Does Snow = Drought Relief?

The counties in red on this map all
declared drought disasters in 2012!

In the past several years, states in the southern portion of the Great Plains have suffered from extreme drought conditions.  Last year, these conditions spread to include a large portion of the nation and had a major impact on crops nationwide.  However, little gets said about the drought during the winter months.  Many people wonder why that is.  The answer can be summed up in one word: snow.

During the winter months, much of the nation sees precipitation fall in form of snow or other frozen precipitation.  This frozen precipitation falling on a cold ground does not get absorbed into the soil until it begins melting AND any frost has left the ground.  In other words, even though it is snowing like crazy outside, it will not improve the drought conditions until it melts.  And how quickly it melts is important as well.  If we get a fast melt of the snow pack, there will be plenty of runoff with the water flowing right into area river ways (even more so if the frost has not left the ground yet)!  Thus, not much of the water is absorbed by the drought stricken ground.

Another reason why snow has little impact on drought conditions is the fact that there is actually very little water in most snow.  Most snow that falls in the Upper Midwest has a snow to rain ratio of 12: 1, meaning that 12 inches of snow is equivalent to just one inch of rainfall!  And sometimes this ration can be as high as 30:1!!!  Talk about dry snow.  The truth is that there typically is just not enough water in snow to offset our drought conditions.

U.S. Seasonal Drought Outlook valid Feb. 21 - May 31, 2013.
Released Feb. 21, 2013.
Courtesy of the Climate Prediction Center.

So what does that mean for our drought conditions now?  Well, the drought has improved very little over the winter months.  And the drought is expected to persist for a good chunk of the nation (especially over the Great Plains) into the next several months.

On another note, some may be wondering what caused the drought in the first place.  Well, scientists of the Potsdam Institute for Climate Impact Research (PIK) have proposed that a common physical cause is to blame.  They suggest due to man-made climate change, the atmospheric flow pattern (known as the jet stream) is repeatedly disturbed through a subtle resonance mechanism.



Meridional windfield over four different timespans.
(Credit: Image courtesy of Potsdam
Institute for Climate Impact Research (PIK))

The jet stream, that fast current of air circulating the globe high up in the atmosphere, oscillates between the tropical and arctic regions of the globe, bringing cold, dry air from the arctic toward the tropics and warm, moist air in the other direction.  However, lead author Vladimir Petoukhov stated “What we found is that during several recent extreme weather events these planetary waves almost freeze in their tracks for weeks. So instead of bringing in cool air after having brought warm air in before, the heat just stays. In fact, we observe a strong amplification of the usually weak, slowly moving component of these waves.”  And when the heat stays, the heat keeps building and building which leads to a heat wave like what the United States and Russia have seen in the past few years.

Example of a heat dome on a weather map.

In other words, the droughts are caused by heat waves?  In a way.  Like stated above, the heat is brought in from the south repeated, and forms what is called a heat dome under a stationary ridge of high pressure.  As the heat keeps building, the ridge remains quite strong and prevents storm systems from passing through.  And if one or two do happen to slide through the ridge, they are so weak that they produce little in the way of precipitation!

Example of the jet streams moving air around the Earth.

But how does climate change cause the jet stream to freeze in its track?  Man-made climate change does not mean uniform global warming.  The relative increase in temperatures in the Arctic is higher than on average because it is amplified by the loss of snow and ice.  This in turn reduces the temperature difference between the Arctic and say Europe (Temperature difference is the main driver of air flow around the globe!).  In addition, continents generally warm and cool more easily and quickly than the oceans.  These two factors result in an unnatural pattern of the mid-latitude jet stream so that for extended periods slow synoptic waves (ridges and troughs, i.e. highs and lows on the weather map) get trapped in place.

So will we see this pattern over the United States again this year?  Only time will tell.  But for now, let’s hope, and pray that our drought stricken areas get much needed rainfall this spring to help relieve the drought!

Beware of Q!!!!!! It is going to get you!!!!!

If you haven’t tuned into The Weather Channel this winter, you may or may not have heard about how The Weather Channel is now naming winter storms.  Just like NOAA giving names to tropical storms and hurricanes, The Weather Channel has been issuing names for strong winter storms during the 2012 – 2013 winter season.  This has caused quite a bit of discussion in the meteorological community and has lead to many shaking their heads in amusement or wonder.

Some people may be asking why?  Well they offered a few reasons for the naming idea:

1. Naming a storm tends to raise awareness.
2. Attaching a name makes it much easier for the public to follow a weather system’s progress.
3. In today’s social media world, a name makes it much easier to reference in communication.
4. A named storm is easier to remember and refer to in the future.

I do have an issue with a few of these.  Naming a winter storm to raise awareness is a bit ridiculous.  When the public hears that there is a storm coming towards them that is going to drop a ton of snow or ice on their area, it tends to keep their attention because they want to know how to plan ahead.  Naming a storm does little for this.  I can see where giving it a name would make it easier to talk about on social media like Facebook and Twitter, but it’s not going to help with the awareness factor much.  As far as a named storm being easier to remember, I can see some point to it.  However, most people will either name the storm themselves or remember it without the need for a name.  Here in the Midwest, if you mention the Halloween Blizzard of 1991, most people 27 and older will know what you are talking about.  A name the people come up with is often easier and catchier than any name that is assigned by an organization or network.

Another point is the fact that winter storms are much less predictable than hurricanes.  Hurricanes get their name early in their life cycle (the tropical storm stage) and our current weather models are fairly accurate for 3 to 5 days into the future in determining whether or not a tropical storm will actually develop into an actual hurricane.  However, the same is not true for winter storms.  Winter storms can change in intensity and track in a different direction in a relatively short period of time (sometimes less than a day!) when compared to what our weather models predict.  So what happens if a modeled predicted storm that you have now named fails to develop?  You end up looking foolish and have just confused the viewing public.

Also, I want to point out that the names that The Weather Channel has chosen for this winter follows no rhyme or reason.  (See the list below.)  Unlike names chosen for tropical storms which alternate between male and female and tend to be common names, The Weather Channel has been using rather odd names with no pattern of any kind.  We just had winter storm “Q” roll through the area.  Really?  Q?  Is that all they could come up with?  Yeah, no one is going to remember the storm that dumped over a foot of snow on parts of the Central Plains as “Q.”

 

Another issue I have with The Weather Channel’s naming scheme is that there appears to be no sort of criteria that decides if or when a storm gets a name.  NOAA gives names to tropical storms only when they reach a certain sustained wind speed.  However, this new winter naming system has no criteria at all and seems to only apply to storms when The Weather Channel needs something more to talk about.

So I don’t know what your thoughts are on this new winter storm naming idea of The Weather Channel’s, but to me it is a bit ridiculous.  Frankly, I believe it to be a silly marketing gimmick and that it will soon fade from existence.  The Weather Channel should just leave the storm naming ideas to the experts at NOAA and just continue to report on the weather and forecasts in a way to keep the public informed without the confusing names!