Texas Sizzles Before Summer, Yet Again

Location: New York
Author: Michael Schlacter
Date: Friday, May 12, 2006
 

In one of the latest rounds of pre-Season heat (that commenced on March 1st), Corpus Christi hit 103°F yesterday while Loredo TX hit 112°F. By May 10th, this was already the 8th day that Corpus Christi has broken 90°F (while they normally only do so 6 times the entire month), and typically break 100°F in May on one day every 10 years!

The West-Ridge/East-Trough pattern that we are most familiar with in Wintertime, but that also plagued May 2005, will be with us through the medium-term, further supported by a negative-phased NAO. As we progress through May, we will see this pattern slowly transform into more of a Trough-Ridge-Trough alignment, which we have believed will be the general theme for the June-September 2006 Summer Season.

This places some regions on tap for a big warm-up by June, others for a big cool-down, and others for more of the same (which will be quantified as always in our forecast tables). To help you better prepare for June (the first of the true Summer/CDD months) we will include key climate & forecast bullet-points in our discussions next week, for each of 6 spatial U.S. zones (Northeast, North-Central, Northwest, Southeast, South-Central and Southwest).

2006 Hurricane Season Outlook Update:

Yesterday, May 10th, we released updates to our 2006 (Atlantic) Hurricane Season Outlook. This also included our analysis to help you anticipate what NOAA/NHC will declare in their first official 2006 Hurricane Outlook, scheduled for release on Monday May 22nd.

Forecasting the Forecast:

NWS Outlooks have only slightly budged the Warmth in the West away from the coast; however, with models clearly showing more of a trough-ridge-trough pattern across the country, the above normal temperatures should be eroded from the Coast. Also, some contraction of the cool temperatures from the Plains is something to watch for, as ridging encroaches from the West.

From previous discussions, re-included for pertinence:

When an uncomfortably cool May 2005 only reverted to one of the hottest U.S. Summer Seasons of all-time, people were reminded of the disconnect, but also falsely believed they are always opposites (or inverses). Temperatures for the month of May are pretty much mutually exclusive of temperatures in the June-September Summer Season, so a cool May can be followed by a Hot Summer just as easily as a cool, normal or hot May could be followed by a cool, normal or hot Summer. Quantitatively, this is illustrated in a brief research excerpt for New York City:

<http://www.weather2000.com/nyc.html> http://www.weather2000.com/nyc.html

On a statewide or local level, May weather often sets the table for Summer weather as we've described on numerous occasions, but there are very different oceanographic, meteorological and hydrological mechanisms at work in the Summer vs. May. If you try and tie May temperatures to Summer outcomes in a tidy little bow, you'll just drive yourself crazy without a comprehensive understanding of the physical mechanisms in play. For example, while Orlando Florida has consistently rattled off 6 consecutive days breaking 90°F (and counting), Richmond Virginia hit 82°F (May 6th) but then only 54°F (May 8th). Amarillo Texas took it one step further by hitting 90°F (May 2nd), only 53°F (May 5th) but then 90°F (May 8th).

May is a key month for vegetative blossoming, tornadoes, and the icing on the cake for either enhancing soil moisture or exacerbating surface drought. When it comes to significant Mean Temperatures and Cooling/Growing Degree Days, May is usually in a holding pattern. As we approach Summer weather, (whether you notice more of the same, a gradual shift, or a dramatic flip), we hope our commentaries, forecast tables and ENSO Reports provide you with the best insights ahead of time.

In any event, there will be cool cities embedded in warm regions, hot cities embedded in mild regions. Some locations will make their mark this Summer via anomalous Cooling Degree Days and others will make their mark with anomalous Critical Days (e.g. Days >90°F). Consequently, please do not hesitate to let us know if there are any site-specific analyses you'd like us to examine and prepare, should there be exact locations, time-frames and weather variables that are critical to your operations. Some case-studies can be found at:
http://www.weather2000.com/fcst_discussion.html