Back To Home
The Story Behind the Weather - By Forecaster John Ensworth M.S. - 

The Discussion of Weather Events Daily for Philadelphia and Pennsylvania

 Last updated: 04/03/2004 10:24 AM
 

Good Afternoon Philadelphia!   

    I'm glad to announce that these discussions will continue until at least the end of February (it's a short month)! 
    I have the necessary server space (especially with missed days!).  

In short:  Clouds and fewer showers, colder air on the way. This isn't the spring you sprung for.  

 In long: The low discussed over the last two days has oozed out to sea, but our troubles aren't over yet.  Other than the scattered showers around, the cold front in the Great Lakes means business. 

We're rain free in Philadelphia, but showers are wandering around out west. 

Winds in the city are still out of the north while winds across western PA are westerly. 

These north winds are keeping it a bit chilly in the 40's. The real warmth in Illinois, Indiana and even Ohio is yet to push in... and it won't get a chance. 

The cloudiness is more impressive than the rain.  The low itself is actually sitting out in a clear spot in the ocean. We are socked in though with no sun in sight. 

As is typical, the real story in the forecast starts with the upper air pattern.  The 500mb map shown below shows how winds are blowing as they go west to east across the continent at about 18,000 feet above sea level.  The low that has plagued us this week is marked with a red L and is not quite as far east as the surface extent of it.  The real story (believe it or not) is the trough coming down from Hudson's Lake marked with a dashed red line.  That cold air will be 'refilling' the trough over the east coast. 

By Saturday night, it has moved into the lakes...

By Sunday morning a good piece of it is moving towards us east of the Lakes. 

And by Sunday night the trough has put a NEW low sitting just to our east.  The original low center is almost off the map to the upper right. 

At the surface, this progression looks like a couple of cold fronts with a band of snow with them in Canada. 

By Sunday night, that new Low is sitting east of NY State with snow to the north and distant west of Philadelphia and showers possible here at home. 

As that trough pulls towards us, we have lows Sunday morning only around 38F... but...

We plunge into the upper 20's locally for Monday morning. Bad trough! Bad trough!

And things aren't much better by Tuesday morning with lows hovering just below freezing. 

Unfortunately, the toughighness in the east looks like a stable pattern for the month.  Don't look for a lot of heating in the near future (except the northern hemisphere should be generally getting warmer as time goes on... right?!)

I'll see you again Monday!

Meteorologist  John Ensworth

Surface Station sky cover color key: