Warm thundery weekend; Dissecting a lightning bolt; Active Arizona monsoon

87F high temp at MSP Airport Friday at 4:55pm

22 days at or above 90 degrees at MSP in 2012 (and holding)

Scattered early AM thunder possible this weekend

Latest Twin Cities radar loop

Source: Twin Cities NWS

"Near 90" this weekend in the metro , very warm but no major heat wave

60s dew points in the metro this weekend

Tropical 70s dew points in southwest Minnesota

100+ core of heat wave bakes areas just SW of MN

Isolated weekend thunderstorms can't be ruled out in MN

50 mile long "derecheo bolt" lightning strike hits Washington D.C.

Welcome rain - Arizona getting soaked with active 2012 "summer monsoon"

Life On The Edge: Minnesota rides the edge of the heat wave this weekend

You can almost pick your spots, and the kind of weather you want in Minnesota this weekend.

Want a cooling breeze? Head for the shores of Lake Superior where temps will be mostly in the upper 70s this weekend at Grand Marais.

Want warm, but not too hot weather for the lake? How about the Brainerd Lakes, where temps will push into the upper 80s with light breezes.

Aquatennial bound? Look for "almost hot" temps a few degrees either side of 90 in the metro this weekend.

Want to feel the heat and humidity? Pipestone and Blue Mounds State Park are your best bets with mid 90s and dew points in the sweaty 70s.

Minnesota is on the edge of the heat wave this weekend, which has shifted to the south & west.

Crispy lawns in the Chicago suburbs these days

Photo by Leslie Underwood

That's welcome news from the Twin Cities to Chicago all the way east to Boston and New York where temps hovered in the 60s Friday afternoon with clouds and cooling rain showers. Yes there is heat and drought in the Midwest, but alas the entire world is not on fire after all...and they'd gladly trade Friday's cool rains for some sunshine and warmth out east this weekend.

100 degree heat will still bake the plains of Nebraska and South Dakota this weekend.

In Minnesota we can't rule out a stray T-Storm or two, SPC does not have any "severe risk" up for Minnesota this weekend so far.

Dissecting a "Derecheo Bolt:"

You may recall the amazing derecheo that blew trees down from Chicago to D.C. in late June.

Now a photograph of a lightning strike in D.C. has been analyzed, and shows just how amazing and dangerous lightning can be. The bolt eventually travelled over 50 miles from the point of origin 22,000 feet up, before striking ground in the Capital City.

Source: Capital Weather Gang

The excellent analysis here form the Capital Weather gang.

Arizona Monsoon 2012: "You're as welcome as rain"

Things are good in the Sonoran desert so far during the annual "summer monsoon."

Rainfall is well above average at most reporting sites, turning the desert lush green in many spots.

Source: Tucson NWS

At the risk of being picky about monsoonal nomenclature, the term "monsoon" comes from the Arabic word "mausim" and means "season." You hear people say "monsoon season" but that's really redundant...like saying "season season." The most accurate way to describe the monsoon in the southwest is to say "summer monsoon."

Monsoon refers to the seasonal wind shift in the upper atmosphere that brings moisture from the Gulf of Mexico and Gulf of California into the desert southwest. The individual storms are not "monsoons"...but rather best named "monsoon thunderstorms."

"Monsoons" occurs in different parts of the globe, and in the southwest USA the technical name is "The North American Monsoon."

No matter what you call it, people in Arizona celebrate the monsoon this time of year as it brings cooling T-Storms, spectacular lightning displays and sunsets, and precious rainfall to the desert.

I spent 9 years forecasting weather in the Arizona desert in Tucson, and the summer monsoon is the time of year I miss the most. If you ever get the chance, pay a visit to Tucson in late July or August. You'll be rewarded with some of the most picturesque skies you have ever seen.

PH