Elsewhere in Weather News: August 4th, 2012

Matthieu Leave a comment

Another Typhoon Churns in the Pacific

Yet another typhoon, Saola, has made landfall in the Western Pacific this past week, this time hitting Taiwan hard. The “disturbed area” talked about in last week’s EIWN is the culprit for producing typhoon Saola, which made landfall Wednesday, August 1st (Thursday August 2nd Taiwan time), bore winds of around 155km/h. The capital city of Taipei was completely shut down because of this typhoon: financial markets were closed, all businesses were closed, and residents urged to stay inside.

Saola

Typhoon Saola just as the strongest part of the storm made landfall on Taiwan (taken August 1, 2:32pm). (Source: NEXSAT Satellite)

Saola swamped streets and downed large trees as it passed over Taiwan, not to mention the enormous amounts of rain it dumped. Since Tuesday, some areas of Taiwan have received more than 1,000mm of rainfall – that’s about double our yearly amounts here in Winnipeg! The death toll from the extreme flooding Saola caused has reached 27, mostly Taiwan and Philippine residents. The flood waters are still receding and in turn more casualties may be discovered. Taiwan has deployed 48,000 soldiers to the area to help with the cleanup of Taipei and surrounding regions, and rescue teams are also currently hard at work. The typhoon has disrupted flights going in and out of Taiwan and caused chaos in the railway industry.

Flooding

Snapshot of the flooding Saola caused in Taiwan. (Source: AFP)

Unfortunately, typhoons don’t seem to be letting up in this already battered region of the Pacific where yet another typhoon has spawned east of China and will make landfall somewhere north of Shanghai. Saola will continue west and is predicted to make a second landfall west of Taiwan on China’s south-east coast on Friday (Winnipeg time).

Typhoons

The tracks of typhoon Saola/Damray as of Thursday evening. (Source: HKO)

In other hurricane-related news (Atlantic basin), a tropical storm, Ernesto, has spawned in the Atlantic eyeing to the Carribean where it will dump massive amounts of rain on the Lesser Antillies. Early Thursday morning a 101km/h gust was recorded at St Lucia where a tropical storm warning has been issued for the Lesser Antillies and residents have bunkered down. Ernesto is expected to make a north northwesterly track and most models show it ending up in the southern Gulf of Mexico by early next week. However, that is still a ways away and hurricanes can sometimes make unpredictable turns, in consequence, a constant eye needs to be kept on the most current satellite and model data.

Stormy Start to the Long Weekend

Brad Leave a comment

The August long weekend will be off to a stormy start today as the threat of severe thunderstorms bears down on the Interlake, Red River Valley and Whiteshell this afternoon.

Tornado near Lake Diefenbaker

One of a couple of tornadoes that the incoming system spawned in Saskatchewan yesterday. Photo by @TheMrsCogs.

A very powerful low pressure, responsible for at least two tornadoes in Saskatchewan yesterday, will move into Southern Manitoba today and push a cold front across the province through the day. Very strong dynamics will accompany this system, a stark contrast from the last few systems which have had comparatively strong thermodynamics instead. Despite the lack of strong thermodynamic parameters that are often looked at when diagnosing severe thunderstorm potential, such as CAPE, EHI or LIs, the strong dynamics will present a significant severe weather threat over south-central and southeast Manitoba.

Dynamics are physical, kinematic properties of the atmosphere, such as jets, shear and lift. Thermodynamics are thermal/energetic properties of the atmosphere such as temperatures, humidity and instability.

A band of showers will push into the western Red River Valley early in the afternoon ahead of the upper low. As the afternoon progresses, the upper low will begin to deepen and enhance the destabilization over the Red River Valley. By mid-to-late afternoon, despite the cool temperatures and cloudy skies, there should be rapid development of storms along the cold front. Tornadoes are unlikely, although not impossible, here in Southern Manitoba; that threat should be relegated to the Dakotas where even greater dynamics and substantially better thermodynamics are present. If any tornadoes do form tomorrow, it’s likely that they will be of the short-lived variety and relatively weak. The greatest threat from today’s storm will be extremely heavy rain giving rapid accumulations of 1-2” (25-50mm) given precipitable water values of 40-50mm and large, damaging hail given the cool temperatures aloft.

Thunderstorm Outlook

Day 1 thunderstorm outlook valid 18Z today through 12Z tomorrow morning.

The storms will exit the province overnight, and we’ll have a brief reprieve from precipitation. On Saturday, some showers will wrap down into the RRV on the back side of this system. Amounts will vary across the region, but in general less than 5mm is expected. Temperatures will struggle to climb to even 20°C; daytime highs of only 18 or 19°C are expected. Winds will be breezy from the NW.

This system will clear out Saturday night before nicer weather builds back in. The second half of the long weekend will see increasingly sunny skies and daytime highs near 25°C.

Warm, Unsettled Weather Continues

Brad Leave a comment

Warm weather will continue to dominate Southern Manitoba as we climb into the high 20’s almost every day this week. We’ll continue to see active weather as multiple systems move through the province over the second half of this week.

500mb Wind Field Valid Friday Night

Forecast 500mb wind field with heights depicting powerful upper low entering Southern Manitoba on Friday evening.

July ended up being a very hot month for Winnipeg, with 14 days of the month with daytime highs over 30°C. The month ended with an average temperature (highs and lows both considered) just over 22°C, which is about 2.5°C above the normal average temperature of 19°C. July marked the 13th consecutive month that Winnipeg has seen above-normal temperatures.

July marked the 13th consecutive month that Winnipeg has seen above-normal temperatures.

We’ll see a chance of afternoon thunderstorms across most areas of Southern Manitoba as a weak disturbance rounds the cold trough left behind yesterday’s system that brought a thunderstorm threat to Southern Manitoba. Chances for thunderstorms will be significantly higher through SW MB northwards through the Parkland region while the Red River Valley will see just a chance of thundershowers in the evening as the upper feature passes by. Daytime highs will be near 28°C through the Red River Valley with an overnight low tonight near a comfortable 15°C.

We’ll see a reprieve on Thursday, with no precipitation expected and a high near 28°C again. A powerful upper low will begin pushing across the Western Prairies bringing rain and cooler temperatures tommorow and will be the main weather-maker on Friday for us. Showers and thunderstorms will push into Western Manitoba on Thursday night and slide eastwards across the province through the day on Friday. It’s likey that we’ll see little precipitation on Friday as most of it pushes through the Interlake, however there’s a good chance of showers overnight on the backside of this system. We’ll see a daytime high of 24°C on Friday and a considerably cooler high near 20°C on Saturday.

Conditions will rapidly rebound through the end of the weekend as sunny skies return and temperatures shoot back up to 30°C.

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.