Update: 5:00 pm. Doppler Radar out of the Twin Cities shows strong/severe T-storms rumbling out of eastern South Dakota, about to brush far southwestern counties of Minnesota with marble-size hail, torrential rains and wind gusts as high as 50-60 mph. A few warnings may be issued for individual counties. These storms will pass off south/west of St. Cloud and the Twin Cities, in fact we probably won't see any significant rain, locally, until Thursday at the earliest. Meanwhile southwestern counties may pick up some 1-2" rainfall amounts over the next 36 hours. A difference of 75-100 miles in the storm track made a HUGE difference, the difference between beneficial, soaking rains and "partly sunny." So close...
* 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.
Paul's Outlook for the Twin Cities
Today: Sun dimmed by increasing high clouds. Showers/storms should stay south/west of the immediate metro area. Winds: E/SE 10-15. High: 81
Tonight: Partly cloudy, probably dry. Low: 60
Tomorrow: A mix of clouds and sun, seasonably mild. High: 82
Thursday: Clouds increase, unsettled, a few showers and T-storms. High: 84
Friday: Sun much of the day. Showers and T-storms arrive Friday night. High: 83
Saturday: Damp, gray start, but quickly becoming mostly sunny, breezy and cooler. High: 79
Sunday: Probably the nicer day. Plenty of sun, warming up. High: 83
Monday: Better chance of showers and storms, some possibly heavy. High: near 82
Tuesday: Muggy, leftover T-storms in the area. High: 835
Here's the very latest Drought Monitor update for Minnesota, showing dry conditions over the southern 2/3rds of the state, moderate drought near Granite Falls and the entire Twin Cities metro area, Rochester and southeastern Minnesota - severe drought conditions east of St. Paul. Just 3 months ago only 15% of Minnesota was deemed to be "too dry." That number is up to 43% as of early July. Moderate drought conditions are impacting nearly 14% of Minnesota, compared to just over 8% in early April. To get the latest report click here.
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.
I'm not picking on the local National Weather Service office - they do an amazing job, in fact after working in a number of cities around the nation I've found the local Twin Cities office to be among the very best in the USA. But this shows how quickly the forecast can change, especially when winds are blowing from the northwest in July. Yesterday's predicted weather map showed showers and storms spreading as far north at St. Cloud and the Twin Cities. Overall they placed the heaviest rain predictions in the right spot - focused on southwestern Minnesota.
Forecast for 7 pm today (WRF/NMM model). Here's the weather intelligence that made me change my tune, issued late last night (there are 4 model runs every day, each one is usually different, but it's possible to discern trends with each passing run). The map shows predicted rainfall amounts between 1 pm and 7 pm today, with the heaviest rains projected for far southwestern and south central counties of Minnesota, little or NO rain reaching Alexandria, St. Cloud and the Twin Cities. Again, a slight shift in the storm track, no more than 75 miles, will make the difference between showers and partly sunny. This is why Minnesota meteorologist have gray (thinning) hair, and ulcers on our ulcers.
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.
Check this out: a small, focused "microscale" lake effect taking place around Lake Mille Lacs. This high-resolution image was taken yesterday afternoon by NASA's "Terra" weather satellite, which is in low orbit, roughly 250 miles above the earth. During the day land heats up more than water, so cooler air above Lake Mille Lacs spreads outward, away from the lake, a miniature cool front responsible for focused upward motion, and a circular cloud formation of bloated cumulus (congestus) surrounding the lake, bulging toward the southeast, in the direction of surface winds. To get the latest image (with amazing resolution as high as 250 meters (!) click here). Unless you have a friend in the CIA this is about the highest-resolution satellite image you're going to find (with near real-time data) on-line. You can also see the tops of thunderheads that popped up over far southwestern Minnesota along a stagnant front that will whip up more heavy weather, most of it staying south/west of our area through Thursday.