July to End on a Hot Note

Brad Leave a comment

July looks to end hot as temperatures remain near thirty degrees for the first two days of the week.

Temperatures will be in the upper twenties or near thirty in Southern Manitoba on Monday

Temperatures will be in the upper twenties or near thirty in Southern Manitoba on Monday

The month of July will end just as it started, very warm. Temperatures on Monday will be in the upper twenties in Southern Manitoba. On Tuesday highs are expected to be around thirty degrees in all of Southern Manitoba. There will be a risk of thunderstorms Tuesday, with Western Manitoba having the greatest chance of seeing a storm.

The first couple days of August are expected to remain hot as well. Highs on Wednesday and Thursday should once again be up near 30C. At this point models are hinting at the potential for a thunderstorm outbreak later this week across parts of the Prairies provinces. At this point it is too early to say how Manitoba might be affected by this upcoming weather system, but it is something to watch.

Pleasant Start to the Weekend

Brad Leave a comment

After a few days that threatened storms for the Red River Valley, we’re heading out the other side with most communities seeing little to no rain. Steinbach is a notable exception, with over 100mm of rain falling1 through a rather unusual rainfall event early Wednesday morning which produced significant overland flooding2.

24hr. Precipitation Totals valid Sunday Evening

24 hour accumulated precipitation from Friday Saturday evening to Sunday evening.

A pleasant start to the weekend is ahead, with no chance of showers until Saturday evening and overnight. Today we’ll see mainly sunny skies as our temperatures rebound from yesterday’s system up to a high near 26°C. The overnight low tonight will be around 15°C. Warmer air pushing in aloft will allow temperatures to climb higher on Saturday and Sunday, with daytime highs close to 30°C expected. Humidity will remain relatively low for Saturday, however things may get a little uncomfortable on Sunday as dewpoints begin to climb closer to the 20°C mark.

On Saturday a disturbance entering the province will generate some showers and thunderstorms over SW Manitoba through the late morning and afternoon hours. The (thunder)showers will spread eastwards through the evening and overnight, however it’s currently looking like the bulk of precipitation will occur through the Interlake. The northern half of the Red River Valley looks to have a decent chance of seeing some sort of precipitation, however the odds look very slim that the southern half will see anything.

We’ll see increasing cloud Sunday afternoon as the back side of this system prepares to swing through Sunday night. As it does, there will again be a chance of showers for Winnipeg and, as it looks now, the eastern RRV. We’ll be sure to provide updates in the comments as this system approaches.

new TWTR.Widget({
version: 2,
type: ‘list’,
rpp: 30,
interval: 30000,
title: ‘July 2nd, 2012’,
subject: ‘AWM Storm Chase’,
width: ‘auto’,
height: 500,
theme: {
shell: {
background: ‘#3c3c3c’,
color: ‘#eeeeee’
},
tweets: {
background: ‘#eeeeee’,
color: ‘#2c2c2c’,
links: ‘#489ce1’
}
},
features: {
scrollbar: true,
loop: false,
live: true,
behavior: ‘all’
}
}).render().setList(‘WeatherInThePeg’, ‘awm-team’).start();

  1. http://www.steinbachonline.com/index.php?option=com_content&task=view&id=30218&Itemid=100413 ↩
  2. http://www.steinbachonline.com/index.php?option=com_content&task=view&id=30192&Itemid=100413 ↩

Elsewhere in Weather News: July 28th, 2012

Matthieu Leave a comment

Severe Typhoon Vicente Plows through Southern Asia

This past week, typhoon Vicente spun up in the Pacific Ocean and made landfall near Hong Kong on July 23rd. The severe typhoon, of category 2 hurricane strength, amassed winds of between 155km/h just before it made landfall about 100 kilometres to the south-west of Hong Kong’s city core. Although the typhoon first touched land outside of Hong Kong, its hurricane-force winds did extend out into the city. In consequence, the Hong Kong Observatory (HKO) issued a level 10 advisory – the highest possible on the scale – advising residents to stay inside and closing non-essential services as well as schools. The level 10 advisory had only occurred 13 times since 1946, with this most recent advisory being the first in the 21st century (the last level 10 advisory was issued in 1999). Vicente had somewhat of an unusual track, being stationary 300 kilometres to the south of Hong Kong for 15 hours then strengthening significantly before moving inland the following day. The strengthening that occurred with Vicente, within this short amount of time (48h), had never been observed this close to land with prior significant typhoons that struck the region.

