"The Return of the Blog"

Back when Cheatham County Weather was first created, I used to update this blog twice a week on Sunday and Wednesday.  That will once again be the case.  From now on, you can get your latest extended weather for Cheatham County, TN right here!  Be sure to check out the rest of the blog.  Notice on the left hand column of the page, we are now of Google+ so be sure to add Cheatham County Weather to your circle.  Also, if you're a weather nerd (like me haha) be sure to check out all of the pages on the left hand side of the page.  Notice on the right hand side, there is the Twitter Feed for our Twitter page.  If you haven't followed @CheathmSevereWx, do it right now!  I will have a full write up on the upcoming Winter Weather set up for Thursday on Wednesday's edition of the blog.  May the force be with you.  

Snow mid-week?

Current Conditions:

Mostly sunny conditions today allowed for the temperature to reach a high of 52 across the county with the low this morning being 26. Currently an upper level low is located over northern New Mexico with a ridging pattern over our area. Associated with the upper level low is moisture which is causing blizzard conditions across Oklahoma and Kansas. At the surface, low pressure is located over western Texas with a stationary front stretching from the Texas panhandle over into Missouri. High pressure is located over southeastern Ohio and West Virginia which is the reason for our mostly sunny conditions today. The temperature as of 8:30 P.M. is 37 with winds out of the Northeast at 3 mph.

Surface map valid for 7:20 P.M. on February 24, 2013.

Forecast:

The winds overnight will be coming out of the east and getting wrapped around the low pressure over Texas. Temperatures overnight will get down to 33 by midnight and in the morning the temperature will start out at 32 and the high will be 56. The upper level low out west will progress to the east becoming closed. The moisture with this low will increase at the 700mb level as it moves toward our area by 3:00 A.M. Tuesday. The timing of rain as of right now is 2:00 P.M. tomorrow afternoon as the low moves up toward Illinois. Moderate to heavy rain will move through the area Monday night into Tuesday.  The snow chance at this time looks very slim. There will be moisture that will wrap around Tuesday night and Wednesday and since temperatures will be at or below freezing, snow is possible. Travel problems are not anticipated at this time.  The rain totals out of this system in the end will be 0.50" or more.

NAM 6hr accumulated precipitation valid for 3:00 A.M. Tuesday, February 24, 2013.

Tuesday:  High- 58  Low- 39  Rain throughout the day ending later that night.  Chance of precipitation is 80% with winds out of the south at 17 mph  with a few snow flakes Tuesday night.

Wednesday: High- 42  Low- 35   Winds out of the southwest with gusts up to 17 mph.   Slight chances of rain/snow later in the evening.  Chance of precipitation is 60%.

Thursday:  High- 40  Low- 32  Winds out of the northeast at 14 mph.  Light rain/snow throughout the day.  Chance of precipitation is 50%.

Forecaster:  Tyler Binkley 

Rain moving in Tonight

Current conditions:
The current temperature across the county is 59 with winds out of the south at 20 mph with gusts up to 29 mph.  The current visible satellite shows mostly sunny skies with clouds off to the west associated with the front that will be moving through later.  An upper level ridge axis stretches from west Tennessee up into Ontario with an upper level trough axis stretching from Manitoba down into Kansas.  Associated with the trough is lift and slight moisture is associated in the upper levels.  There is warm air coming up out of the south with strong gusts at times which is why a Wind Advisory has been issued until midnight tonight.  Surface cold front stretches from Iowa down to the panhandle of Texas over into New Mexico.  The low is centered over Wisconsin and the surface high is on the east coast of north Carolina.

Visible Satellite valid for 10:30 A.M. on February 18, 2013.

Forecast:
As the cold front pushes toward the area, it will have 700mb moisture streaming in from the Gulf of Mexico.  There will be no severe weather associated with this system, only rain.  The only concern is the winds ahead of the front could become gusty at times.  According to the latest HRRR radar output, it has the rain moving into Cheatham at 7:00 P.M. and lasting throughout the night.  The latest NAM has the rain moving out of the area at 3:00 A.M.  The HPC has 0.50" of rain by the time this system moves out, however I feel that it will be less.  The temperature tonight at midnight will be 50 with light rain in the area.

HRRR radar valid for 7:00 P.M. February 18, 2013.

Tuesday: Rain moving out in the early morning, chance of rain 70%, high of 50 with partly   cloudy skies, temperatures dropping throughout the day, low of 32 . 

Wednesday: Mostly sunny skies with a high of 42 and a low of 23.  Winds out of the northwest at 8 mph.

Thursday: Mostly cloudy skies with a high of 50, rain will move in that night.  Chance of rain 80%.  Low of 40.


Forecaster:  Tyler Binkley   

    

Severe weather for Sunday?

