Archives for March 2010

I was just looking out of my window at a small tree nearby here in Bradley Stoke, festooned with a variety of bird feeders.

A few sparrows come-and-go over 30 minutes, along with blackbirds, magpies and the odd dove. Very few tits, however, and no sign of any finches.

Thankfully, the feeders - installed by a neighbour - are beyond the grasp (if not gaze) of my cats. It's just as well, because the recent weather, let alone any feline intervention, has apparently caused a significant reduction in some species of birds.

The RSPB has released results today from it's Annual Big Garden Birdwatch, undertaken by over half a million people across the country on the 30 and 31 January. Their data indicates a considerable decline in some species, such as long-tailed tits, with the reduction strongly correlated to the very cold winter conditions.

The study emphasises how our efforts to feed garden birds and other widlife during harsh winters are genuinely important. There's another chilly snap underway into the middle of this week, but not sufficiently harsh to cover the feeders on the tree opposite my house with snow and ice. Hopefully, in the fortnight thereafter, the leaves will be starting to appear and a chance of the birds - and us - enjoying a return to spring-like weather will be underway once again.

ROUND 3: MALAYSIAN GP, Sepang, 2-4 April 2010

(This forecast will be regularly updated. This entry: Sun. 4 April, 07:15hrs BST)

NOWCAST UPDATE, Sunday 09:40hrs: No immediate threat of showers - doubtless a relief for certain teams!

NOWCAST UPDATE, Sunday 08:45hrs: As noted below, the distinctly capped look to the clouds was very evident as a backdrop to Martin's gridwalk a moment ago. Bernie Ecclestone suggests rain at 4.15pm but the clouds say otherwise! Dry running for the start; probably the 30mins thereafter and we'll then see how the shower threat increases as the race is underway. It could all change very quickly indeed.

NOWCAST UPDATE, Sunday 08:15hrs: Crucially, there's less potent convection around compared to the same time yesterday; the growth of the cumulus clouds is presently capped aloft, preventing widespread showers for now. However, if this capping breaks-down later (and it probably will), we will see the shower cells tower up very quickly and energetically. But where, exactly? And when? Later in the race looks at risk. It's going to be another situation where watching radar alone is not sufficient insurance against red faces on the pitlane: cloud watching will be equally important.

NOWCAST UPDATE, Sunday 07:15hrs: Well, the day has followed a familiar pattern thus-far: a very hot, sultry, dry morning in Sepang. Latest forecast expecations continue much as previously advertised, with showers expected to tower-up through the late afternoon before turning thundery in places and organising into bands parallel to the west coast. The influences of topography and low-level convergence will again tend to preferentially form shower cells east of the circuit, before these move west in the prevailing light winds. Risk of wet weather at some stage of the race is around 70%. As we saw yesterday, this could be realised even before the lights go out at 4pm local time...

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NOWCAST UPDATE, Saturday 09:55hrs: These conditions are exactly as I expect by this time tomorrow, too. No real surprises. I'm amazed that some teams followed the radar so slavishly as to assume a dry window earlier in Q1. In these developmental situations, it was always very likely that the cells would rapidly evolve into thunderstorms. As any storm chaser will attest, a clear slot evident on the radar in this type of set-up doesn't equate to a guarantee of dry weather... far more cloud-watching is required, me thinks, rather than myopically watching the radar feed!

NOWCAST UPDATE, Saturday 09:28hrs: Further heavy showers imminent.

NOWCAST UPDATE, Saturday 08:50hrs: And as expected... the first sign of showers duly arrives over the pitlane.

NOWCAST UPDATE, Saturday 08:45hrs: Towering cumulus around the circuit now; showers look imminent and it's all about exactly where they start to deliver rain. In this rapidly-developing situation, a few hundred metres makes the difference between a wash-out or staying dry!

NOWCAST UPDATE, Saturday 08:10hrs: No significant change to the original forecast - showers expected to edge ever closer towards the qualifying hour and so it'll prove a nail-biter for the teams (and us!). Worth adding a clarification from my colleague Sarah Holt, in Sepang: "We understand the rules of rain to be as follows. If it comes down at 1600 local time (0800 BST) to delay qualifying, then there is a three-hour window to get the job done. If it's not safe to get out on track in that time then qualifying will be held on Sunday morning. If the first qualifying session opens but no times are set then the teams will also come back on Sunday. If times are set from Q1 onwards, but the weather prevents the third session taking place, then those times will dictate how the grid will be formed for the race."