Vicente

RADAR image of Vicente as he made landfall on the afternoon of July 23rd. (Source: HKO)

Although Vicente forced the HKO to issue a level 10 advisory, damage was fairly minimal in the city – only minor damage to buildings was reported, but no structural damage. Flights in and out of Hong Kong were either cancelled or delayed which did cause some grief to travellers in the region.

Vicente did not stop its tracks in Hong Kong. It continued westward towards Southern China and Northern Vietnam where it dumped large amounts of rain during its passage. This in turn caused landslides and flooding in the mountainous region of Northern Vietnam, killing seven people with three still missing. The Vietnamese government has sent out rescue teams to look for the residents still missing. Damage is quite significant in the region, with most houses and crops destroyed due to the flash flooding and landslides.

Vicente Track

Red line depicting Vicente’s track, green circle are the areas of Vietnam affected by the flooding and purple circle is the area where Vicente intensified quickly. (Map credit: Google Maps)

Another tropical depression appears to be forming to the east of the Philippines with some thunderstorm activity, which is something to keep an eye on in the coming week!

Tropical disturbance

The tropical disturbance east of the Philippines. (Source: HKO)

Thunderstorm Risk Returns

Brad Leave a comment

The risk for thunderstorms returns to the Red River Valley today as a cold front with a history of producing severe weather pushes into the region.

850mb Analysis from the GFS

850mb Analysis from the GFS model for mid-morning today.

We’ll see some clouds/light showers clearing out early this morning across the Red River Valley, leaving us in sunshine for the latter half of the morning and early afternoon. By early afternoon, a cold front will be draped N-S over the western RRV. With temperatures climbing into mid-to-high 20’s by mid-afternoon, there should be enough heat and moisture to get storms going along the cold front. It’s likely, but not certain, that some thunderstorms will deveop on a north south line from near Winnipeg south towards the International Border. These storms will track eastwards across the RRV through the mid-to-late afternoon.

They will certainly have the potential to be severe. This cold front has a history of producing storms capable of damaging winds, large hail, and isolated tornadoes. For us, conditions don’t look quite as favorable as they did yesterday in SK or the day before in AB. We’ll be looking at:

  • 1000-2000 J/kg of CAPE
  • LI values near -7
  • Bulk shear values of only 20-35kt
  • 0-3km EHI values only 1-1.5

Wind shear will be the biggest limiter to storm development today. Storms may struggle to develop a distinguished structure, which could result in a relatively tame outcome. There’s just enough support to not be able to rule a severe storm out, however, and I expect we’ll likely see some watches issued for the RRV midday. The main threats for these storms will be heavy downpours with rapid rainfall accumulation and large hail. There’s a secondary threat of strong winds and, while tornadoes cannot be ruled out, the threat for the RRV is nowhere near the threat yesterday in Saskatchewan. Ultimately, though, the chance for seeing storms depends highly on the speed of the cold front; we’ll have to wait and see how quickly it moves into the RRV today to refine the thunderstorm forecast.

Things should clear out in the evening before a chance for showers returns late overnight and Thursday morning as the main upper low tracks over the RRV. We’ll see a mix of sun and cloud on Thursday with a high near 25°C. Friday heading into the weekend looks fairly nice. Sunshine should dominate and temperatures will climb back into the high 20’s or low 30’s. We’re certainly shaping up for another above-average month for temperatures. If July’s mean temperature is above normal, it will be the 13th consecutive month with above-normal temperatures in Winnipeg.