Your daily forecasts from Boards.ie weather forum (NO CHAT)

Thursday, 3 September, 2009
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Gradual improvements are on the way, or so it seems from the trend of the models. It will take about a week to lift the jet stream and then some higher pressure can build into the region.

TODAY and FRIDAY will be breezy to windy at times, mainly from the west, and with some dry intervals in the east at first each day, followed by a buildup of clouds and outbreaks of showers that will be more frequent in the west, in some cases lasting through tonight as well. In general, highs will be close to 16 C and tonight's low around 8 C, with rainfalls about 2-4 mms per day on average, and some risk of hail or thunder especially in the northwest and southwest.

THE WEEKEND is looking rather similar to last weekend, expect Saturday to be more cloudy than sunny, but fairly dry except for some light rain around western and northern coastal sections, sometimes breaking away to light showers elsewhere; winds will be moderate westerly, and highs near 18 C. Sunday looks warmer with considerable cloud, some intervals of rain likely but more to the west and north than elsewhere, and winds southerly 15-25 mph, highs near 21 C at best.

MONDAY and TUESDAY features another warm, rather active frontal system that could bring another 15 mms of rain possibly, and highs to about 21-22 C, with strong S to SW winds developing. Although this sounds like the same old weather pattern, the jet stream will be lifting during this episode and the rain could be more drizzly and less showery and thus a bit lighter than in previous similar events.

From WEDNESDAY onwards, higher pressure is likely to build in from the Atlantic and a larger daily temperature range will develop, from lows of 6-9 C to highs of 20-23 C, governed by light northerly winds at first that could become more east to southeast eventually.

Let's hope this change in the weather comes about as evidently many parts of the country have suffered from excessive rainfalls and need a chance to dry out for a couple of weeks at least.

Saturday, 5 September, 2009
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TODAY will be rather cloudy but the sun may appear for a while in the southeastern counties; otherwise, expect mostly dry conditions except for some drizzly showers over western counties at times. Winds today will be much slacker than the past two days but still managing some 20-25 mph gusts from the west before backing to southerly late in the day. Highs should reach 17 or 18 C.

TONIGHT will have some clear intervals to start, allowing temperatures to fall to about 8-10 C by midnight, then fog is likely to form as cloud moves in over the cooler air, and by morning there should be a heavy dew and some light rain falling in the west. Temperatures will tend to rise towards sunrise, to near 12-13 C.

SUNDAY will feature some stronger southerly winds in the morning, with periods of rain, but there may be a drying trend by afternoon from west to east with a few glimpses of the sun, and highs of 18-19 C.

MONDAY is looking fairly good at this point with a weak ridge overhead allowing for some hazy sunshine, although rain may not be too far away from the southwest coast by afternoon. Highs may touch 20 C in eastern and northern counties.

TUESDAY at this point is still looking quite windy and rather warm with sunshine possible in the south and east but cloud and eventually showers in the west ahead of a very strong southerly gale that will develop over the near Atlantic (gusts to 50 knots on the west coast and 65 knots further west over the ocean). With all that, highs may reach 23-24 C away from the south coast which will have the strong onshore wind cooling temperatures to near 17 C. Any slight change in this situation with such a strong low could bring the storm force winds over western and northern counties during the afternoon and evening, so stay tuned on this ... the low blasts north towards Norway and is well clear of even Malin Head by sunrise in terms of strong winds overnight. Actually, the gale to storm force winds would subside very rapidly, but swells and waves on the west coast would probably take longer to settle down through Wednesday.

WEDNESDAY and onwards, the models continue to promise a long interval of dry, seasonably warm weather under strong high pressure, with light winds, overnight fog and hazy sunshine in the daytime. Eventually (after several days) enough of an easterly gradient forms to suggest more low cloud and possibly drizzle than unbroken sunshine, but there would still be a prolonged dry spell which seems like good news all around.

