Model Output Discussion 31/03/14 onwards.

[Polar Maritime]

A two day 'cool' spell next week, before a return to warm spring sunshine with high pressure dominating - so says the ext ecm ens & gefs. CFS ens now showing a mild/warm May. So, another cool period has been reduced to a day or 2.

 

Really.. The meto see it much different.

 

 "Clearer, colder conditions will spread to northern parts late Tuesday and into Wednesday, with some heavy showers giving a risk of snow over high ground in the far north. Later in the week colder conditions and showers will likely spread south to most. It will feel warm in drier, sunny spells, but temperatures will generally be trending downwards to just below average for late April."

Edited April 24, 2014 by Polar Maritime

[Captain Shortwave]

Really.. The meto see it much different.

 

 "Clearer, colder conditions will spread to northern parts late Tuesday and into Wednesday, with some heavy showers giving a risk of snow over high ground in the far north. Later in the week colder conditions and showers will likely spread south to most. It will feel warm in drier, sunny spells, but temperatures will generally be trending downwards to just below average for late April."

Metoffice pretty much saying what the models show, a cold front pushing very slowly south during next week but only clearing during Thursday for southern areas. They do mention more settle weather developing over the bank holiday weekend with temperatures recovering to average, which pretty much backs up the models too.

Main uncertainty will be this cold front pushing south, and which places get unlucky and experience several cloudy and damp days under the cold front before the Scandi trough eventually wins out.

 

One last thing I will say is that a couple of days back we were supposed to get cold weather by next Monday for which that isn't going to happen now. Given the timeframe of cold air arriving to most of the UK is 7 days away, I wouldn't treat it as a given.

Edited April 24, 2014 by Captain shortwave

[johnholmes]

Looks pretty good now, bit wary of the northern block, but considerably better 8-14 day cpc run than what we had at the beginning of the week, got high hopes for the weather for may now:http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

 

not sure about May as a month pj and the noaa outputs have been consistent in predicting first a cooler/colder unsettled spell for this month end becoming a bit milder/warmer into the end of perhaps the 1st week of May but how settled is far from clear. Don't read too much into a prediction for 8-15 days for extending it into longer periods unless it consistently over 3-5 days suggests this AND is backed up by longer term links.

[Polar Maritime]

Metoffice pretty much saying what the models show, a cold front pushing very slowly south during next week but only clearing during Thursday for southern areas. They do mention more settle weather developing over the bank holiday weekend with temperatures recovering to average, which pretty much backs up the models too.

Main uncertainty will be this cold front pushing south, and which places get unlucky and experience several cloudy and damp days under the cold front before the Scandi trough eventually wins out.

 

One last thing I will say is that a couple of days back we were supposed to get cold weather by next Monday for which that isn't going to happen now. Given the timeframe of cold air arriving to most of the UK is 7 days away, I wouldn't treat it as a given.

 

My point was the upcoming colder weather will last longer than 2 days.

 

The meto have never forecast cold weather until after Monday, But i also understand the models are all about timing after they have picked up a strong signal, as is usually the case.

Edited April 24, 2014 by Polar Maritime

[Scorcher]

Cold uppers can produce preety chilly temperatures well into May under a cloudy/wet sky. Early May 97 brought very low maxima with most places struggling to hit 10 degrees on 6th May and over northern half of the country temps barely scraped 5-6 degrees. May is a deceptive month. I remember May 96 all too well. days and days of maxima in 7-10 degrees thanks to winds off a cold N Sea - uppers were not that cold.

 

Northerlies at this time of year generally mean significant convection thanks to the strong sun, temps climb in the sun but fall rapidly under showers. Double figures certainly not a guarantee.

 

This time of year is peak time for northerlies as well.

 

Double figures are not a guarantee but highly likely where the sun appears for any length of time in early May. I can count the number of sub 10C maxes I've recorded in May on one hand. I barely remember May 96 and even in that cool first half of May 2012 there were only 2 days in these parts that didn't reach 10C.

[knocker]

The morning snapshot.. ( I know, I know, just feeling whimsical)

Edited April 25, 2014 by knocker

[Captain Shortwave]

Well the models still keep the cold air spreading to all areas through Thursday into Friday. There are differences after this with the GEM building heights right over the UK, the ECM keeps core heights south of the UK but the UK remains dry. The GFS looks more unsettled and more progressive with the Atlantic compared to the rest. 

[Frosty.]

