Whoops

Okay, I admit to screwing up the DeKalb forecast. I put overcast, and it was clear, all day. I can only blame myself for trusting model data, instead of myself. Initially, MOS (model output statistics) guidance indicated overcast conditions all day in DeKalb. I was not fully convinced, but just to make sure I did not miss anything, I checked the area forecast discussions from 3 National Weather Service offices: Chicago, St. Louis, and Davenport. All three indicated cloudiness, but all three had different reasons. One suggested clouds were moving in from western Illinois, which after looking at infrared satellite, showed no clouds in or around Illinois. Another suggested a 500 mb shortwave trough, which after looking at a 500 mb map (and practically squinting at it), I could barely find evidence of a shortwave. The third office suggested moisture flowing in with the low level jet, which is what I went with after seeing a nice low level jet off the Gulf of Mexico at that time. My initial thoughts made me question whether the discussions were trying to explain what was happening or if they were trying to verify what the model suggested.

Needless to say, instead of forecasting with my instinct, which told me little to no clouds in DeKalb, I went with the "meteorological cancer" (which is going with what the model suggests). I regret my decision, especially since I had read a few hours before forecasting that the models were not handling the weather very well. So, I admit my mistake. To avoid this next time, I am going to "challenge" the models to a forecast contest. Next forecast, I will NOT use any models, only data (which includes observed conditions, satellite, radar, and hand analysis maps) and my meteorological knowledge and instinct. After this, I will post a forecast using model guidance, without my input (meaning I will just put down what the models suggest, none of my own thoughts). My goal is to show that meteorologists need to use models only for guidance, and not base a forecast on them alone. Stayed tuned for the contest of man vs. machine!

February 25

The pattern remains pretty zonal at 250 and 500 mb. Surface fronts are developing which could bring precipitation into the forecast areas later Wednesday evening. Forecast surface maps show this system moving across the area (just click on the box to advance the maps at the link). These appear to bring precipitation with them. It appears that a low level jet will bring moisture across the forecast areas, which looks to be a cause of cloudiness.

It appears that Wednesday will be fairly cloudy with a small chance of rain.

DeKalb: Overcast, Hi 42. Low 29. Chance of rain 30%. Winds 12-17 mph.

Alton: Mostly Cloudy, Hi 61. Low 44. Chance of rain 10%. Winds 5-10 mph. However, with the front, there is a chance of storms in the evening.

Feb. 23 Forecast

The current weather pattern seems to be ridge/trough. Upper air maps as of 6 pm show this pattern (250 mb , 500 mb)(**Note, links will change with time. I previously forgot to mention this.**). The ridge will move into both areas of interest (DeKalb and Alton), along with surface high pressure. This will bring clear skies and mostly calm winds into both forecast areas.

Basically, this just becomes a temperature forecast.

DeKalb: High 24, Low 16. Sunny. Winds should be at most 10 mph

Alton: High 38, Low 24. Sunny. Winds should range between 5-10 mph.

Hopefully some "weather" will happen when I have time to go in depth. This weekend woulb have been nice, but I was unfortunately busy. Maybe next time.

Video From 2/21/09

Here is the promised video from Feb. 21. The constant "rushing" noise and "cracking" pops are both wind. Just an idea of what was going on.

2/21/09

Sorry there were no forecasts the last couple of days, school has kept me busy.

Currently it is very windy and is snowing in DeKalb. Currently the National Weather Service has DeKalb in a winter weather advisory.
Here is what they have to say:

A WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST
/7 PM EST/ THIS AFTERNOON.

THERE HAVE BEEN 2 TO 4 INCHES OF SNOW THIS MORNING. WE
EXPECT ANOTHER 1 TO 2 INCHES OF SNOW THIS LATE MORNING
AND AFTERNOON. THE WIND WILL BECOME NORTHWEST WITH
SPEEDS OF 15 TO 25 MPH AND GUSTS OF UP TO 34 MPH. THIS
WIND MAY PRODUCE BLOWING AND DRIFTING SNOW THIS LATE
MORNING AND EARLY AFTERNOON.


