Thursday, September 14, 2017

Welcome rain finally on the way for southern MB..

It's been awhile, but it finally looks like southern MB will have its first decent rainfall in weeks beginning tomorrow and continuing into early Saturday.  Models are indicating a general 20-35 mm of rain for most areas in southern MB Friday into Saturday morning, with locally heavier amounts of 50 mm thanks to embedded thunderstorms firing up over ND later Friday into Friday evening (spreading into southern MB mainly closer to the US border)

As for Winnipeg.. models are all over the place in terms of amounts here, but generally it looks like 25-40 mm of rain is possible from Friday afternoon into Saturday morning, with the bulk of rain falling Friday night when it could be heavy at times. Some models show heavier amounts due to embedded convection moving in Friday evening (GDPS shows over 70 mm for us!) Here are the various model outputs of rainfall for Winnipeg through midday Saturday.. (12Z or 18Z run)

RDPS... 32 mm
GDPS... 72 mm
NAM.... 43 mm
GFS.... 23 mm
ECMWF.. 26 mm
SREF... 18 mm
GEPS... 41 mm 

Multi-model average is 36 mm. Taking out the highest and lowest values gives a mean of 33 mm. Whatever the case, it'll be the most significant rainfall we've had here in weeks! In Winnipeg, only 2 mm of rain has fallen so far this month, coming off its 13 driest August when only 14 mm fell the entire month. Since July 23rd, Winnipeg airport has received only 21 mm of rain, a mere 18% of the normal 119 mm that should have fallen over that time. We are certainly overdue for a good soaking!     

Sunday, September 03, 2017

Cool windy end to Labour Day weekend, but summer-like warmth to return by end of week

The last long weekend of the summer season will be ending on a cool and windy note as a strong northwest flow pushes in a  fall-like airmass over Manitoba on Monday, along with a few showers. Highs temperatures will only be in the upper teens, with gusty northwest winds up to 60 or 65 km/h at times. Although we can use the rain, rainfall amounts Monday will be light with only a few mm expected in passing gusty showers. Things will clear up Monday night with better weather Tuesday and Wednesday under a mix of sun and cloud and temperatures in the upper teens to 20C.

The second half of the week is looking wonderful as a southerly flow spreads warmer air back into Manitoba. That should bring sunny and dry weather for Thursday through Sunday, along with increasingly warm and windy conditions with temperatures in the mid to upper 20s. In fact, it's possible much of the RRV will be hitting the 30C mark again next weekend, although it will be accompanied by gusty south winds. So if the onset of cooler weather is getting you down, don't worry.. summer is still not quite done yet!

Tuesday, July 25, 2017

Seasonably warm weather to close out July.. but 30C heat continues to elude Winnipeg

It will be a nice warm week ahead with high temperatures generally in the mid to upper 20s over the RRV and southern MB. Conditions should be generally dry as well with little in the way of showers or thunderstorms expected through Friday. The next threat for organized showers will be on Saturday as a weak frontal system slides through southern MB. The greatest heat through the end of the month however will still be focused out west over SK and AB which have experienced multiple days of 30C or more this month. In Winnipeg, we have yet to hit the 30C mark in July, even though precipitation has been below average and sunshine has been plentiful. The upper pattern this month has brought the bulk of the heat over western Canada with cooler temperatures over eastern Manitoba into Ontario.  There is a chance Winnipeg may be close to the 30C mark by the end of the week. Since 1872, there have been 12 Julys in Winnipeg that have failed to reach the 30C mark, most recently in 2009. With one week to go, we'll see if July 2017 is added to that list.

Saturday, July 01, 2017

Coolish Canada Day 150.. but then heat builds for first half of July over Prairies

Happy Canada Day!  Canada is 150 years old today, founded back on July 1st 1867, and celebrations marking the milestone event will be held throughout the country. In southern MB, skies on Canada Day will likely start off cloudy as a disturbance tracks across southwest MB into North Dakota tonight into Saturday. This system will spread a few showers across SW Manitoba tonight and into the Red River valley overnight into Saturday morning. The bulk of showers will likely be mainly south of Winnipeg, but there is the chance the city may see some showers Saturday morning. The system should be out of southern MB by midday leaving a mix of sun and cloud Saturday afternoon along with a northerly breeze of 20 km/h. Temperatures will be on the cool side of normal with highs around 21C, a few degrees shy of the average of 25C for July 1st, but quite comfortable for outdoor activities. There is the chance of some isolated showers popping up Saturday afternoon with daytime heating, but most areas should be rainfree for Canada Day festivities. Skies will be clearing by Saturday evening, with ideal conditions for fireworks at 11 pm.. although a little on the cool side with temperatures near 15C by that time. The rest of the holiday weekend is looking good with sunshine on Sunday and highs of 24C and 27C by Monday under partly sunny skies and increasing southerly winds.  

Pattern change will bring increasing heat over western Canada and Prairies first half of July

Large upper ridge building over western Canada next week
will bring increasing heat over the Prairies, especially west
850 mb temperature anomaly shows core of heat next week
will be over western Canada with highs of 30-35C
A pattern change is expected for the first half of July over western Canada and across the Prairies as a large upper ridge builds over the High Plains and Rockies. This will bring increasing heat over much of the Prairies over the next 1-2 weeks, with a prolonged heat wave possible over Montana, southern AB, and SW Saskatchewan with highs in the mid 30s to possibly 40C in some localities. Look for widespread heat warnings to be issued for much of Alberta and Saskatchewan early next week. Here in southern MB, temperatures won't be quite as hot as out west, but they will climb to above normal values with highs in the upper 20s to low 30s this week, with mid 30s possible near the SK and North Dakota borders. There may be a day or two with thunderstorms as weak fronts pass through southern MB, but overall precipitation is expected to average below normal for the first half of July over much of the Prairies. There is a chance that the upper ridge may build east into southern MB by the second week of July which would bring more intense heat here as well (highs of 35-38C). However, that is still a ways off and we'll have to see how models handle the upper ridge pattern in the days ahead. Regardless, get ready for an extended period of hotter temperatures over the next week or two.. as we get into the climatologically warmest part of the year in southern MB.    

Sunday, June 18, 2017

June to end on a cool note..

Temperature outlooks from CPC show favour below normal temperatures
across the Prairies for the next 1-2 weeks at least 

After a nice warm first half of June, the weather pattern has shifted over the Prairies this past week, with the warmest air now suppressed south of the international border. The jet stream has shifted south allowing cooler air from the north to move across the Prairies. And it looks like this pattern will likely persist for the rest of the month into early July. Tomorrow and Tuesday should see a mix of sun and cloud with highs of 18-21C, then a system passing through southern MB will likely bring some showers and thunderstorms Wednesday with highs in the low 20s. Cooler temps will follow for the end of the week, with below normal temps in the teens and scattered showers likely next weekend.  A return to sustained heat in southern MB isn't expected before early July.