Current Conditions:
The current temperature as of 6:36 P.M. for Cheatham is 47 with winds out of the east at 7mph.  The high today was 51.  Visible satellite valid for 4:30 P.M. shows few clouds over the area which is getting wrapped into a surface low over southeast Colorado.  There is an upper level low centered over northeast Utah with a ridge pattern over Cheatham.  There is a diffluent flow over Missouri, Arkansas and Kansas and associated with the flow is rain.  Also, associated with the upper level low is moisture at the 700mb level.  Warm Air Advection in the upper levels is taking place which is bringing us winds out of the south and warmer temperatures.  At the suface, there is a surface low over Colorado with a cold front stretching from southeast Colorado down into Mexico with a warm front stretching from Colorado up into Nebraska.  The warm front is connected to a stationary front that stretches from northwest Iowa over to Wisconsin.  A surface high pressure is located over the coast of South Carolina which has been dominating our weather yesterday and today.  A Wind Advisory has been issued for Cheatham by the NWS office in Nashville starting tomorrow at 9:00 A.M. and lasting until Midnight.  To view the advisory, click here.    

Visible Satellite valid for 4:30 P.M. on February 9, 2013.

 Forecast:
 The upper level low will continue to move to the east tomorrow and by noon, Cheatham will be in a diffluent flow indicating rising motion at the surface.  At the 700mb level, moisture will be coming in from the Gulf of Mexico.  Warm air advection will continue to take place over the area until tomorrow night.  As the rain moves through, the cold front will move through late Sunday into early Monday.  The surface low will track from Colorado up to Wisconsin.  The main brunt of the rain will move through Cheatham at 3:00 P.M.  All precipitaion will be out of the area by 8:00 P.M.  The main threat with this system is the winds ahead of the cold front, however not expecting anything like January 30.  The overall accumulated rainfall for this system will be up to 0.50".  Due to the winds coming out of the south, expect a high of 60 tomorrow and a low of 40.  If anyone is planning on heading out to church tomorrow morning or tomorrow night, there should be no issues.  Temperatures will be cooler on Monday.     

NAM 6 hr accumulated rainfall valid for 9:00 P.M. Sunday, February 10, 2013.

                      

Rain moving in!

Current Conditions:
Currently there is an upper level low located well into Canada with a minor shortwave over southeast Tennessee.  At the mid-levels there is another shortwave over Kansas and Oklahoma which has helped for rain to develop over southeast Missouri and Illinois.  Associated with the shortwave at 700mb is moisture which is fueling the rain over the area.  Over Cheatham, the moisture has not moved into the area but should over night into early Friday.  Warm air has moved into the area this evening and we reached a high of 67 with mostly to partly cloudy skies.  Currently over Cheatham at the surface there is winds out of the south with a Low centered over Illinois and Indiana with a cold front stretching from Illinois down into Oklahoma with temperatures on the back side at 48 and below.  The current radar for Cheatham shows nothing, however expecting this to change overnight into the early morning with an approaching cold front. 

Radar imagery valid for 6:39 P.M. on February 7, 2013.

 
Forecast:     
The upper level trough to the north will move off to the east and by Friday afternoon we will have an upper level ridge over the area.  There will be upper level moisture associated with the cold front over Cheatham at 3:00 A.M. as the rain moves through.  As the cold front passes through the area, temperatures will begin to fall throughout the day.  The winds will be coming from the north at 17mph.  The rain will be moving through the area around 12:00 A.M. according to the latest HRRR output.



HRRR radar output valid for 12:00 A.M. on February 8, 2013.

The rain that will move through will not be severe.  The rain values associated with this system will be between 0.10" - 0.25".  I am not expecting much in rain across the area.  The rain will be out of Cheatham by 7:00 A.M.  The temperatures across Cheatham tonight at midnight will be 52 ahead of the cold front then as the rain moves in, the temperature will drop.  The high for Friday will be 52 and the temperature will drop throughout the day.  The low for tomorrow will be 38.  If you are not a member of the Cocorah's Network, they would love for you to join today and start reporting the rain that you receive at your house.  For more information go here.       
Forecaster: Tyler Binkley

January 30, 2013 Cheatham Tornadoes

Analysis of the Wednesday, January 30, 2013, early morning Tornadoes
On the morning of January 30, 2013, a squall line came through Cheatham bringing with it two brief tornadoes, strong winds, and rain.  The system entered the county at approximately 2:37 A.M.  Figure 1 shows the line as it entered  the county.  If you look due south of Charlotte, there is a "notch" which shows where the winds are spinning counter-clockwise indicating rotation. 

Figure 1: Radar valid for 2:37 A.M. on January 30, 2013.

A problem with this type of severe weather event is picking up on the "notches" because they are embedded and the line itself is moving fast.  One product that meteorologist use to pick out if true rotation is taking place is Base Velocity.  Base velocity shows winds moving toward and away from the radar, and if winds are confined and moving toward and away from the radar rotation is taking place.  Figure 2 shows the Base Velocity for 2:37 A.M. (same as Figure 1).  Notice the light counter-clockwise spin of the "notch" within the line of storms indicated by the red circle.

