Where are we with the drought?
Despite colder and sometimes snowy weather pattern in many areas of the USA since mid December, we have seen very little or no significant help with the drought situation across the lower 48 states. There have been some very small improvements in a few areas, but most drought areas have seen very little help, despite some precipitation in many areas.
If you look the drought status a month ago (as of December 18, 2012).
And compare it with the latest drought update as of January 22, 2013. You will find that the maps look almost identical.
The only good news, is that there were no rapid areas of expansion of the drought over the past month.
Despite some snow and one rain event in the central plains, the severe drought continues.
It should be pointed out, however, that from late December through late January is not necessarily the time of year that you would expect drought relief. The Arctic air masses that have invaded the lower 48 states over the past month, tend to be the type of air masses lacking good moisture. Also, the cold, Canadian dominated pattern in many areas also tends to cut off any good feed of moisture from the Gulf of Mexico and the Pacific.
So, climatologically speaking, putting a dent in a drought this time of year is difficult. This is why the next few months will be critical as we head into February and March, when storms can become more and active and better at producing precipitation.
There are some encouraging signs that February will produce a higher number of storms than January as the Pacific will be a bit more active at producing storms. The key month, however, will be March.
A major factor in the dry conditions that developed last year and into early 2013, is a cold sub-tropical Pacific. Remember all the talk of an El Nino (warmer than normal sub tropical Pacific) this year? Well, it never materialized, which is bad news for the central plains.
As a general rule of thumb, when the sub-tropical Pacific is colder than normal or close to normal, the central plains are susceptible to dry conditions. The implications that warmer water temperatures were coming this year, led to some hope that the winter would be more wet for many areas. However, as you can see below, El Nino never materialized. Temperatures have been colder than normal or close to neutral. We will be watching very closely over the next two months to see if sub-tropical Pacific water temperatures warm a little heading into early Spring. If so, that would be good news for the central plains, as the chances for better rain/snow producing storms in March, April and May could take place. However, if temperatures remain close to neutral or get colder, that would not bode well for the drought situation.