Winter finally arrives later next week from the north according to the Gfs 00z op run, much colder air spreading south, eventually reaching southern england, cold enough for snow on higher ground in the north, especially the scottish mountains which would be a huge bonus for the ski resorts. I had almost given up on anything cold but these synoptics showing a blocking high to the northwest and a scandi trough are a wonderful late surprise if they verify with arctic reloads stretching through early to mid may and a threat of snow is there, along with frosty nights..better late than never IMO.   :winky:

Edited April 25, 2014 by Frosty.

[knocker]

To paraphrase Sam Langhome, the arrival of winter may be greatly exaggerated. The ECM upper air pattern over the holiday period is a ridge to the west of the UK with the cold air to the east overlapping the UK giving slightly lower than average 850hPa temps. On the surface a large area of high pressure dominates proceedings giving a westerly flow on Sunday. A fairly nondescript weekend I would think.

 

Plus a quick look through the looking glass with Alice. Oh.

Edited April 25, 2014 by knocker

[Frosty.]

Since the ecm has been woeful for months, i'm backing the gfs 00z for a mass of cold blue heading south, which is what the bbc forecasts will show next week if the gfs is anything like, some surprise snow could occur..snow stopped play at the cricket in June 1975

[snowmadchrisuk]

Since the ecm has been woeful for months, i'm backing the gfs 00z for a mass of cold blue heading south, which is what the bbc forecasts will show next week if the gfs is anything like, some surprise snow could occur..snow stopped play at the cricket in June 1975

 

Sorry Frosty , although I am a fan of your comments , especially in Winter , all I am seeing is the same thing that has happened with Cold shots all winter , it is getting more and more Watered down , and High pressure is moving in from the West. Only good thing I can see is that another Cold spell that could rapidly end up being another hot and Sunny spell , which at this time of year is good, The 6z is starting to look much more like ECM in the reliable . 

[Polar Maritime]

Sorry Frosty , although I am a fan of your comments , especially in Winter , all I am seeing is the same thing that has happened with Cold shots all winter , it is getting more and more Watered down , and High pressure is moving in from the West. Only good thing I can see is that another Cold spell that could rapidly end up being another hot and Sunny spell , which at this time of year is good, The 6z is starting to look much more like ECM in the reliable . 

 

Unless you have been looking into the extreme side of the up-coming cool/cold spell then nothing has really changed.

 

What happened last Winter has nothing to do with it. When did the UK last see a  "Hot" spell ?

Edited April 25, 2014 by Polar Maritime

[East_England_Stormchaser91]

Hope this progged cold gets shunted away or diverted by some shortwave drama. Want a warm bank holiday, not a delayed reminiscence on the extreme back edge of this written off winter. That high pressure may well come into it a bit more in the up coming runs I think. 

[Summer Sun]

Could be some troublesome frosts around later next week for Gardeners if GFS is right these are the maximum temperatures for later next week

 

 

Minimum temperatures for the same time

 

 

If GFS was to be right it would be very cold for the time of year especially so out in the sticks Gardeners and Farmers need to keep a close eye on later next week the temperatures above could be quite damaging for crops

 

The risk of any wintery precipitation looks low away from high ground in Scotland

 

 

The longer term prospects remain unchanged with high pressure shown to build in later next week allowing temperatures to recover slowly

 

 

Beyond the BH weekend it looks more uncertain but we could see a return to something more unsettled in the north how far south this would get who knows but you can below the difference in air pressure on the ensemble for Aberdeen and London

 

Edited April 25, 2014 by Summer Sun

[knocker]

Well it seems to me that the 06 GFS upper air set up is not a million miles  away from the ECM. Tsk.....both woeful

Edited April 25, 2014 by knocker

[Frosty.]

Sorry Frosty , although I am a fan of your comments , especially in Winter , all I am seeing is the same thing that has happened with Cold shots all winter , it is getting more and more Watered down , and High pressure is moving in from the West. Only good thing I can see is that another Cold spell that could rapidly end up being another hot and Sunny spell , which at this time of year is good, The 6z is starting to look much more like ECM in the reliable . 

Met office still going for colder weather from the north next week with frosts and showers, wintry across high ground in the north, which is pretty much what the Gfs 00z showed earlier.

 

cheers

Edited April 25, 2014 by Frosty.

[knocker]

I'm sorry regarding those max temps for May the 3rd. Are we saying the max in some places are -3C? This cannot be correct. Looking at another chart.

Edited April 25, 2014 by knocker

[Dancerwithwings]

SS... pointed out maximum temperatures of the -1 -2s....Regarding temperatures out in the sticks they will be lower,

But as we enter May i wasn't expecting a chart showing up like this!!!

