Heavy Snow at times next week especially after midweek

looks to me like a week when you're better off sticking you're head out the window and hoping,i have a feeling we will all get a nice surprise at some stage during the week.

Su Campu wrote: »

The way I see it tonight there is virtually NO chance of snow below about 250m this week. We just don't get the really cold air, we're on the wrong side of marginal. :rolleyes:

Ever the voice of reason Su Campu, I think I will go with your forecast after the disappoinments of previous weeks. I think rain is most likely for Ireland given the marginality of the situation allied to the often overlooked fact that we are in the firing line of the Gulf Stream!

Darkman2, love your ramps however most of the time they are wrong
I hope though this week you are right, would like to see a bit of snow.....however instinct tells me snow will not materialise :mad:

Derek

Deep Easterly wrote: »

2 foot of snow on a hill is nothing surprising or unusual. I don't doubt that you got down to -13c. Many parts of Ireland (yep, even in the "south") seen temps that low, and lower, during the last cold blip. You don't stand alone! :eek:

Oh don't be giving your senses to him , DE

OwenC, no hurt intended but I scan the posters to the left of the page and skip your posts at all times. They are a lot of the times off-topic, irritating and revolve around the whole notion that weather is only interesting if the temperature is below 0oC. Also your tantrums when snow does not head your way are to be it mildly, annyoing :cool:

Derek

Afternoon Everyone

Introduction

As we prepare to enter another week that will contain below average temperatures, it's interesting to take a look at the synoptic evolution & as to what may develop over the coming medium term. Before discussing all of the associated background signals, it is noteworthy that in the next 7 Days, it is quite likely that some exceptionally deep cold pooling, with 850mb temperatures of -15 and below will develop across Scandinavia & to the Northeast. Should cold troughing develop just south of the UK & Ireland, then there is a definite risk of this deep cold being advected towards us quite rapidly. Some of the coldest air of the entire Winter season is about to develop over this region & it's something to watch going forward.

These developments are a direct response to the Major Warming event that has taken place at the 30mb level. Tropospheric developments have manifested in the form of extreme discontinuous High Latitude blocking to the Northwest & Variable North. Going forward, there are increasing signs of even more sustained blocking all across the variable North.

To an extent, developments during the coming week are similar to those which took place during the last week of December 2009. From Day 1 - Day 3, the country will be enveloped in an RPM (Returning Polar Maritime) airmass. From Day 3 onwards, the flow will become more Polar Maritime in nature, increasing the risk of wintry precipitation, with a subsequent fall in 850mb temperatures.

Synoptic Evolution

At 09.30 Hrs this morning, a Polar Trough of 1005mb is forming to the East of Greenland. A largescale blocking High of 1025mb is currently retrograding towards Greenland. An increasingly unstable pattern begins to develop across Ireland much later in the Day, with frontal systems beginning to move down across the country from the North/Northwest.



This Polar Trough will make significant southward progress over the coming 36 Hours & will be centred just north of Scotland at 12 Hrs, Monday. An RPM airflow will cover Ireland, with shower activity developing at times, particularly across more Northern areas.



During Tuesday, this trough will make even further southward progress, becoming centred just off the Northwest coast of the country. Conditions will become increasingly cyclonic at this point, with rain becoming more widespread later in the day. Sleet is possible over high ground in particular, especially overnight on Tuesday.



Conditions will remain unsettled during Wednesday & Thursday as this feature becomes centred just to the South of the country, before transferring gradually Eastwards. As it begins tracks Eastwards, rather colder air will begin to make inroads across the country from the North. Frosts could well become increasingly sharp to severe again at night time, with ice formation after rainfall. There is a low risk of back edge snowfall across Northern areas in particular, later on Wednesday & into Thursday. During both of these days, there is an increasing risk of snowfall across high ground in particular.



Looking further ahead towards the weekend & there are certainly signs towards a continuation of cold conditions, perhaps even colder in nature with a low risk at the moment of Easterly/Northeasterly winds developing as a series of undercutting lows form to the south. Confidence is high in the general pattern up to Friday, at which time the main trough feature will have filled to leave slack, cold conditions across the country. Confidence is generally much lower thereafter.

ECMWF 00Z 14/02 - T+216



ECMWF 00Z 14/02 - T+240



Summary

In summary then, rather cold to at times cold conditions persisting through the coming week. Temperatures generally below average throughout, with an increasing risk of overnight sharp to severe frosts & icy stretches from Day 3/4 onwards, with a risk of precipitation increasingly wintry in nature. Towards the weekend, confidence is much lower, with a general signal for the persistence of cold & a low risk of even colder conditions returning from the East/Northeast. There is also a low risk of conditions turning less cold from the Southwest, however signals generally favour a cold pattern, approximately 60:40, at the present time.

SA