Environment Canada To Close Kelowna Upper Air Station ↦

CBC reports on ECCC’s upcoming closure of the Kelowna upper-air station:

ECCC is shutting down the Upper Air station at the end of June because, with the parking lot expansion, it will no longer be safe for technicians to launch weather balloons from outside the station.

A spokesperson says the agency knew in October 2015 that UBC Okanagan was planning to expand its parking lot but it only found out a week ago the project was going ahead.

Upper-air stations, of which there are 31 across Canada, are locations where a compact set of instrumentation is attached to a large balloon and launched into the atmosphere. The instrumentation measures temperature, dew point1, wind direction and speed, and pressure. These measurements are combined to create a graph called a sounding and gives weather forecasters an understanding of how the atmosphere changes in the vertical.

These measurements are also crucial in supplying accurate data for weather models to ingest and use for their forecast production.

An example of a sounding graph created from data obtained by a morning launch from the upper air site in Stony Plain, AB.

The loss of the Kelowna sounding site will have a direct impact on the ability to forecast weather in the region, as well as likely contributing to a small degradation in the quality of weather models.

There is a quote in the CBC article that should be pointed out as wrong:

The data collected at the Kelowna Upper Air Station is not essential for local weather forecasting, according to ECCC, but the station is an important source of information for weather models.

In the world of weather forecasting, real data is the single most valuable resource. Forecasters have more weather models spitting out forecasts than they can reasonably assess2 but models can only be so accurate. Real data, while significantly less in quantity, is the real deal and crucial for many forms of weather forecasting. The soundings generated from these upper air sites are actively used by meteorologists to help them forecast weather such as: thunderstorms and thunderstorm severity, freezing rain, snowfall intensity, blizzards3, and drizzle/freezing drizzle.

The measurements taken by upper air stations provide crucial information used meteorologists for improving the accuracy of severe summer weather forecasting.

Here at A Weather Moment, we’ll use whatever real soundings we determine could be representative of what the weather here will be like4 before resorting to using model-generated soundings. They are a very important piece in the puzzle of weather forecasting.

Lastly, I think one of the questions that needs to be raised is what value ECCC assigns to upper air data. The CBC article states that they’ve known of the plans for 2 years already, but in the meantime have developed no plan for what to do about it. It seems like that would be ample time to create a plan for relocation in case it was needed, but the article paints a picture that shows an unprepared organization that has to close the site while they figure out what to do. The situation as presented seems to suggest that ECCC has devalued upper air data, which would be of deep concern to me.

Over the past winter, I decided to keep an eye on how well the models handled the forecast of major storm systems at two points:

  1. Before they make landfall and are contained entirely in the Pacific with no upper-air stations able to launch balloons to sample them.
  2. Once they make landfall and are sampled by upper air sites.

I was interested in the results as the general trend in the modelling community has been to rely more and more on remote sensing; data that is generated not by being directly measured, but derived by running direct measurements through mathematical equations to calculate them. This is used often with satellite data. The idea is attractive: we have satellites that are looking at everywhere, so we could get these values everywhere instead of just where we have upper air stations. It seems perfect.

Unfortunately, the reality is that for many of the elements important for weather forecasting, the accuracy of remote sensing is simply not good enough yet. In The academic community, there has been a search for a replacement for sending up balloons for several years now that has led them through technologies such as LIDARS and WV-DIAL, but the accuracy has yet to reach a point where they can be relied on as replacements.

Technician Afeworki Mekonnen about to launch a weather balloon from the Upper Air weather station in Kelowna, B.C. Credit: CBC News/Afeworki Mekonnen

In my qualitative assessment of model performance over the winter, I found that before these storm systems reached land, model forecasts were highly variable and there tended to be little agreement between different models. Once they reached the west coast, however, and began being sampled by actual upper air stations, the models quickly trended towards similar solutions, with greater consistency in the forecast from run to run. Given the wide variety of storms that I kept track of through the winter that spanned a wide range of intensities and speeds, I don’t think that the improvement in forecast skill is simply a correlation. I’m willing to say that upper air stations make forecasts better, both those generated by weather models and those improved on by meteorologists.

But it doesn’t end there. Also mentioned on Saturday via Twitter:

I can only hope that the short-term closure at Iqaluit is not a further indication on a devaluation of upper air data. The quality of remotely-sensed data will continue to gradually improve, but it still can’t match the quality provided by balloon launches at upper air stations. If Canada is serious about improving the quality of the weather forecasts it offers Canadians, it needs to be serious about improving the density of its upper air stations across the country.

  1. The dew point is a measure of how much water the air contains. 
  2. Off the top of my head: RDPS, GDPS, REPS, GEPS, NAM, 3km NAM, RAP, HRRR, HRRRX, GFS, ECMWF, CFS, ECMWF… 
  3. Both of the heavy snow and wind variety as well as the more common “clear sky” blizzards produced by strong winds in much of the eastern Arctic and portions of the eastern Prairies. Clear sky blizzards are fairly common in the Red River Valley. 
  4. The closest upper air stations to Winnipeg are in International Falls (MN), Bismarck (ND), and The Pas (MB). 

