Advertisement
If you have a new account but are having problems posting or verifying your account, please email Niamh on [email protected] for help. Thanks :)
New AMA with a US police officer (he's back!). You can ask your questions here

Cold Spell - Feb 7th to 13th 2021 - Technical Discussion

  • 08-02-2021 12:54am
    #1
    Registered Users Posts: 8,421 ✭✭✭ Danno


    Technical Discussion for the current spell of cold with potential for snow...

    Any non-technical chat can be posted here: https://www.boards.ie/vbulletin/showthread.php?t=2058155857

    Apologies for locking the wrong thread for a few moments, a big oops!

    The Up to 120hrs Thread has been locked.


«13456730

Comments

  • Registered Users Posts: 2,728 ✭✭✭ Rebelbrowser


    The Euro 04 precipitation charts for the next 48 hours make no sense. Showers coming from the east but it seems skipping over the east and south coasts and causing accumulations inland in the likes of Kerry and Galway. Current model run is at https://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=euro4-high&MODELLTYP=1&BASE=-&VAR=prty&HH=12&ZOOM=0&WMO=&ARCHIV=0&LOOP=1&RES=0


  • Moderators, Science, Health & Environment Moderators Posts: 15,184 Mod ✭✭✭✭ Gonzo


    tonights GFS 18z is turning out to be very much a mild outlier from the 12th. Most members keeping it cold. The mean shows an even smaller mild blip compared to the 12z.

    ens_image.php?geoid=64969&var=201&run=18&date=2021-02-07&model=gfs&member=ENS&bw=1

    Thursday into Friday is now looking rather snowy across all the country except for coastal parts of the far south-west.

    102-780UK.GIF?07-18


  • Registered Users Posts: 8,202 ✭✭✭ Gaoth Laidir


    Cloud has really broken up overnight but cloud top heights have not increased at all. Soundings from the UK show them ranging from 850 - 750 hPa. Watching for any signs of increases during the day.


  • Registered Users Posts: 8,202 ✭✭✭ Gaoth Laidir


    Nottingham sounding from 06Z.

    542504.png


  • Registered Users Posts: 15,847 ✭✭✭✭ Villain


    HARMONIE showing some more shower activity tomorrow:

    https://twitter.com/MetEireann/status/1358675740590567425?s=20


  • Advertisement
  • Registered Users Posts: 2,728 ✭✭✭ Rebelbrowser


    Gonzo wrote: »
    tonights GFS 18z is turning out to be very much a mild outlier from the 12th. Most members keeping it cold. The mean shows an even smaller mild blip compared to the 12z.

    Thursday into Friday is now looking rather snowy across all the country except for coastal parts of the south west]

    For us south coasters to cling to, I see the GEM has Thursdays front stalling over the southern half and retreating. Very different outcome if that happened!


  • Registered Users Posts: 5,951 ✭✭✭ munsterlegend


    For us south coasters to cling to, I see the GEM has Thursdays front stalling over the southern half and retreating. Very different outcome if that happened!

    Yep ECM looking quite snowy for a while down here as well..


  • Registered Users Posts: 15,847 ✭✭✭✭ Villain


    Met Eireann update on Morning Ireland:

    Monday to Wednesday showery setup, mainly in East, 1-2cms in Ulster and Leinster, tomorrow more widespread with 1-2cms anywhere most likely in Leinster. Thursday could see significant snowfall and significant accumulations, looking at up to 5cm widely. Milder weather from Friday so snowfall Thursday may not stick around.


  • Registered Users Posts: 21,821 ✭✭✭✭ Kermit.de.frog


    GFS has two snow events - one on Thursday/Friday and the other Sunday/Monday...


  • Registered Users Posts: 8,202 ✭✭✭ Gaoth Laidir


    Met.ie Harmonie shows a very broken band of precip over the country Thursday.

    https://www.met.ie/


  • Advertisement
  • Registered Users Posts: 2,728 ✭✭✭ Rebelbrowser


    Met.ie Harmonie shows a very broken band of precip over the country Thursday.

    https://www.met.ie/

    That would tally with the 5cm Villain says was referenced on Morning Ireland. You'd expect more from an intact front surely?


  • Registered Users Posts: 14,307 ✭✭✭✭ nacho libre


    That would tally with the 5cm Villain says was referenced on Morning Ireland. You'd expect more from an intact front surely?

    Yes you would. Is 5 cm considered significant by them? Surely the ground will be cold enough inland for the snow to stick from the get go. I would prefer this Harmonie scenario even if it means we only get a modest covering before it all fizzles out. Rather than a quick snow to rain event.


  • Registered Users Posts: 348 ✭✭ Donegal Ken


    Met.ie Harmonie shows a very broken band of precip over the country Thursday.

    https://www.met.ie/

    That timeframe for Thursday is the output from the ECMWF model. Harmonie only runs up until 12:00hrs Wednesday 54hrs. If you look at the bottom right you will see this.


  • Registered Users Posts: 4,045 ✭✭✭ arctictree


    Latest GFS has snow all day Thursday and into Friday for east. Total amounts seem to be fairly light though for a frontal event. Sunday/Monday seems to be the one to watch, not out yet though as I type...


  • Registered Users Posts: 1,376 ✭✭✭ Reckless Abandonment


    arctictree wrote: »
    Latest GFS has snow all day Thursday and into Friday for east. Total amounts seem to be fairly light though for a frontal event. Sunday/Monday seems to be the one to watch, not out yet though as I type...

