Tornadoes in January

Severe Weather Rips Through Florida

Severe Storms produce five tornadoes in Florida (map from www.spc.noaa.gov)

Snow Update

Some observations in Eastern Iowa are reporting light snow currently.  I think the snow will arive late this evening between 9pm-12am with the snow picking up in intensity during the overnight hours.  Total accumulations between 1-3 inches.

All of what you see on radar over Illinois may not be reaching the ground just yet.

Snow Tonight into Tuesday

A low pressure system will track through central Illinois tonight into Tuesday providing light snow for Northern Illinois.   Total snowfall totals for Northern Illinois will be 1-3 inches.  The snow will taper off Tuesday afternoon, but there could be a few light snow showers/flurries Tuesday night and Wednesday.

Maps from www.Accuweather.com

Forecast Update Sunday January 9 2011

Current Surface Map @ 15z

A high pressure system is currently centered over Kentucky and northern Tennessee right now with another high pressure system located over northern Minnesota.   These areas of high pressure are keeping Northern Illinois free from any precipitation but allowing for the cold air to take hold over the area.   There is a low pressure system along the Gulf Coast of Texas that is triggering some heavy rain and thunderstorms in southeast Texas.   This low will move to the east and cause wintry weather over the Southeast during the next 24 to 48 hours.   Another low pressure can be seen over the eastern rockies.   This system is providing large snow totals for much of Colorado, Montana, Wyoming, and the Plain states.

National Radar @ 11 am Sunday Morning

 The national radar picture shows the large area of precipitation being generated by the Low pressure system sitting over the Southeast coast of Texas right now.  Again this system is going to reek havoc over the Southeastern U.S. for the next 24-48 hours.   Providing snow and even freezing rain for much of the Southeast.   The current radar picture also shows the snow over Colorado into northern Kansas, northwest Missouri, Iowa, Nebraska, and into the Dakotas.  Fortunately for Northern Illinois we are dry and we have clear skies for today, but come Monday and Tuesday the system over the central plains will be pushing off to the ESE so we will see an increase in clouds and we will have a chance of snow showers to begin the week from this system.

Upper Level Winds @ 250 mb 12z Sunday Morning

The winds at 250 mb shows very strong winds over the Southeast.  These winds will carry the low pressure system at the surface over Texas to the east over the next 24-48 hours.  There is also a trough over the Pacific NW where there is another low pressure system at the surface providing some precipitation for the Pacific Northwest.  This trough will also provide needed energy for the low pressure system currently over the rockies that is providing snow for much of Colorado and the northern Plains.  

700mb Winds, Temperature (C), Humidity at 12 z Sunday Morning

Looking closer to the surface at 700 mb we can see the moisture over the Gulf Coast and in the Plains.   Right now over northern Illinois we are dry so skies will be clear today, however, the northwesterly flow will keep us very cold for today.

MODELS:   The NAM and GFS appear to differ not necessarily in the progression of the systems but the intensity of the precipitation.   I am going with the NAM for today.  

NAM Model run includes Sunday night thru Tuesday morning.

Again, high pressure will dominate our weather for today.  However, come Monday the high pressure system is going to move off to the east, northeast as the low pressure system over the rockies progresses to the east, southeast.   As this low pressure system moves off to the ESE  Northern Illinois will experience snow showers Monday night into Tuesday morning.  

NAM prediction for Tuesday night.

The snow will linger into the afternoon and evening of Tuesday as depicted by the NAM model run for Tuesday @ 0z.   The GFS is showing a small chance of some light snow/flurries for Wednesday at the low pressure system moves into the Northeast.


SHORT TERM FORECAST FOR DEKALB AND NORTHERN ILLINOIS:

Today (Sunday):  Clear Skies High: 26 Winds: WSW around 5 mph

Sunday Night:  Increasing clouds.  Low: 15  Winds: ENE 5-10 mph

Monday: Mostly Cloudy High: 28  Winds: ENE 5-10 mph

Monday Night:  Cloudy with a chance of snow showers.   Low:  20  Winds:  ENE 5-10 mph.

Tuesday:  Snow showers continue.  High:  30  Winds:  NW 5-15 mph.

Tuesday Night:  Snow showers begin to end otherwise cloudy skies.  Low: 21 Winds: NW 10-15 mph.

Wednesday: Mostly cloudy.  High: 22

Thursday:  Partly Cloudy.  High: 18  Low: 9

Forecast Update Monday Jan 3 2011

An Alberta Clipper system has triggered a few light snow showers and flurries across the region.  The low is centered over the great lakes and the front is currently passing through Northern Illinois.  Little or no snow accumulation is expected.   Once this system passes we will dry out tonight and skies will gradually clear for Tuesday.  This system will also usher in some colder temperatures for tomorrow.  Today temperatures climbed into the low to mid 30s, but tomorrow temperatures will be in the 20s for highs. 

Infrared Satellite

Current Radar

 The infrared satellite imagery shows the clouds associated with the Alberta Clipper, but the highest clouds are located over Wisconsin.  Most of the snow showers right now are located over the Illinois/Wisconsin border, which is evident based upon surface observations where most locations in southern Wisconsin are reporting snow (shown below).  Winds are coming out of the SSW, but are rather weak right now.  The gradient associated with system is weak, hence, one of the reasons why the precipitation is not that heavy.

National surface map shows the colder temperature just off to our northwest.  Those temperatures will be here for Tuesday as this system progresses to the east.  You can also see the ridging of warmer temperatures ahead of the system from Oklahoma, Missouri, Illinois and further north and east into Ohio.  High Pressure is located over the central plains and will be over Illinois tomorrow providing us with quiet but colder weather conditions.

