The Donegal Weather Channel Monthly Long range forecast issued every week looking up to a month ahead using data from the ECMWF and GFS models.

Please note that the longer range forecasts are more uncertain and should not be used to plan outside activities from over a week out.

Extended Range Output

The output is rather different from the shorter period output of HRES and ENS products.  It provides a more general overview of the forecast up to Day 46, focusing mainly on the week-to-week changes in the weather rather than attempting to give unsupportable detail on individual days.  Output is mostly in the form of anomalies relative to ER-M-climate and is mainly shown as 7-day means for calendar weeks Monday-Sunday.   Specialised products for the extended range also include information on potential tropical cyclone activity and the MJO during the coming month.

SPONSOR THE LONG RANGE FORECAST

If you have a business and would like to sponsor our weekly month long range forecast for a period of 1 week or 1 month please do contact Donegal Weather Channel at info@donegalweatherchannel.ie or message our Facebook page . Donegal Weather Channels service relies on sponsorship/advertising. Without sponsorship/advertising Donegal Weather Channel would not be able to give so many hours and a daily service.

The forecast will be issued by myself Kenneth and i will try to keep it simple making it easy for everyone to understand. If there is a term I use in the forecast which you may not know what it means I will explain what I am talking about .

Before I start with the long range forecast I will just explain what we will be looking at and how the forecast will work.

The forecast will be broken up into 4 section Example below :

• Week 1 - Monday 7th June 2021 -Monday 14th June 2021

• Week 2 - Monday 14th June 2021 -Monday 21st June 2021

• Week 3 - Monday 21st June 2021 -Monday 28th June 2021

• Week 4 - Monday 28th June 2021 -Monday 05th July 2021

Things we will look at in the forecast:

• Mean sea level pressure: Weekly mean anomalies

• 2m temperature: Weekly mean anomalies

• Wind

• Precipitation: Weekly mean anomalies (eg. rainfall and snowfall for a example.

• Dust forecast ( Only in Week 1)

• UV forecast outlook

• Potential Pollen Levels

Forecaster - Kenneth Mc Donagh

Week 1 - Monday 7th June 2021 -Monday 14th June 2021

Mean sea level pressure: Weekly mean anomalies

Higher pressure than average across Ireland early this week especially towards the end of the week and over the weekend when a ridged of high pressure will extend northwards up across Ireland and the UK. This will bring up a tropical airmass bring warmer and humid conditions over the week and will be most noticeable at night.

Precipitation ( Rainfall ): Weekly mean anomalies

Rainfall amounts over the week gone by where well below average across much of Ireland. Amounts range from trace 0mm to 17mm. The only exception was the Met Eireann Valentia Observatory in County Kerry which recorded 28.0mm of rainfall. The east and northeast was driest with 0mm recorded at Dublin airport.

Over the coming week rainfall amounts are expected to below normal again for much of Ireland . The only exception is western coastal areas which will see there normal rainfall amounts over the coming week. The east and southeast of Ireland will be the driest parts of Ireland this week with some areas there receiving very little to no rainfall over the coming 7 days.

Tuesday, Wednesday and Thursday will seethe most rain this week with a spell of heavier rainfall expected across the west and northwest on Tuesday night and Wednesday morning. Away from the northwest, west and southwest it will be much drier with the least amounts of rainfall

Rainfall amounts between Tuesday 08st June to Sunday 13th June 2021

ULSTER

Across much Ulster rainfall amounts are expected to be below average this coming week. Highest amounts will be across west Ulster mainly across Donegal over the higher ground areas with between 10mm to 25mm expected there. Across the rest of Ulster amounts will range between 3mm to 10m lowest amounts in the east of Ulster.

CONNACHT

Away from west Connacht rainfall amounts are expected to be below average this coming week. Highest amounts will be across west Connacht mainly across Galway & Mayo over the higher ground areas with between 15mm to 45mm expected around Galway and 10mm to 25mm across west Mayo. Across the rest of Connacht amounts will range between 3mm to 10m lowest amounts in the east and north Connacht.

MUNSTER

Away from west Munster rainfall amounts are expected to be below average this coming week. Highest amounts will be across west Munster mainly across west/south Kerry & south/west Cork over the higher ground areas with between 15mm to 30mm. Across the rest of Munster amounts will range between 1mm to 15mm lowest amounts in the east Munster.

LEINSTER

Overall Leinster will be the driest province this week with only between 0mm to 5mm. it will be driest in the southeast and the east of Leinster with the highest rainfall amounts across the west of the province.

