week to complete. As this occurs all areas will be susceptible to periods of rain and showers, heavy at times perhaps with thunder, mostly in the SW at first but anywhere from Tuesday. It looks reasonably likely that a brief ridge of high pressure could affect the South for a time next weekend but in general it looks like it may be quite short-lived as there is reasonable support for more changeable weather to develop through Week 2 but it would never be desperately cold with any frost and fog risk very low at this stage.

 

http://www.norton-radstockweather.co.uk/Model-Analysis%282859336%29.htm

 

[Captain Shortwave]

Well the ECM was over-doing the upstream low at day 6 and hence you do not get the amplification required to build heights over the UK, but you get the amplification around day 8 which has good agreement from the GFS which results in a trough just west of the UK with a renewed ridge to our east which again suggests a warm southerly flow. So potentially a rinse and repeat exercise of the coming week perhaps.

 

So the pattern looks to remain mixed rather than full blown unsettled with temperatures holding above average for the majority of the time.

[Frosty.]

The Ecm 00z operational run shows no end in sight to the very mild / rather warm weather with winds of variable strength generally sourced from either southern europe or the azores during the next 10 days, a nw/se split as the jet becomes aligned sw/ne with the most unsettled weather gradually becoming focused further west & north with the south and east having the best of the dry, warm and sunny weather, especially the southeast being closest to continental high pressure where it would be very warm for the time of year at times, even at T+240 hours, the thickness chart shows a warm plume covering the whole of the uk.