FACTORS SHAPING THE WINTER...................
Factors shaping the upcoming winter are the unusually cold waters in the eastern & North Atlantic, the unusually warm waters in the north-central Atlantic, the colder Indian Ocean, lack of sunspots & the incredibly cold spring & summer Newfoundland & northward in northeastern Canada. Currently the equatorial Pacific is in a neutral mode (El Nino, La Nina, etc.) with no major temperature anomalies & the Pacific as a whole is overall pretty neutral.
However, most data suggests that a weak to moderate El Nino Modoki will evolve this fall & winter. It is unclear when it will peak, but it will have some far-reaching effects on the winter (combined with other factors). This type of El Nino has unusually warm water placed in the mid of the Equatorial Pacific, rather than farther east, like in a typical El Nino. This type has a blob of anomalously cold water west & east of it, while a typical one has it west. I digging into how these blobs of water will evolve in the coming months & trying to predict what they will do.
Of course, as in all sea surface temperature anomalies, the colder or warmer they are compared to normal, the bigger the effects will be. A strong El Nino or El Nino Modoki that is strong will have stronger, pinpointed effects on the world & our region.
There is also a strong tie in our region to the Indian Ocean & it's tie to the MJO or Madden-Julian Oscillation. Depending on what phase it is in weekly determines not only our weekly, but monthly weather& can greatly influence seasonal conditions overall. The MJO can greatly influence whether we get into a cold or warm pattern & can even affect flooding events in our region. By forecasting the MJO phases & then seeing how these phases interract with the strength of the El Nino type & whether we have wet soil or drought somewhere or snow pack, all works to paint a weather pattern picture that we can see in previous years.
WHAT IS THE DIFFERENCE BETWEEN EL NINO & EL NINO MODOKI?
So, taking into account all of the factors mentioned above & the emphasis on a weak to moderate El Nino Modoki, this is what the analogs are saying. I took all years with some similarities to this one & all with an El Nino Modoki of varying strength.
Here are the results. This is not a forecast yet, per sey, but references to a trend noted in the data. Every year is different with lots of factors, but this is an average of the anomalies or showing if there is a strong signal favoring cold, warm, average, wet, dry, etc. compared to an average based on the 1950-2007 period.
OVERALL TYPICAL EL NINO MODOKI PATTERN COMPARED TO A TYPICAL EL NINO IN WINTER (JUST LOOKING AT MODOKI, NOTHING ELSE) BELOW (IMAGES COURTESY OF JAMSEC)...................
THE DIFFERENCES? IT IS MUCH DRIER IN CALIFORNIA TO NEVADA THAN A TYPICAL EL NINO & IT TENDS TO BE MUCH WARMER IN THE WEST, WHILE COLDER IN THE CENTRAL & PART OF THE EASTERN U.S. MODOKIS TEND TO BE COLDER, BUT STILL DRIER HERE WITH ABOVE NORMAL SNOWFALL.
HOW DO THE EFFECT OF EL NINO & EL NINO MODOKI VARY IN THE U.S. & OUR REGION?
El Nino Modokis tend tbring drier, but colder than normal winters with above normal snowfall in our area.
El Ninos tend to bring drier & warmer than normal winters with below normal snowfall in our area.
It is interesting to then take all of the data, take all of those similar years together & see how they compare to an El Nino Modoki.
Here are the analog results for what may transpire for the upcoming winter (& a look at March).
DECEMBER-FEBRUARY (OVERALL WINTER) TEMPERATURE ANOMALIES PER CLIMATE DIVISON (DOT IS OUR AREA):
Colder & drier than normal winter, overall is noted with above normal snowfall.
DECEMBER 2018 TEMPERATURE ANOMALIES PER CLIMATE DIVISON (DOT IS OUR AREA):
Temperatures in December come out near to slightly-above normal with below normal precipitation.
JANUARY 2019 TEMPERATURE ANOMALIES:
January temperatures come out below normal with normal precipitation, signaling the peak in snowfall for the winter.
FEBRUARY 2019 TEMPERATURE ANOMALIES:
February shows a trend toward a bit above normal temperatures with below normal precipitation.
MARCH 2019 TEMPERATURE ANOMALIES:
March trend shows below normal temperatures & precipitation. Should this follow, winter's grip may ramp up in March after some relief in February.
Stay tuned to the actual winter forecast due out in September! However, I will do this updates on the trends for the winter right through summer & into fall. I'll also have fall forecasts out.