Elsewhere in Weather News: May 26th, 2012

Matthieu Leave a comment

Already an Active 2012 Hurricane Season

The first major hurricane of the year for the Eastern Pacific Ocean spun up on May 22 to the south-west of Mexico and will likely make landfall on the west coast. As of Friday afternoon, Hurricane Bud was cruising along at a northerly trajectory as a category one hurricane, packing winds of 120km/h in its core and releasing very heavy rains within its spiral banding.

Hurricane Bud Friday afternoon

Infrared satellite picture of Bud near Mexico’s coast on Friday afternoon. (Source: NOAA)

Bud is forecast to decrease slightly in intensity as it hits the mountainous regions of Mexico’s west coast and interacts with the dry air to its north. However, Bud is still predicted to bring winds from 90km/h to 110km/h, as it makes landfall just to the south-west of Puerto Vallarta, between a weak category one hurricane and strong tropical storm status.

Bud's track

Bud’s track and coastal warnings; in blue a hurricane warning, in red a tropical storm warning, in pink a tropical storm watch. (Source: HEWS/NHC)

The worrisome part of this storm, however, is not the winds that accompany Bud, but the rainfall associated with it. From 150mm to 200mm are expected to fall with even higher amounts locally along the coast. As it makes landfall on the hilly coast, mudslides are a big threat to towns in the vicinity. A hurricane warning has been issued for a small part of the Mexican coast that is sparsely populated in the area where Bud’s centre will make landfall.

Interesting facts on Bud:

  • Bud is the strongest hurricane ever recorded in the Eastern Pacific this early in the year; it reached category three (185km/h) late Thursday night.
  • Only 12 hurricanes have been recorded in the Eastern Pacific in May since 1949, Bud is one of them.
  • Two meter high waves were already experienced on the Mexican coast Friday afternoon ahead of Bud.

Mexico officials say they are ready for Bud; they have cancelled schools in 11 municipalities for Friday and have 15,000 spots ready in rescue shelters if evacuations are needed. Bud will reach land on Friday night and slowly curve back out to the Pacific as a tropical depression by the end of the weekend.

The hurricane season in the Eastern Pacific officially started May 15th and it has already been very eventful at its outset with two named storms. In the Atlantic, where the season officially kicks off on June 1st, an area of low pressure is already forming off the coast of Georgia and has a very good shot of becoming a subtropical/tropical storm by this weekend. So, lots to keep an eye on during this active start to this year’s hurricane season as there will certainly be more to come!

Low off the east coast

Possible tropical storm forming off the east coast in infrared satellite. (Source: NOAA)

Cool, Wet Weather For The Weekend

Brad Leave a comment

Winnipeggers: get ready for a shock. The next few days are going to be startling chilly with daytime highs over 10°C below normal and overnight lows over 5°C below normal. Another thing that will be noticably absent other than warmth? The sun will make only a few rare appearances over the next several days as another system pushes into Southern Manitoba, bringing another round of rain and thunderstorms to the Red River Valley.

850mb Temperatures valid 00Z Friday

850mb temperatures vaild at 00Z Sat. May 26 (Friday evening). An elongated cold trough is sweeping across Southern Manitoba, bringing 850mb temperatures in the -2 to -5°C range.

This cool weather has brought late-season (or is it early-season now?) snow to several communities over Western Manitoba including The Pas, Flin Flon and higher elevations over SW Manitoba (Duck Mountain & Riding Mountain areas). A few leftover flurries will scoot across the Interlake this morning and exit out of the province. The Red River Valley wil be spared, however we’ll be stuck under low clouds with a daytime high that struggles to make it to 10°C.

Tonight, a widespread frost potential exists over the most of Southern Manitoba. As a surface ridge moves into our area, winds will abate and we’ll see the cloud begin to break up a bit this evening. The greatest potential for frost looks to be over Southwestern Manitoba in the Virden, Melita, Pilot Mound & Brandon regions. Further east, here in the Red River Valley, some scattered clouds and a bit of moisture trapped in the valley should help temperatures stay above freezing, with overnight lows in the 2-3°C range. Areas outside the City of Winnipeg in the RRV certainly have a slight risk of a light frost. Winnipeg will likely be frost-free, with an off-chance of patchy frost in outlying areas near the Perimeter Highway.

