As of 4pm Tuesday, the Twin Cities was around 1.00″ behind normal precipitation since June 1st and a little over 5.00″ behind normal precipitation since January 1st. Tuesday night’s rain was a nice slow soaker. Gully washing convective thunderstorms are always dangerous if the ground is dry. Instead of draining into the soil, heavy rain cascades over concrete-like lawns and gardens and collects into drainage pipes and sewers that have a hard time accepting all the rain at once, which sometimes can exceed 2 inches of rain per hour in heavier thunderstorms. Instead, the pitter patter of raindrops on the window Tuesday night was just the right tempo; steady enough for a good drink across the entire Twin Cities metro. More rain is expected this week with, perhaps, our first shot at severe storms statewide on Thursday afternoon/evening. Spongier soil from Tuesday’s rain will have an easier time accepting rainfall that may come down heavy at times later this.
Image credit Pekka Parviainen
Did you know that weather on earth forms in the lowest layer of the atmosphere called the troposhpere? Cloud formation comes in many makes and models in this layer: Cumulus (low clouds), Alto (middle clouds) and cirrus (high clouds).
Here’s a nice visual from Enchanted Learning:
Cumulonimbus clouds are the tallest clouds in the troposphere, which can grow to a height of nearly 12 miles high or more (60,000 ft.)
Image courtesy NASA’s Earth Observatory. This picture was taken high above Africa looking down at at thunderstorm towering to nearly 12 miles high.
Have you ever wondered what the names of clouds mean. Here are some Latin cloud meanings from the weather notebook:
So, now that I’ve given you an overview of typical cloud formations, take a look at this video:
These are called NLC’s or “noctilucent clouds” and I’ve actually never seen these. They are very rare and only happen during the summer months in the northern hemisphere and occur during twilight. First, take a look at this graphic: (Just mouse over the different objects to get a quick description)
What layer do you think noctilucent clouds form in?
If you said Mesosphere, you were correct!
Noctilucent clouds are the highest cloud in the Earth’s atmosphere, developing around 50 miles high – the same layer that shooting stars appear. Because they are so high, they are visible long after the sun disappears below the horizon.
Image courtesy NASA
These clouds are still somewhat of a mystery to scientists, but some speculate these clouds form due to ice crystals/water vapor from space shuttles.
Read this report by NASA:
Space Shuttle Endeavour is set to lift off early Wednesday morning after a hydrogen leak postponed their launch on Saturday June, 13th. Here’s the bad news, if they get off the ground Wednesday, they will have to wait until mid-July. If you’d like to follow their mission, check out Endeavour Astronaut Mark Polanski as he TWEETS from space:
* Damp start. Break in the showery pattern Wednesday midday into Thursday afternoon.
* Next chance of organized showers comes late Thursday into Friday. Some storms may be strong to severe. The Storm Prediction Center has MN and WI under a slight risk of severe weather.
* Saturday rain may linger over Wisconsin, clouds and showers can’t be ruled out over far eastern Minnesota. Overall, the weekend is looking drier and warm
*Sunday (Father’s Day) showers and storm return late
* Long-range guidance: highs mostly in the 80s the last full week of June. No more cold fronts in sight.
Today: damp start, then becoming partly sunny with an unsettled afternoon sky. High: 81
Tonight: Another round of showers and storms slides into western Minnesota. Low: 61
Thursday: Partly sunny. Showers and storms developing late in the day, some strong to severe. High: 81
Friday: Unsettled with a few widely scattered showers or storms. High: 77
Saturday: Drying out. Sunshine returns with June-like temperatures. High: 84
Sunday: Sunny start, clouds increase late with showers and storms by evening. High: 84
Monday: Partly sunny with a chance of scattered showers and storms. High: 85
Tuesday: Still unsettled, getting warm and muggy. High: 87