Cool Spring Drags On

Brad Leave a comment
The NAFES continues to forecast below-normal temperatures.
The NAFES continues to forecast below-normal temperatures.

Those looking for warmer, summer-like weather are going to have to look elsewhere as the unsettled, below-normal temperatures we’ve become so familliar are set to continue through the next week or two.

Wendesday
10°C / 1°C
Mixed skies with a chance of showers.

Thursday
10°C / 0°C
Mainly sunny.

Friday
10°C / 0°C
Increasing cloud; chance of showers.

We’ll see mixed skies today as cloud cover pushes westwards from Northern Ontario as the Colorado Low that’s been the genesis for the massive tornado outbreak in the Deep South over the past few days. Closer to home the weather won’t be dangerous in the least; we’ll see just a slight chance of some shower activity pushing into the Red River Valley from the east. We’ll see a high near 9 or 10°C with winds out of the north at 30 gusting 50km/h. Things will clear out tonight as we drop to around 0°C.

Thursday will be quite similar to Tuesday: mainly sunny, a high near 10°C and a bit of a wind out of the east. Otherwise quite unremarkable. We’ll drop to near 0°C on Thursday night.

Friday will bring the next batch of slightly unsettled weather as a disturbance slumps southeastwards out of the Northern Prairies. Our temperature will once again climb to around 10°C, but we’ll see more cloud than sun and what, at this point, looks to be a decent chance of some more shower activity. Expect a low near – surprise! – 0°C once again.

Cool Weekend

Things become sunnier for the weekend, but temperatures don’t look to improve for the weekend. Any potentially lingering shower activity will move off on Saturday morning, leaving us with some sunshine and a high near 9°C. Sunday will be mainly sunny with a high near 10 or 11°C.

The below-normal temperatures[1] will continue through the next week. Another chance for rainfall looks to move into the region early next week as a low pressure system works it’s way thorugh the Northern Plains of the United States.

  1. Normal daytime highs for this time of year are around 16°C.  ↩

A Glancing Blow

Brad Leave a comment

A Colorado low responsible for a tragic severe weather outbreak yesterday across the the Southern United States, and Arkansas in particular, has spread rain northwards into Southern Manitoba this morning. A decent soaking is in store today and then see a cooler, unsettled week ahead as the Colorado Low persists through much of central North America.

Monday
8°C / 0°C
Periods of rain ending by the evening. 10-15mm. Breezy.

Tuesday
10°C / 0°C
A few clouds.

Wednesday
7°C / 0°C
Showers likely.

Late last week it looked as if we were set to get as much as 25-30mm in a widespread swath through much of Southern Manitoba, however we pointed out the complexities of the setup and how minor changes in the positioning of features could cause big changes in how much precipitation is produced.

It turns out the models did fairly well with the overall picture. Thanks to a little more tilt to the upper trough and the upper low being captured a little sooner than originally forecast, the system as a whole won’t push as far northwards as it looked last week and as a result we’ll see a little less rain than it looked like then.

We’re still in for a decent soaking today, though. Periods of rain will persist through the late afternoon or early evening, and in general much of Southern Manitoba will see 10-20mm of rain. Areas further north, towards the Interlake and much of Parkland Manitoba will see in the 5-10mm range, but it does appear that, for the most part, anywhere along and south of the Trans-Canada corridor in SW Manitoba and the Red River Valley will see between 10 and 20mm with the higher amounts closer to the U.S. border. The temperature will sit around 8°C today with breezy winds out of the east at 30km/h with gusts to around 50km/h.

Total rainfall expected today across Southern Mantioba.
Total rainfall expected today across Southern Mantioba.

Near the border there’s a slight chance of accumulations creeping up towards 25mm (1”) or so, but that will depend on fairly heavy rain and some lingering rainfall a bit longer than it seems like it’s likely too. The rain will taper off by this evening and we’ll see gradual clearing through the evening. The temperature will drop to around 0°C.

Another Short-Lived Break

Tuesday looks to be a cool but pleasant day with a high temperature of around 10°C and mostly sunny skies. Temperatures will drop to around 0°C once again on Tuesday night with increasing cloudiness.

Wednesday brings back the showery weather as another shot of rainfall pushes into Southern Manitoba from east to west on the back-side of the Colorado Low. Accumulations don’t look significant at this point, perhaps 3-5mm on the high end, but it does seem like it will be a cool, dreary day with a high of only around 7°C. The showers should taper off by the evening as we drop to the freezing mark yet again, this time under cloudy skies.

