Archive for January 2008

Record radical temperature swing

Posted: Tuesday, January 22, 2008 at 11:54 am
By: Administrator
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Sixty-five years ago today, the largest temperature swing ever recorded in North America occurred. It happened here in South Dakota, in Spearfish, on January 22, 1943. The temperature at 7:30 a.m. was –4°F. Suddenly, a blast of hot air hit, and two minutes later, the temperature had risen to 45°F, the fastest warmup ever recorded in the U.S. By 8:45 a.m., the temp reached 55°F — before plummeting back to 0°F 45 minutes later. A recording themometer at the Montana-Dakota Utilities building documented the event for history. On the left is the original thermograph, and on the right is the data on a flat graph for easier viewing:Images courtesy Dr. Dennis Todey, SDSUHere is the way the event was reported in the Spearfish Queen City Mail: "[Tommy] Thompson said the IOOF building immediately turned white with frost. Car windows iced up, and drivers had to stop in the middle of the street because they couldn’t see. By the time Thompson arrived at work, a crowd was gathering in front of the MDU office to watch the thermometer. Marion Vaughn was working as cashier at MDU. She said, ‘People crowded the window all the day and there was lots of excitement. Finally we took the recording and laid it down in the window so people could see it easier. It was really a phenomenon, almost eerie. People couldn’t understand it.’"The fluctuating temperatures damaged many pine trees in the Spearfish area. The Guinness Book of World Records called the Spearfish episode the "world’s greatest variance in temperature." But the pool of hot air also invaded other nearby places. According to Black Hills Believables, "At mid-morning downtown, Rapid City’s temperature was near zero, while the Canyon Lake neighborhood basked in 55 degrees. Motorists crossing from the ice box zone to a warmer part of town were forced to pull over, their windshields instantly obscured by peculiar frost. Here’s what the Rapid City Journal said the next day: "The phenomenon was striking at the Alex Johnson Hotel corner at 11 a.m. On the east side of the hotel, winter was in all its glory, biting legs and faces, while around the corner on the south side, not fifty feet away, spring held sway."A lot of places around the country claim their weather can change from minute to minute. In the Black Hills, they can prove it.

