Tag: Rain

Active Weather Pattern, but Inactive Weather?

Brad Leave a comment

A couple of weather systems are in store for this week, but that doesn’t mean the forecast is wet for everyone.

A Cold Front Will be Positioned Through Manitoba on Monday

Monday

Monday

Mix of Sun and Cloud. Chance of Showers.
22°C / 8°C

Today will be a warm day by late September standards. High temperatures will be in the low twenties in the Red River Valley. A bit further east in south-eastern Manitoba some areas may approach the mid twenties. But a bit further west in western Manitoba, temperatures will struggle to reach the upper teens. The discrepancy in temperatures over Southern Manitoba today is resulting from a cold front located over western Manitoba. In the vicinity of this front there is extensive cloud cover and some rain activity. Further east, skies are clearer, allowing for the atmosphere to heat up a bit more. Some of the rain showers over western Manitoba may sneak into the Red River Valley later today (as cloudiness increases later today), but little in the way of accumulating rain is expected. Over western Manitoba the rain will probably amount to between 5 and 15mm in general.

Tuesday

Tuesday

Mainly Sunny
21°C / 7°C

Surprisingly, Tuesday will be quite a nice day despite the passage of a cold front on Monday night. High temperatures on Tuesday will be in the upper teens or lower twenties in Southern Manitoba, under sunny skies and light westerly winds.

Wednesday

Wednesday

Mainly Cloudy
22°C / 14°C

Wednesday will see cloudier conditions return ahead of a developing weather system. Temperatures on Wednesday are expected to max out in the low twenties in Southern Manitoba and the wind will be gusty and from the south-east. Some rain may occur over Western Manitoba on Wednesday, but it’s too early to speculate on the location or intensity of it.

Long Range

The long range outlook will be dominated initially be the weather system mentioned in Wednesday’s forecast. This low pressure system is currently expected to track through Manitoba, with its main impacts likely to be confined to the Western half of the province. However, it is possible that this system may change track, so it could potentially affect other parts of Manitoba as well – more details on that will be available in Wednesday’s post.

Once that weather system passes by, conditions should return to near seasonal values for the end of the week. Next weekend is looking fairly pleasant, with near to slightly above seasonably temperatures…but of course that could change before the weekend actually arrives!

Elsewhere in Weather News: September 14th, 2013

Matthieu Leave a comment

Historical Flooding in Colorado

This past week Colorado has been absolutely swamped thanks to moisture streaming up from the Gulf of Mexico, riding up the Rocky Mountains (upslope flow) and then falling as rain. High pressure sliding down from the north in the US Plains as well as an upper-level low to the west drew in the moist air from the southeast. Generally, 850mb dewpoints could be found in the 15°C range and PWAT values around 40mm in Eastern Colorado. Plentiful moisture was in place – a recipe for heavy rains that had the possibility to fall for a long period of time. This became the case for Wednesday evening through Friday morning for Boulder, Colorado and surrounding communities.

850mb moisture transport

Radar with overlay of the 850 moisture transport, notice the vectors all pointing towards the Rockies. Taken Friday 3am. (Source: SPC Mesoanalysis image archive)

As best described by NWS Boulder, flooding of “biblical” proportions took place is continues as of Friday night. Small creeks easily turned into raging rivers that inundated whole towns and mudslides blocked highways, took out buildings. The death toll is already at four but concerns of more as 172 people are still missing and some communities are literally cut off, with no roads leading in or out of town. Interstate 25 had been closed due to water running over it as well as numerous other highways that had simply been washed away.

The average rainfall per year for Boulder, CO is around 525mm, this means that in a few days Boulder got over half its annual rainfall at 310mm. This easily beats out the old record for rainfall in September (243mm), and average of 43mm (this month; 721% above average September rainfall). Interestingly enough, the area which received all this rainfall was under a moderate to extreme drought as per the Drought Index.

