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FI Charts ( T120+ onwards) Winter 2018 / 2019 **READ MOD NOTE IN FIRST POST**
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The trend is certainly Hp now and looks fairly solid out to +240 hrs, GFS goes further. For quite a few runs over a number of days now it goes on to show the HP strengthen as hatricpatrick mentioned in a previous post. Some signs of it getting cold at the end of the ECM 12Z run but it has been the case that this keeps getting pushed further and further out as the HP becomes more established. We will see.
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Europe looks to be cooling down considerably over the coming week which would be a good thing if the Easterly came , helping to keep the air mass colder if it made its way to Ireland , maybe a bit of it making it all all the way over to Tralee also !
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Meteorite58 wrote: »Europe looks to be cooling down considerably over the coming week which would be a good thing if the Easterly came , helping to keep the air mass colder if it made its way to Ireland , maybe a bit of it making it all all the way over to Tralee also !
I don`t know though. The Atlantic is on its Christmas holidays at present but it will surely be back in action at full throttle before too long.0 -
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Meteorite58 wrote: »The end of the GFS 18Z run looks like potential very cold / snow from the N / NE ( cant post chart atm ). Long way off but it is the kind of chart that could pave the way for the long anticipated cold blast from the effects of the SSW which a lot of commentators are saying is under way. Will be interesting to see if there is a cold trend developing over the next couple of days or will it just fade away ?
As long as the gritters are functioning and the road's are safe, bring it on 0 -
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As was expected, models have been playing with tons of different solutions for the first half of January due to the ongoing sudden stratospheric warming event which is now really beginning to take off as the zonal winds reverse to an easterly for a couple days and the Polar Vortex attempts to split tomorrow Wednesday onwards.
The latest GFS below shows quite a long reversion of the zonal winds through the next week with them not recovering to 0 m/s or above by the end of run (+384 hrs). This is the sign of a very weak stratospheric Polar Vortex which is important in determining if we can get blocking going over the Arctic.
The warming is continuing to downwell into the lower stratosphere at 30hPa and the ECM has started to now show a sign of the 30hPa zonal winds reversing. Whether this all propagates further to the troposphere is another matter and complex equation but the models have trended recently on downward propagation occurring into the lower stratosphere which is a start. Let's take it step by step.
The MJO is currently going into its 6th phase which during El Nino events is conducive to a trough of below average heights over eastern Europe. We know this is going to happen from the model output with a potent northerly wind bringing cold air from the Arctic to those regions including Scandinavia through later today and the next few days.
The GEFS and EPS forecast the MJO to go to its 7th phase through the second week of January but there is some divergence between the two ensemble prediction systems. The GEFS is quite confidently going strongly on the 7th phase with decent amplitude whilst the EPS is barely going for 1.0 sigma and a lot of varied ensemble members in its set that it's hard to really forecast going strictly by this.
If the phase 7 forecast verifies especially using the latest GEFS, this is the kind of setup that should be showing up in model output. This shows an area of below average heights over central and southwestern Europe with a blocking area of high pressure just to the northwest of Ireland pulling in a northeasterly wind here.
This pattern from the MJO forecast is given weight by the fact that a SSW event is occurring and the Polar Vortex is set to split. However, remember that many things can change such as failure of downward propagation to the troposphere from the stratospheric warming, the blocking to the northwest could be too far south to pull in a northeasterly/easterly flow etc.
Any impacts from the stratospheric warming won't be until the end of the second week of January minimum. Yes, some models have started to show pretty cold scenarios for the second week of January, including the latest ECM (which as Villain pointed out is an outlier in its ensembles), though I don't think they hold that much weight.... for now.
The outlook remains very settled with a lot of high pressure influence, cooler than it recently has been.Photography site - https://www.sryanbruenphoto.com/
Weather photo portfolio - https://sryanbruen.myportfolio.com/weather-1
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ECM12Z a bit less cold than the 0Z but looking cold nonetheless out past +120hrs . Two runs in a row showing some cold , not exactly a trend yet but signs of the HP being eventually eroded and replaced by a longwave trough at the end of the run.
A way off and liable to change but the current charts showing LP S of Ireland helping to feed in a cold SE and E'ly winds out at +240hrs ( just a marker to see if following charts look anything like tonights ) .
