lorenzo

Fax updated within the last hour, a true Northerly.

Fax John mentions deserves a post, it is a beauty.

Gust charts for the further 6 hours.

Gusts approx 90mph into West Coast of Scotland. One of those situations where looking at the charts here before the event is nice, however the eery element remains that a system like this can catch folk out. The introduction of the cold air is rapid. 6am - noon - 6 pm

Wind gust chart from the 18z run, SLP can be deceptive.. Also a dedicated thread here http://forum.netweather.tv/topic/78664-severe-storm-system-arctic-blast-thursday-5th-onwards/?view=getnewpost

Not long in from work and pretty damn cold and breezy out there already. From the Eumetsat eport, this grab shows the RGB Airmass and Satellite. The overlays in beige are for the 300hPa streamlines, and also the Isotachs which highlight the jet in yellow. 80 meters per second equates to a 178mph jet. Classic European windstorm.

Never mind the rest of December. This rag have it all worked out... LOL !!

It will if hopefully we end up with something like the mean, from mid FI to extreme FI. Control run, not so bullish. Reforecast product also hints at the same, although neutral NAO will look appealing after that week or so of heavily positive NAO.

Guess it is relative to the size of population impacted by St Judes versus the number of folks due to be in line for this one. Still, I would hope an Amber warning does go out, ESPECIALLY considering timing, as Liam mentioned, right on the school run, don't need anymore hellish accidents that can totally be avoided.

Still as fierce on the latest run.

Bomb. 12mb drop in 6 hrs..

We can but dream.. A Bartlett High. Couple of links here explain all.. http://forum.netweather.tv/topic/67869-bartlett-set-up/ http://weatherfaqs.org.uk/node/117

Expect to read... Winter is Over. It's spring time. Mildest Winter Ever. It's only one run... really is one Ugly looking slug of a Bartlett !

Some ugly output from the ECM too this evening. Unless you like Bartletts of course.

HC, just raided an old folder full of Bawbaggery... very similar.. And, in all it's trampoline glory..

This is a grim looking forecast from the afternoon models. Mentioned the Amber warning last night, wonder how the UKMO see this low developing, if anything like this then surely Amber. 92 mph gusts. GFS / UKMO Jet The only positive if you can call it that is the system barrels through and out to sea in a few hours.

Nice post CH, the Scandi ridge certainly has support from the 100mb profiles, checked both ECM and GFS this time, reference ECM Berlin plots throwing us dodgy data earlier in the season. Well defined at 168. Both ECM and GEFS provide the illustration of the Wave 2 Activity, some cross polar perturbations may indeed be kicking around soon. 30mb temp - encouraging signs but would love a Torque event to really test things. Re - trailing segments of vortex, I know that these are complicated charts representing vorticity across an atmospheric layer, however without losing your mind to the physics involved provide an illustration of how the vortex is stretched. Apologies for mixing the strat charts into the model thread, synoptics of the NH ridges are the key elements in play here, and trying to highlight the heights support. On a bias front the ECM 00z ramps up Scandi blocks at 144-168, whereas the 12z is more moderate, something to also consider along with it being amped.

With the usual caveats re: extreme FI and paying attention to the mid/long term trend as advertised by the ECM weeklies this morning. The control run shows this. Would be a nice week before Xmas on Netwx model thread if we were being tempted with retrogression and a Greenland high..

Into Sting Jet territory now...

Yes Weatherbell charts are subscription ones. They occasional appear on twitter from Joe B or Dr Maue.

Just re-posting from the mod. GFS invigorates the LP and it is looking pretty lively to say the least.. In fact very lively.. Somewhere is going to get an absolutely wild time from that..!

Quite a vigorous low on this run. Edit - add wind gusts from GFS. Amber warnings from that I would think.

What Northerly ? Could be a valid question to ask when comparing the amazing output from the 00z runs on Sunday morning and now looking at the way events are unfolding, through last night 12z and this morning. The main areas affected are certainly being discussed in the Regional thread. With the model thread catering for the whole of the country, it is logical for folks to look at the potential set up for the rest of the month, I am sure if this Northerly had remained undiluted then it would still be getting the discussion it deserves. Plus, it just wouldn't be Winter on the model discussion without our annual hunt for an easterly. It's some kind of weird exorcism and catharthis of last years demons created by the ECM.

Thanks for the further explanation, it is something I was beginning to look at before being distracted by the Northerly, the above bit in bold was generally what I was trying to say. The chart I am looking at and getting my head round for this is located here http://www.atmos.albany.edu/facstaff/roundy/waves/hovsdet/0_7.5N/ Latest forecast example The MJO CPC update comes out each Monday evening. Mike Ventrice site is also an amazing resource of everything in the tropics, can't begin to describe everything here http://mikeventrice.weebly.com/tropical-waves.html MJO shown in red here with Kelvin Waves in Black Plotted a couple of composites to try and fathom whether MJO activity would add bearing to the first half of December. Looking at the phase of the GWO, phase 2 Northward momentum transport, a low AAM state and taking into account the neutral ENSO state. These are all dates since 74, filtered for phase 2/3 of GWO and ENSO -1 > 1 values. Then again with MJO filtered for phases 2/3/4. Not withstanding the west atlantic ridging am unsure about these plots, what is clear from the dates when filtered that there is a healthy split between developing positive NAO regime and the Scandi Block. At present, the positive NAO I believe has the edge. Not great news for folks hunting cold, and hope to be wrong ! Having talked myself out of the Scandi high verifying, for reference this morning 00z normalised Ensemble mean, advertising the Scandi High, this for 14th, which helps change my mind back the other way ! ECM will have to do 'very' well with this to help everyone get over 'that ECM'..

Well the main models have shifted a fair bit since yesterday morning and the Epic output on offer, 12z last night saw the Eastward shift in the cold plunge, which may be some short term pain for longer term gain as this will serve to give Europe a real chill. Looking at the impact of the northerly, we are still on course for a solid cold blast, don't let the downbeat thoughts in the model thread kid you. Thursday Fax from 6am this morning, will see what the 850hPa temps look like on UKMO 12z run later, still a good true Northerly hit, so whilst transient, it is decent. Few charts from the GFS this morning too.. Snow still on the cards for some, however wind becoming the other main part of the story, with some strong gust profiles being modelled now. It seems that so far this Autumn / Winter the models themselves are attracting as much debate as the actual output. Yesterday morning runs were at the top end of the scale for what we could get, and this is still a tricky one to call at 84 hrs out. No denying the depth and duration have downgraded since Sunday a.m. Simply put, the models don't like the vortex shifting around as SK pointed out the in model thread, for me the transfer from Scandi > Canada looks even at present a little quick. Let's hope it slows a little and lets the Northerly extend. And, it wouldn't be a Winter on Netweather without the annual hunt down the Easterly !!