Jump to content
Snow?
Local
Radar
Cold?
IGNORED

Winter Model Discussion 18Z 8/1/13. The hunt for cold (is closer).


Recommended Posts

Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

I think comments by NOAA on the Michigan state forecast sum things up perfectly!

OVERALL LOW CONFIDENCE IN THE BULK OF THE LONG TERM AS MODEL

DISCREPANCIES ARE QUITE APPARENT ESPECIALLY AT DEEPER RANGES INTO

THE FORECAST. THIS WINTER HAS SEEMED TO FEATURE MODEL RUN TO MODEL

RUN INCONSISTENCIES IN BOTH THE GFS AND ECMWF AND THIS LONG TERM

PERIOD AND BEYOND SEEMS NO DIFFERENT.

Earlier regarding the important shortwave track:

AFTER SATURDAY CONFIDENCE REALLY DIPS GIVEN MAJOR DIFFERENCES IN THE

MODELS. THE GFS BRINGS A WAVE THROUGH THE AREA SUNDAY WITH

SIGNIFICANT PRECIP WHILE THE ECMWF TAKES THE HEAVIEST PRECIP WITH IT

SOUTH OF THE AREA. A SIMILAR SETUP OCCURS MONDAY NIGHT INTO TUESDAY.

HAVE 30-50 POPS OVER MUCH OF THE AREA WITH THE SUNDAY SYSTEM AND

ONLY 20 POPS IN FOR THE MONDAY NIGHT TUESDAY SYSTEM GIVEN THE MODEL

DISPARITIES.

Link to comment
Share on other sites

Posted
  • Location: Brighton, East Sussex
  • Location: Brighton, East Sussex

So this post by you earlier where you state, "normally I'd back the ECM over any other model by a long, long distance but I'm not so sure here. Especially as this run has 6hrs more data. Still very much 50-50 I'd say either way." Does that mean in less than two hours you have gone from 50-50 to 80-20 in favour of cold?

Because earlier I was judging the ECM vs the GFS only. Hadn't had a chance to look at the other models. Seems as though the GFS has no backing from anywhere hence my change of stance. Think it would be very unusual for all to be wrong?

Link to comment
Share on other sites

Posted
  • Location: Near Thame, West Bucks,
  • Weather Preferences: Snow, Ice and Sunshine
  • Location: Near Thame, West Bucks,

Can somebody tell me, with regards to models, as there is so many ensemble lines, how does the operational or control, or the pretty maps we see actually get chosen? I assumed that the charts we view would be bang on the "mean" of all the models ensembles but this doesnt seem to be the case?

I believe operational and control and ens are all run individually and not chosen from the ens as such and the maps are computer generated? someone correct me if i'm wrong

Edited by Balls Of Snow
Link to comment
Share on other sites

Posted
  • Location: Orleton, 6 miles south of Ludlow
  • Location: Orleton, 6 miles south of Ludlow

I think comments by NOAA on the Michigan state forecast sum things up perfectly!

OVERALL LOW CONFIDENCE IN THE BULK OF THE LONG TERM AS MODEL

DISCREPANCIES ARE QUITE APPARENT ESPECIALLY AT DEEPER RANGES INTO

THE FORECAST. THIS WINTER HAS SEEMED TO FEATURE MODEL RUN TO MODEL

RUN INCONSISTENCIES IN BOTH THE GFS AND ECMWF AND THIS LONG TERM

PERIOD AND BEYOND SEEMS NO DIFFERENT.

Earlier regarding the important shortwave track:

AFTER SATURDAY CONFIDENCE REALLY DIPS GIVEN MAJOR DIFFERENCES IN THE

MODELS. THE GFS BRINGS A WAVE THROUGH THE AREA SUNDAY WITH

SIGNIFICANT PRECIP WHILE THE ECMWF TAKES THE HEAVIEST PRECIP WITH IT

SOUTH OF THE AREA. A SIMILAR SETUP OCCURS MONDAY NIGHT INTO TUESDAY.

