Ticker for July 19, 2009

                
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July 19, 2009      July 19, 2009      July 19, 2009      July 19, 2009


As Gary mentioned, the Ticker staff loves suggestions.  The Ticker staff also digs it when someone guest
writes a Ticker.  The one below is brought to you by Brad Illston who is a research associate at the
Oklahoma Climatological Survey and manager of the Oklahoma City Micronet.  Brad also likes to mine
through data and find interesting nuggets of info - sounds very Tickerish, eh?

However, before we get to the fun part, here are a couple of updates.  The Ticker folks have really bought
into using Facebook and Twitter to quickly disseminate cool weather information in near real-time.  So, follow
along with our tweets at:

http://twitter.com/OCSTicker
http://twitter.com/OKCNET

Also, we've moved away from groups to pages on Facebook at:

http://www.facebook.com/pages/Oklahoma-Mesonet/101813120731
http://www.facebook.com/pages/Oklahoma-City-Micronet/108107256598

If you are on Facebook, become a fan of the pages and you'll get our regular updates.  Now on to the Ticker!

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While the OKC Micronet is showing beautiful weather for Oklahoma City in mid-July, we want to look
back to last weekend's heat wave for just a minute. Temperatures from last Thursday (July 9) through
Thursday (July 16) got pretty ugly. From an OKC Micronet data perspective (~13.5 months now and
growing), 9 of the Top 10 daily high temperatures were broken. Here is the current Top 10 list as of
July 16:

KCB104 - July 12, 2009 - 105.6?F (40.9?C)
KCB105 - July 12, 2009 - 105.6?F (40.9?C)
KCB104 - July 11, 2009 - 105.4?F (40.8?C)
KCB108 - July 11, 2009 - 105.4?F (40.8?C)
KCB108 - July 13, 2009 - 105.4?F (40.8?C)
KCB108 - August 4, 2008 - 105.3?F (40.7?C)
KCB105 - July 11, 2009 - 105.3?F (40.7?C)
KCB108 - July 12, 2009 - 105.1?F (40.6?C)
KCB109 - July 12, 2009 - 105.1?F (40.6?C)
KCB109 - July 11, 2009 - 104.9?F (40.5?C)

These record setting temperatures surpassed (mostly) the August 2008 heat wave recorded which
had a similar length of duration. It is also not surprising that all of the record temperatures were
measured in the Central Business District (CBD; e.g. downtown) of Oklahoma City (as noted by the
CB in the station identifier). Taking humidity into account, the Top 10 highest daily heat index values
for the OKC Micronet are:

KCB109 - July 10, 2009 - 107.8?F (42.1?C)
KCB107 - July 13, 2009 - 107.1?F (41.7?C)
KCB107 - July 10, 2009 - 106.7?F (41.5?C)
KCB105 - July 10, 2009 - 106.5?F (41.4?C)
KCB108 - July 10, 2009 - 106.5?F (41.4?C)
KCB107 - July 15, 2009 - 106.5?F (41.4?C)
KCB107 - August 1, 2008 - 106.3?F (41.3?C)
KNW202 - July 10, 2009 - 106.3?F (41.3?C)
KCB107 - July 11, 2009 - 106.3?F (41.3?C)
KCB101 - July 10, 2009 - 106.2?F (41.2?C)

One thing to notice is that the highest heat index values typically occur at the beginnings of
heat waves as the humidity is higher at that point. As a heat wave continues, the humidity will
drop and the air temperature will increase leading to an overall drop in heat index values. As can
be observed in our recent heat wave, the highest heat index values preceded the highest air
temperature values by a day or two. Finally, let us look at the Top 10 warmest low temperatures
as recorded by the OKC Micronet.

KNW103 - July 14, 2009 - 84.7?F (29.3?C)
KNW202 - July 14, 2009 - 84.2?F (29.0?C)
KCB102 - August 5, 2008 - 84.0?F (28.9?C)
KNW105 - July 14, 2009 - 84.0?F (28.9?C)
KCB103 - August 5, 2008 - 83.8?F (28.8?C)
KNE101 - July 14, 2009 - 83.8?F (28.8?C)
KNW103 - July 12, 2009 - 83.7?F (28.7?C)
KCB102 - July 14, 2009 - 83.7?F (28.7?C)
KCB105 - July 14, 2009 - 83.7?F (28.7?C)
KCB101 - August 5, 2008 - 83.5?F (28.6?C)

Along with maximum air temperatures being higher as a heat wave continues, the low temperatures
follow a similar pattern as you can see that all of the record warmest low temperatures occurred
towards the end of their respective heat waves. One difference between this recent heat wave and
last August's heat wave are the record setting low temperatures away from the downtown area.
Typically, the CBD will have the warmest lows as the high percentage of concrete and asphalt in a
downtown area will better store the heat and re-radiate it back during the nighttime hours resulting
in warmer temperatures. While half of the Top 10 does include CBD locations, this past heat wave
showed some very unpleasant conditions on the northwest side of town. From a statewide perspective,
this heat wave was focused on the northwest portions of the state from Buffalo down towards
Kingfisher and down into the northwest portions of Oklahoma City.

Analyzing nighttime low temperatures is geared more towards a human health standpoint rather
than a meteorological one. The NWS will use low temperatures as a criteria for issuing heat advisories
and excessive heat warnings for the next day. When nighttime low temperatures do not drop below
80?F there becomes a serious concern about human health, especially for those without air
conditioning and with the elderly. EMSA reported that since June 1st, they have had to treat nearly
double the number of people as last year in the same time period.

The Oklahoma City Micronet has been operational for only just over a year and has already
observed two intense heat waves using high spatial and temporal data. Try to put last weekend's
heat behind you and enjoy the much cooler weather.

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