Tuesday, June 30, 2015

Tuesday Morning: Taking a Look at this Week Through the Holiday Weekend

A tricky forecast is in store for the next five days, especially as we head towards the 4th of July. This is all due to the overall synoptic (large scale) pattern that will be in place over the region this week. Looking below you can see a pattern that is charactorized by a western ridge and eastern trough. If this looks like a pattern that is more common in the winter you are correct! In fact, that is why you are seeing temps on the cooler side as the trough over the east brings in cooler air from Canada. 


What this pattern is going to end up being responsible for is multiple upper level disturbances and front crossing through the area. This is what is going to make the forecast difficult. Every model will handle each disturbance differently especially as we get closer to the weekend so the solutions could range from a Sunny 4th to a rainy 4th. At this time I am not calling for rain on the weekend, but acknowledge it could be possible. That is why I will have to have antoher update as the weekend closes in. 

First lets focus on today into tonight as a warm front will cross into the area...


This will give us a chance at showers tonight into tomorrow morning but then should clear for the bulk of the day Wednesday. 

The weather systems corresponding cold front then crosses through Wednesday night but there will be limited shower activity at that time. 

The very difficult part of this forcast comes as that frontal boundry stalls just to our south late in the week. Anytime you have a stalled front, it acts as a boundry between warmer and colder air. This can cause unsettled weather when you get upper level disturbances that spin up this warm and cold air creating precipitation. The problem is every model is handleing this differently. For example lets look at the Canadian..


It models the upper level disturbances will interact with the front and bring rain into the area for Friday and Saturday. In fact, you can see it has two low pressure centers forming as a result of this.

The GFS on the other hand keeps this all to the south..


Again this all will depend on where and how the upper level energy enters the pattern. As an example you can see how in the Canadian example it is modeling a strong wave of upper level energy as seen by the deep yellows and reds near the area..

The GFS much flatter, thus not as wet at the surface..


And there you have it guys, the 4th of July weekend's fate rests on what model ends up being correct! Stay tuned I will update on this as we get closer to Thursday.

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