NOWCAST UPDATE, Saturday 07:00hrs: So, some close calls as showers passed by the circuit during P3 but will Sepang evade them in qualifying?

NOWCAST UPDATE, Saturday 06:30hrs: McLaren suggesting showers imminent. A tricky aspect for all the teams at this stage of the afternoon is how rainfall radar can be misinterpreted. The growing convective cells can often seem suggestive of rain on the radar, whereas in reality no precipitation is actually reaching the ground...yet. But we're now at a tipping point, weatherwise, where the showers will increasingly become a reality.

NOWCAST UPDATE, Saturday 06:10hrs: The first showers are starting to appear on rainfall radar near the circuit. A growing prospect now of some interruption from wet weather... depending on the precise trajectory of the slow-moving shower cells.

NOWCAST UPDATE, Saturday 05:55hrs: A very hot day has been developing at Sepang and we've got the risk of heavy showers developing through the afternoon now. The Cumulus clouds are already starting to readily tower-up near the circuit but for now it's dry and should stay that way for at least part (if not all) of P3. Air temp. 31C; track temp. 46C.

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NOWCAST UPDATE, Friday 09:30hrs: P2 escaped the showers, but they were visibly building east of the circuit by the end of the session as the outflow winds from these cells began blowing the palm fronds about. Rain has duly arrived across Sepang just after 4pm local time... and clearly, a repeat performance of this during tomorrow's qualifying could really throw a major variable into the eventual pecking order. We shall see!

Rainfall radar at 3.40pm local time on Friday (TOP) shows heavy showers starting to form just east of Sepang Circuit (red dot) and moving west. Just after 4pm, rain started falling across the track. By 4.40pm (BOTTOM), the shower and thunderstorm cells were become organised as a line, orientated and forced by sea breeze low-level convergence and threatening further torrential downpours into Sepang. Could Saturday see a repeat as qualifying gets underway? (Image: Courtesy Malaysian Meteorological Department)

NOWCAST UPDATE, Friday 06:35hrs: Showers are forming east of the circuit inland, some looking quite lively on rainfall radar. Sepang at risk of some into P2; they've already seen one over the circuit as my colleague Sarah Holt can attest! Track temperature has reached over 50C... tyre degradation could prove very interesting to monitor.

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So, what a difference a bit of rain makes.

As Andrew Benson blogs here, the Australian Grand Prix served as a timely reminder that Formula One can still deliver a highly entertaining and unpredictable spectacle, not least after the processional race witnessed in Bahrain.

Throw a sprinkling of wet weather into the mix and anything can happen in Formula One, "...and usually does," as Murray Walker would say.

Off next to steamy Malaysia, where the risk of further spells of wet weather, this time in the shape of heavy showers and thunderstorms, is almost omnipresent.

Climate & Local Weather

And guess what? April is the wettest month of the year... albeit not at Sepang itself!

On average, the capital Kuala Lumpur - just north of Sepang - sees 279mm (11 inches) of rain falling during April, with temperatures typically close to 30C and humidity usually around 70-80%. The regional rainfall pattern throughout the year in this equatorial climate is very variable across Malaysia, with distinct drier (inter-monsoon) periods coupled to much wetter months. In the southwestern coastal districts of Peninsular Malaysia - including Sepang - the daily weather at this time of the year tends to follow a broadly similar pattern, but local affects of topography, prevailing sea breezes, urban 'heat islands' and other factors can greatly influence rainfall distribution.

At the Sepang Circuit, March typically yields 154mm of rain, but April only 98mm. Both months see an average of 15-16 rainy days (data supplied by Malaysian Meteorological Department). The wettest months there are typically October, November and December.

Mornings at this time of year are typically dry, partly sunny affairs. The temperature - which remains noticeably high and oppressive even overnight - then peaks into the mid to late afternoon, aided in part by insolation. This thermodynamic forcing, combined with generally light winds and a sea breeze convergence zone offering additional lifting mechanism; high humidity and deep instability aloft in the atmosphere, is a recipe for rapid thunderstorm development and these can prove slow-moving once formed.

Typically, the storm cells initially form into the late afternoon and evening - east of the circuit, in the convergence zone - and then migrate westwards, steered by the prevailing gradient winds aloft. A variation of this, where an organised, vigorous line of storms develops through convergence over the Straits of Malacca and then moves east to affect southern Peninsular Malaysia, is known locally as a Sumatra Squall. 

