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Cool signals from the NAO and AO and hints of spring

All pointers are towards the weather turning cooler as we head through the coming weeks of February; and there are pointers there for spring too. I know many watching this are farmers and growers as well as agricultural traders. You're thinking about spring right now, and we may be starting to see some telltales coming from the atmosphere as we enter the final stages of winter.

But the signals are getting confused.

The evidence so far is a stratospheric warming event, the GFS jumping back and forth, and ECMWF every so often dropping in a colder run.

Then add the NAO (below) based on the CFS and from Kyle MacRitchie's excellent site. Notice how strongly it's in the negaticve, signalling colder air slipping from the Pole. In fact, it stays negative until the end of March; don't take it too literally, but it may just back up our ideas of a colder spring.


Now, for colder winter weather in the UK, Ireland and northern Europe one would like to see the NAO in negative territory. But it ain't! Yes it's weak and bouncing aorund in neatural/positive territory. So this suggests the westerly winds in the Atlantic stays with us.

But the signals combined do stack up with the idea we've had of the cooler February, although one dominated by a westerly flow. That cool water out west sees the westerly wind flowing over it, all from a cold source, bringing cooler air through the UK.

yes there will be times when warmer air wafts through, but generally we go through a chillier month. Oh, and then there's mid month, we are still eyes-out for a more signifcant snap of cooler weather and the risk of some snow. I still hold this around the 30% risk mark.

Just keep watching because we'll stay with this story throughout and heading into spring.

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