ghoneym

Yes, this is the significant factor right now Imo. Its predicted to trend as a -ve MT event in the next week which has the downstream effect of a weaker jet stream causing splits in the flow, more troughs / ridges to appear, more blocking pattern - -ve AO.

What I see is the ongoing effect of what is causing the SSW. Not the after effect of the SSW. That is yet to come Imo. The SSW from earlier this year was official from the 12th of Feb I think and the AO trending largely negative from the 20th of Feb onwards. I think the 10 days to 2 weeks rule of thumb is a good guide for trop effect from SSW.

The zonal mean wind reversal on the 84 into 85 chart below is being shadowed by 2018 into 2019, I checked these last night and compared all other available years to this years footprint. Thats 1979 to present. 84 into 85 are the closest match to my eyes

Same again at 216

GFS(P),GFS, ECM at 192

Time for things to start getting interesting in the trop within a week or 2 hopefully following this. Great graphic of the split from earthnull school. The third lobe of the vortex can be seen over the pacific in the next screenshot, not as large as the Mother/Daughter vortices over Europe and the Atlantic but the little lad is still impressive non the less. Note - 2 days down the line these images are forecast for.

KP5 aurora activity expected tonight, northern parts of Scotland may get lucky. May go for a long drive later....

Some heavy ass snow predicted on the WRF late tomorrow afternoon through into Tuesday. Mega slush fest?

Neat new feature on Earthnull, now the aurora is included

Mossmorran doing their bit to help the snow melt and advance the spring forward

Some nice early spring weather in Fife today, had a walk with the kids from dysart to kirkcaldy, 10 deg C very gentle breeze, sun strong enough to heat the beach sand so you could walk bare foot. What will next week bring ? "polar opposite" possibly?

The timings look perfectly correlated to me. The wave forcing shaped by the AAM spike surely cannot be denied. In terms of time taken to impact the start I believe several days, 6km per day so reaches 100mb in 36 hours or so, during this time waiting for further wave activity the 10mb and 1mb are effected by the previous wave. It takes another few days for the next wave to take effect and an adiabatic heating process starts taking shape giving us the warming. Could you give us your thoughts please regarding this. A bit more detail would be helpful.

I think if he was to expand on his comments then he would be referring to tropics > extra tropics > MT> Stratosphere > troposphere > high lat blocking > Easterly > further assisted by continued downwelling courtesy of SSW ? Lets ask him mr Sciaffe in the comments section of his blog

Thanks for your views / opinions Interitus.

Interested to know thoughts in here regarding the final warming. Looks to me currently like a very weakened stratosphere polar vortex, but hasn't been fully finished off yet like some had expected (Amy Butler tweet quoted at top this page of the thread, 17th March as possible final warming based on GEFS/GFS data). Looking at the available stratosphere charts from meteociel at 10mb and our very own 30mb chart it looks like another small warming hit end of March start of April? current 60 N winds trending close to the mean, total heat flux barely noticeable currently but enough to finish things off towards the end of the month? I had a read of the following abstract and to me its clear from this, that during years with late winter major warming, the final warming will also come later.

As we are heading towards the second half of March it could be thought that any snow falling would fail to settle. However wet bulb temperature is a good way to determine if falling snow will settle. Taking a Buch of averages from the south east, 2m temperature, relative humidity, SLP, dew point and firing it into the calculator the wet bulb temp looks good for the south east. Average -2 for the times of shown precipitation on Arpege / WRF / Hirlam. Anything below zero is what your looking for. Dew points can be found on meteociel Arpege 0.1 called "point rosee" A link to the calculator is attached. Wet bulb temperature calculator https://www.weather.gov/epz/wxcalc_rh

Been snowing here all morning, footprints refilling as we speak ?

Just ran the gauntlet home from work. Cowdenbeath through lochgelly, then balingary, then lochore, kinlassie, glenrothes - leven. 4x4 old Honda CRV with winter tyres and it was mental scary! The snow was pretty impressive too ? seriously tho I've never seen anything like it, the drift of the fields would make all these roads inpassible if it wernt for the snowploughs who are doing a great job imo ??? oh and a wee total update from leven....yee ha ?

Leven, Fife 28th Feb 2018

@Hawesy bang on 3 inches here mate, radar showing potential for another wee bawhair but can't wait up to measure at midnight, getting picked up for work at half 4 in the morning

The trampoline is a bit slippy ?

Whats the roads like up your way, was supposed to be going to the car auctions tonight

Get the camera out and get us some pics! Sounds like an Artic tundra up your way

Im just the wrong side of the standinstane road, we've had nothing here now for an hour. 7 miles away