Here’s a look at a typical meteogram that our team uses to forecast temperatures. Each line represents a computer model. The green line is the NWS forecast and the black dots are the observed values from today.

You can see the opportunity of a 56° afternoon one model gives us for Sunday afternoon. Also of note, the only two models that go out to Thanksgiving are pointing toward high temperatures in the low 30s! Yikes!

Posted under cold blast, weather

I love sharing cool pictures, so I have some more to share.  This is really a eerie but cool sight to see.  As if rocket launches weren’t spectacular enough, sometimes viewers are treated to a special light show when rocket trails are illuminated by high altitude sunlight. Called twilight phenomena, these giant colorful doodles in the sky leave us wondering… how are these formed??
These twilight phenomena or twilight effects occur when the unburned fuel particles in the rocket trail and water condense, freeze and then expand in the thinner upper atmosphere. Because rocket trails extend really high into the stratosphere and mesosphere, they can catch high altitude sunlight long after the sun has set. The small exhaust particles diffract sunlight and produce pink, blue, green and orange colors, making the twilight phenomenon all the more spectacular.

Happy Weekend Everyone!!!

Posted under weather

An ice spotter training session will be held at 10 AM on Saturday November 21, 2009 at the Public Safety Building in Dixon, IL located at 220 S Hennepin Ave. Registration is required.

To register for the ice spotter training, please contact Bill Morris, Hydrologist with the NWS Chicago office.  Include your name, address, and phone number.  Contact: William.morris@noaa.gov or phone 815-834-0600 x493.

Why River Ice Spotters?

The National Weather Service (NWS) is responsible for the issuance of river forecasts and flood warnings. We rely heavily on a network of river gages owned and operated primarily by the U.S. Geological Survey.  During the colder months, ice jams can result in flash flooding.  However, ice jams are typically localized and river gage readings do not always accurately indicate what is occurring when ice is involved.  For accurate ice assessment, one needs to know information such as the extent of the existing ice cover, if there are any open areas, has the ice begun to breakup…etc. This information can only be obtained by visual observations.

What qualifications are required?

No special qualifications are required other than living or working near a river and a willingness to report river and ice conditions. Access to the internet is preferred.  We may also have a need to contact you directly as well.

What kind of information will I be reporting?

The information could include observations of river freeze-up, percent of ice cover, or if the ice cover is beginning to break. High priority would be given to reports of ice jam formation, breakup of an ice jam, or ice jam flooding. Observations are requested weekly December through April or whenever existing conditions change.

Safety

Safety is important! All visual observations of ice conditions will be done from a safe location only.  Under no circumstances should ice spotters venture out on the ice to take an observation.

Posted under flooding

…low pressure is finally exiting the building!

Five days of cloudy, drizzly, and rainy weather comes to an end tomorrow

. The problem with this exiting low pressure is the fact that we’re not drying the atmosphere out in a quick enough fashion. This will lead to fog development tonight and thick cloud cover for the first half of Friday. Dewpoints will eventually drop Friday afternoon to allow some patchy sun to work in.

The weekend looks to be pretty nice. Make plans for that because some wons backward is in the outlook for Wednesday. (I’m just not ready to type that word yet.) -ES

Posted under cold blast, weather

Yesterday, Nov. 18th, something exploded in the sky above the western United States. Witnesses in Colorado, Utah, Wyoming and Idaho say the fireball “turned night into day” and issued shock waves that “shook the ground” when it exploded just after midnight Mountain Standard Time. The fireball was so bright it actually turned the sky noontime blue.  Although the fireball appeared during the Leonid Meteor Shower (we could not enjoy that… thanks to the cloud cover), it was not a Leonid. Infrasound recordings of the blast suggest a small asteroid hitting Earth’s atmosphere and exploding with the energy of 0.5 to 1 kiloton of TNT. WOW!!

Check out this link from our NBC affiliate KSL-TV in Utah… this is sooo cooool. They caught it on tape.  Amazing!!!   http://www.ksl.com/?nid=148&sid=8714738

Posted under weather

Natural gas tumbled more than 6 percent, the biggest drop almost seven weeks, as mild weather trimmed demand for the heating and power-plant fuel. Natural gas for December delivery fell 27.6 cents, or 6.1 percent, to settle at $4.254 per million British thermal units on the New York Mercantile Exchange, the biggest one-day drop for a contract closest to expiration since Oct. 1.

As we have been mentioning on air and on the blog, our temperatures so far this November have been above average, with 16 of the 17 November days reporting at or above average highs. Also, with the effects of El Nino this winter, the region may be warmer than usual for the majority of the season, which means lower prices!

Posted under 13 Climate Authority

Just wanted to post a follow-up to yesterday’s initial thought of a wintry mix Tuesday. It certainly seems plausible (not probable) that we’ll have some rain/snow mix Tuesday afternoon and evening. This system is expected to carve out a trough in the middle of the country which will allow for more wintry precip next week.

Right now, I’m being cautious not to term this a “winter storm” as our recent warmth has allowed the soils to remain quite warm. We’ll continue to monitor this system closely on all of our global and in-house models as it comes during a time when many people will be traveling. -ES

Posted under rain, snow, winter storm

If you live in the Arctic/Polar Circle then that is what you are experiencing right now…sun rising in the south and setting in the south only an hour later.  Sky watchers around the Arctic Circle enter the long polar night when the sun doesn’t rise at all. How long this period lasts depends on your latitude. In northern Norway, the sun won’t be back until the end of January 2010.

A common misconception is that the shortest day is totally dark at each point where the midnight sun occurs inside the polar circle. In places very close to the poles this is true, but in regions that are located at the inner border of the polar circles where midnight sun is experienced, this is not true. Due to twilight, these regions experience polar twilight instead of the polar night.

The opposite of Polar Twilight is Midnight Sun.  The midnight sun occurs in the summer months at latitudes north and nearby to the south of the Arctic Circle where the sun remains visible at the local midnight. Given fair weather, the sun is visible for a continuous 24 hours, mostly north of the Arctic Circle. The number of days per year with potential midnight sun increases the farther poleward one goes.

So I guess everyone in Norway is saying “Goodbye sun, see you in 2010.”

Posted under weather

Putting money down on a forecast a week out based on global computer models is not a task I’d advocate, however there are some signs out there that there will be a bout of winter next week.

Low pressure will eject out of Wyoming into the Central Plains. Attendant moisture will then move in out of the Gulf. Both Climatology and model consensus suggest that it’s still too early for a whopper. However some flakes of snow will be in the outlook for Tuesday. Keep tabs on this with us through the week!

Posted under rain, snow, weather, winter storm

Here are some funky looking clouds, that are not seen very often here in Illinois.   But if you have lived near mountains, then you have probably seen these before.  Enjoy

Lenticular Clouds are stationary lens-shaped clouds that form at high altitudes, and are perpendicular to the wind direction. Lenticular clouds can be separated into altocumulus standing lenticularis (ACSL), stratocumulus standing lenticular (SCSL), and cirrocumulus standing lenticular (CCSL).

They form from stable moist air that flows over a mountain or a range of mountain.  If the temperature at the crest of the wave drops to or below the dew point, moisture in the air may condense to form lenticular clouds.  As the moist air moves back down, the cloud may evaporate back into vapor.   The clouds have been mistaken for UFOs because these clouds have a characteristic lens appearance and smooth saucer-like shape. 

Posted under weather