US Weather Commentary

Location: New York
Author: Weather 2000, Inc.
Date: Friday, August 10, 2007
 

U.S. braces for Round three of August 2007's intense Heat & Humidity again next week....

As is typically the case, such atmospheric patterns can get locked in, with positive feedback cycles bringing heat & humidity episodes back again & again. These intense Summer regimes were going to make their mark in 2007 one way or another, so what we may have been spared in parts of July was simply going to come back in spades on top of what was already set to be a Hot August.

Let's also not forget our good friend Soil Moisture which models do not properly account for.  Moist ground conditions are the main region New York City was 95°F and Sticky yesterday instead 100°F and dry, and the main reason behind Dallas still failing to crack 100°F this entire year. Whereas, moderate drought helped propel Washington D.C. to 102°F and Cincinnati to 100°F.

The danger with these magnanimous heat events is that pencil & paper thermodynamics and surface flux feedbacks can quantify this heat pretty well two weeks ahead of time, but the computer models and local zone forecasts most rely on, have to be substantially revised seven, five, three and even one day out. {Demonstrating this "surprise factor", last week was forecasted (as late as Saturday July 28th) by the NYC NWS to get no hotter than low-mid 80's every day, and meanwhile New York City broke 90°F for five straight days including 98°F on Thursday}.

There has been lots of buzz recently about this model or that model predicting formidable Hurricane scenarios several days out.  If certain computer models designed for land-based weather have enough problems, errors and biases in predicting Domestic weather, how well can they be expected to handle the Tropics?  Ignored or not, many of these models have spun up hurricanes every few weeks since February, so their enormous False Alarm Rate deserves mention.  If you tell someone today that your favorite baseball team is going to score nine runs on September 14, it's a feasible outcome, but sounds gutsy, but also has no physical basis behind such a call this far out.

That being said, water temperatures remain warmer than normal especially across the Gulf, Caribbean and Bahamas.  Moreover, the dry air environment of late should transition to a much moister environment from which convective systems will flourish (particularly surrounding the Yucatan Peninsula). When the next favorable MJO phase arrives next week, we need to be prepared for Tropical flare-ups.  If and when a legitimate tropical concern emerges, you will hear from us regardless of whether it's in vogue (i.e. our de-emphasis of the hype surrounding Dean which never materialized) or unpopular (i.e. our emphasis that Chantal would indeed be classified off the East Coast).

There are numerous misstatements, incorrect facts and erroneous information circulating around the press & media, regarding the New York City Tornado on August 8.  We'd like to take this opportunity to professional and accurately set the record straight:

  • The EF-scale that is used to rank Tornado intensity/damage, stands for ENHANCED FUJITA scale, and has nothing to do with the word "extreme".  This is an updated version to the former Fujita or F-scale, implemented in February 2007. So now an F-2 Tornado is simply called an EF-2 Tornado.
  • The New York City Metro area gets struck by Tornadoes much more often than people realize. The five Boroughs of New York City alone have experienced six Tornadoes since 1985, and the surrounding suburbs have been struck by strong (at least F-2) Tornadoes, 23 times since 1970!
  • Any Tornado records & reports prior to 1950 (when official government [NCDC] documentation & archiving began), are sketchy, inaccurate and anecdotal to say the least.

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