HAVE 30-50 POPS OVER MUCH OF THE AREA WITH THE SUNDAY SYSTEM AND

ONLY 20 POPS IN FOR THE MONDAY NIGHT TUESDAY SYSTEM GIVEN THE MODEL

DISPARITIES.

Nick, what does POPS mean?

Link to comment
Share on other sites

Posted
  • Location: littleover,Derby 76M above S.L.
  • Location: littleover,Derby 76M above S.L.

After the post above by Nick S. surely its the end of all squables on here, Nobody Knows whats going to happen !! just wait and see .

Link to comment
Share on other sites

Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

Nick, what does POPS mean?

I think its the percentage chance of precipitation.

Thankfully our forecasters in the UK are much more classy in their diction!!! POPS lol NOAA do have some quite funny expressions if you've followed them.

Edited by nick sussex
Link to comment
Share on other sites

Posted
  • Location: Ireland , Newbridge 91MT ASL
  • Weather Preferences: Cold and lots of Snow
  • Location: Ireland , Newbridge 91MT ASL

The irish met use the ECM only. Dont even look at the gfs in creating a forecast.

They use a blend of ECMWF, UKMO, GME, Hirlam, Harmonie for there forecasts

Its always spouted the Irish met only use one which is rubish , dont use the GFS Il give you that

Link to comment
Share on other sites

Posted
  • Location: South Essex
  • Location: South Essex

The GFS solution has not been without support tbh. There have been clues within the ensembles in recent days and although a minority solution it cant be ignored. A number of ensembles have also been showing the dreaded height rise over iberia in the last 24 hours which is a game over situation if it happen.

All that said, it goes against what we believe to be the background signals and also on this run looks suspect to me. I actually still think the heights over Scandi are being undercooked by the models generally and that they will be more resilient than is even being shown by some of the current runs. ECM is logical and has a decent amount of support in its ensembles so being dispassionate about things I'd favour that solution. We can't be that lucky though can we?

Whilst uncertainty will remain I suspect that in terms of the GFS 06Z veryfying that we will know one way or another in a few hours. Doesnt mean other things cant go wrong, but IMHO given the timeframes this particlar question is likely to get answered shortly.

Jason

Link to comment
Share on other sites

Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.

Well we were warned of the likelihood model-flips!

Link to comment
Share on other sites

Posted
  • Location: cork Ireland 80m ASL
  • Weather Preferences: severe weather, tornadoes,intersting synopsis ,snow
  • Location: cork Ireland 80m ASL

personally a lot hinges on the gfs ens, if support grows for the Atlantic i will start to get worried. hoping its just a bug in the data

Link to comment
Share on other sites

Posted
  • Location: Eastbourne, East Sussex (work in Mid Sussex)
  • Location: Eastbourne, East Sussex (work in Mid Sussex)

Well. it must be time to open a new thread for the 12z later. Hang on folks while I go and forge one in the fire......

Link to comment
Share on other sites

Posted
  • Location: Purley, Surrey - 246 Ft ASL
  • Weather Preferences: January 1987 / July 2006
  • Location: Purley, Surrey - 246 Ft ASL

Problem I have is that we have seen this before.

The GFS always seems to be the best at picking these little shortwaves out.

HUGE 12z coming up in my opinion. The 6z built upon a theme seen in the 00z GFS, we need to see no continuation of this on the 12z.

We have sprung a leak in the boat, hopefully we can plug it in 5 hours time!

Edited by Radiating Dendrite
Link to comment
Share on other sites

Posted
  • Location: Live Haddenham (Bucks). Work Heathrow Airport
  • Location: Live Haddenham (Bucks). Work Heathrow Airport

I think shannon entropy might top the lot though

I remember her in the Euro Vision contest, Useless she was.

Edited by No balls like Snow Balls
Link to comment
Share on other sites

Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

Talking about NOAA wouldn't it be great if we had a UKMO discussion just like theirs that was open to the public.

