A lot of folks have asked me lately what is a “Miracle March”.  What it is, is a colloquial term not scientific, that relates to a very dry winter followed by a wet March. There are no guidelines for this term and it has nothing to do with ending a drought, although it certainly can take the edge off one.  As an example, the term Pineapple Express or Mango Express and several other such colloquial terms, now have been defined by Meteorologists as Atmospheric River’s. The term Atmospheric River is a scientific term with guidelines as to intensity; water vapor transport within a baroclinic band on a time scale. Wind speeds of greater than 12.5 meters per second in the lowest 2 kilometers; and a shape that is long and narrow, no more than 400–500 kilometers wide, and extending for thousands of kilometers, sometimes cross entire ocean basins.  Recent research at Stanford has even put Category’s on the Atmospheric River like Hurricane’s,  which may catch on and become mainstream at a later time.

So far this wet season, Mammoth Mt reports between 122 inches of snow and 204 inches of snow for the month of March. A bit more will come this weekend. When you consider that for all the months of the Fall and Winter through the end of February, the total was 81.5 inches.  It is pretty amazing that over the Course of the winter of 2018, on the average, only 16 inches of snow fell a month!  So to me, as in comparison to the rest of the winter it is a Miracle!  Was this a record Miracle March?….No.  The winter of 1991 totaled 176 inches at the Main Lodge.  Additionally, this tally is in inches of snow fallen and not water content, which may also make a difference for comparison purposes.

Going forward:

Were approaching the end of March and weather patterns during the month of April are beginning to emerge.  To begin with, the remains of the current pattern shows the cold portion of the pattern of the past several days coming through this weekend with snow showers and light accumulations. IE (1 to 6 inches)  Colder than normal temperatures are expected to continue through Monday with highs in the low 30s today through Monday then moderating to the 40s by Tuesday and 50s by Thursday and Friday. Nights will be in the teens and 20s.  Expect gusty winds this  weekend with continued wind chills.


Longer Range:

Something to watch;  The MJO is in an amplification mood. See:  http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ncfs.shtml

The MJO Amping in this area will set up a strong (-WPO) (Blocking High pressure over the Bering Sea). Looking at both ECMWF and GFS teleconnections, it is noted that the WPO is forecasted to go strongly negative this end of this month, while the AO and NAO are only weakly negative and the PNA is weakly negative.  This pattern change is a lot different from what we have experienced this winter. The past Winter has been highlighted by Meridional flow (N/S) while the upcoming pattern for early April looks more Zonal in nature across the Pacific. With the MJO moving into Phases 7, 8 then 1, look for strong amplification of the eastern pacific ridge first, leading to -WPO, then the possibility of undercutting of the westerlies during the end of March or the first week of April. This may lead itself to another west coast “AR” event around the 4th of April. With La Nina weakening, and ENSO trending neutral, this is another teleconnection that may lend a hand in its evolution.  By the way, this pattern the first week of April for week 2 looks similar to what we experienced during the Winter and early Spring of 2017…..Miracle April anyone?  😉


DR Howard and the Dweebs…………………:-)