Missing: Summer

Decidedly un-summer-like weather lies ahead for Winnipeg as an outbreak of cooler air from the north entrenches the Red River Valley in below-seasonal temperatures under cloudy skies.

Daytime highs will be nearly 10°C below seasonal for late June today and tomorrow as Winnipeg sits under the influence of a large cold trough slowly rotating across Manitoba.

Today, Winnipeg will see highs struggle to reach just 14°C with breezy northwesterly winds at 30 gusting 50 km/h. The cool and windy weather will be accompanied by cloudy skies, making for a bit of a lousy end to the work week. While no significant rain is expected, there’s a small chance of some scattered light showers through the day.

Temperatures will dip down to a low near 9°C tonight with winds continuing at 20-30 km/h. A more organized band of showers will slump southwards into the Red River Valley early- to mid-evening and then persist for much of the night. Amounts will be relatively light, however, with just 2-5mm expected in the valley.1

2-5mm of rain is expected in the Red River Valley on Friday night into Saturday morning.
Saturday will bring more cloudy skies as the showers taper off in the morning. There may be another light sprinkle or two through the day afterwards, but it should remain fairly dry. Temperatures won’t improve much compared to Friday; highs are only expected to reach around 16°C with winds strengthening back to 30 gusting 50 km/h. Skies will being to clear late Saturday into Saturday night as temperatures head to a low near 8°C.

Sunday will bring some sunshine back to Winnipeg, particularly in the morning. For the afternoon, we expect more cloud to build back into the region with a chance of some afternoon/early evening showers. Temperatures will be warmer with highs reaching about 20°C and the winds will be lighter, at around 20 km/h. Expect clear skies on Sunday night with a low near 10°C.

Long Range

More seasonal warmth returns for Monday & Tuesday, but then it appears things turn unsettled again mid-week and then below-normal temperatures spread southwards again for the end of the week.

Winnipeg’s seasonal daytime high is currently 24°C while the seasonal overnight low is 12°C.

  1. Higher amounts closer to 10mm will be possible if any locally heavier showers develop.

A Return to Unsettled Weather

After an all-too-brief respite from the wet conditions of the past week, more chances for rain are on the way as a series of disturbances move through southern Manitoba.

The rain train is heading back to Winnipeg Station today as an occluding frontal wave moves across the southern portion of the province ahead of a deepening low pressure system. As the wave approaches this morning, mostly cloudy skies will be in place and there is a chance that some morning showers will materialize.1 The main action — a mix of showers and thunderstorms — will begin developing near midday over southwestern Manitoba and then quickly expand and move eastwards into the Red River Valley for the afternoon. These will move out of the region by the early evening.

Severe thunderstorms are not expected over a widespread area, however there are just enough energetics and dynamics that an isolated storm or two may become marginally severe.2

Showers and thunderstorms are expected across much of the Red River Valley, Interlake and points eastwards today.

Temperatures will climb to a high near 21 or 22°C today with southerly winds of 30-40 km/h gusting up to 60 km/h shifting to westerly after the frontal passage in the afternoon. Expect some clearing in the evening, then variable cloudiness developing towards morning. Temperatures will dip down to a low near 13°C.

Thursday will bring mixed to mostly cloudy skies to Winnipeg and much of the Red River Valley as strong westerly winds of 40-50 km/h build into the region. There will be a chance of showers as rain wraps around on the back side of the passing low pressure system, but much of the guidance suggests that the rain will remain mainly north of the Red River Valley. Temperatures will climb to a high near 19°C and head towards a low near 12°C under mostly cloudy skies with light rain likely on Thursday night.

An area of light rain/showers will slump southwards through the Interlake into the northern Red River Valley on Thursday night.

Friday will bring cloudy skies with a chance of showers as the overnight activity on Thursday tapers off through the region as an upper-level trough exits. Winds will be out of the northwest at 30-40 km/h with gusts up into the 50-60 km/h range. Skies continue cloudy overnight with a chance of showers as temperatures drop to a low near 10°C.

Long Range

Saturday will remain unsettled with a chance of showers as a weak disturbance ripples through the region from the north and cooler air spills southwards. Conditions finally improve on Sunday, which looks likely to be a fairly sunny day. Temperatures will remain below normal, however, through the weekend and into early next week as Manitoba remains under the influence of a large upper low over Hudson Bay.

Winnipeg’s seasonal daytime high is currently 24°C while the seasonal overnight low is 12°C.

  1. These showers would be elevated, meaning they are formed at higher altitudes and would occur ahead of the incoming front.
  2. In this case, we would expect either wind gusts just over 90 km/h or severe hail in the 20-25mm range.