US Weather Commentary

The multi-month evolution of Lithographic, Atmospheric and Oceanographic parameters that our research believed would mature in late-May 2007, have indeed done so, setting the framework for the 2007 Summer Season.  Yesterday, temperatures in the mid to upper 80's (10=B0F - 16=B0F warmer than normal) spread as far north as Wisconsin and Michigan, and expanding eastward, temperatures in the NYC-metro region should break 90=B0F on =46riday (normally around 75=B0F).  More significantly however is the fact that computer models underestimated these temperatures by notable margins even just a few days prior, a scenario which will have more serious consequences as the real heat of deep Summer approaches.

Coincidentally, Memorial Day Week(end) is also the social kick-off to the Summer, so 2007 weather patterns are permitting everyone to get their ducks in a row at a convenient time. You have been familiar with our Summer outlook for some time (ENSO Reports, Summer research highlights below), and our =46orecast Discussions and Tables will guide you through the chronology of the Season as well as provide advisories and data verifications.  Thus, as we traditionally do when a new Season is about to commence, we have provided some "psychological pointers" to help you better navigate through the plethora of information you are bombarded with:

1.) Summer is not Winter.  Besides the obvious, dominant Winter regimes can be a lot more persistent than Summer regimes.  While 20, 25 or even 30 consecutive Below Normal Days in the heart of Winter are witnessed, a frontal passage here, a foggy day there, a downpour here, a sea-breeze there, all make 'interruptions' to the overall monthly & seasonal regime quite common in the Summer.  Hence, even the hottest Summers in recorded history have numerous cool days and cool weeks thrown in, so don't miss the forest for the trees and always keep the NET outcomes we research in the back of your mind.

2.) Don't need Heat to be Hot.  Another difference between Summer and Winter is that small anomalies can go a long way.  Monthly Summer Standard deviations for most U.S. locations are around 1/3rd the Monthly Winter Standard Deviations.  For example, in June 2005 (which happens to also be a good, recent analog to this year) New York City "only" had 4 days >90=B0F and ended up "only" 2.8=B0F above normal for the month (including 10 below normal days), but that was good enough to be 1.5 sigma above the mean and the "hottest" June in NYC since 1994!

3.) Models do great.....when the weather is boring.  All those aforementioned 'interruptions' give computer models a hard time, so their output becomes fickle, and consequently the short-term forecasters who rely on them put out very changeable or 'all things are possible' type forecasts.  Matters get even worse when extreme drought, soil moisture and sea surface temperature anomalies come into play, which often triggers records to be set well beyond the scope of the models of short-term forecasts.

4.) Beware of Meteorologists in Climate Scientist clothing.  Short-term forecasters (of which 95% of them are) provide valuable insight into hourly load-forecasting, 3-Day forecasts, synoptic rainfall and severe weather development.  However, when they cross the line into 1-3 week outlooks and monthly climate predictions things get noticeably (and often deliberately) fuzzy.  Consequently, hemispheric parameters (such as El Ni=F1o and La Ni=F1a) are incorrectly attributed, surface fluxes are undervalued, and Tele-Connections are misunderstood. Please let us know if you'd ever like us to comment on, decipher, explain or debunk any climate research or predictions you may come across from other weather sources, conferences or the Internet.

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