I think I may have neglected to mention my own weather for a couple of days now, but it was rather bland, partly cloudy with a few light showers each day Thursday-Friday with highs near 21 C.

Monday, 7 September, 2009
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TODAY will start out dry in most of Ireland with some sunshine boosting temperatures rapidly in a southerly wind of 10-20 mph. By afternoon there will be increasing cloud followed by some spotty light rain mostly over the south and west, and temperatures near 21 C. Winds will also pick up to about 15-30 mph. Gale to storm force winds from the south will be developing over the Atlantic around 20 W and spreading closer to the west coast by late afternoon.

TONIGHT will become windy and very mild with further showers, mostly rather light, but some risk of heavier thundershowers in the southwest. Winds will pick up to SSW 30-50 mph in western counties (40-65 mph over exposed coasts and hills) but should remain more like 20-35 mph in eastern Ireland. Lows will be around 14 C and it could be as warm as 18 C by sunrise.

TUESDAY will remain very windy although Connacht will have the strongest winds, SSW 45-70 mph with some higher gusts, veering to W 40-60 mph. Other regions will be in the range of 35-55 mph with a mid-day frontal passage that could set off some heavier showers. Following this front, the skies should clear for a while and temperatures will peak around 22-24 C in eastern counties, 17-20 C in the west. We'll be tracking this front and the strong winds fairly continuously through the next 24 hours.

TUESDAY NIGHT the strong winds will rapidly abate and after midnight it may be almost calm especially inland, allowing fog to form under the partly cloudy to clear skies. Lows will fall to about 6-8 C in rural areas and 10 C in larger cities and near the west coast.

WEDNESDAY will be a much calmer day with the fog slowly lifting then some sunshine and light northerly winds becoming easterly but only 5-10 mph. Highs will reach 19-20 C.

This should be followed by several more days of similar dry, calm weather with extensive fog or low cloud at night, and some hazy sunshine each day, with temperatures generally near 7 C overnight, 20 C during the daytime hours. Eventually more of an east to southeast wind will develop in this spell and bring more extensive low cloud to southern counties, but this may take almost a week on current indications.

Updates about the strong low will be posted during the day ... currently it is located near 45N 30W (992 mbs) but is expected by mid-day Tuesday to be near 57N 17W (965 mbs).

UPDATE _ Monday, 3:45 p.m.
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Currently the developing low is around 52N 22W at about 982 mbs. Rain is spreading into the west coast but taking a mostly northerly track there so it will only spread eastwards gradually through this evening and the tendency will be for it to become sporadic further east, could be some moderate bursts giving 5-15 mms in parts of Galway and Mayo as well as the coastal sections of other counties further south. I think the strongest winds for the west coast will arrive late tonight and continue through Tuesday morning, not sure if the front will be quite as calm as the map above suggests in eastern Ireland as the gradient looks more into the 20-40 mph range for Dublin, and any shower development along the cold front could result in stronger wind gusts locally. I'll post another update around 8 to 10 p.m. ... as today is Labour Day, I am doing nothing. My local weather yesterday was rather dull with some rain at times, and a high of about 18 C. Looks about the same today so far.

Tuesday, 8 September, 2009
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Situation (0630) ... A band of frontal rain now covers most of northern and western counties of Ireland, while it remains generally cloudy, but dry, in eastern and southeastern counties. This rain band could develop into some gusty thundershowers as it moves east, followed by gradual clearing from the west. Winds are quite strong along the front and behind it, and are increasing ahead of it as well. Forecasts for today are divided into several regions as the weather situation is rather complex.

TODAY (eastern Ireland) will start out cloudy with strong southerly winds locally gusting to 40 mph. Rain will arrive by about 0900 and persist for several hours. There could be a gusty thunderstorm for some regions, then winds will veer rapidly to WSW 30-50 mph, with gradual clearing by late afternoon. Highs today will be around 21 C.