We saw the dramatic results of diurnal / sea breeze convergence thunderstorms during the 2009 race, which was ultimately red-flagged as lightning struck repeatedly around the circuit and a downpour of biblical proportions started drenching the track and pitlane by lap 31.

Red flags bring the drenched Malaysian Grand Prix to a premature finish in April 2009. Organisers will hope that with a 4pm local start (9am BST) this year, thunderstorms remain at bay for a while longer...

Weather at previous races

The history of this event is, for the most part, actually one of dry races - despite running in three different months.

The inaugural F1 race at Sepang was in October 1999. It was dry. Ditto 2000. In 2001, it was moved forward to March - with a heavy shower affecting the race - and it remained a March event through to 2006, with dry running largely prevailing during this time (2004 was an exception, in part).

In the 2007 calendar, the Malaysian GP shifted to April, with showers a constant looming threat during practice and qualifying sessions, albeit they didn't materialise during the race. The following year - with the race moved back into March - it remained dry. 

The return to April in the 2009 season brought the torrential rain and utter chaos noted earlier. At the time, with the race finishing so prematurely on lap 33, there was considerable criticism of the 5pm local start time (to suit European TV audiences) when storms were likely to be very prevalent. But Bernie Ecclestone's response was typically bullish:

"No, I just have regrets about the rain," he said. "I don't see anything wrong with the start time, we just didn't know about the rain." 

Well, forewarned is forearmed. And this time, the race starts an hour earlier - but will that prevent the risk of a repeat performance? Don't count on it... 

Sepang weather prospects for 2010...

The precise forecast detail for each period of track action in Sepang will prove impossible to pinpoint until very near to the time, because of the localised nature of shower and thunderstorm development. For that very reason, it would be a forecasting folly to even attempt this a few days ahead - and I won't try to! The rapid storm development means teams need to be sky-watching and ready to change strategy extremely quickly - as Steve Nielsen, Renault's sporting director, stresses:

"There's a good chance of heavy rain showers, which may only last for a few seconds, but completely soak the circuit."

Indeed so. However, by definition, there's a higher statistical chance of dry running during any one session rather than wet, so in the comments below I've emphasised the broad % risk of showers.

I do stress it'll be very much a nowcasting situation - something the teams will be very acutely aware of in their preparations and assimilation of weather predictions. Vice-President of Mercedes-Benz Motorsport, Norbert Haug, sums up the Sepang scenario thus:

"As usual for this race, we have to expect extremely hot and humid conditions, usually accompanied by torrential rain showers every now and then - a race in sauna conditions, virtually. This climate is the greatest challenge for the teams, cars and drivers."

Surface observations around Sepang reported at 0900hrs GMT (5pm local) on Wed. 31 March illustrate the weather lottery posed for qualifying and the race. Had this been Sunday, the race would have been running an hour by this stage. Moderately heavy thunderstorms and 27C are being reported at nearby Kuala Lumpur, whilst it remains dry and hazy further south in Malacca. An hour earlier, showers were already falling around Kuala Lumpur, which had reached a sizzling 33C. 

Note that the Lifted Index values (combined with CAPE) from coarser-scale forecast modelling across Peninsular Malaysia offer a latent risk of thunderstorms across almost every session but as you'd expect, this is most pronounced into the late afternoon when some storms could turn very lively indeed. Radars at the ready, then...

Here's the early forecast essentials:

FRIDAY:Should be effectively dry running.

Practice 1 gets underway at 10am local time. Hot & sultry, as temperatures reach 30C with light winds, predominantly easterly. Latest modelling suggests dry, partly sunny weather should prevail, with a low chance of scattered showers even at this stage (20%). By Practice 2 (2pm local time), there's again a good chance of dry running for the teams, but a somewhat higher prospect of showers or thunderstorms looming (40%) as temperatures peak around 33C. Winds remain light. Latest meteograms for nearby Kuala Lumpur continue to suggest Friday could ultimately prove the wettest 24-hr period of the weekend, but it's very likely the heaviest downpours will gather only after the track action finishes and then develop into the evening.

SATURDAY:A growing risk of thundery downpours developing by and during qualifying.

