- Anonymous
What's that old saying, "when in a drought, don't predict rain?" That old, sage bit of advice comes to mind this morning. Yes, I'm a fan of sunny weekends and stunning summer days, like the one we enjoyed yesterday. Yesterday was something cooked up by the Minnesota Chamber of Commerce: blue sky, popcorn cumulus clouds, a gentle breeze, low humidity. Even the mosquitoes seemed to be lethargic, charmed by a brilliant blue sky draped from one horizon to the other. Truth be told, if the weather was like this every day (San Diego comes to mind) a). it wouldn't be special anymore, and b). Minnesota would have a population of 15 million. I-494 would be 6 lanes in every direction, we'd be stuck with condo's and high-rise apartments on every one of our wondrous lakes, that magical, mythical quality of life would go right out the window. Our cruel winters are an insurance policy, preventing us from morphing into "L.A. with lakes."



Here's more evidence that the drought is expanding. This map shows water volume in Minnesota's rivers and streams, compared to normal for early July. The red dots show streams where volume is less than 10% of what it should be this time of year! Almost all the orange and red markers, showing lower than normal stream flows, can be found in eastern Minnesota. The farther west you go, the more the situation improves, in fact stream/river flows are above average in the Red River Valley, where flooding woes have been fairly persistent ever since the Fargo/Moorhead area was threatened by massive flooding back in April. Lake water levels are lower than average too across much of eastern Minnesota, including the Twin Cities. It's a tale of two Minnesotas: growing drought in the east - but a nagging flood risk far northwest, where soil is saturated and streams are overflowing their banks. Go figure.
Personally I was happy about the prospect of rain this week. Up until last night it looked ripe for significant rains, central Minnesota teetering on the edge of sweltering heat just to our south, and unusually cool, Canadian air lurking over Manitoba and northern Minnesota. A classic tug-of-war was brewing, computer models forecasting a veritable parade of clipper-like disturbances racing southeast, each one irritating the front over Minnesota, showers and storms blossoming overhead as this cold swirl passed overhead. That was yesterday. This is Minnesota, where if you blink, sneeze, look away for just a split-second, the weather is bound to change.
Upper level winds, the fabled jet stream meteorologists love to babble about, are blowing from the west-northwest, a little unusual for this, historically Minnesota's hottest month. I've found that the weather models tend to be more unreliable than usual. A slight shift of 50-100 miles can make the difference between 2" of rain and "partly sunny." So it is today, and much of tomorrow and Thursday too - significant rains sliding off JUST to our south and west, soaking much of southwestern Minnesota with beneficial rains, but missing the Twin Cities area. Yesterday it looked like many towns would pick up .5 to 1.5" of rain by midweek. Now it appears we'll be lucky to pick up a paltry .10" of rain by Thursday. Meanwhile Pipestone, Windom and other towns in far southwestern Minnesota may pick up 1-3" of rain over the next 72 hours.


To get the latest WRF/NAM model and see for yourself how fast our weather can change, click here, then check WRF-NMM, "USA or Great Lakes" view, then go down the left column until you see SLP/6 Hr Precip. You can click on a 6, 12, 18, 24 etc hour forecast to see a Java map pop up that displays expected rainfall during the previous 6 hours. Pretty cool.

Weather Headlines
* 85 degree high Monday; the first 6 days of July are running nearly 3 degrees cooler than average.
* Latest weather models: most significant rains pass south/west of the Twin Cities through midweek, about .10" of rain predicted by Thursday.
* Best chance of rain? Thursday appears to be the wettest day of the week.
* More showers/storms predicted late Friday and Friday night.
* Damp start Saturday morning, but sun should quickly return behind a cooler front, temperatures stuck in the 70s statewide.
* Sunday: probably the sunnier, warmer, more lake-worthy day of the weekend, highs should reach the 80s over most of the state.
* Don't write summer off just yet. GFS model hinting at a string of 90s from July 17-20.

No comments:
Post a Comment