SNOWFALL TOTALS

Posted: Tuesday, January 22, 2008 at 4:51 am
By: Administrator
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Here are snowfall totals from this most recent storm. Feel free to add your totals to the comments section below!0650 AM SNOW PICKSTOWN 43.07N 98.53W01/21/2008 M5.5 INCH CHARLES MIX SD CO-OP OBSERVER0700 AM SNOW 4 WNW HERRICK 43.14N 99.26W01/21/2008 M5.5 INCH GREGORY SD CO-OP OBSERVER0700 AM SNOW HERRICK 43.12N 99.19W01/21/2008 E4.0 INCH GREGORY SD CO-OP OBSERVER0700 AM SNOW 11 S WHITE LAKE 43.57N 98.71W01/21/2008 M3.0 INCH AURORA SD CO-OP OBSERVER0700 AM SNOW FAIRFAX 43.03N 98.89W01/21/2008 M4.5 INCH GREGORY SD CO-OP OBSERVER0700 AM SNOW 8 SSW HERRICK 43.01N 99.25W01/21/2008 E6.0 INCH GREGORY SD CO-OP OBSERVER0930 AM SNOW FAIRFAX 43.03N 98.89W01/21/2008 M4.5 INCH GREGORY SD CO-OP OBSERVER0312 PM SNOW 4 N CURRIE 44.13N 95.67W01/21/2008 M1.0 INCH MURRAY MN TRAINED SPOTTER EVENT TOTAL SO FAR ON NORTHEAST SIDE OF LAKE SHETEK0320 PM SNOW BROOKINGS 44.31N 96.79W01/21/2008 M0.8 INCH BROOKINGS SD CO-OP OBSERVER0322 PM SNOW FLANDREAU 44.05N 96.60W01/21/2008 M1.6 INCH MOODY SD CO-OP OBSERVER0327 PM SNOW 2 S WINFRED 43.97N 97.36W01/21/2008 M1.3 INCH LAKE SD CO-OP OBSERVER0329 PM SNOW MARION 43.42N 97.26W01/21/2008 E2.6 INCH TURNER SD CO-OP OBSERVER0330 PM SNOW 3 SE SIOUX FALLS 43.51N 96.68W01/21/2008 M3.0 INCH MINNEHAHA SD NWS EMPLOYEE0335 PM SNOW YANKTON 42.89N 97.39W01/21/2008 E7.0 INCH YANKTON SD CO-OP OBSERVER0339 PM SNOW VERMILLION 42.78N 96.93W01/21/2008 E8.0 INCH CLAY SD CO-OP OBSERVER0340 PM SNOW WAKEFIELD 42.27N 96.87W01/21/2008 M5.5 INCH DIXON NE CO-OP OBSERVER0351 PM SNOW 4 W WORTHINGTON 43.63N 95.68W01/21/2008 E3.0 INCH NOBLES MN CO-OP OBSERVER0400 PM SNOW SIOUX FALLS 43.54N 96.73W01/21/2008 M2.7 INCH MINNEHAHA SD OFFICIAL NWS OBS MEASURED AT JOE FOSS FIELD0400 PM SNOW ROCK RAPIDS 43.43N 96.17W01/21/2008 E4.0 INCH LYON IA CO-OP OBSERVER0408 PM SNOW SPENCER 43.15N 95.15W01/21/2008 E4.0 INCH CLAY IA CO-OP OBSERVER0412 PM SNOW 2 E STORM LAKE 42.65N 95.16W01/21/2008 E5.0 INCH BUENA VISTA IA CO-OP OBSERVER0415 PM SNOW 2 NE LAKEFIELD 43.70N 95.14W01/21/2008 E3.5 INCH JACKSON MN CO-OP OBSERVER0415 PM SNOW SIOUX CITY 42.50N 96.39W01/21/2008 M8.3 INCH WOODBURY IA OFFICIAL NWS OBS0418 PM SNOW CANTON 43.30N 96.58W01/21/2008 M4.0 INCH LINCOLN SD CO-OP OBSERVER0420 PM SNOW MARSHALL 44.45N 95.79W01/21/2008 E0.8 INCH LYON MN CO-OP OBSERVER0427 PM SNOW MITCHELL 43.73N 98.03W01/21/2008 E2.0 INCH DAVISON SD LAW ENFORCEMENT0438 PM SNOW EVERLY 43.16N 95.32W01/21/2008 E6.0 INCH CLAY IA CO-OP OBSERVER ESTIMATED 5 TO 6 INCHES.0456 PM SNOW IDA GROVE 42.34N 95.47W01/21/2008 E7.0 INCH IDA IA LAW ENFORCEMENT0458 PM SNOW HURON 44.36N 98.22W01/21/2008 M1.0 INCH BEADLE SD TRAINED SPOTTER0500 PM SNOW ALTON 42.99N 96.01W01/21/2008 E3.0 INCH SIOUX IA CO-OP OBSERVER0527 PM SNOW HOLSTEIN 42.49N 95.54W01/21/2008 E5.5 INCH IDA IA CO-OP OBSERVER0534 PM SNOW HARDWICK 43.78N 96.20W01/21/2008 M2.5 INCH ROCK MN CO-OP OBSERVER

Monday Snow

Posted: Monday, January 21, 2008 at 8:53 am
By: Administrator
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Snow is still falling across much of southern and southeastern KELOLAND this morning.  The snow is very light and fluffy because of the temperature.  You can see the bands of snow are in an east-west orientation right now…a trend that will continue today.The total water content of the snow is very low.  This is about a 20:1 or even 25:1 ratio event.  Normally, we would say .10" of water would yield an inch of snow.  Today…it’s about half that.  Thankfully, the wind is not strong, but a breeze will increase from the northwest a little more tomorrow…especially in western SD in the range of 15-30 mph.  The Hills had about 2-4" from this system.Before I go…here are some snowfall totals as of 8:30am.  More later today…Sioux Falls   1.5"Sioux City      7"Tyndall      4"Yankton   5"Rapid City   3.7"Huron    .6"Mitchell     .8"White Lake 2"

Winter's Wrath

Posted: Sunday, January 20, 2008 at 6:57 am
By: Administrator
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First it was the frigid temperatures and now we have SNOW on the way!!!  I think a lot of people thought we were just going to coast through the rest of this winter, after some of the nasty winter weather we saw in December.  Well, it looks like that won’t be the case.  This next snow maker will mainly affect southern portions of South Dakota, although some light snow showers will most likely spread into northern portions of the state as well.  Because our air temperature is so cold the snow will be very light and fluffy and thus will add up quickly where it does fall.  The challenge with the system moving in will be how strongly the cold, dry air to our north will affect it.  We know there will be a very sharp cutoff on the snowfall because of this cold, dry air, but exactly where that line sets up is a little more challenging.  Right now it looks to basically cut right through the center of the state, but that is something we will have to watch.  As far as snow totals, quite a few people will be looking at 3-5" of snow especially south of I-90.  I think that 2-4 inches is a pretty good bet for areas around Sioux Falls, although some isolated spots could end up with a little more especially just south of Sioux Falls.  Out west there will be a large area looking for 3-6" with some isolated spots looking for more like 7 or 8 inches.  Either way the snow will be fairly easy to clean up because of its light fluffy nature, but could also lead to some reduced visibilities as the winds pick up out west.  The snow will gradually work its way eastward through the day Sunday and should last well into the day Monday as well.  If you have any snow reports or pictures of the snow you can send them to weather@keloland.com.  Stay tuned!