Overnight spells of heavy rain from thunderstorms are likely, leaving the circuit 'green' once again. By the time of Practice 3 (1pm local time), largely cloudy weather will prevail with a 50% chance of showers; surface pressure about 1010mB and temperatures around 32C. By Qualifying (4pm local time), the risk of local showers is rising (and has been enhanced in latest modelling) to around 60% and effectively increases throughout the hour (something the teams will be monitoring closely towards Q3!); winds remain light easterly and typically <5kts (unless actually in the vicinity of any storm cells, where they'll be noticeably gusty and variable) and humidity up above 90%. Very uncomfortable sitting snugly in a cockpit wearing racing overalls, for sure. The modelled rainfall accumulation signal for Saturday is 'noisy' - as expected for this location - but somewhat less enhanced, compared to Friday. 

SUNDAY: Risk of thundery downpours during the race, most especially after mid-distance.

The previous evening's showers have likely 'washed' the circuit once again. A minority of models keep any (decaying) nocturnal shower activity alive cross coastal parts of western Peninsular Malaysia even until about 0800hrs local time. The morning then looks dry, continuing in similar fashion into the early to mid afternoon. The race gets underway at 4pm local time and critically, some models (plus recent persistence forecasting) offer a risk of isolated downpours even by the start. Thereafter, the risk of shower or thunderstorm development continues to gather pace over the next 2 hours and as on each day of this event, the 'devil will be in the local detail'. Again, the broader cumulative rainfall signal is less pronounced than Friday but similar to Saturday. The risk of wet weather is around 45% at the start of the race, rising to 65% by the end; winds remain light east to east-southeasterly; humidity about 90% and temperatures around 30C.

Note: Due to ongoing upgrade work with national rainfall radar network (also in Singapore), updates to the Malaysian Meteorological Department's real-time radar feed on their website are currently intermittent. They tell me efforts are ongoing to resolve any disruption to this service.

Last week's double-figure temperatures will be in stark contrast to a decidely chilly feel developing by Wednesday - indeed, some more northerly areas of the British Isles could see some significant snowfall before midweek.

It's a decidely unsettled flavour to our weather through the next 7 days or so, with frequent spells of rain, showers and quite windy conditions at times.

Billows of snowflakes fall from showers above South Gloucestershire in February. It's not impossible some areas of the West Country will see fleeting glimpses of this again by Wedneday...

Wet weather will arrive into the West Country later tonight and tomorrow (Monday) morning; spread quickly north and east; and from then onwards, the working week has the term 'inclement' stamped all over it.

Into Tuesday and Wednesday, as an area of low pressure passes northeastwards over England, we'll find the prevailing flow turns progressively from the north. It'll knock temperatures back by quite some margin and introduce a reminder - albeit temporary - of some weather more akin to winter.

The cumulative result across parts of Wales, northern England (North Pennines especially), S. Scotland and perhaps Northern Ireland is expected to be a mixture of heavy rain - possibly exceeding 60-75mm in some areas - plus disruptive snow, especially but not exclusively over higher ground. The Met Office has issued a set of advisories to cater for this outcome.

Here in the West Country, it'll be feeling pretty cold by Wednesday. Daytime temperatures in parts of Gloucestershire, for example, might struggle to exceed 5 or 6C and with the added factors of cloud cover, breeze and rain, it'll be a case of reaching once again for those winter coats only recently tucked-away at the very back of coathooks! 

It's also not impossible we could see something of a wintry element to the precipitation in parts of our region, at least over higher ground, later on Tuesday and into Wednesday as the colder northerly air digs-in across all of the country. Brrrrr....

But it should prove a fleeting glimpse of any white stuff: by the end of the week, albeit still a tad chilly, temperatures should be returning closer to the norm . The weekend looks wet and windy and so realistically, the barbecues can remain firmly locked-away in garden sheds - at least for the time being for the time being. 

If you are after some spring-like weather, there's a hint at drier, brighter and milder spells for parts of the south from next week and into the 10 to 15 day period ahead. Fingers-crossed!

Meanwhile however, the consensus signal from all the forecast models is for quite the opposite!

(NB: THIS FORECAST WILL BE PERIODICALLY UPDATED.)

CLOSING REMARKS: What a race! The early rain certainly made all the difference - plus some fantastic track action all-round. Well done Jenson; let's see what Malaysia brings - early indications offer a threat of wet weather emerging again as a factor...

NOWCAST UPDATE, SUN. 07:10HRS BST: I expect it to turn dry for a while now... tricky stuff!!

NOWCAST UPDATE, SUN. 06:15HRS BST: Further showery outbreaks of rain likely across the circuit in the next 45mins.

