Weather Discussion

Sorry for the lack of updates this month. Here is a brief summary of what has been going on lately.

We finished the month of August about three times wetter than average, with 142.6 mm of rain, compared to the normal of 49.3 mm at the airport.

Meanwhile, September is set to finish about three times DRIER than average, with only 22.2 mm of rain recorded at the airport as of the 25th, and little or no rain expected in the final week of the month. The normal for the entire month is 75.9 mm.

On the morning of September 23rd, the temperature officially dropped to 3.8 C at the airport, and even colder in other areas (down to 2.8 C at this station). I observed frost on the rooftops around my house. While below average, this is neither unusual or record breaking.

I have also completed some work on the station recently, including:

-Calibrated tipping bucket rain gauge using a manual gauge (most accurate). Final rain totals are still taken from the manual gauge.

-Added fan to radiation shield for more accurate temperatures and humidity.

-Replaced some wires and connections, making them more water resistant.

Hopefully all of these efforts will pay off with more accurate and reliable readings this winter.

We dipped to 7.4 C last night, which I believe is the coolest it's been since last spring, but I'd have to check the official lows to confirm that. Temperatures have also been cool during the day, struggling to only about 18 C.

Thankfully, we shouldn't have to worry about frost for another few weeks at the very least. By that time we'll be happy to only get down to 7 C at night.

In the meantime, we'll take a bit of a warming and drying trend, with temperatures by the end of the week approaching normal values once again. In case you've forgotten, that's around 22 C during the day and only down to about 12 C at night.

As if June-uary wasn't enough... it looks like we have a new month to add to the calendar.

While temperatures have not been too bad in August, it has been an abnormally wet month. In fact, as of the 27th we have received over twice the normal amount of rainfall for the entire month - and we're not even done counting.

Interestingly, this month also has the distinction of being the only month so far in 2008 that we've reached or exceeded our average monthly precipitation. Yes, surprisingly, it has been quite a dry year overall; though you might argue that there has been less sunshine than average, possibly diminishing the subjective "dryness".

MesoMap Live allows you to easily view detailed weather data from up to 50 weather stations around the south coast and northwestern Washington. You can view this new feature by locating it in the main menu on the left.

Yesterday we reached 32.6 C, concluding three days with highs above 32 C, officially qualifying as a heat wave in Abbotsford. The first two days broke records, but yesterday came up a couple of degrees short.

Sunday will be warm, but also cloudier, and should stay below 32 C. It will be quite humid though, so any sun that does break out will make it feel quite uncomfortable.

The main story is the threat of thunderstorms. We have isolated weak storms moving through this morning, but a more organized band moving through tonight. Some of these may be severe, with frequent lightning and possibly hail.

The threat of thunderstorms begins to ease on Monday as temperatures cool and we get a more typical pacific air mass moving back in.

A heat wave on the south coast is defined as three consecutive days with the temperature reaching or exceeding 32.0 C.

Abbotsford officially hit 32.1 C on August 14th, just barely breaking the previous record of 32.0 C. The record for August 15th was also broken despite some high cloudiness preventing the temperature from soaring quite as high as expected. Once again, the record was broken by just 0.1 C as we reached 32.9 C, a degree shy of the expected high of 34 C.

Saturday's record high is a more respectable 35.0 C, which will be difficult to beat, but not impossible. The forecast high is once again 34 C.

Temperatures will begin to cool on Saturday night and Sunday with a threat of thunderstorms.

We reached a very warm 33.4 C here today, but a bit lower officially at the airport (still waiting for the official high, but I don't think it's going to be a record). Wednesday will likely be the warmest day this week, possibly reaching 34 or 35 C, which could be a record.

The thermal trough responsible for the hot weather is scheduled to move off to the east Wednesday night, but there is a small chance of thunderstorms Wednesday night and Thursday during the transition period.

Thursday will not be nearly as hot, but it will be humid, so won't feel much different. Temperatures cool dramatically on Friday and Saturday with a chance of showers, but rebound slightly for Sunday, with perhaps more heat next week.

