Major Chill Down On The Way !

Baltimore, MD - MIKE MASCO

ABC 2 METEOROLOGIST

FOLLOW ME ON FACEBOOK: CLICK HERE

FOLLOW ME ON TWITTER:      CLICK HERE

Amazing what a few weeks can do in the weather world. We somehow went from 90 degree high temperatures with oppressive humidity and storms to now comfortable days and cool to near chilly nights! September has been an interesting month so far and I do feel we have a lot more chilly days to come across much of the east.

The forecast models we use to track weather indicates one trough after another infiltrating the eastern seaboard bringing shots of Canadian air over the east. Areas that were hard hit by the drought will wind up with -15 degree below average temperatures during the night with 10 degree below average afternoon highs by the end of September!

The main game changer has been the NAO or North Atlantic Oscillation which as we know in a negative phase brings cold shots of air into the eastern USA.

If you remember, my forecast for September was to be below average temperature wise going into much of this month. So far the forecast is holding up nicely.

The NAO forecast which is currently in a near positive phase, will

dip well south into negative territory to finish out this month. Note the radical dip south after Sep 15th.

This means we will sustain a trough over the eastern USA longer bringing a cross Canadian airflow on top of areas east of the Mississippi river.

.

 

 

 

 

 

The AO or Arctic Oscillation will also play nice with the NAO and dip well below into negative levels as well reinforcing the shot of cool air into the US. REMEMBER last winter both indexes ran extremely positive shutting down the cold air source and bringing several shots of warm air towards the eastern seaboard.

 

 

 

 

Our forecast models continue to pick up on this idea as it shows below average temperatures for much of the east. What this means is we should expect overnight lows to near the upper 30 mark over Western Maryland, PA, OH, WV, Western Virginia. There could be freezing conditions for overnight lows over New England and the upper Midwest with days that struggle to get to 70 (middle 70s are average highs for the middle of September)

Here's a look at the GFS forecast anomalies (departure from normal temperatures) going into the rest of this month. NOTE the green coloring which indicates an average of temperatures that are -6 to -10 degree below where we should be! That is impressive!

 

The GFS and EUROPEAN model both suggest sustained troughiness in the east for the next 8 - 10 days reinforcing the idea of cold overnights and cool afternoons for the next few weeks.

Get this! The GFS model even shows accumulating snows for Wisconsin! Not sure if that verifies BUT it is an indication that this cold air does mean business !

I am currently working on the October forecast.. and will share with you soon! Remember to like me on Facebook and Twitter ! :)