Temperature: Weekly mean anomalies

Temperatures over this week (week 1) will be above average across Ireland. There will be no risk of frost this week . The week will be warm and humid across Ireland with very muggy conditions. Overall day time temperatures will range between 14C/22C on Tuesday , Wednesday, Thursday and Friday. This weekend is set to become that but warmer with temperatures forecast to rise into the mid 20s in places with temperatures across Ireland ranging between

Tuesday and Wednesday but a little cooler on Thursday and Friday with temperatures recovering a little over the weekend into the high teens in some places. 18C to 25C. Warmest across the midlands east over much of the week but feeling warm everywhere especially with such humid conditions.

Wind forecast

No Strong winds are expected this week.

UV forecast

UV levels will be Moderate to high this week and possibly rising to very high this weekend with the risk of sun burn possible.

Pollen Forecast

Pollen levels will be moderate to high over the week with pollen levels lowest during cloudy and wet weather and highest during any sunny & dry periods. The main type of pollen will be grass this week.

Dust forecast

Dust levels will be low across Ireland during week 1.

Week 2 - Monday 14th June 2021 -Monday 21st June 2021

Mean sea level pressure: Weekly mean anomalies

The latest outlook from the ECMWF long range forecast shows higher pressure than normal to the southeast and east of Ireland with lower pressure between Ireland and Iceland to the west and northwest which will see a mix of weather conditions over the week.

Precipitation ( Rainfall): Weekly mean anomalies

The latest trend for this week shows rainfall amounts below average across the southern and eastern half of Ireland but near normal our slightly above across western and northern areas. The main risk of rain looks as the will come from low pressure systems moving close to Ireland from midweek and over the later stages of the week. The risk of a few thundery showers can also not be ruled out.

2m temperature: Weekly mean anomalies

It looks set to be warmest on Monday and Tuesday of week 2 before a cooler airmass with a northwesterly to westerly airflow bringing below average temperatures across Ireland from around the mid point of this week in to the weekend. Temperatures will be in the high teens over the early days of the week but falling back into the low to mid teens from midweek.

Wind Forecast

From midweek and over the latest stages of the week there may be the risk of some unseasonably windy conditions.

UV forecast

UV levels will be Moderate to high in any sunshine with the risk of sun burn even in cooler than average conditions.

Pollen Forecast

Pollen levels will be moderate to high over the week with pollen levels lowest during cloudy and wet weather and highest during any sunny dry periods. Grass pollen will be the main type.

Week 3 - Monday 21st June 2021 -Monday 28th June 2021

Mean sea level pressure: Weekly mean anomalies

Confidence in this week is rather low and more uncertain. Higher pressure is indicated to sit to the south of Ireland with lower pressure to the north putting Ireland in the middle which is likely to bring a westerly airflow across the country bring some unsettled weather at times.

Precipitation ( Rainfall): Weekly mean anomalies

Confidence in this week is rather low and more uncertain but the latest signal is for average rainfall amounts with some showery weather expected at times over the week.

2m temperature: Weekly mean anomalies

Again confidence in this week is rather low but the latest long range forecast from the ECMWF model indicates temperatures near normal for this time of year in the mid teens to high teens.

Wind forecast

There may be some windy conditions this week due to a more westerly airflow. Overall the risk of very strong winds will be rather low

UV forecast

UV levels will be Moderate, High in any sunshine with the risk of sun burn.

Pollen forecast

Pollen levels will be moderate, high to very over the week with pollen levels lowest during cloudy and wet weather and highest during any sunny dry periods. Grass pollen will be the main type

Week 4 - Monday 28th June 2021 -Monday 05th July 2021

Mean sea level pressure: Weekly mean anomalies

And finally week 4 confidence is even lower as you can see from the above pressure chart attached it does not show any strong signals of higher pressure or lower pressure meaning that the weather looks set to see a stable weather pattern.

Precipitation ( Rainfall): Weekly mean anomalies

Rainfall amounts are signaled to be near normal our just below this week meaning not very big rainfall amounts are possible.

2m temperature: Weekly mean anomalies

Again confidence in this week is rather low but the latest long range forecast from the ECMWF model indicates temperatures near normal for this time of year in the mid teens to high teens.

Wind forecast

There are not clear signals for this week

UV forecast

UV levels will be Moderate, High in any sunshine with the risk of sun burn even with cooler weather as the sun this time of year is stronger.

Pollen forecast

Pollen levels will be moderate to high over the week with pollen levels lowest during cloudy and wet weather and highest during any sunny dry periods. Grass pollen the main type