Wintry Week Warning

After a week long lull of the onslaught of winter cold and wintry precipitation, it appears to me that another extended period of winter weather will be with us through February and possibly into March.  It will commence early this week with a weak clipper disturbance followed by 2 stronger systems that will run a storm up into the Great Lakes with a second weaker low pressure forming along the east coast, both attacking a big arctic high...never a good outcome for those not wanting wintry precipitation!  And this active storm track looks to be in play at least through this month and I believe into March.  Allow me to explain...

First, a digression.  I mentioned the Great Lakes.  I always like to look at how frozen they are at this time of year.  As you can see, even with this past week's thaw, the total ice coverage is well above the 30 year mean (1980-2010).  I have a feeling the ice coverage will be above normal until "ice-out" later this spring! 

Closer to home, the weak "clipper" which is essentially a minor jet stream disturbance that will make the Monday morning commute a real "pleasure"...I'm showing you a map that indicates a saturated atmosphere up 2 miles...this is usually a good indication of precipitation occurring and though some will evaporate as it makes it to the surface, a wide area across the southern half of PA should end up with 1-2" snowfall especially with the high ratio snowflakes. It will be plenty cold for snow...

Then Monday night into Tuesday, a much stronger system will drive towards the lakes and bring a vast amount of moisture towards the northeast.  The initial onslaught will be snow, but I fear a prolonged period of sleet and freezing rain Tuesday with temps very hard pressed to get to freezing by day's end...the numerical guidance is also suggesting the same!  By late Tuesday, the Euro has a moderate snowfall accumulation and a major ice storm accumulation across central PA. 

These situations are always tricky to pinpoint, but I'm thinking snow to brief sleet, but then freezing rain as the arctic high will cold air dam the surface at or below freezing for most of the day Tuesday.  Note the 1040 mb high posted across Quebec...bonjour!

Then next weekend, the parade of storms continues...

And why do I believe we are continuing this into March?  It has to do with the MJO phase.  Madden-Julian Oscillation is the lesser known of the major ocean oscillations.  Most have heard of El Nino/La Nina...or ENSO.  Essentially, the science is that the pressure and precip patterns in the tropical Pacific and Indian oceans have a major influence as to how the large scale Rossby waves (jet streams) react and position themselves.  So as to not bore you any further, just 2 final graphics...here is the Euro's seasonal MJO prediction over the next month.  You'll have to trust me when I tell y'all that most of the other numerical guidance is indicating similar movement into phases 8-1-2...What the heck am I looking at Smitty?  Start at the green line where the yellow is most concentrated (phase 6) and notice how it quickly moves through 7 into 8 and the strongly into 1.  The inner circle is where there is minimal affect.  As you move outward from the center, the atmospheric effects are more significant. 

And below is the effect on temperature here in the USA during the JFM time frame...we were just in 6 and 7, the warm phases, but are now heading towards the colder phases of 8-1-2.  We just wait and see how all of this plays out?  I do find it rather intriguing to say the least!

Hey...Blame it on El Nino!  Enjoy!

Happy weekend!

Smitty

AA:  Another wintry week this week with likely disruption of schedules.  The song is kinda funny!