Where’s Summer?

Unfortunately, not here. Below-normal temperatures are once again forecast for the 7-14 day outlook, meaning we’ll likely see high temperatures only in the high single digits or low teens for the next week or two.

But it’s gotta warm up eventually, right? Right? Here’s hoping for a big turnaround in May.

Elsewhere in Weather News: April 26th, 2014

Matthieu Leave a comment

Tornadoes Tear through North Carolina

It was an active day severe weather-wise for parts of East Coast yesterday, where tornadoes, large hail and strong winds were all experienced. These severe storms were triggered by a shortwave racing across the mid-section of the US and approaching the East Coast. Moisture was plentiful streaming up from the tropics which promoted low cloud bases and sufficient amounts of Convective Available Potential Energy (CAPE). In addition to this, wind shear was significant enough to support supercells as well as an approaching cold front from the west acting as a trigger mechanism. Considering all of these, conditions were primed for supercells in North Carolina and Virginia.

Trucked flipped in Chicod, NC. (Source: WITN)
Trucked flipped in Chicod, NC. (Source: WITN)

Supercells quickly formed Friday afternoon across eastern parts of North Carolina and Virginia as the atmosphere destabilized. Elizabeth City appeared to be the hardest hit, likely by straight line winds and not a tornado. As of Friday evening, several injuries were reported because of the strong winds downing trees and power lines in the city. According to the SPC there were 10 different tornado reports which appeared to account for three different tornadoes. Fortunately, no injuries or deaths were reported to be associated with any of the tornadoes.

This event comes at the same time a significant negatively-tilted trough arrives ashore on the west coast. The trough is expected to bring severe weather from the US plains this weekend, to the East coast for the beginning of next week. Sunday through Tuesday look to be the most dangerous days where numerous tornadoes could touch down across Dixie Alley and the Midwest. As of Friday evening, the SPC had already issued a Moderate Risk, mentioning strong tornadoes in their discussion and suggesting a high risk (highest tier) upgrade could be in order in future updates.

With only 89 tornadoes reported in the US as of April 13th, that number could easily double within the next few days.

A Brief Reprieve

Brad Leave a comment

This weekend will bring a brief reprieve from the wet weather before a Colorado Low begins impacting the region for the start of next week. Temperatures will remain below normal, but we should see plenty of sunshine with just relatively light south-easterly winds.

Friday
8°C / 0°C
Mainly cloudy. Chance of showers or drizzle.

Saturday
10°C / 3°C
Partly cloudy.

Sunday
11°C / 4°C
Increasing cloud.

Today will bring mostly cloudy skies with a chance for some lingering showers or drizzle as the system that’s been impacting us over the past few days slides off into Ontario. Clouds will begin to break up a bit in the afternoon as we head towards our high of around 8°C, however it won’t be until the evening or overnight period until we see the clouds actually begin to clear out.

Saturday look like the nicest day of the next few, with more sun than cloud and a high near 10 or 11°C. The wind will be out of the southeast at around 20-30km/h, but otherwise it’ll be a pleasant – albeit cooler than normal – spring day. We’ll drop to around 2 or 3°C on Saturday night under mainly clear skies.

Sunday will herald the arrival of the next storm to impact the Prairies: a massive Colorado Low that looks to stall out over the northern Plains of the United States and absolutely smother the Prairies in precipitation.

24hr. precipitation forecast from the GDPS showing anywhere as much as 30-40mm of rain from Sunday night through Monday.
24hr. precipitation forecast from the GDPS showing anywhere as much as 30-40mm of rain from Sunday night through Monday.

This system looks to be extremely complex with multiple features interacting with each other: the Colorado Low itself, a large inverted trough that looks to develop along a north/south line through Saskatchewan, and the occlusion of the upper-level low centre that will stall the system out over the Northern Plains. Subtle variations in any one of these features can dramatically alter the weather outcome, let alone how those variations will interact with each other across these features. In addition, there will be a fairly significant high pressure system through Northern Manitoba that will surely do it’s best to inject dry air into the system and really sharpen up the northern edge of it. Needless to say, we’ll be keeping a close eye on this one and have more details on where, and how much, precipitation might actually happen in the comments below as things begin to come together.