Figure 2: Base Velocity valid for 2:37 A.M. on January 30, 2013.

The importance of focusing on this notch is that it goes on to produce the tornado that goes through Dickson and into Cheatham effecting Kingston Springs.  At 2:46 A.M. the line officially enters Cheatham and at 2:51 A.M. it enters Kingston Springs.  Figure 3 shows the radar signature and you can clearly see the notch with impressive rotation.

Figure 3: Radar (left) and Base Velocity (right) valid for 2:51 A.M. on January 30, 2013.

The overall length of the tornado path was 6 miles and the width was 100 yards.  For more info on the logistics go here.  The second tornado occurred in Ashland City, however was not as long as the Kingston Springs tornado.  An analysis of the radar focusing on Ashland City shows a small "notch" to the northeast of Charlotte (Figure 4).  Base velocity was not that great at this time.

Figure 4: Radar (left) and Base Velocity (right) valid for 2:41 A.M. on January 30, 2013.

  As the radar progressed through time, the notch became very defined over Ashland City indicating rotation.  At 2:51 A.M. the storm moved into Ashland City the same time as the Kingston Springs (Figure 5)

Figure 5: Radar (left) and Base Velocity (right) valid for 2:51 A.M. on January 30, 2013.

  The path of the Ashland City tornado was 0.25 miles long and the width was 50 yards wide.  For more info on the logistics go here.  The overall name of this system is known as a QLCS or Quasi-Linear Convective System.  QLCS' have the ability to maintain small updrafts overtime and are multi-cellular.  The reason these tornadoes were not powerful like most, is the set up of the system.  If these storms had been in the form of super cells, the outcome would have been different.  The biggest problem associated with this system was the timing.  This occurred during the early morning while most people were asleep.  This is why it is important to invest in a NOAA Weather Radio so that if a system like this ever comes through, you will be alerted of the threat.

Forecaster: Tyler Binkley

Winter Weather Early Sunday?

Current Analysis:
The rain/snow system that pushed through Cheatham County today has now moved off to the far northeast corner of the state.  The temperatures as of 6:40 P.M. throughout the county showed 37 for Ashland City, 36 for Pleasant View, and 37 for Kingston Springs.  In the upper level part of the atmosphere, there is a trough located north of Manitoba which has been the dominating factor for the cold weather that has been dominating the area.  A jet max is located over Canada, just north of North Dakota stretching down South Dakota.  The importance of this jet max is that it is the reason for the formation of the surface low that is currently located over Northwest Iowa that could impact our area tonight with some light snow.  Associated with the surface low there is moisture at 700 mb which helps support this low in producing snow.  Very light Cold Air Advection is taking place keeping our temperatures in the upper atmosphere below freezing indicating any precipitation that falls would be snow.  Over Cheatham winds are coming from the Northwest.    




Surface map, take note of the Low at the Southeast corner of Minnesota just barely out of frame. 

Forecast:

The low that brought in the precipitation over the the area will move off the east coast this evening.  Colder temperatures will occur overnight with a temperature at midnight at 30.  The morning low will start out at 28 and the surface low located in Minnesota will move into Kentucky bringing with it snow.  The latest for Cheatham is a few flurries are possible, with no accumulation.  The farther east you go (e.g. the Cumberland Plateau), the more accumulation will occur.  Anyone having to travel in the morning should not have a problem.    

HRRR projected radar for 4:00 A.M. February 3, 2013.

Forecaster:  Tyler Binkley

Winter Weather Update

Currently the temperature is 28 with calm winds which means no wind chill.  We reached a high of 30 today keeping us below the freezing mark.  An upper level low is located over Manitoba which has brought colder air down into our region over the past couple of days.  Relative Humidity values across the county are high considering the cold air over the area.  If you plan on going out tonight, be sure to grab the coat, scarf and mittens.  Expect a temperature of around 25 at 9:00 P.M. with calm winds.  Expect temperatures to start out Saturday at 26 at 8:00 A.M.  The latest on the winter weather is we have cold air in place which has helped in cooling off surfaces.  A current road analysis as of 6:30 P.M. showed all main roads just above freezing.  The major highways such as Hwy. 12 and Hwy. 49 will take longer to cool off while secondary roads are below freezing currently.  The latest model outputs suggest the precipitation will move through Cheatham County starting at 6:00 A.M. with a light band of snow turning heavier by 7:00 A.M.  Accumulation totals will vary throughout the county with most people seeing up to 0.5 inch.  As the system moves out it will change over to all rain because temperatures will warm up due to a warm front that will move into the area.  All rain will be out of Cheatham County by 12:00 P.M.  The most accumulation with this system will be on the Cumberland Plateau due to elevation and the temperature will be cooler.  Driving in the morning could be hazardous therefore be careful!

This is the GFS model output for snow accumulation with Cheatham in the 0.5" - 1.00".

This is the NAM model output for snow accumulation with Cheatham in the 0.00" - 0.01".

Forecaster:  Tyler Binkley