NOWCAST UPDATE: SUN. 05:30HRS BST: The Met Office's model got it spot-on in terms of timing: some rain has already fallen across Albert Park ahead of the race starting, but it'll now prove quite knife-edge in terms of how much affects the race itself. Patchy outbreaks of drizzle and light rain are quite extensive to the NW, feeding towards Melbourne, albeit as expected the heavier pulses are crossing away to the southwest. Intermittently damp weather looks decidely likely for Albert Park, but any such conditions (assuming rain doesn't become persistent) should quite readily dry off the circuit given the breeze and temperature. Wind currently northerly, about 13mph, gusting to 25mph.

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This is a 'new style' approach to the weather forecasts I've previously provided on the BBC's 606 Forum, alongside our live online, radio and TV coverage of all the action during each Formula One race weekend.

The 2nd race of the 2010 season - the Australian Grand Prix - takes place at Albert Park, Melbourne, this coming weekend and I'll keep you updated here on the developing weather prospects.

Dry running is pictured here at Melbourne, but will this year's event escape the rain entirely? (Photo: William West/Getty Images)

Unlike the dry, almost cloudless conditions experienced a fortnight ago in Bahrain, there's a chance of some rain falling periodically in Melbourne to add additional on-track uncertainty through the coming weekend. And don't underestimate the wind: this could prove quite an issue later on Sunday!! 

Since I first opened this blog entry, it's been noteworthy how the essential forecast theme has changed very little - irrespective of whatever meteorological model is followed. This continuity provides high confidence in the broad thrust of the Melbourne forecast, albeit the local detail will inevitably now prove more of a 'nowcast' issue.

And with this in mind, you can keep an eye on the local rainfall radar (as the teams surely will!) through this link. 

So, here's the current forecast thinking:

The UK Met Office's Global Model, above, hints at the expected proximity & generally light intensity of rain during the Australian Grand Prix (which starts at 5pm local time). Other forecast models offer a broadly similar solution.

SUNDAY FORECAST:

Summary & model assessment: Light to moderate rain highly likely during the race. Turning quite windy. Overcast but very warm.

Unsettled conditions are spreading eastwards as an area of low pressure (circa 1000 mB) moves across the Great Australian Bight towards Tasmania, swinging a trough and a band of rain, some heavy, into coastal districts of South Australia and then across parts of SW Victoria.

The various forecast models we employ (UK Met Office's Global Model; USA's GFS; plus the Australian Bureau of Meteorology's own prediction) all offer agreement on the evolution and provide improving continuity regarding the timing of rainfall progression into Melbourne. 

Precipitation & cloud cover: Some showery outbreaks of light rain have crossed Melbourne overnight and it's likely the circuit will prove rather 'green' again by dawn. 

It'll be an overcast race with cloud cover becoming quite extensive well before the race start at 5pm local time. The probability of light to moderate rain affecting the event, more especially post-6pm local time, is now considered high.

The Met Office's Global Model suggests the rain could arrive patchily (as drizzle or generally light intensity) even by the start of the race. This could increase a little in intensity later, albeit peak rainfall rates are unlikely to ever exceed 3-5mm per hour.

The US-GFS model, running at similar resolution, has flip-flopped repeatedly in recent runs between offering light rain above Melbourne by the race start, or holding it out west until later. The latest (1200 GMT) output reverts back to the slightly slower solution, with light rain arriving towards the end of the event.

The Australian Bureau of Meteorology's prediction, combining the output of 9 national and international models, further supports the notion of any rainfall being light in nature. 

So broadly, the UKMO, GFS and other models offer comparable forecasts in terms of both the high likelihood of some damp weather arriving into Melbourne districts at some stage during the race (if not actually by 5pm local) and the generally light to moderate intensity of any precipitation once in-situ. So it's now a nowcast issue....

Temperature: With the prevailing flow off the hot continental interior, it will become very warm at around 29-31C mid-afternoon. Ambient temperature during the race likely to be 28-29C.

Wind: Could be key factor, in my opinion. It will turn noticeably breezy during the afternoon, with the north to northeasterly wind gusting 25+mph at times and possibly over 30mph periodically by the start of (and during) the race. The Met Office modelling suggests a prevailing NNE wind averaging from 10-15mph. 

