Current Weather Conditions for Sunday April 29th, 2012

Current Conditions
Temperature - 57.6 degrees Fahrenheit
Dew point - 31 degrees Fahrenheit
Relative humidity - 36%
Wind direction - SE (http://hint.fm/wind/index.html)
Wind speed - 4 mph
Barometric pressure - 1030.08 g/kg
Cloud cover - overcast (altostratus)

Happy Sunday everybody, if you haven't noticed yet I am going to be using the wind map that I have been posting next to the wind direction under the current conditions section. So if you want to get the full experience out of my posts please look at it before you read any further.

We actually have some interesting weather patterns today, so let's get to it. Notice the rain currently falling over mostly over Missouri, Illinois, and Iowa to the north of the stationary front. I am sure if you looked at the wind map today you noticed the winds northward from the Gulf of Mexico. What is happening is those winds are warm moist and conditionally unstable. In order for precipitation to occur the airmass needs a lifting mechanism which is where the cold airmass comes into play and forces itself underneath the warm moist airmass in a process called convective lifting. 

So what does this mean for us? Well essentially that warm front is going to take over the cold front and begin moving in a northerly direction and as the low pressure system over New Mexico dies out a cold front from the Rockies will move across the Great Plains. These conditions are what will cause the formation of a mid-latitude cyclone. Guess what it is headed for the upper Midwest too! So as for tomorrow expect cloudy skies, some rain off and on, and temperatures similar to todays. Once the mid-latitude cyclone develops more the Eau Claire area will likely experience thunderstorms and temperatures in the mid-70's beginning on Tuesday.

Current Weather Conditions for Friday April 27th, 2012

Current Conditions
Temperature - 53.8 degrees Fahrenheit
Dew point - 19 degrees Fahrenheit
Relative humidity - 24%
Wind direction - SE (http://hint.fm/wind/index.html)
Wind speed - 6 mph, gusting up to 11 mph
Barometric pressure - 1030.11 g/kg
Cloud cover - clear

We have some really cool weather patterns to look at today in the United States. The Eau Claire area is not so exciting however so we will only spend a little time talking about it. I hope you all checked out the wind map today, if you had trouble viewing it I recommend that you use Google chrome as your browser. Notice the dry line running between the low pressure symbol on the border of Canada and the low pressure symbol over Wyoming. There is also a fair amount of rainfall being produced by the stationary front in the southern United States. What is most interesting about the weather today is the mid-latitude cyclone over Nebraska that is in its developing stage. As you can see in the image below.

My prediction for the course of this storm may differ slightly from what you have seen on the weather channel. As this system progresses I don't foresee the Eau Claire area receiving much rainfall if any at all, which differs from the weekend forecast on weather.com. What I think will likely happen in the mid-latitude cyclone will break off from the area where that dry line is currently. While the the mid-latitude cyclone is going to track towards Florida. A lot of forecasts predict showers in the Eau Claire area tomorrow due to the low pressure system below the dry line. However I predict it will just miss us and move across South West Wisconsin. 

Current Weather Conditions for Wednesday April 25th, 2012

Current Conditions
Temperature -51.3 degrees Fahrenheit
Dew point - 45 degrees Fahrenheit
Relative humidity - 79%
Wind direction - SE, http://hint.fm/wind/index.html (Check out the link to see the mid-latitude cyclone over Wisconsin currently, I recommend using Google Chrome as your browser!) 
Wind speed - 4 mph, gusting up to 7 mph
Barometric pressure - 1029.66 g/kg
Cloud cover - overcast

The Eau Claire area along with much of Minnesota and other parts of Wisconsin has experienced rainfall, however the system I was talking about yesterday has not proved particularly fearsome.

The atmosphere is unstable in the Minneapolis area as indicated by the KI value and the orientation of the environmental lapse rate to the left of the DAR and MAR on the SKEW T graph. That said, rainfall amount from 2 am up until now (12:20pm) is under 0.25 inches. I don't expect the Eau Claire area will see anything more than another quarter of an inch from this system. Let's take a look at why that is.

If you took a look at the wind map I posted under the current conditions you can see the movement of the mid-latitude cyclone in the area very well. It is very difficult to make it on this satellite water vapor image. This is due to the lack of moisture in the system, something I didn't fully expect. However what I do expect is for the storm to strengthen.

By observing the course of today's jet-stream on the 300 millibar map it allows us to gain a general understanding of how this mid-latitude cyclone will track. In this case the storm will track over the southeast United States. As this storm moves farther south the low pressure system will draw up more warm moist air, which in affect will strengthen the storm and cause an increase in rainfall.