    It looks snowy on Saturday too. :)


  • Posts: 0 ✭✭✭ [Deleted User]


    It looks snowy on Saturday too. :)

    Friday morning very snowy in SE Wicklow and north wexford

    GFSOPUK06_96_53.png

    Saturday 6pm after a lull back at it with Gusto :eek:
    If these two were to verify,that would be a fair pile of snow in South Leinster

    GFSOPUK06_132_53.png


  • Registered Users Posts: 475 ✭✭ bazlers


    The energy will more than likely get zapped (very techical term) out of that front as it moves across the country rubbing shoulders with that high.


  • Closed Accounts Posts: 1,220 Davaeo09


    bazlers wrote: »
    The energy will more than likely get zapped (very techical term) out of that front as it moves across the country rubbing shoulders with that high.

    and the counties that happens over are in for a treat :D


  • Registered Users Posts: 2,001 ✭✭✭ piplip87


    I see GFS precipitation type chart makes multiple attempts of fronts coming up from the south from Thursday. Northern half of the country looks like just snow until it the rain finally comes on Tuesday.

    If that where to verify thay could mean rather disruptive snow from the Dublin to Galway line and above. Cavan,Monaghan North Meath look like the sweet spots here.

    Whooohoooo my first post commenting on charts lol


  • Registered Users Posts: 21,821 ✭✭✭✭ Kermit.de.frog


    bazlers wrote: »
    The energy will more than likely get zapped (very techical term) out of that front as it moves across the country rubbing shoulders with that high.

    Under pressure alight but if it does it mean colder air has won out and probably another front with snow risk following behind.


  • Advertisement
  • Registered Users Posts: 21,821 ✭✭✭✭ Kermit.de.frog


    anim_hnj5.gif


  • Registered Users Posts: 5,836 ✭✭✭ TheMilkyPirate


    That would be a fair dumping for the south/East


  • Registered Users Posts: 8,421 ✭✭✭ Danno


    That would be a fair dumping for the south/East


    Excellent setup for keeping the cold locked in for another front, with the snow fields keeping the air frigid as it comes up from the southeast.


  • Registered Users Posts: 14,307 ✭✭✭✭ nacho libre


    Yes, if the front on Thursday has too much oomph, it could mean a quicker transition to rain. The best case scenario as has been mentioned is for it slowly to run out of juice. From an imby perspective, I just wish it was all a bit further west. Still if the cold air does win out there maybe further opportunities over the weekend.


  • Registered Users Posts: 2,728 ✭✭✭ Rebelbrowser


    That would be a fair dumping for the south/East

    If this trend this morning continues, by Thursday I'm not sure we will even see rain down here in Cork..... Up til two days ago this was an all rain affair in Cork on the models, then it was a few hours snow followed by lots of rain. Now that's flipped completely. In fairness, all tallies with Met E's attitude as far back as late last week. Its almost as if the professional meteorologists knew better than us keyboard warriors (with the obvious exceptions to that description!)


  • Registered Users Posts: 15,847 ✭✭✭✭ Villain


    The Met Eireann meteorologist commentary has been updated:

    https://www.met.ie/forecasts/meteorologists-commentary

    Shower risk:
    ECMWF-Forecast-snowfall-risk-Mon-Wed.png

    Thursday into Friday:
    ECMWF-forecast-rain-sleet-and-snow-Thur-06-12UTC-768x879.png
    ECMWF-forecast-rain-sleet-and-snow-Thur-18-2359UTC-768x879.png


  • Registered Users Posts: 14,307 ✭✭✭✭ nacho libre


    If this trend this morning continues, by Thursday I'm not sure we will even see rain down here in Cork..... Up til two days ago this was an all rain affair in Cork on the models, then it was a few hours snow followed by lots of rain. Now that's flipped completely. In fairness, all tallies with Met E's attitude as far back as late last week. Its almost as if the professional meteorologists knew better than us keyboard warriors (with the obvious exceptions to that description!)

    As Auntysnow mentioned previously they have access to data we don't see. The Chief forecaster seemed confident something would happen on Thursday, but obviously would not commit to anything until she had to. I imagine Met Eireann also share data with the UKMO. Bear it mind it was mogreps (UKMO'S own model) ,afterall, that indicated that this cold period would be extended, and that the other models would start to back that scenario. It now looks like that will happen.


  • Registered Users Posts: 2,728 ✭✭✭ Rebelbrowser


    Very interesting Met E update indeed. Their take on Thurs / Fri as of now is "...current projections indicate a spell of sleet and snow spreading north-eastwards over Ireland on Thursday and into Friday bringing accumulations of snow to many areas. However, the snow may transition to rain in some southern and western parts as milder air attempts to move in from the Atlantic...". The word "may" in the final sentence is a big change and has me very interested in the end of the week all of a sudden....


  • Registered Users Posts: 8,421 ✭✭✭ Danno


    Very interesting Met E update indeed. Their take on Thurs / Fri as of now is "...current projections indicate a spell of sleet and snow spreading north-eastwards over Ireland on Thursday and into Friday bringing accumulations of snow to many areas. However, the snow may transition to rain in some southern and western parts as milder air attempts to move in from the Atlantic...". The word "may" in the final sentence is a big change and has me very interested in the end of the week all of a sudden....

    Updated by Matthew Martin on 08/02/2021

    Our old friend Weathercheck has clearly been browsing this forum recently! :p

    Quite an upbeat read and very well written. I do wonder if the first front stalls/fizzles out before getting over to the east?


  • Advertisement
  • Registered Users Posts: 1,607 ✭✭✭ snowgal


    Danno wrote: »
    Updated by Matthew Martin on 08/02/2021

    Our old friend Weathercheck has clearly been browsing this forum recently! :p

    Quite an upbeat read and very well written. I do wonder if the first front stalls/fizzles out before getting over to the east?

    yes thats my concern too. It may change before Thursday and the East may not actually get the front at all...


Advertisement