It will offer a headwind component on the pit straight; a tricky, gusty crosswind in some of the other sections not well sheltered by the trees and perhaps critically, a noticeable tailwind element through the back of the circuit from turns 10-13. Local funnelling effects of the wind through the adjacent urban areas and down the walled sections of the circuit such as from turns 10 to 11 could be quite an issue, affecting braking stability into the (ever-tricky) high speed left-right switch at 11-12; ditto into the quite fast right-hander at turn 13. 

All the latest forecast model runs continue to hold any threat of heavy rain W/SW of Melbourne until later into the evening. However, even intermittent light rain will add a real lottery to proceedings, as emphasised by Hirohide Hamashima, Bridgestone's director of motorsport tyre development:

"If there is rain before tomorrow's race we will face quite a difficult track, and those starting on the soft tyre will have the concern of graining on the left tyres, either front, rear, or both depending on the car and set-up. If a driver can protect their tyres then a one stop strategy should be possible...The soft tyre is around 0.5 seconds faster for its fastest lap than the harder tyre, but we really don't have sufficient data to know how long it will last here. This, and the variable of the Melbourne weather, will be the biggest unknowns for tomorrow's race." 

I do urge keeping a close eye on the rainfall radar (here's an alternative version, if you so prefer) - this will offer a real-time answer as to whether it'll rain by race start (and save me trying to type innumerable updates; I'll find it tricky due to mounting excitement / stress level as the race unfolds!)

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(Previous forecasts:)

NOWCAST UPDATE, FRIDAY 0606GMT: The current shower will soon fade - some running likely again soon thereafter, assuming the track dries speedily. But more showers still likely in the next 30mins.

NOWCAST UPDATE, FRIDAY, 0555GMT: The first shower duly arrived and more look likely before the end of this session. Signs of moderate intensification of these shower cells on rainfall radar... doubtless the teams well aware that they need to take full advantage of the current dry window.

NOWCAST UPDATE, FRIDAY, 0500GMT: Light to moderate showers crossing eastwards, as now seen on rainfall radar, look likely to affect the Melbourne district towards 2nd Practice. Currently the heavier (and in places thundery) showers are remaining well south of the city.

FORECAST: An area of high pressure slowly eases eastwards from southeastern Australia, with another established out west across the Great Australian Bight. An ever-weakening cold front will sit between the two anticyclones during Friday, arcing northwards above Tasmania but quickly losing intensity in-situ.

Dry weather should thus dominate during both practice sessions, with a small chance of isolated showers appearing as the day develops. Most of these should be light in nature, but there's sufficient instability aloft to offer a scattered sharper (possibly even thundery) shower. It'll prove a hit-and-miss situation, more especially into 2nd practice. So worth watching the rainfall radar link I provided earlier in this blog... 

Increasingly cloudy skies will be above Albert Park during the afternoon as temperatures reach about 25-27C. Winds will shift from N/NW around to SW by midday; a tad breezy, averaging approx. 10-15mph but closer to 15-20mph by midday.

The combination of ambient / track temperature plus a moderate breeze will readily clear any dampness that might arise from light showers, so on current forecast expectations I expect nothing other than slick tyres being employed during both sessions unless the circuit catches an isolated heavier downpour. Unlikely, but possible!

(NB: REGULAR UPDATES WILL BE MADE TO THIS FORECAST)

I'm usually busy providing the weather forecasts on the BBC's 606 Forum ahead of each F1 Grand Prix, but now my attention shifts to racing of a four-legged kind.

The Cheltenham National Hunt Festival runs this week from Tuesday to Friday, with over 200,000 spectators expected to attend. So, how's the weather shaping-up for those visiting - and competing in - this year's meeting?

Much as captured in this photo from the 2009 Ryanair Chase, grey skies will again prevail at Cheltenham but not all the time! (Photo: Julian Finney/Getty Images)

It'll certainly be mild throughout the event - a consistent theme for the weather this week. Spring-like dry and fine conditions will prevail at start the Festival and the risk of any significant wet weather during most races has lessened, based on the very latest forecast modelling.

So, here's some forecast detail...

TODAY: FRIDAY 19 MARCH (Cheltenham Gold Cup Day): It's a dry, mild (about 7C) and partly cloudy start, with rather misty visibilities around parts of the Cotswolds in the early morning - a legacy of Thursday evening's rain. The light southwesterly winds continue. 

Sunny spells will develop during the morning and - after a good deal of dry, settled but increasingly overcast weather - further rain is expected to arrive towards the mid afternoon.