TODAY (central Ireland and most of Ulster) will start out wet and windy with periods of rain and a possible thundershower (10-20 mms will fall) and rather erratic winds sometimes gusting to about 50 mph and sometimes dropping off considerably (strong winds above the surface are not always mixing down to the ground in the frontal zone) ... around mid-day this rain should taper off to drizzle or light showers then clearing will gradually develop. Winds will become westerly 30-55 mph and highs will be level near current readings of about 18-20 C.

TODAY (western Ireland) will become very windy from the SW to W as the last of the rain departs northeast, then some breaks in the overcast will develop despite the continuing very strong winds (40-60 mph with some higher gusts, and 50-80 mph near the Donegal and Mayo coasts). Highs will reach about 17 C. The southwest could have prolonged morning rain and a gusty thundershower but winds in the afternoon will be less severe, westerly at about 30-50 mph.

Then for TONIGHT (in all regions) the weather will rapidly calm as the strong winds leave for Scotland, and much higher pressure builds in. After midnight there will likely be some dense fog patches developing especially inland and in lower elevations. Lows will reach 6-8 C outside the larger cities but about 10 C on the west coast.

WEDNESDAY will be a pleasant, mainly sunny day once the morning fog or low cloud dissipate. Highs will reach 19 or 20 C and it will be almost calm with just a very light northwest wind.

THURSDAY to SUNDAY is looking quite fabulous compared to much of the past few months; dry, often sunny after morning fog dissipates, and with rather light easterly winds. Expect lows each night to be about 7 or 8 C with some lower readings in the usual "frost hollows" (even a light touch of frost in some northern valleys) but highs should be around 20 or 21 C each day, with very light east winds (moderate breezes near south coast). High cloud may become a frequent part of the weather picture in the south from distant fronts well to the south and west. This pattern seems likely to persist for about a week or ten days and should gradually transform into a warmer southerly type of flow that could still be relatively dry.

Watch for updates on today's active weather.

Wednesday, 9 September, 2009
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I second that motion ... high pressure is building up over Ireland and will hang around through the weekend. The latest guidance stresses that this will be quite a warm high so I expect that dense fog will become an issue the next few nights, especially with the surplus moisture in the ground after weeks of above normal rainfall and high humidity.

TODAY will see any morning fog disappearing rather quickly, and it will eventually warm up to about 18 or 19 C with very light northerly winds but local sea breezes and other variable winds likely to set in.

TONIGHT (and the next several nights) after a clear start many places will see dense fog after midnight, and it may be quite thick by morning, giving near zero visibility in some rural locations. Lows will average about 6 to 8 C but could be even lower in a few spots, although higher in mid-town and coastal locations. Note that this fog situation will redevelop each night until the high breaks down, and some places could be stuck in the fog until 0930 or later.

THURSDAY to about SUNDAY, the high stays put and will act like a magnifying glass making the sunshine feel quite warm or even hot locally, as temperatures rise to around 20 C or perhaps a bit warmer in the western half of the country as a light southeast flow sets in. It will be quite a contrast from the chilly nights to the warm mid-afternoon conditions under this high, but the one thing we need to watch out for would be any persistent low cloud left over from the morning fog. It is early enough in the autumn season that this should not be much of an issue, but sometimes these inversions can combine with a sea-breeze to create a tenacious layer of low cloud or fog, and places like Dublin (Dun Laoghaire in particular) or coastal Wicklow could be at risk for this during the calm spell of weather, so don't be too surprised if the sunshine is not universal across the country. However, these fog banks can also drift around in the light winds and give intermittently misty and sunny conditions too. We get this same phenomenon here in the autumn, and sometimes some very localized fog that just covers the first few blocks inland from the coast.

Eventually, I think this high pressure will sink into western Europe and it will be back to a more mobile Atlantic pattern but not nearly as wet as before, possibly just a few weaker frontal systems that may continue a mostly dry regime although without the foggy, calm nights at that point (probably into middle of next week).