 

Edited April 25, 2014 by Dancerwithwings

[knocker]

I'm not querying what SS is saying I'm querying the chart. Just to confirm we are saying the max temp in the UK on the 3rd of May is forecast to be -3C in some places!!!? I don't understand why this is entirely different to the chart from the same run that I posted.

Edited April 25, 2014 by knocker

[phil nw.]

Looking at the last run and ens outputs that colder incursion looks quite dry with broken cloud and few showers as it comes through later next week.

Very much a glancing blow as it gets eroded by building pressure from the sw-maybe a 48hr cooler feel before things start to improve the following week end.

The 06z GFS run around the end of next week pretty much reflecting the 00z means

 

 

Shade temps will be suppressed for  2-3 days but with broken cloud  and little in the way of rain/showers away from some eastern and northern coastal areas it wont feel too different in the strong sunshine.We do have the risk of some frosts however for a couple of nights.

 

The next few days look cloudier and wetter for sure with the low pressure taking it's time to fill as it lingers around the south of the UK.

 

 

Still the prospect of a warmer and settled spell from next week end though as the Azores high is modeled to build towards the UK.

 

so a changeable week to come and then the prospect of a fine weekend which may well last into week 2 especially for the south.

 

 

 

 

 

[Dancerwithwings]

I'm not querying what SS is saying I'm querying the chart. Just to confirm we are saying the max temp in the UK on the 3rd of May is forecast to be -3C in some places? I don't understand why this is entirely different to the chart from the same run that I posted.

I know you wasn't :happy: But you have a point, If you look at that chart i posted... -4 -5s at 8am 'MIN' Temps yes!.... but normal 2m Temps showing 3c at 8am... Not for me either

Edited April 25, 2014 by Dancerwithwings

[SW Saltire]

I'm not querying what SS is saying I'm querying the chart. Just to confirm we are saying the max temp in the UK on the 3rd of May is forecast to be -3C in some places!!!? I don't understand why this is entirely different to the chart from the same run that I posted.

Knocker look at the charts below that, indicating a 24 hour clock being used. I.e 18:00 being 6pm thus I believe SS's charts say at 3am on thurs, Friday etc the warmest it may be at 3am is -3 in some spots and may be lower (at 3am) so obviously with the now strong sun maxes (afternoon) would be nearer 10c. Correct me if I'm wrong...EDIT: I think I slightly misinterpreted what you meant. I.e -3 is a very damaging frost for May. Yeah, ignore the above, I understand what you meant now. I wasn't trying to patronise Edited April 25, 2014 by SW Saltire

[knocker]

Streuth time for a nap. A min chart for the 3rd.

Edited April 25, 2014 by knocker

[William of Walworth]

I'd be surprised if those 3 am maximum temperatures of -3C shown in SS's chart earlier don't get watered down in the end, that's VERY cold for beginning of May nighttime.

 

Liking the look of building High Pressure into next (Bank Holiday) weekend, if that modelling verifies many of us could see pleasant daytime conditions -- albeit not spectacular or anything.

Edited April 25, 2014 by William of Walworth

[gottolovethisweather]

Looking at the last run and ens outputs that colder incursion looks quite dry with broken cloud and few showers as it comes through later next week.

Very much a glancing blow as it gets eroded by building pressure from the sw-maybe a 48hr cooler feel before things start to improve the following week end.

 

The 06z GFS run around the end of next week pretty much reflecting the 00z means

 

Shade temps will be suppressed for  2-3 days but with broken cloud  and little in the way of rain/showers away from some eastern and northern coastal areas it wont feel too different in the strong sunshine.We do have the risk of some frosts however for a couple of nights.

 

The next few days look cloudier and wetter for sure with the low pressure taking it's time to fill as it lingers around the south of the UK.

 

Still the prospect of a warmer and settled spell from next week end though as the Azores high is modeled to build towards the UK.

so a changeable week to come and then the prospect of a fine weekend which may well last into week 2 especially for the south.

 

Hi Phil, Thanks for this. I know it is still valid discussion but I had been left wondering what the weather was likely to do next week, given that most of the focus (as often is the case) is on synoptic patterns some t+168 hours away. So a continuation of cool wet showery interludes (aside from today's deluge) and fleeting glimpses of warmer sunnier spells looks the way of things. I won't even reserve judgement on the next Bank Holiday weekend until next Monday's and Tuesday's charts reveal themselves as it could go either way.

Edited April 25, 2014 by gottolovethisweather