Rainfall estimates

Estimated rainfall from KFTG as of Friday 3am. Notice the dark purples/white; areas above 200mm estimates. Map storm total accumulation. (Source: GRLevel3)

It appears as though Boulder might get a break from the rain today as the upper-level low weakens and moves further east though there is still a slight chance for pop-up (non-severe) storms. Tomorrow will likely bring with it more rain for the region, unfortunately.

An Oasis on the Horizon?

Brad Leave a comment

After weeks of dry weather, some rain is finally on the way. However, for those desperately wanting rain, the water works may only come after the rain has ended.

A Low Pressure System will Spread Rain Over the Northern Plains on Monday

Monday

Monday

Mainly cloudy. Chance of showers.
23°C / 14°C

Today will see rain over some parts of Southern Manitoba as a powerful upper low approaches the region. This system will tap significant moisture over the Northern Plains, generating an area of moderate to heavy rainfall over the Dakotas. The core of this rain will slide mainly south through North Dakota and Minnesota, however the northern fringe of it may clip areas along the International Border up into south-eastern Manitoba. In these border regions rainfall amounts will be very hard to predict in advance, but a reasonable estimate would be for 5 to 15mm for the entire day. Actual amounts could be slightly higher or lower than this depending on the track of the system. In the rest of Southern Manitoba, little to no rain is expected. There will be a constant threat of showers today and tonight, but most areas including Winnipeg, should see very little if any rain. Other than the rain it will be a cloudy, but mild day, with light winds.

Tuesday and Wednesday

Tuesday

Mix of Sun and Cloud. Chance of Showers or Thundershowers.
27°C / 10°C
Wednesday

Mainly Sunny
21°C / 6°C

Tuesday should be a fairly nice day in Southern Manitoba. Skies will be a mixture of sun and cloud with temperatures in the mid to upper twenties. Late in the day a cold front will come through, likely triggering some showers and thunderstorms. These storms are not expected to be severe.

Not surprisingly, Wednesday will be a cooler day as colder air moves in behind that cold front. High temperatures will be in the low twenties with gusty north-westerly winds. Some fair weather cumulus clouds may develop during the day, but otherwise it will be mainly sunny.

Long Range

The long range outlook is a bit ambiguous at this point. It appears that we’ll probably see conditions begin to warm up around the weekend, only to be knocked back down by another cold front later on the weekend or into next week. This sort of up and down pattern makes forecasting fairly tough, so rather than making any sort of grand prediction I’ll just suggest that we’re in for a variable pattern with some warm weather interspersed with cooler periods.

Generally Nice Weekend In Store

Brad Leave a comment

A generally nice weekend is in store, with the exception of possible rain or storms on Saturday.

Areas outlined in red over Manitoba are forecast to be between 27 and 29C by the NAM model

Friday

Friday

Mainly Sunny
28°C / 18°C

Today will be another beautiful day in Southern Manitoba. High temperatures will be in the upper twenties under mainly sunny skies. The wind will be fairly light and from the north.

Saturday

Saturday

Mix of Sun and Cloud. Chance of showers or thunderstorms.
27°C / 15°C

Saturday looks to be the only possible wrench in the weekend forecast. It appears that skies will be a mix of sun and cloud or mainly cloudy on Saturday with a chance of rain and risk of a thunderstorm. Any storms that roll through will be non-severe, but possibly enough to cause disruption to outdoor activities. It is possible we may entirely avoid rain and thunderstorms on Saturday, so hopefully that will be the case. If we steer clear of precipitation, temperatures on Saturday may reach the upper twenties in Southern Manitoba. However, if it stays cloudier then highs will end up in the mid twenties.

Sunday

Sunday

Mainly Sunny
27°C / 15°C

Sunday should be mainly precipitation free in Southern Manitoba, except for perhaps a stray shower or thundershower. Temperatures are expected to be in the mid or upper twenties with light winds and mainly sunny skies.

Long Range

As we move into next week the heat is expected to crank up once again. Temperatures in the upper twenties or near thirty degrees are expected on most days. Models hint at the potential for storms later in the week, but it is too early to discuss that any further.