MODEL DISCUSSION/FORECAST
GFS and NAM models appear to be in fair aggreement for the short term.  

The GFS shows the system currently impacting the area pushing off to the east tomorrow.  Skies will gradually clear throughout the morning hours and we will stay dry for most of Tuesday and early Wednesday.  The next system begins to enter Northern Illinois between 6-8pm Wednesday evening (shown below).  Accumulating snow is more likely with this next system.  However, I am expecting the accumulations to be around one inch of snow.

SHORT TERM FORECAST FOR DEKALB AND NORTHERN ILLINOIS

TONIGHT:  A chance of a passing flurry or quick snow shower.  Little or no snow accumulation expected.  Low: 19      Winds: shift from SW to W overnight 5-15 mph.

TUESDAY: There will be clearing skies in the morning with partly sunny skies.   High: 25  Winds: 5-15 mph.

TUESDAY NIGHT:  Increasing clouds as the next system approaches.  Low: 15  Winds: SW 5-15 mph.

WEDNESDAY:  Partly cloudy to start the day.  Clouds will increase during the afternoon and light snow could begin between 6-8pm.  High: 30  Winds: shift from SW to W 5-15 mph.

WEDNESDAY NIGHT:  The chance for snow continues light accumulation possible.  Total accumulations up to an inch possible.   Low: 12  Winds: NW 5-10 mph.

THURSDAY: Mostly Cloudy with another chance of snow.  Little or no snow accumulation expected.  High: 22

Sunday Jan 2 2011 Updated Forecast

Official Observations in DeKalb for Sunday at the DeKalb Taylor Municipal Airport

Actual Low: 12   I forecasted Low: 10 

Actual High: 26   I forecasted High: 24

I did not have enough time to put a full forecast discussion together.  However, in quick summary will have some clouds trying to move in tonight so skies will become partly cloudy.  No precipitation tonight.  Temperatures for overnight lows will be in the mid teens fbefore climbing to near 32 degrees Monday afternoon.   There is a chance of a flurry or two possible Monday night.  There will be NO snow accumulation with this system.   Temperatures will become drastically colder mid to end week.

 SHORT TERM FORECAST FOR DEKALB AND NORTHERN ILLINOIS

 TONIGHT: Increasing clouds with partly cloudy skies.  Low: 16 Winds: SSW 5-10 mph.

MONDAY: Partly cloudy with  clouds becoming more prevalent after lunchtime.  High: 32 

Winds: SW 5-10 mph.

MONDAY NIGHT:  Mostly cloudy with a slight chance of a flurry.  Low: 18  Winds: W 5-15 mph.

TUESDAY: Skies clear, mostly sunny.  High: 25    Winds: W 5-10 mph.

WEDNESDAY:   Partly cloudy and dry.    High: 28    Low: 12

7 Deaths from Tornadoes on Friday

NEW YEAR'S EVE TORNADO OUTBREAK LEAVES 7 DEAD CLICK HERE FOR MORE!

Forecast for 1/1/2011

The cold front that provided us with the rain Friday has now pushed off to the east and is located right along the Appalachain Mountains.   There are two Low Pressure Centers associated with the cold front.  One can be seen in the southeastearn U.S. and the other is located North of the Great Lakes with a pressure value of 992mb.  Since we are on the backside of the Low Pressure system our winds have shifted.  This has allowed our temperatures to drop back in the teens and twenties today instead of the upper forties to low fifties, which we had for highs yesterday across Northern Illinois.

Current infrared satellite picture shows the thicker cloud cover associated with cold front now off to the east along Eastern Ohio, Western Pennsylvania, and into the Southeast.  Northern Illinois is under partly to mostly cloudy skies behind the system.  Some areas may see a few flurries tonight on the backside of the Low.

Current surface temperatures for Nothern Illinois are in the upper teens and low twenties.  This map depicts the cooler temperatures moving into Northern Illinois from the Northwest quite nicely.  Winds have gusted up to 30 mph in DeKalb at times this afternoon.   Winds should slow during the overnight as the Low continues to push off to the east, northeast.

 The GFS (shown on left) and NAM models (shown on right) appear to be in fair agreement for what is to come over the next few days.  Although the NAM is moving the systems a bit slower when compared to the GFS.  High pressure will dominate our weather for Sunday and Monday so conditions will be dry with partly cloudy skies both days.  Temperatures will remain below freezing as the freezing line (the solid yellow line depicted in the models) stays well off to our south.  A weak area of low pressure will develop over the great lakes providing a slight chance of light snow showers or flurries late Monday night (shown below on the left by the GFS)  into early Tuesday morning (shown below on the right by GFS).  At this point little or no accumulation is expected. 

 SHORT TERM FORECAST FOR DEKALB AND NORTHERN ILLINOIS


TONIGHT: A small chance of some flurries otherwise dry with mostly to party cloudy skies.  Low: 10 Winds: WSW 10-15 mph

SUNDAY: Clouds break up during the late morning then becoming mostly clear.  High: 24 Winds: WSW 5-10 mph

SUNDAY NIGHT: Partly cloudy.  Low: 17 Winds: WSW 5-10 mph

MONDAY:  Increasing clouds with the low pressure moving over the great lakes.  Chance of light snow Monday evening into early Tuesday.  High: 30  Winds: WSW 5-10 mph

TUESDAY:  Any snow that is occuring during the overnight ends during the morning hours of Tuesday.  There will be some clearing in the afternoon to partly cloudy skies.  High: 23 Low: 10