Saturday will be our transition day with temperatures reaching 13-14°C and cloud streaming northwards from the Dakotas with the next incoming system. Rain will push up towards the International Border by morning, likely staying in the States but certainly poses the chance of a few showers along the border. The rain will stay near the border until Sunday, when the next big northward push arrives.

24. hour precipitation accumulation Saturday morning to Monday morning](https://img.skitch.com/20120525-mkq1sh9w3aa3twa7r6stuq9j2q.png)

Precipitation accumulation from the GEM-GLB model for Saturday morning to Monday morning. A broad swath of rain is forecast to fall from extreme SW Saskatchewan through Southern Manitoba.

And what a push it will be! Showers and thunderstorms will rapidly develop into an expansive area of rain on Saturday night, slowly pushing northwards across the Red River Valley. Most regions across Southern Manitoba should expect rain to start fairly early on Sunday and last through most of the day. Rain will likely taper off from west to east overnight, with only a few wrap-around showers moving across the RRV on Monday. It’s still early to give accurate estimates of rainfall totals for this next system, however in general, most regions across Southern Mantioba look to see at least 10-20mm of rainfall, with the potential for nearly 30mm in some areas of the RRV if some embedded convection can get going. Regions of Southwestern Manitoba that end up north/northwest of the main upper low track will see higher amounts as well, with 20-30mm of rain likely. This isn’t the best news for this year’s Teddy Bears Picnic, but hopefully shouldn’t dampen spirits too much at an event that has, historically, had to deal with some pretty awful weather. Wait, I’m getting deja vu…

Conditions look to improve through the middle of next week, with temperatures pushing back towards the 20°C mark and some sun finally making an appearance. That’s a ways to go, though, so grab your slippers and heat up some soup! We have some great stay-inside weather coming up. We’ll be sure to keep a close eye on this system and provide updates in the comments.

Some Simple, Seasonal Weather

Brad Leave a comment

After a hectic few days across Southern Manitoba, Winnipeg is in for a few relatively calm, seasonal days before the next system moves into the region this weekend.

We’ll see the clouds breaking up this morning with a temperature that makes it up to around 19°C by this afternoon. We’ll see a slight chance of showers this afternoon, however they shouldn’t amount to very much and will quickly move out this evening. Tonight’s low will be around 10°C here in Winnipeg. Thursday and Friday will bring us a mix of sun and clouds with chances of afternoon showers across most of the Red River Valley as the upper low from yesterday’s system slowly tracks out of the Province. The daytime highs over the next couple days should be near 19°C.

A more significant system is forecast to move into our region this weekend, bringing what currently looks like a pretty rainy day to this year’s Teddy Bears Picnic.

Stormy Weather To Return to Southern Manitoba

Brad Leave a comment

After a cool night, temperatures will rebound nicely today before more unsettled weather pushes into the province tonight and lingers through mid-week.

850mb temperatures valid Tuesday Evening

850*mb* temperatures valid 00Z Wed May 23 (Tuesday Evening). Warm and cold front are represented by red and blue lines, respectively. Orange arrows represent warm air lifting northwards over the warm front.

Temperatures today will work their way to 20°C today with increasing cloud. The first of several impulses forecast to track across Southern Manitoba will push a warm front across the Red River Valley late this afternoon, bringing with it a good chance of showers
through regions along the Trans-Canada highway and northwards into the Interlake. Regions in the southern half of the Red River Valley will see just a chance of showers through the afternoon and evening today.

Tomorrow, a low pressure system will push into North Dakota, strengthening a warm front draped across the region. Southern Manitoba will stay north of the warm front, keeping daytime highs in the 20-23°C range. Strong capping will restrict surface-based thunderstorms to Central/Southern North Dakota where a cold front advancing across the Plains will help trigger storms later in the day. For us, however, we’ll be in great placement for the development of nocturnal convection. A strong 30-40kt low-level jet overriding the warm front will pump fairly moist air northwards; dewpoints at 850mb over Southern Manitoba are expected to rise to the mid-teens. Combined with negative lifted indicies, CAPE values are expected to climb to nearly 1500J/kg.

This will likely result in the development of showers and thunderstorms on Tuesday evening, developing somewhere over Southern Manitoba and pushing northeastwards through the night. Nocturnal convection is always a very tricky thing to forecast, so we’ll definitely keep a close eye on things and provide updates in the comments as we get closer.

The upper low associated with this system will push across the Prairies through the week, bringing a mix of sun and clouds and some unsettled weather and more chances of showers.