A WINTER WEATHER ADVISORY FOR SNOW MEANS THAT
ACCUMULATING SNOW WILL CAUSE PRIMARILY TRAVEL
DIFFICULTIES. BE PREPARED FOR SNOW COVERED ROADS
AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

Hopefully, I will be able to do a forecast discussion soon,
but I am a little pressed on time at this moment. Later
I will post a video clip from 1:30 pm, showing conditions
in DeKalb at time of this post. It is a little hard to see,
since there is a lot of little snow flakes being blown in
high winds.

Correction

Naturally, after you post "there were no tornadoes", they decide to drop. As of now 3 tornado reports. Pure irony. Here are the storm reports.

Stormy South

Earlier today(Feb. 18), the Storm Prediction Center had a moderate outlook in the south. There was about a 10% probability for tornadoes, but no tornadoes were reported. There were plenty of tornado warnings, but all were "Doppler Radar indicated." From what I have read, these storms produced funnel clouds, but just could not make the stretch to tornado. There was a fair amount of hail reports with these storms. The nice thing is it gave us weather fanatics a little convection in what seems to be an endless winter. The Storm Prediction Center reports for this event can be found here.

Snowy DeKalb

I just missed the slightly heavy snow with my camera, but was able to get this clip of snow around 4:30pm.

2/19/09 Forecast

The pattern appears to be similar. Mostly zonal flow across the country at 250mb. However, that includes "mostly." There is a ridge/trough pattern shown at 250 and 500 mb. These links provide a look at the maps presently. The nice thing about this is it should break the clouds in DeKalb. It will also provide clear skies in Alton (but this is also due to the frontal passage). There is also some high pressure in the Dakotas and Canada that will move in with this. This will bring the sun! The surface chart shows the basic set up (from what data I had) as of 4:00 pm Feb. 18, 2009.
The trick was looking at MOS guidance for highs and lows. DeKalb is a mess. We should have clear skies under high pressure, and IR satellite imagery shows clouds moving out at this time. MOS shows cloudy. Therefore, I am not confident with its results for DeKalb. It is slightly better for Alton, as in it shows clouds moving out, but not quick enough.

It all (with a lot more not included in this discussion) comes down to this for Thursday:

DeKalb: Sunny. Windy (due to the pressure gradient), with winds around 20mph. High should be about 21 degrees. The low will be about 12 degrees.

Alton: Sunny. Winds should be about 15 mph (the pressure gradient is slightly weaker). High should be 32, with a low of 20.

Precip On The Way

OK, so the first run is a late-night forecast. I am not intending to go too in depth this time, more or less just getting a test run in. I am not sure what maps and such can be displayed, so, I apologize in advance that this discussion will have no maps.

The situation appears to be fairly zonal flow at 500 mb, at this time. 500 mb maps are showing undulations within this pattern. 250 mb maps are almost zonal, except for a small ridging over the Midwest. Skipping around to 850 mb, there is plenty of warm air advection to be found across both Alton and DeKalb. There is also a fair amount of moisture at this level. Maps looked at were from http://www.rap.ucar.edu/weather/

The trouble appears at the surface. Currently an extratropical cyclone is sitting in Eastern Kansas. The Hydrometeorological Prediction Center is forecasting the low to track between the two sites, meaning north of Alton and south of DeKalb. The low is projected to cross over the Northern Illinois region. This will probably give DeKalb a mix of precipitation. Bufkit data from nearby Rockford indicates a deep level of moisture, but the temperature "dances" around the zero degree line.

After looking at MOS guidance, this quick forecast comes down to this:

DeKalb is going to see a high around 38 and a low of 14. It looks to be cloudy, and as typical of DeKalb, windy. Winds will probably be about 10-12 mph, but pick up to about 20-25mph. It is looking like a 70% chance of precipitation, switching from rain, snow, sleet, and some freezing rain. All I have to say is "Yuk!"

Alton will see highs around 47 and lows around 22. There is a 30% chance of rain, which could switch over to snow in the evening. It will also be cloudy in Alton, and should be breezy. Winds will probably pick up from 10-12mph to 18-20mph.