Updraft: May 25, 2012 Archive

Wettest May? Weekend severe risk; 97 Sunday? Grays Bay Dam open

Posted at 5:07 PM on May 25, 2012 by Paul Huttner
Filed under: Climate, Rainfall, Record, Severe weather

8.18" rainfall at MSP Airport so far this May

2nd wettest May on record so far at MSP Airport

Wettest May on record for some metro & Minnesota locations
(More from Mark Seeley below)

Mixed weather bag Memorial Day Weekend - some rain, sun and heat

Hot sticky Sunday 90 degrees & humid (60s dew points)

Severe late Sunday? Severe storm risk late PM & evening into early Monday

Mixed Memorial Day: Rain early, some PM sun?

This "Bud's" for you? (no not the beer) - Dissipating Hurricane "Bud" may inject some moisture into by Minnesota Monday

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"May-soon"

Welcome to the May Monsoon.

Another month, another record in Minnesota. When did "extreme" weather become "normal" weather in Minnesota?

According to my MPR colleague Dr. Mark Seeley, this is already the wettest May on record at several Minnesota locations, and we still have a week to go.

It's the 2nd wettest May at MSP Airport with 8.18" so far. Another 2.16" is doable this month, even this weekend. That would make it the wettest May on record at MSP Airport.

Several additional locations arte in the top 5.

Here's an excerpt from Mark's earlier Updraft post.

With the frequency of heavy thunderstorms dominating the Minnesota landscape this month, some observers are reporting one of the wettest Mays in history. Currently on a statewide basis this May ranks among the top ten wettest in history. For some individual climate stations it is already among the top five, including:

Chanhassen 9.22 inches (wettest ever)
Chaska 8.53 inches (4th wettest)
Jordan 9.17 inches (3rd wettest)
MSP Airport 8.18 inches (2nd wettest)
Forest Lake 9.62 inches (wettest ever)
Windom 8.40 inches (2nd wettest)
Pipestone 8.29 inches (4th wettest)
New Ulm 8.16 inches (4th wettest)
Mora 8.56 inches (wettest ever)
Floodwood 7.32 inches (wettest ever)

Tonka up 5": Grays Bay Dam open for 1st time since Labor Day weekend

I've recorded nearly 4" of rain at the Huttner Weather Lab this week on the east end of Lake Minnetonka. It's no surprise that the lake is responding, and the water level is up 5" (.42 feet) since Wednesday according to the Minnehaha Creek Watershed District web site.

The Grays Bay Dam feeds Minnehaha Creek, and the dam has now been opened by MCWD (12CFS) for the first time since it was closed early last September.

Source: Minnehaha Creek Watershed District

Further downstream, Minnehaha Falls is back to life and roaring away these days. 3"+ rainfall pushed level of Minnehaha Creek about 3 feet higher this week, and the Falls look and sound great.

Source: USGS

This is a great weekend to visit Minnehaha Falls. Sea Salt anyone?

Mixed Weather bag: Pick your "sunny" spots this weekend

This will actually be a pretty typical Memorial Day weekend in Minnesota. Some thunder & rain, some sun, and even some heat.

Our active pattern will continue this weekend. Timing summer rain is one of the tougher forecasts we make. The models do a much better job with big, "stratiform" winter rain/snow events than with finicky, "convective" summertime thunderstorms.

That said, here's my best shot at picking your "sunny spots" this weekend.

Friday night: Scattered showers & T-Storms Low 57. Wind E 5-12 mph.

Saturday: Mixed clouds with scattered shower/T-Storm chances. Trending sunnier late PM & evening? High 78. Wind SE 10-20 mph. Choppy lakes.

Saturday Night: Clearing, warmer and more humid. Starting to feel like summer. Low near 66. Balmy south breeze 5-15 mph.

Sunday: Instant July. Best beach & lake day. Mostly sunny hazy, stinking hot & humid. Record hgh near 97! (Record is 95) Wind S 5-15 mph. Growing severe risk late PM.

Sunday Night: Severe storm risk. Heavy rainfall again possible. Low near 65.

Memorial Day: AM showers & T-Storms may linger. Chance for PM & evening sun? High 74. Wind NW 5-15 mph.

Severe weather: Keep the weather radio (and MPR) handy

There is a slight risk for a severe storm Saturday, but all the ingredients may come together late Sunday for severe storms in Minnesota and western Wisconsin.

A cold front will cut into a hot, steamy air mass over Minnesota by late Sunday. Severe storms may rapidly erupt along the front as the "cap" breaks Sunday afternoon.

SPC has already placed a risk "bull's eye" over Minnesota for late Sunday.

Source: NOAA/SPC

Of the 3 summer holiday weekends in Minnesota; you're "climatologically" most likely to get wet during Memorial Day Weekend. It's no big surprise that we'll see some ran this weekend, and maybe some severe weather.

We're now working into the peak time of year for severe weather in Minnesota. Severe weather frequency climbs rapidly in May, and peaks in June.

Is it any big surprise that we should see a few severe storms on Memorial Day weekend?

This "Bud's" for you!

As if another potent low jetting for Minnesota wasn't enough, how about a little "tropical moisture" with your thunderstorms?

Hurricane Bud reached Cat 3 this week. That's the earliest ever for the eastern Pacific according to Jeff Masters at Weather Underground.

Category 2 Hurricane Bud is weakening, but still presents a formidable rainfall threat as it continues north-northeast towards an expected landfall between Manzanillo and Puerto Vallarta, Mexico late Friday night. Thursday night at 11 pm EDT, Bud peaked at Category 3 status, with 115 mph winds, becoming the earliest Category 3 hurricane on record in the Eastern Pacific. Recent Satellite loops show that Bud has weakened, though. The eye has disappeared, and the cloud pattern has shrunk and appears squashed, due to an increase in dry air, wind shear, and cooler sea surface temperatures affecting the storm. These hostile conditions should continue to weaken Bud to a Category 1 hurricane or strong tropical storm by the time of landfall.

Source: NASA MODIS

The remnants of dissipating Hurricane Bud along the Mexican coast may get picked up in the upper flow ahead of our low pressure system, and "injected" into Minnesota by Sunday night and Monday.

Source: NOAA/NHC

The extra infusion of tropical moisture could enhance rainfall in Minnesota. It's relatively rare, but moisture from the tropical Pacific does occasionally get pumped into our storms, and this weekend could be one of those events. Sometimes the models "misunderestimate" the amount of additional moisture being pumped into this systems. If it does, there is a chance that we could see another bout of torrential rains linger into Memorial Day.

MPR (and former WCCO radio) meteorologist Bill Endersen will man the MPR weather lab this weekend and have updates as needed.

Stay tuned, and have a great weekend!

PH