Tuesday, 31 March 2015

A Very Early Spring: The Story of March 2015

From one extreme to the next. That's how March has been like the last few years.

March 13 south Winnipeg - Source: CBC
Similarly to 2010 and 2012, spring arrived much earlier than normal in southern Manitoba this year with April-like temperatures and disappearing snow cover by mid-March. Snow cover disappeared in Winnipeg by March 15, tying with 1995 for 3rd earliest snow melt on record since 1955. In comparison, 2012 had the second earliest melt on record with snow disappearing by March 14. This is in sharp comparison to 2013 and 2014 when snow didn't disappear until April 28 and April 21 respectively.

After a frigid start to the month, temperatures skyrocketed by the second week of March. Record breaking warmth arrived March 14 and 15 with highs in the mid teens, about 15°C above normal. Winnipeg reached 13.2°C on March 14, breaking the old record of 11.4°C in 1981. A high of 14.3°C was achieved the following day, just shy of the old record of 14.4°C in 2012. We could have broken that record if it wasn't for the early day cloud cover. The morning low of 6.7°C that day was the warmest morning low on record for so early in the year since 1953. Previously, the earliest we had a morning low as warm or warmer than that was on March 19, 2012 with a morning low of 16.0°C. A record high minimum for the day was not broken thanks to plummeting temperatures in the evening.

The warmest temperatures during the warm spell were near the US border in general. Morden reached 18.3°C and 17.6°C on March 14 and 15 respectively. These not only obliterated the old daily records but were also the earliest occurrences of temperature over 16°C on record since 1904. Amazingly, the high of 18.3°C on March 14 broke the old 2012 record by 7.1°C!

Seasonal to above seasonal conditions continued for the remainder of March with highs mostly above zero. Three days in the low teens occurred at the end of the month, a fitting end to the 20th warmest March on record since 1872. In the end, 5 days exceeded 10°C in Winnipeg in March, slightly above the normal of 2 days.

The year's first thunderstorms also occurred this March. Isolated thunderstorms developed north and south of Winnipeg with lightning and pea-sized hail on March 30. Thunderstorms are certainly not unheard of in March. In fact, back in March 2012, 6 days reported lightning strikes somewhere in southern Manitoba. Pea-sized hail also fell in Winnipeg on March 27, 2012. Nonetheless, they are unusual. For instance, in Winnipeg specifically, a thunderstorm in March is statistically about a one in eight year event (only 4 thunderstorm days recorded at the airport in March in the last 30 years). No lightning occurred in the city yesterday though, but hail did fall in the south end.

The very first lightning strikes of 2015 in southern Manitoba on March 30

Saturday, 28 March 2015

Rain Tonight; Warming Up

The remnant snow from mid week's storm will melt away this weekend as rain and warm temperatures return...

For today, clouds will thicken this afternoon ahead of a clipper system. Although we should reach mid single digits for a high, a very strong south wind will ruin the day. Winds will be sustained up to 50 km/h at times and gusts as high as 60-70 km/h. Rain with the clipper system will begin late this evening and end later in the overnight hours. 4-8 mm looks likely. Note that this system could even bring some weak thunderstorm activity to western North Dakota and southeastern Saskatchewan this afternoon and evening. However, thunder is not expected in Manitoba.

Skies will clear tomorrow morning, giving way to a nice sunny day. Unfortunately, strong northwest winds will somewhat ruin the day again. We should manage to reach mid to high single digits.

A weak system could bring some light showers on Monday. Nonetheless, it looks very mild Monday and Tuesday with highs in the low teens not out of the question if we can get enough sunshine.

Another system is expected for Wednesday-Thursday. There is still some disagreement on precipitation amounts and type. Any precipitation that falls on Wednesday so far looks to be rain as temperatures will be quite mild. Transitioning to snow may occur Wednesday night. Will update in the comments below as things become more certain. One thing's for sure, we will be cooling down again behind the system for late next week.

Tuesday, 24 March 2015

Update on Storm System

For today, we'll remain cloudy in Winnipeg and the RRV with drizzle and light showers at times. Generally mild as well with highs in the mid single digits this afternoon and evening.

Rain is expected to begin sometime this evening with light rain continuing into the overnight hours. Rain should transition to snow later in the overnight hours probably sometime between 2 and 5 am. In total, close to 5 mm of rain looks possible before switching over to snow, but this amount will depend highly on how early the switchover occurs.

The worst of the snow looks to be tomorrow morning. Snow may be quite heavy at times with significantly reduced visibility at times. Blustery northerly winds are expected to begin in the early morning as well with sustained winds of 50 and gusts to 70 km/h or more possible through the morning and afternoon. This will make for a very unpleasant day. The heavy wet snow combined with the strong winds could cause some localized power outages. Snow should end by the afternoon. In total, 5-10 cm of snow is expected for Winnipeg. Can't rule out a bit more if rain transitions to snow earlier than expected or if the snow is even heavier than expected.

Sunny, but cold for Thursday with highs in the -7°C to -4°C range. Chilly but a bit milder on Friday. So far, warmer conditions are forecast to return by the weekend and early next week which will allow melting of the new snow.