Another frontal system is moving onto the coast Thursday afternoon. This one appears to be a bit wetter than the one that moved through on Tuesday. It's shaping up to be a fairly wet night and start to the month of August, before the rain tapers off to a few showers on Friday morning.

For those keeping track, it looks as though we'll end July with about 25 mm of rain - about half of the normal amount. This continues our streak of months with below average precipitation. We are now running well below average for the year.

Next week is looking dry and pleasantly warm, with temperatures in the upper 20's.

So it's late July, statistically the driest period of the year, with only about a 10-20% chance of rain on any given day. Yet after 20 long days without any rain at all, I guess our good fortunes have to fade sooner or later, so what better a time than when it's least likely?

A weak trough is moving onto the coast Saturday morning, bringing a chance of showers inland later in the day and lingering throughout the remainder of the weekend.

It's still looking pretty clear outside at 9 am Saturday. With some luck, we may escape the showers this weekend, but there is a greater threat of precipitation on Tuesday, and it's looking not like showers, but good old fashioned rain - something that is almost unheard of at this time of the year.

I'm going out on a limb and saying the forecast models are overdoing the rain, and it will end up just being a few isolated showers. We could certainly use the rain, though.

It has been 13 days since any rain fell and there is none expected until at least the middle of next week. Thankfully the temperatures have been near the average of around 24 C, under a pleasant mix of sun and clouds.

At this time of the summer it is not uncommon to have a stretch of hot weather, but there is no indication of that happening in the current forecasts.

Thunderstorms began Wednesday evening and have affected the region almost continuously ever since. Frequent lightning and occasionally heavy rain has been the order of the night.

The stormy conditions will continue on Thursday, with some severe thunderstorms possible during the morning hours.

Plenty of rain fell Wednesday night, but the rain gauge is not picking anything up. This is most likely due to wasps obstructing the inner workings. I've already cleaned out their nests twice this year, but they're persistent.

The recent hot weather has helped us avoid breaking the record for the coldest June. We will end the month averaging just above 14 C, which is still on the cool side, but comfortably far from the record of 13.0 C.

It has also been very dry in the second half of the month. Only 2.1 mm of rain has been recorded in the last 21 days. Lawns are starting to turn their typical shade of summer brown. The month will still end with slightly above normal precipitation due to the wet start.

There is a chance of thunderstorms later Monday afternoon and evening as a slightly cooler airmass invades the region.

While originally expected to be cool and wet, this week has shaped up to be anything but, just in time for summer to begin this afternoon.

If the pattern continues trending warmer it's unlikely we'll break the record for the coldest June. Of course, there is still plenty of time for things to change.

As of the 19th, our running average is 12.4 C. We now only need to gain 0.6 C to avoid breaking the record... and it looks like we'll be able to do that by early next week.

Despite the warmer weather we are still well on our way to the coldest June on record. As of the 15th, the mean temperature for the month is 12.0 C. The record coldest June was 13.0 C in 1952.

We will need to gain an entire degree for this not to be the coldest June, which means that the remaining 15 days need to average at least 14 C. With cooler conditions expected this week and into the weekend, we will need a stretch of warm weather in the final week of the month if we hope to avoid shattering this dismal record.

I made up a graph showing the mean June temperature from 1945-2008. You can see that we came close to breaking the record a few other times, so with any luck we'll warm up enough to avoid it once again.

Graph can be viewed here: June Mean Graph

The graph also shows that our June is 1.7 C warmer now on average than it was in 1945. This is in keeping with the temperature increase we have seen year round due to climate change.

Monday's strong storm knocked out power for several hours in the evening, causing the weather station to go offline. Power was restored around midnight, but I didn't restart the system until later in the morning. All data was recovered without incident.

At one point yesterday, rain was falling at a rate of 55.9 mm an hour (that's over 2 inches). Luckily, the heaviest rain only lasted for about 20 minutes, otherwise we'd have seen flooding in more areas (most of the flooding occurred in White Rock).