Just a note, my own weather here on Tuesday was hazy sunshine with increasing cloud ahead of an expected heavy rain for Wednesday, so we are now going in opposite directions weather-wise.

Enjoy the fine weather, it has been a long time coming. :cool:

Thursday, 10 September, 2009
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TODAY will become sunny in most places once any fog burns off, then it should be a near-perfect day with light winds and warm afternoon highs of 17 to 20 C.

TONIGHT (and the next several nights) dense fog will redevelop around midnight and become very thick in some rural areas around sunrise. Some other places will get low cloud or mist rather than fog, while others stay clear. Lows will drop to about 5-8 C in rural areas and 10-12 C in warmer places like mid-town and coastal locations. This cycle will continue until about Monday at least.

FRIDAY to SUNDAY, expect very similar conditions to today, possibly a degree or two warmer in some spots, especially in western and central counties as there will be a very light southeast wind flow in southern counties. As I discussed the other day, there is always a slight risk of fog hanging around much of the morning at least in a few locations, and you'll probably know where those are from past experience, either deep valleys or some coastal locations where the sea-breeze can cause fog to hang around. But that will be the exception as most places bask in warm sunshine each day, with highs 18-22 C.

MONDAY to WEDNESDAY it's possible that the high will drift off to the west for a couple of days and promote a light northeasterly flow; this will have the effect of reducing the overnight fog formation, and adding some partly cloudy skies to eastern counties at times, but temperatures will remain about the same or drop a degree or two, to the 17-19 C range. This high is in no hurry to leave the general area and could then be back overhead later in the week for more dry, calm weather, and when it does break down it seems likely that the more mobile westerly systems will be weaker than before and still somewhat on the dry side later this month.

(My weather on Wednesday was cloudy with some rather heavy rain in the morning giving about 25 mms; later on it was dry with temps near 18 C).

UPDATE _ Thursday, 7 p.m.
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I'm sure everyone is enjoying the change in the weather ... the high has built up to about 1041 mbs just to the north of Belfast, which means that tonight's fog potential will be even greater than last night, also some parts of the north and central counties could see some very low overnight readings and a trace of frost in one or two locations can't be ruled out here, probably the lowest screen temperatures will be 2 or 3 C in these locations, but that can lead to a ground frost. Most places will bottom out near 5 or 6 C and if you live in any larger town, 8 to 10 C. This is the kind of weather pattern in which the "urban heat island" effect is maximized (a strong wind being the other extreme where the urban effect is almost removed).

My weather here today is about the same as yours after some rain yesterday moved away overnight, and we have had cloud-free skies all day so far, with 18 C at 1100. Not quite as calm here as this high is weaker and drifting across in a two-day period, so only a few patches of ground fog in rural areas rather than widespread fog during the early morning hours.

Friday, 11 September, 2009
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This is indeed like an Indian summer weather pattern, never too sure how the term is used in the British Isles, but in North America it would technically be a long spell of calm weather like this, but somewhat later in the year, after the first frosts. These are very common patterns in Ontario where I used to live, and made more pleasant by the spectacular colour change usually at its peak during such a spell. October or early November would be the time for these, with the current spell it's more like a delayed summer perhaps. Although it has proven to be quite chilly in most places overnight, I saw a couple of places at 5 C in my look around the reporting stations.

And the basic idea is that the spell may last another week. You have to realize, all of us doing weather forecasts are facing the same problem with this sort of spell, the computer models may show it breaking down eight days from now or whatever, but that has to be taken as a rough estimate in these situations, it could be five days or it could be fifteen -- so the potential errors in long-range parts of these forecasts would be quite large (if the high breaks down earlier than expected, the weather will change much faster).