The Gold Cup's wet-or-dry fortunes will very much hang in the balance! The main band of rain is expected to arrive into Prestbury Park around 3pm but it's highly likely some drizzle and outbreaks of patchy light rain could appear before then. So it'll likely prove touch and go as to how wet the course will have become by 3.20pm, as the race gets underway! 

Winds will be light to moderate SSW, gusting around 15-20mph by 3pm. It's a mild prospect once again even under the cloud cover, as maximum temperatures settle around 12-13C.

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(Earlier race day forecast details follow:)

THURSDAY 18 MARCH (Ladies' Day): Dry and mild in the early morning and despite a good deal of high and medium-level cloud, some hazy bright spells will greet spectators arriving at Prestbury Park. It will become the breeziest day of the Festival - so ladies, pin-down those hats! However, with gusts probably only to around 30mph or so by afternoon, the wind strength will not prove especially troublesome for the course officials or the riders. 

Dry, mild & increasingly breezy weather is expected during all of the morning and early afternoon. Always a lot of cloud around, but some brighter spells at times until midday.

A band of rain will arrive from the west into the afternoon and early evening period, perhaps preceded by a few showery outbreaks of light rain earlier in the afternoon as the cloud tends to thicken-up. Despite some moderately heavier bursts later in the day, the total rainfall accumulation should not trouble Prestbury Park ahead of Friday - perhaps amounting to between 1 to 5mm, tops. Current forecast predictions suggest the main band of rain will appear towards 4pm and - ever-weakening after dark - clear around 10pm, leaving mostly dry, mild but very cloudy / murky weather overnight, with some localised mist and hill fog.

It'll certainly prove another noticeably mild day, as temperatures again reach a positively balmy 13 to 15C into the early afternoon.

WEDNESDAY 17 MARCH (St. Patrick's Day): A milder start this time and the moderate SW breeze is just a little more noticeable compared to yesterday. A lot of cloud around in the early morning, potentially thick enough to give one or two spots of drizzle as a weakening front crosses eastwards, but this very readily fizzles-out and it's looking decent enough thereafter through the rest of the day.

With the unlikely exception of one or two spots of light rain, once again dry weather will prevail today. There'll generally be a lot more cloud compared to Tuesday, but some bright or sunny spells will start to appear later this morning and into the afternoon. The breeze will ease even further through the day, with gusts no higher than 15mph - so winds are again not a feature of concern. It'll again feel pleasantly mild, even with any cloud cover, as temperatures reach around 14C. 

Later through the evening and overnight, much of the low-level cloud clears and it will remain dry. It's unlikely temperatures will fall sufficiently for even a touch of grass frost and indeed quite the opposite is forecast as minima hold up at about 3 to 5C...

Much of this week has brought some quite glorious weather for our region and there's more to come into the weekend and beyond.

With a sizeable area of high pressure locked - for now at least - in-situ to the NW of the British Isles, the prospect of any precipitation here in the West Country remains firmly surpressed for quite a number of days ahead. The settled conditions will allow some very muddy lawns, footpaths and parks a chance to dry out somewhat!

Albeit cloud cover will tend to come and go, there'll be plenty of March sunshine on offer over the coming days and indeed today's readily-clearing weather has been wonderfully picked-out in a pass by the METOP satellite at a fairly low level orbit this morning - as shown below in an image taken at 10.19am (photo courtesy of EUMETSAT).

If you've been out and about, you'll have noticed the keen, chilly and rather gusty breeze blowing from the E/NE and this will remain a (rather unwelcome, for most folk!) feature of our weather into next week, too. Nonethless, as I emphasised in our TV and radio forecasts this morning, if you find somewhere sheltered from the breeze and soak-up the early March sunshine, it'll feel distinctly springlike!

My cats certainly agree... they're currently sprawled over parts of the back garden, basking like a pride of lions (the youngest is shown, right - it's her first-ever spring).

The snow threat is gone for the West Country and potentially it's vanished now until next winter. On current reckoning - albeit with many uncertainties at present - the Met Office predicts the dry, settled but chilly weather to prevail until the following weekend (13/14th).

A change to more unsettled cyclonic conditions is likely at some stage around the 15-17th. As this occurs, a westerly influence is expected to take over - thus returning temperatures to the average for this time of year. So, as we eventually lose the current cold easterly flow, hopefully the long, noteworthy winter of 2009-2010 finally takes a bow... at least for southern parts of the British Isles.