National Forecast (4/09/13 - 4/12/13)

Main forecast concern: Low pressure center forms in Wyoming on Monday 4/08/13 and forms a secondary low pressure system to the south located in northern Texas. The low pressure center and the secondary low pressure center exchange energy and forms a mid latitude cyclone over the central plains. This will be the weather producer for the forecast period. The mid latitude cyclone (low pressure system) does not gain organization until Tuesday at 8pm. This low pressure system will have a pronounced cold front and warm front associated with the storm as seen in the kinks in the surface isobars. Severe weather is a strong possibility with this storms progression throughout the United States. There is a strong upper level trough set up over the west. The trough along with steep mid-level lapse rates and moisture will yield a recipe for possible tornadic activity. I broke down the forecast in 4 hourly increments and highlighted key areas to look out for.

Tuesday 2pm

This storm becomes more active throughout the day through an intensification of the cold frontal boundary. This intensification will yield some severe weather around 8pm. The primary concerns for the severe weather (primarily heavy rain and thunderstorms) will be seen in Nebraska, Kansas, and Arkansas. The severe weather indicators show high CAPE (convective available potential energy) values and SWEAT/K index values which are indicative of strong severe weather and possibly isolated tornados.

Tuesday 8pm

As this storm propagates eastward the area for severe weather increases as the severe weather indicators show. There is an increased area of low lapse rates as well as SWEAT and CAPE values. These are indicative of severe weather. The area of interest for severe weather is Arkansas, Louisiana, Mississippi, and Missouri. Heavy Rain will also be a concern near Iowa and Minnesota.

Wednesday 2am

Severe weather breaks out in a strong line of thunderstorms over Tennessee and Mississippi as the cold front propagates eastward. This strong front may yield high winds, strong rain, thunderstorms, and possibility of tornadic activity. Heavy rain will be seen in Iowa, Nebraska, South Dakota, and Wisconsin. There is no escaping rain while you travel westward here, but there are better areas to travel than others.

Wednesday 8am

As this storms center continues to move northeastward, it becomes more vertically stacked. This means the storm will begin to go through a phase where it will start to die off. This does not rule out severe weather though. Simple diurnal heating (heating by the sun) can enhance vertical motion allowing for severe weather to pop up, and the cold front to continue its severe weather history. Rain will become wide spread over the northern portion of the United States, and severe weather will continue to be prominent in the southeast.

Wednesday 2pm

At this point you may be already ahead of most of the precipitation and well on your way to Nevada, but I have to note that the southeast will be seeing a severe weather threat (yet again) Wednesday Night with the possibility of strong thunderstorms and heavy rain. At this moment I do not see much in the way of storms in the mid-west where or Nevada. There is a small possibility of a storm in Colorado as seen by the light green shading. There also could be the pop up isolated thunderstorm. This time period out in this area is notorious for severe weather and tornadic activity. I will continue to look to see if I see anything of interest that I may add.

Wednesday 8pm

It appears that High Pressure will begin to build into Central US as an upper level trough moves eastward. This eastward moving trough will result in ridging to begin to build and allow for nicer weather at the surface. Yet again, there is always the possibility of an isolated storm, but as of right now I do not see anything.

Thursday 2am

The National Weather service puts out graphics of severe weather daily. These graphics shade in areas of interest that show where severe weather will be expected. Their analysis and my analysis seem to coincide.

Remember with some of these thunderstorms that will occur there may be the possibility of tornadoes, hail, high winds, and heavy rain. This will make for bad driving conditions. A person that I have met a while ago in a conference has an image of possible areas of tornadic activity on his Facebook, and most of those areas he highlighted coincide with my severe weather areas. I hope this helps out with your decision of road travels.