It looks to me as though this high is not going anywhere very fast, but the weather will vary slightly as it drifts to one side or the other (the high that is). From now to about Sunday the high will be a little closer to Scotland, and this will allow a weak southeast flow across Ireland. This means that it could be as warm as 20 or 21 C away from the south or east coasts each day through the weekend. The nights will stay about the same as last night, extensively clear at first, then with some dense fog patches forming. Lows will tend to be 4-7 C for most places, a bit warmer in the mid-town areas.

So that takes us through to Monday and the first half of next week is looking just very slightly cooler as the high drifts west from Scotland and may get slightly west of Donegal for a day or two. This will place Ireland in a weak northeast flow that won't be quite as toasty warm in the daytime, although still around 17-19 C. The fog situation may ease slightly because of the breeze picking up to 10 mph or so. However there will probably still be some fog.

Then later next week it could be like "deja vu all over again" with the high back overhead for a last stand and a return to weather conditions like today's. Eventually (the models are suggesting about the end of next week) the high will weaken, depart, and it will be back to a more normal southwesterly flow pattern, but even then, the systems may be weakened and it may not rain very much when the fronts do arrive at that point, although the cloud cover will increase back to 50-70 per cent again.

All of this is somewhat speculative because this is a "blocking" pattern and these are notoriously difficult to time and predict end stages, so expect these forecasts to change as the models pick up better signals.

If you've heard about "Fred" in the Cape Verde region, it seems like a non-issue, a storm that is destined to meet a slow death in the "Sargasso Sea" area southwest of the Azores. But we'll keep an eye on it, just in case.

Well, I hope you'll continue to enjoy this fine spell, nice that it comes over a weekend too -- we had a pretty fair day here too, sunny and 21 C, currently clear at 10 p.m., and I just saw the ISS fly over a few minutes ago (got the times from a website which I will post here tomorrow, I think there's a link that you can use for timing satellite appearances in Ireland too.)

Saturday, 12 September, 2009
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Very little has changed since the last forecast, but I will post an update as follows ...

TODAY, once any fog burns off it should be a glorious sunny day in most places with a rather warm feel to the sunshine too, highs could reach 22 C in most favoured locations (inland west) and 18 C just about everywhere, at least. As I was saying days ago, there is always that slight risk of a rogue fog-bank drifting inland somewhere but you could probably walk out of it.

TONIGHT will be back to clear skies, cooling off again well after midnight to lows of about 6 to 9 C mostly, and fog is once again going to become fairly widespread by dawn.

SUNDAY should be just about the same as today, the one thing that may change slightly is that more high cloud (cirrus mostly) will begin to spread across the sky and perhaps dim the sunshine slightly in a few places, but it won't be a big deal, and highs will reach about the same values, 18-22 C.

MONDAY, after a cool clear start with more fog, it should once again become mostly sunny and hazy with highs of about 19 C. A slight northeast wind is going to begin to affect east coast locations especially south of Dublin, but only 10-15 mph.

TUESDAY and WEDNESDAY look about the same as previously advertised, just slightly cooler in a weak northeast flow that will drop the daytime readings to 17-19 C mostly, and perhaps reduce the amount of fog forming overnight, but these will be subtle changes and it will generally seem like the same weather pattern continuing.

THURSDAY, if the models are "bang on" then the ridge returns from the west and cuts off the northeast flow so it should be similar to today again, only with increasing cloud from distant Atlantic fronts that are beginning to break out of their stalled pattern.

FRIDAY will then be a day of possible breakdown of this pattern with cloud and a little rain possible, but as I stressed before, these model timings for blocks to break down are not always very reliable, this could turn into a postponed breakdown event that we keep waiting to see in "real time," or it could on the other hand speed up and show its hand earlier.

I posted some info on the ISS in the previous post and it looks quite interesting for Ireland because you just happen to be under the point where sunlight suddenly stops hitting the space station, and it goes dark while crossing your night sky around 9:50 p.m. See above for more details. I just saw it here but it stayed sunlit, and actually went right overhead on its way past.