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ECM 12Z hanging on to the HP out to the end of the run at +240 hrs but getting cooler with cold air being drawn in to the HP from the N initially and later from Europe's cold air mass.
That is a few runs now showing a trend for colder air from the N and E rather than Atlantic weather.
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This is from this morning's GFS 6z
Its not going to pan out this quick,it's for next Tuesday:eek: unless we're in for a surprise quick trop response to our SSW
However look closely,it is a beautiful synoptic starter for 10
It's basically what you want to see because that low to the east is travelling SW,which would effectively cause the trigger of extreme cold to the north in the light blue,dark blue AND purple colours at the top to flow and flow down to the UK and Ireland
It's a very nov Dec 2010 scenario
What's important for now is an NWP op run thinks it's a possibility
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Seems like there are upgrades across the board this morning, I think ICON gets a bad rep sometimes, I remember it was very good last Feb/March. Of course a week is a lifetime in weather terms so it could be all change by 4pm. Hopefully we get some January action this year!
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Easterly Beasterly wrote: »Seems like there are upgrades across the board this morning, I think ICON gets a bad rep sometimes, I remember it was very good last Feb/March. Of course a week is a lifetime in weather terms so it could be all change by 4pm. Hopefully we get some January action this year!
ICON DWD has been hinting for colder weather since last few days now. Latest has high pressure just south of Iceland with a northeasterly flow from the 9th Jan0 -
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I reckon the charts will start getting colder in the coming days
Hard frosts on way with light snow also possible in East and North but still some developments required
Your 100% correct. The models will start to take into account the SSW. Its going to get emotional with the big swings in the output.
This Sundays farming forecast and the one after will be classics.
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Mod Note: Following suggestions from hatrickpatrick and sryanbreun I have reopened Winter 2018 thread and renamed to include winter 2019. I have moved the posts from the now closed 2019 thread into the new Winter 2018 /2019 thread.
Hope it makes sense , have the foggy christmas head
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Baby steps. Big change in the GFS now showing decent cold for a few days next week whilst the ECM has backed off a bit with the cold but this could change as fairly marginal on the edge of the cold air mass ( suppose it could swing either way but most models showing a cold spell at least for a couple of days ). UKMO showing cold also Tues and Weds next . Gem : Mon, Tues and up until late Weds on the E coast showing cold uppers.
Mention of ICON above. Showing the coldest airmass of all the models from most of Monday to Fri ? Worth studying how the model fares with the rest, don't use it much this far out but good to compare.
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Just saw this on Netweather - Sounds like Ian Ferguson talking!
“Latest ECMWF Monthly output, in keeping with thoughts from various sub-seasonal forecast centres (incl. delaying colder risks until late Jan), sees significant height/SLP rises to the N/NW by late Jan on into early Feb. The outcome sees a mean NE'ly flow, with strong anomalies for below average temps across much of the UK (England especially) by late Jan. The signal is all the more compelling given lead time, but it's clear the model has likely reached some tipping point in terms of better assimilation of both SSW and MJO impacts (the latter now with more amplified phase 8). Nonetheless it provides only a broad sense of future direction for now, whilst operational models play catch-up and ultimately capture better detail and timeline.”
Apparently ECMWF Monthly is showing some action for week 3 & 4 - So Jan 21st being the starting point, this ties in with the UK Mets long range forecast, although they been pushing out any cold from early January to late January in their latest update - I still remain optimistic!0 -
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In general the models have backed off on the lowest upper temps next week as the LP that was bringing down the Northerly airflow now tracks further E keeping the coldest temperatures over the UK and mainland Europe ( clipping the NE , E of Ireland at best perhaps for a brief time ) . Still looks cooler than this week though and ECM showing it to be colder again by next weekend with an air mass sourced from more a NW direction. GFS , ICON not showing this, GEM and GFS bringing the colder NW'lys in on Monday week.
So the uncertainty goes on, big fluctuations over short space of time in a couple of runs.
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Yep but fast forward another week on the 06z and it shows a little glimpse of what we are hoping for
https://twitter.com/matthugo81/status/1081140468837216256?s=210
This discussion has been closed.
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