Strong winds in the wake of the storm knocked trees onto power lines in several areas. Lightning also knocked out power in a few areas.

The storm also brought unusually cold temperatures. At 10 PM last night, it was only 5.3 C. Snow fell at many locations in the mountains above 1000 meters.

It continues to be cold on Tuesday. As of 1:40 pm, it has only reached 11 C. The normal daytime high for this time of year is about 20 C.

Temperatures are expected to slowly warm to normal by the end of the week.

May has concluded with a mere 57.6 mm of precipitation, compared the normal of 99.1 mm. So far in 2008, every month has been significantly drier than average, with the possible exception of January (169.3 mm compared to the normal of 198.1mm).

On the plus side, our temperature for the month finished above normal, with a mean of 13.2 C, compared to the average of 12.5 C. We can thank a couple of record breaking warm days in what was by and large a normal month temperature-wise.

If May left us wanting rain, it looks like June is set to deliver. We're off to a cold and wet start, and there is no real sign of that pattern breaking any time soon. And if long range forecasts are any indication, this could end up being one of the colder Junes in memory, if not one of the wetter ones, too.

Record high temperatures have been recorded in Abbotsford on both Friday and Saturday.

On Friday, the mercury officially rose to 29.5 C, breaking the previous record of 28.9 C; while on Saturday, it peaked at 30.6 C, breaking the previous record of 30.0 C, set in 1958.

My station recorded slightly higher temperatures on both days, with 30.8 C on Friday and 31.2 C on Saturday.

Vancouver shattered their record on Saturday, with a whopping 28.8 C breaking the previous record of 24.9 C, set back in 1985.

Seattle also broke their record high on Saturday, with a recording of 90 F (32 C) - the earliest in the year they have ever recorded a temperature of 90+ F.

Sunday will be slightly cooler, so it's unlikely we'll break the record of 31.7 C (also set in 1958).

In April no less, and it appears to be sticking. It's certainly not unusual to see a little snow in April, but rarely so late in the month.

The chance of snow has been well advertised over the last few days, but we weren't really expecting any accumulations, at least not until Friday night/Saturday morning, and even then it was a slim chance.

I guess it's more than a chance now, since the snow is sticking outside my house. It's hard to say how widespread any accumulations will be, but I'd expect it to melt quickly in any case.

It's going to be an interesting weekend, with more chances for snow through Saturday night. The expected high on Saturday is only 5 C, which is 20 C colder than it was last Saturday when we hit 25 C.

We may also see freezing temperatures overnight Saturday and Sunday morning, and then again on Sunday night and Monday morning. It might be a good idea to keep an eye on any sensitive plants.

It's been a chilly couple of nights. I think we may have set a few low temperature records, as we hit -3.5 C officially at the airport on Tuesday morning, and -2.6 C Wednesday morning. I believe both were records low minimums for those days. It was a little milder Thursday morning, but still -1.5 C. This would not be unusual for the beginning of January, but it is April after all. We should only be getting down to about 4 C overnight.

On the flip side, at least the afternoons have been more pleasant, though still a couple degrees below average. We've hit about 12 C the last few days, which seems nice compared to what we've grown accustomed to, but it should be about 13-14 C.

Just when our daytime highs were starting to recover, it looks like we'll dip back further below normal this weekend. Showers will become frequent by Sunday, and the threat of wet snow creeps back into the forecast by early next week.

The numbers are in and March was officially 1.1 C cooler than average (at Abbotsford International Airport). This makes up for February being 0.8 C above average. If you look at the average temperatures for November to March, we are about 0.1 C cooler than average this winter.

We received 4.8 cm of snow during the month, which is only slightly above the average of 3.8 cm. Meanwhile, 94.5 mm of rain was recorded. In total, only 99.5 mm of precipitation was recorded, well below the normal of 146.4 mm.

April is looking to continue that dry trend, with no precipitation expected until the weekend. Temperatures should get closer to normal as well.