Wednesday, August 28, 2013

Labor Day Weekend Forecast

Good Morning..let's take a look at what labor day weekend will look like

Friday:

Mostly sunny conditions high of 80-82 degrees

Saturday:

A warm front will approach our area creating the possibility for some unsettled weather in the afternoon. Expect mostly sunny conditions in the morning moving towards partly cloudy in the afternoon with a chance of light showers and storms..chance of passing shower 40%, temps in the low 80's. Overall not a bad day

Sunday:

Chance of showers and storms increases with a warm front becoming more established over our area, partly cloudy conditions by late afternoon..highs in the low 80's, chance of showers 50%. Overall activities are still possible but with expectation that some showers can pass through. 

Monday: 

Cold front approaches from the north creating more unsettled weather, expect mostly cloudy conditions with the sun breaking through at times, temperatures in the high 70's to 80. Chance of rain 70% by afternoon. Overall by the late afternoon it is likely it will rain. Below is Monday at 2pm. Notice the unsettled weather along the cold front in the east. 


In summary, not a bad Labor Day weekend overall. It will start off nice then by later on Sunday into Monday the unsettled weather will enter region likely resulting in showers which could be heavy at times. 



Thursday, August 22, 2013

Winter Teaser Part 2: My Initial Thoughts on Jet Stream

It is becoming likely that my winter forecast will be based on a weak El Nino (warm water off western South America), weak PDO (cold water off northern Pacific Coast, warm water out to sea), and a Moderate AMO (warmer than normal Atlantic). The reason I am not releasing it until Sept. 1st is that I want to continue to see what the models project for these patterns. But for another clue, I ran an analysis of the years that had all of these ocean characteristics above and where the jet stream was in those years. The result is the image below.

I outlined on this graphic where I am beginning to think the northern and southern branch of the jet stream will set up for this winter. The top red dashed black outlined streak is the northern branch, the bottom the southern branch. As you can see it looks like we might have two very active jet streams but they will diverge over the east coast as shown by the arrows I put at the end of each branch. This sets up a battle zone over the East Coast where there will be potential for storms to form, but also potential for warm spells too. If you like snow the good news is that under this scenario it is likely the two jet streams will merge from time to time over the eastern third of the country producing big storms. I outlined high pressure to the north which will prevent these storms from escaping out to sea. 

That's all for now, the detailed winter forecast will be out Sept. 1st. 


Wednesday, August 14, 2013

Winter Outlook Teaser: 1963,1967 Can Be Similar Matches

My winter forecast that I will release in Sept. will be based on what a few large scale ocean patterns are projected to do. Right now it looks like we will see a neutral to weak La Nina along with a weak Pacific Decadal Oscillation. I will go into more detail on what these patterns are but basically it all has to do with the temperature of the ocean in key areas of that globe. The ocean temps dictate how the jet stream will set up over the upcoming season, which dictates temperature patterns and storm tracks. At first glance 1962 and 1967 had a similar set up and here where the temperatures for the winter- departure from normal.

I want to monitor the model projections for these ocean patterns over the next few weeks to see what trends develop. But for now, these two winters can be a clue. Much more detail to come in Sept. 


Monday, August 12, 2013

Unstable Start to Week, Cold in Aug Continues...Warm up in Sept

Today's post will take a look at the rest of Aug and temperature projections for September. The Aug trend will continue which involves colder than normal temperatures over our forecast region. This is the the upper air pattern favoring a trough over the east and ridge out west as shown below..



This has been the pattern all month which we why we have seen more wet weather. Troughs bring along with them lower pressures which causes more unstable weather to effect our area. Here are projected temps for the rest of the month departure from adverage (c).


As I said you can see above that the trend continues. September however will be much different in my opinion. I am predicting that high pressure will return to the northeast and we will see warmer than normal temps. The western part of the country will experience the opposite. The long rang model is starting to show that to an extent...


Winter will be interesting this year as there are a lot of moving parts that are starting to change. I am going to continue to take a look at these seasonal patterns over the next few weeks. 

I will mention that there are hints that tropical activity will develop in the gulf over the next week. At this point I do not see a threat, but it is worth keeping an eye on. 



images from weatherbell.com



Tuesday, August 6, 2013

Not Much Action to Talk About Yet..

Trend of a colder than normal Aug is in tact. Expect overall closer to early fall like conditions for most of the month. I expect tropical activity to pick up by mid month. Keep checking in for updates on the tropics and long term temperature trends including a 2014 Winter Forecast coming in Sept.

Latest Aug Forecast departure from normal...


Friday, August 2, 2013

Aug-Sep Looks to Have Hurricane Potential for Atlantic Regions

Hurricane season is entering its peak phase, and the atmosphere is setting up to be ripe for some possible hurricane development to effect the western Atlantic regions over the next two months and possibly the east coast. This will be due to a cool US, a warm Atlantic, and blocking high pressure to the north. The only inhibitor right now looks to be alot of dry air moving off of Africa that is suppressing tropical development in Atlantic. Lets take a look at the factors..

Projected colder than normal temps in the US due to a through forecast to dominate most of Aug...


Combine this cooler weather with a warmer than normal Atlantic ocean, and you have an imbalance in the atmosphere that could spell tropical development. Current ocean temps compared to average (warm water keeps tropical storms strong)..


The next factor is blocking high pressure to the north that will keep storm tracks from moving too far off the coast (represented in red)..


Interestingly alot of the current pattern setup resembles 1938 which is not something that anyone would want to see for the east coast. The great new England Hurricane hit that year . Here is what the same map at that time looked like in 1938...


Correlation does not equal causation, but it is very interesting to see these similarities. Here where the storm tracks for 1938, the big one hitting long island that year causing devastation (look up New England Hurricane of 1938).....


Due to the high pressure in northern Atlantic notice no storms traveled into that region. Instead  they all undercut it to the west towards the US.

There is one big factor that is preventing current storms from forming and that is very dry air coming off of Africa...


If this dry air dissipates, then watch out, I think we can see a lot of tropical development aimed at the eastern and more likely southeastern US. 

I will keep and eye on all of this over the next few weeks.