No weather update, just a brief report on my weather here today, which has been sunny and very warm, 25 C feels quite hot in the sun ... the usual re-emergence of stunned wasps (and this is not a political commerntary now) who just can't believe their good luck, but can't remember how to fly.

Do you have that problem in Ireland too?

Anyway, a reminder, if you have a few minutes to spare after 9:40 pm, find a dark spot and look to your southwest, you should see the ISS rising towards a high point to your south and according to the website, it is supposed to lose sunlight just at that point (around 9:47 p.m.) and I guess it either disappears or goes very faint at that time. Could be an interesting sight. You'll certainly spot Jupiter rising in the southeast, quite a bright golden colour, the ISS to my eye at least was fairly whitish.

I'd love to hear from anyone who manages to see this fade-out happening, I may get a chance here later on as we also have one scheduled about that time locally.

By the way, on the subject of visible planets, Venus is a bright morning star these days, you would see it in the southeast about two hours before sunrise until daylight fades it out. Mars is also visible in the morning hours, rising before Venus and it would be close to the waning third quarter moon tonight. It might be after 0100 before you'd see these very high above the southeast horizon. Saturn is currently lost to our view in the Sun's glare and is about to move behind the Sun from our perspective later this month. Mercury is sometimes visible too, probably was about two or three weeks ago in the evening (at its brightest it is about like the stars in Orion's belt for visibility) but not at the moment, it's leaving the evening twilight zone of visibility, heading for a pass in front of the Sun on the 20th.

Sunday, 13 September, 2009
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More of the same ... can you stand it? I had to laugh at the dust bowl developing, it's bound to be only a day or two before the "global warming has altered our weather patterns" stories hit the popular press too, as the long dry spell nears day five.

For a forecast, just scroll back to yesterday's effort and that remains valid, a string of warm, sunny days now to possibly Thursday or even Friday before substantial amounts of cloud appear again. There could be higher cloud at times skirting mainly to the south and far north, and a slight increase by mid-week in a weak northeast wind but this is really looking like a marginal change really, it may be noticeable in a few places around the southeast coast in terms of a stronger breeze at mid-day. Highs each day will continue in the current range of 18-22 C and possibly drop off very slightly mid-week.

Nights will remain clear, foggy in many places before sunrise to about 0930 or so, and this will be somewhat of a hazard for driving especially when the sun shines into the fog banks, I always find that difficult around here. Looks as though some light rain could eventually arrive once this spell breaks down in another five or six days time.

I may update this during the day if I see any developments on later runs.

Not that anyone should be inside reading computer screens on a day such as this.

UPDATE _ Sunday, 6:40 p.m.
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Yes, I do remember some wonderful scenery and people from Kerry and elsewhere too, although we were not favoured by such weather except for perhaps one or two days in Galway (which I have come to realize is rather ironic). Well, I just popped by to add this weather update, it seems that a weak push of slightly cooler air is filtering west across England today as the high tends to reposition ever so slightly northwestward, but looking at tomorrow's maps, it seems that this push of cooler air (which is extensively cloud-covered and about 16-17 C) will tend to spread out over a larger area and perhaps lose the slight "edge" that it has so far, in other words, it may turn out to be just a slow increase in cloud cover in the east tomorrow, in part because the wind direction remains southeast until later Monday, so the cloud and slight cooling trend may possibly become more noticeable on Tuesday when the gradient winds become a bit stronger northeasterly. These changes will be more significant in Dublin and other east coast locations than well inland, or western counties. For those regions the warm spell with considerable sunshine returning each day should continue with perhaps only the slightest downturn in temperature. This slight change will also allow the clear nights to cool down even further, which brings a slight risk of ground frost into the equation, more likely in north central valley locations than anywhere else.

Meanwhile, our own sunny and warm spell continues here and it's looking like another high well up into the 20s today as it is 22 C at 1050 local time.