Potential storm Wednesday night into Thurday

I just realized that it is the 7th anniversary of the Feb 2010 blizzards, AKA the best 2 weeks of our lives. Fun times. What I'd give for that again.


It's been a pretty nasty winter across the East for snowlovers. DCA is sitting at 1.4" for the season out of 2 snow events, both in January. Through out the winter, there have been signs of potential improvement in the  models but obviously we have been mislead. No reason to step away from that now. Winter basically never started. Although technically invalid, one could say that we are "due" for a below normal year. Maybe there is a connection. I'll leave that up to the real meteorologists to figure out.

Anyways.... Back to the forecast. After this cutter Tuesday, which should warm us well into the 60s, most of the global models (minus the Canadian) are suggesting that trailing energy will ride up along the front as weak low pressure, bringing precipitation over the area. Verbatim it's a nonevent for the immediate metro. There is a small chance that it will be snow in DC, slightly higher chances the farther north and west you go.  This is what the winter of 2017 has come to.

Forecasted temperatures for Tuesday afternoon

What we would need is for the storm to slow down and allow cold air in ahead of it. We never do well if we depend on cold air to come in on the back side. We also need it to trend a bit farther south. Both are pretty big things to ask for since we are only 3 days out. But considering that the Canadian has absolutely no storm in the same timeframe as all the other models. Who knows, we could get lucky.

CMC (Canadian) model

GFS (American ) model

1/30-2/3 Alberta Clippers and Lake Effect Snow

Over the past week, it has snowed almost every day, which has been just awesome. This is one  of the reasons I like Ithaca. Ithaca averages between 60 and 70 inches of snow a year, although this year (and last) have been rather snow deprived. In addition, snowfall amounts vary greatly between the city central and the outlying areas due to elevation. Earlier during the winter, when it was warmer, I observed that the Animal Science area of campus would have snow accumulation while downtown would be just wet. I bet there probably is also the urban heat island effect at work too. But when it does snow (and stick), it provides a pretty scene.

 

So far, much of the snow has come from lake effect snow bands and weak low pressure systems called Alberta Clippers. My favorite snowflakes are what weather weenies call dendrites. Snowflakes actually come in many different shapes depending on the temperature and moisture available and dendrites are the mot beautiful of them all.

 Dendrites are what a typical person imagines a snowflake to be. However, snowflakes are often not that shape.  There are very specific conditions to the formation of dendrites and they are coveted by snow weenies for their beauty and their ability to accumulate quickly as very fluffy snow. Forming snow crystals is sort of like growing any other crystal. You have a seed where crystallization starts and slowly let the thing grow. The longer it stays the bigger and more complicated the crystal gets. With dendrites the optimal conditions are where temperatures in the cloud (called the snow growth region) are between -10 and -20 C and there is a relative abundance of moisture. Drier air results in thinner crystals and too dry results in needles as each of the arms break off. Too wet results in plates and thick snowflakes. It's all a balance.

Rather thick dendrite

Thinner dendrites

No matter what kind of snowflake falls, it's still pretty.

Looking at the East Ave. bridge over Fall Creek from the footbridge

Another thing that many people don't realize is that larger snowflakes are mostly aggregates of small snowflakes. Dendrites love to lock arms due to all the nooks in crannies in their structure. Another way of getting aggregates to to be rimed (have liquid water) since the water will help with sticking to each other (and other things). The snow that fell this week were not rimed. They were dendrites, as the closeups below show.

Aggregate snowflake

Many snowflakes

Exiting NTRES 2201 into a flurry of dendrites

Behind Mann

Construction of stormwater retention ponds on the Ag Quad

Temporary home of the Project Teams

Frozen Beebee Lake

Thus concludes my first place journal entry about the dendritic snowflakes of Ithaca. They are truely beautiful.

Just one more dendrite