Posted: 3:27 pm Tuesday, February 14th, 2017

Models look ahead to spring 

By Kirk Mellish

Some of the model projections and analog signals are still trying to hint at some sort of last hurrah from winter, but as with the last blog post I have to remain skeptical and figure little or nothing will come of it.

For the past two months almost every time the medium to long-range guidance showed cold and colder, days later it would back off. In the absence of countervailing evidence from the real atmosphere I will have to doubt it.

I have no reason to think we wont get ANY more cold snaps, but I have no reason to think they will be anything but transient and nothing extreme. It’s normal for us to get a frost or even light freeze in March or even April even after a mild winter.

In looking at the models remember they depict the projected mean for the period shown, the overall average, NOT every day or every week.

HERE IS A HOST OF NUMERICAL SIMULATIONS FOR SPRING FROM VARIOUS MODEL OUTPUT:

EUROPEAN NEXT 32 DAYS AND 46 DAYS:

screen-shot-2017-02-14-at-1-20-48-pm

screen-shot-2017-02-14-at-1-21-09-pm

UKMET MODEL:

screen-shot-2017-02-14-at-12-59-54-pm

screen-shot-2017-02-14-at-1-03-20-pm

JAMESTECH MODEL:

screen-shot-2017-02-14-at-1-05-20-pm

screen-shot-2017-02-14-at-1-05-36-pm

IRI Model:

screen-shot-2017-02-14-at-1-08-57-pm

mam17_nam_pcp

A VARIETY OF MODELS FROM THE US AND CANADA, THE MEAN OF THE MODELS IS UPPER LEFT HAND PANEL (monthly breakdown):

screen-shot-2017-02-14-at-12-55-22-pm

screen-shot-2017-02-14-at-12-56-03-pm

screen-shot-2017-02-14-at-12-56-33-pm

Screen Shot 2017-02-14 at 12.55.41 PM.png

screen-shot-2017-02-14-at-12-56-18-pm

screen-shot-2017-02-14-at-12-56-46-pm

The monthly consensus for the SE USA precipitation goes back and forth a bit tilted dry while each month is shown warmer than normal in the average of the models.

THE MODELS ALSO SHOW NEUTRAL TO WEAK EL NINO DURING SPRING AND SUMMER:

c4zpre_waaaaakk-jpg_large

figure1

c4tzbogueaas_yl-jpg_large

3 OUT OF 4 ENSO REGIONS IN + range past 30 day mean

An El Nino spring can be somewhat wet in the south and southeast U.S. and some research has suggested the severe weather season is less extreme with El Nino vs. La Nina. However, each one is different even if they are similar over the long haul so its not written in stone.

enso_thunderstorms_620

In addition, late winter and early spring forecasts are up against what is known as “the spring forecast barrier”. So it’s still a bit early to make any broad solid statements about the coming spring.

The analogs or climate history based off top warm winters suggest only a “mild hangover” or carry-over with regard to temperatures for spring on average with precipitation below-normal on average and temperatures a little above-normal (monthly national breakdown box on left, seasonal mean right):

screen-shot-2017-02-14-at-3-03-45-pm

EL NINO SUMMERS ON AVERAGE:

el-nino-summer-correlation-final

Again, we are a long way off from knowing if or how strong any summer El Nino might be and past performance does not guarantee future results.

 

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