Current Weather Conditions for Tuesday April 24th, 2012

Current Conditions
Temperature - 67 degrees Fahrenheit
Dew point - 30 degrees Fahrenheit
Relative humidity - 26%
Wind direction -n/a (calm) http://hint.fm/wind/index.html (I recommend you use Google chrome, really cool!)
Wind speed - 0 mph
Barometric pressure - 1029.56 g/kg
Cloud cover - clear

Told you guys, the weather was going to be boring in Eau Claire. But it is quiz time for all of you, without looking at the surface map below, tell me what the water vapor formation over New England is called and what type of front is over Missouri, Nebraska, Kansas, and South Dakota. First person to answer correctly in the comments section gets a cookie (seriously I will mail to you if I have to).

If your answers were mid-latitude cyclone and stationary front you are correct! Notice the mid-latitude cyclone is in its dying stages as is indicated by the occluded front. I am sure that many New Englanders are glad to receive that bit of news. Let's shift our attention to the stationary front. Moving into tonight I predict that the warm front will take over the cold front as the cold front in the Northwest U.S. does the same. What this will cause is the development of another mid -latitude cyclone. While this system could produce thunderstorms as early as tonight. I am willing to bet that we won't see thunderstorms in the Eau Claire area until early tomorrow morning due the time necessary for this mid-latitude cyclone to mature.

Current Weather Conditions for Monday April 23rd, 2012

Current Conditions
Temperature - 58 degrees Fahrenheit
Dew point - 33 degrees Fahrenheit
Relative humidity - 38%
Wind direction - NW
Wind speed - 3 mph, gusting up to 7 mph.
Barometric pressure - 1029.95 g/kg
Cloud cover - scattered (cumulis humulis)

Let's jump right into it today. The high pressure system over New England is currently producing the relatively clear cloud conditions and NW winds in the Eau Claire area.

However as that high pressure system moves farther east over the Atlantic ocean, Eau Claire will likely see a shift in wind direction. The wind direction will likely shift to coming from a more easterly orientation. If you look at the photo I took just a few minutes ago you can see there is already some change in direction in the upper atmosphere as is indicated by the straiation in the cumulus humilis cloud.

Honestly weather in the Eau Claire area is going to be pretty ridulously boring tomorrow. Expect slightly warmer temperatures than today and thicker cloud cover. New England is getting drenched on pretty bad so let's check that out.

Pretty cool variety of weather alerts for the Northeast U.S., even some winter weather alerts for some areas on the south shore of Lake Erie.

Looking at the 12 hr forecast surface map above and observing how the storm will track it becomes clear that those areas under winter weather advisory could very likely see some lake enhanced snowfall. Let me explain what will be causing the current storm to strengthen over the course of today and into tomorrow morning. Where you see the low pressure system on the map the cold front is wedging under the warm moist conditionally unstable airmass associated with the warm front on the map.

I'll talk about this more tomorrow. Until then do some storm tracking of your own if you have the time and don't be afraid to leave comments on my posts people!



Current weather Conditions for Saturday April 21st, 2012

Current Conditions
Temperature - 50.8 degrees Fahrenheit
Dew point - 29 degrees Fahrenheit
Relative humidity - 43%
Wind speed - 3 mph, gusting up to 6 mph.
Wind direction - E
Barometric pressure - 1029.87 g/kg
Cloud cover - overcast (stratus)



As I had predicted in yesterday's post, cloud cover has returned this evening after nice clear conditions throughout the morning. Take a look at where the mid-latitude cyclone, which I referenced in yesterday's post, is currently.



Looking at the water vapor satellite image you can just barely see the mid-latitude cylclone. However is the series of low pressure systems that came through Wisconsin and many other states, just a few day ago, is quite evident over the Eastern sea-board.



Although this mid-latitude cyclone is not very strong we will still some rainshowers, very soon I expect. Currently temperatures are similar in the airmasses west and east of the mid-latitude cyclone, however the airmass to the west has a higher moisture content. As we have covered previously, this is known as a dryline and is the reason for the precipitation that will occur within the next hour. As for tomorrow morning the Eau Claire area could still be experiencing rainshowers. From late afternoon on cloud cover will begin to clear however.

Current Weather Conditions for Friday April, 2012

Current Conditions
Temperature - 53.9 degrees Fahrenheit
Dew point - 22 degrees Fahrenheit
Relative humidity - 29 %
Wind direction - ENE
Wind speed - 3 mph
Barometric Pressure - 1029.94 g/kg
Cloud cover - clear



If you look at the surface map you can see the three low pressure systems I talked about yesterday have moved to the east of us today. The cold front associated with these low pressure systems is currently wedging itself under the warm moist unstable air mass from the Gulf of Mexico, which is causing precipitation. Also make note of the mid-latitide cyclone forming over Montana, which is also causing precipitation.



Here is a water vapor satellite image to give you a better idea of the water content in both of these systems. Over tonight expect a continutation of clear skies and a temperature drop to approximately 30 degrees Fahrenheit. By tomorrow evening expect overcast skies followed by a rainshowers produced by the mid latitude cyclone currently over Montana.