Ian F sort this out please!!!smiliz19.gif

I do wonder why we can't have their thoughts about the models without this cloak of secrecy, I know they have commercial concerns but most of those like supermarkets etc just want the forecasts, they hardly want to read a page of which model is better or what the ensembles suggested.

We should start a model anoraks of net weather petition!!!

Link to comment
Share on other sites

Posted
  • Location: North Somerset, UK
  • Location: North Somerset, UK

I was wondering if someonme can help me. Ive been watching this forum for a couple of years now and one thing I cant understand is how people will know it will be very snowy from friday night until Sunday? From going by what alot of you have said over time, snow is very hard to predict and normally can only be predicted in a 24h time scale. Many thanks in advance , Alan :)good.gif

Hi Alan, in addition to excellent answers thus far, another key component we look for on charts is WBFL, or Wet Bulb Freezing Level. In scenarios such as this weekend, the UKMO always provide us with a detailed look and mapping of this: for example, where we see WBFL down at 200m, it suggests snow likely (ie in areas where we have a signal for precipitation!). Alongside factors mentioned by others, we tend to use the WBFL prognosis as a reasoned guide to snow likelihood, and equally it makes for a good steer in an areal sense when forecasting tricky rain-sleet-snow distribution as will prove most certainly the case through the weekend. The forecasters at Exeter also manually tweak output to sometimes chance raw rain signal to snow, based on experience and using a published methodology (Boyden) and another one accounting for heavy precipitation allowing snow to lower levels than would otherwise be expected based on higher WBFL (a process known as evaporative cooling).

Edited by fergieweather
Link to comment
Share on other sites

Posted
  • Location: Wigan 259 ft ASL where it always rains
  • Weather Preferences: Hot Sun ,Snow and Cold
  • Location: Wigan 259 ft ASL where it always rains

Well yeh I know they do, they think the GFS is rubbish, but I haven't seen any consistency in any model over the past several days or so. Therefore I think they have got to be still on the fence wrt next week and beyond.

If the current GFS 06z proves to be correct and we do get an Atlantic push next week (which i pray we won't), will they no longer have that point of view and start referring to the ECM as Rubbish, i'm no meteorologist but i do look at the models regularly and have a slight understanding ,but i have always found the GFS to pretty reliable a few days out, but in this climate of massive uncertainty i would hate to have to call it one way or the other.

Link to comment
Share on other sites

Posted
  • Location: cork Ireland 80m ASL
  • Weather Preferences: severe weather, tornadoes,intersting synopsis ,snow
  • Location: cork Ireland 80m ASL

They use a blend of ECMWF, UKMO, GME, Hirlam, Harmonie for there forecasts

Its always spouted the Irish met only use one which is rubish , dont use the GFS Il give you that

they have a contract with the ecmwf , they use hirlam for short range and 'look in on the ukmo im told' i was commenting in regarding to their long range forecast which is 100% ecm based .

Link to comment
Share on other sites

Posted
  • Location: Eastbourne, East Sussex (work in Mid Sussex)
  • Location: Eastbourne, East Sussex (work in Mid Sussex)

New thread here, you know the score!

Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
  • UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-28 09:16:06 Valid: 28/03/2024 0800 - 29/03/2024 0600 SEVERE THUNDERSTORM WATCH - THURS 28 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather

    More rain on the way: Storm Nelson brings gales Thursday, but rain and wind easing for Easter

    Spells of rain or showers with sunshine in between affecting most areas today, snow over northern hills. Storm Nelson arrives tomorrow, bringing gales to southern coasts and windy elsewhere with further showers. Showers and wind easing somewhat into the Easter Weekend. Read the full update here

    Netweather forecasts
    Netweather forecasts
    Latest weather updates from Netweather

    UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-27 09:35:27 Valid: 27/03/2024 0900 - 28/03/2024 0600 THUNDERSTORM WATCH - WEDS 27 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather
×
×
  • Create New...