The Week Ahead

Posted: Sunday, January 13, 2008 at 3:49 pm
By: Administrator
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The week ahead looks pretty active as we stay in a pattern that will continue to bring Alberta Clippers through the northern plains.  These quick moving systems will bring us light snow, gusty winds and cold chunks of air.We will see a quick cool down for Monday (especially in the East) before we warm back up again by Tuesday.  A more significant cold stretch will move in for the middle and end of the week.  The northeast will be hit the hardest with temperatures moderating a bit as you move farther south and west.  All of KELOLAND will feel the effects of this latest push of arctic air.  Our chances of snow will be spread out across the week.  All of them look to be pretty light snows with only minor accumulation possible.  Timing out clippers can be a bit challenging but it is now looking like our best chances of snow across KELOLAND will be late Tuesday and then Thursday into Friday.It will definitely feel like winter by the end of this week!

The Art of Forecasting

Posted: Wednesday, January 2, 2008 at 8:58 am
By: Administrator
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I couldn’t help putting my 2 cents in on what Jay talked about in the last blog.  In some ways I’m glad I had those days off around Christmas and missed that forecast!  But I also know that with each “wrong” forecast, the dedicated meteorologist will learn from that particular experience.  Delivering accurate forecasts has come along way in the past few years.  To be quite honest, it’s a miracle the “computer models” do as well as they do given the uncertainty in weather data.  And to say a computer model is worse than the "old" ways of weather forecasting isn’t accurate either.
 
So why do we use these “models” and what good are they?  To understand that, it’s important to understand the limitations of weather computers.
 
First, the network of observation sites is limited in some areas where our weather comes from in KELOLAND.  Mexico and to some degree Canada are two spots with big holes with weather data.  Then there’s the ocean…it’s pretty much impossible to put in a bunch of weather stations out there. 
 
Even the data we have can sometimes go bad.  An error in an observation thrown into a computer model gets bigger with time…bad news for the forecaster.
 
Then there are the complex physical processes out there in the weather world.  Differential heating, snow and ice cover, evaporation, and terrestrial radiation…and that’s just the start.  Small terrain differences affect snowfall this time year…just ask anybody in Webster and Britton!
 
This time of year, fog and arctic air are a challenge to forecast because they are usually very shallow…making it difficult for a computer to resolve.
 
Having said all of that, computer models usually do a good job of forecasting big storms.  The smaller they are in size (the Christmas snow for example), the worse they do.   In the past, computer power was a real limitation, but that’s getting better and will continue to improve in the future.  And as more data is added out there in the world, the accuracy has improved.  The perception of accuracy has more to do with the weather is presented today verses 20 or 30 years ago.
 
Take for example these 2 forecasts…which one do you think has a better chance of being right?
 
 
Expect some snow this morning with clouds and mostly cloudy to mostly sunny conditions in the afternoon, although there might be a furry or snow showers sometime later today. The high will be in the 20s and possibly into the 30′s if there is more sunshine. The low tonight will range from 10 to 25 degrees. Winds will be from the North at 5 to 20 miles per hour.
 
This type of forecast has a good chance of being correct, but offers very little useful information to the public. 
 
Here’s another extreme….
 
The snow will end this morning at 9:00am. Expect decreasing clouds this afternoon between 2pm and 4pm with a 100% chance for snow by 6pm.  Evening snowfall accumulation will be ½ inch…with 1 possible on the southern side of the city. The high today will be 30 ° with a low tonight 19 °. Temperatures will start at 22° at 8 am and gradually warm to the expected high. Temperatures will warm most rapidly at 2pm with the increasing sunshine.
 
 
We look great when we get this type of forecasting right!  Chances are, however, something in this forecast is bound to go wrong.  We have the ability to analyze short-term small-scale weather with great detail than even before.  KELOLAND Live Doppler HD allows us to look at real-time weather with better precision and accuracy than at any time in our history.  But it has no way of forecasting the 7 day outlook!There’s a balance between being way too general and way too specific…and then interpreting the reliability of the computer model to give you the best forecast.
 
So that’s my 2 cents…maybe more like a dollar or two!