The More Things Change, the More They Revert to The Same

April 7th, 2014 at 9:50 pm by under 4 Warn Weather

This week will again present us with ups and downs, and a fairly typical early spring lack of consistency. After a Very Wet Monday evening, drier conditions will set in for the midweek with below average temperatures giving way to above average on Thursday, slipping a few degrees on Friday, and coming back above average during the weekend. One feature this spring which has not yet plagued us it the “cutoff low” in a blocking pattern. These tend to become more common in climatology as we move a little closer to mid-spring, but there are no signs yet of such a development in the next 14-16 days. So, there’s THAT–at least. Of course, in a block, you could also get under the ‘sweet spot’, the blocking ridge. THAT would be a good deal. No signs of that either.

Ensemble means (I’m relying on them more than operational models) continue to show those ups and downs into next week. By April 17-19, a flatter zonal flow shows up in the means. However, some of that flatter, low amplitude flow shows up because of the huge spread between ensemble members farther out in time. That is, the members and models cannot see short waves, their amplitudes and their paths so far in advance. When the spread between ensemble members is very large at the 500mb height level, the mean tends to be flatter. It’s a statistical compromise which has little to do with actual predictions for amplitude and teleconnections. What’s been happening so far this spring is a tendency to return to ups and downs the closer we get to the ensemble means prediction of  a flat, zonal flow…as soon as the members and the models are able to “see” the short waves and the wavelengths between ridges and troughs.  We’re certainly out of the extremes of winter, but for the umpteenth blog thread in a row (or so it seems), I still see no sign of a lasting pattern shift to a western trough/eastern ridge.

There are smaller uncertainties about this weekend and the timing for showers either Sunday night or Monday or, if the GFS 18z run were to be believed, showers during Sunday. There will be a transition back to Below Average temps for several days next week. Showers will again cross the region by Thursday night, exiting by early Friday. The weekend is not a lock for Sunday staying dry, but temps both days should be above average…unless 18z GFS (with the GFS’ inherent fast bias) wins out on Sunday and gets those showers and a trailing cold front in here and beats the slower ECMWF.

178 Responses to “The More Things Change, the More They Revert to The Same”

  1. Kevin says:

    I flew in from Florida this afternoon and saw the impressive amount of ice cover at our end of the lake as I flew overhead. My lawn has gotten greener since we left on Monday. It is nice to see us slowly coming back to life this year! It shouldn’t be long now before trees start flowering. That is always beautiful to see around here.

  2. Don Paul says:

    I was running late this afternoon when I saw NWS going for upper 40s for next Wednesday…I went for 50. However, now that I’ve seen later runs and ensemble members, mid/upper 40s it will be for me as well. One good thing about our foliage being behind schedule…frost Wednesday night would be less likely to produce damage.

  3. Lois says:

    A beautiful Easter day here, it hit 72F in parts of Alleg.Cty. Things are looking so alive. Can just about observe buds changing into small leaf form as the sun’s rays cover the trees.
    Hope everyone had a nice day.

  4. Kim from NF says:

    Happy Easter everybody.

  5. Ben P says:

    A lovely weather weekend, and our forsythia are just budding. It was a pleasure to feel hot sun on my face at my in-laws in West Seneca yesterday.

    Happy Śmigus-Dyngus, folks!

  6. Lois says:

    What does Dyngus Day mean? Enlighten me. The weather is coolish but ok with me.

  7. LisaZ says:

    Yes what a beautiful Easter Sunday. That’s the benefit of Easter falling late in April. I must admit however I was concerned up until the weekly forecasts that we could have very well ended up with snow that day, based on how long Winter has hung on for its dear life. Things finally seem to be improving – for once we’re not dealing with a mid week potential snowy forecast with highs below freezing!

  8. Don Paul says:

    NEW THREAD IS UP

Leave a Reply