Sunny and Warm Posted April 13, 2012 Share Posted April 13, 2012 Here's an interesting article I came across this morning that may interest some here: Exerpt: Mark Johnson, Chief Meteorologist of WEWS in Cleveland writes: A friend of mine, Justin Berk, a local TV Met in Baltimore, MD had this story to tell today: “There’s something fishy going on at BWI (Baltimore International Airport),” he says. Hourly obs at BWI airport (April 12, 2012) never went higher than 59 degrees. (See the obs from BWI below – Anthony) But, he noticed the official high temperature was listed as 62 degrees. “There’s no way a jump of 3-4 degrees occurred and then fell back down between obs,” he added. Why the discrepancy? Justin called the local NWS office. For a brief 10 minutes, the steady NW wind that persisted all day at BWI shifted to a westerly direction. That allowed the HEAT from the nearby runway to provide a quick 3 degree warm-up between hourly obs. Once the winds shifted back to a NW direction, the temperature fell back to 59 degrees. The NWS employee concurred that the extra warmth came from the runway. Global Warming is real (thanks to poorly-sighted thermometers)! This is the second time Justin observed a false high temperature reading this week at BWI. http://wattsupwiththat.com/2012/04/13/how-airports-like-bwi-help-set-outlier-high-temperature-records/#more-61227 Link to comment Share on other sites More sharing options...
wxmeddler Posted April 13, 2012 Share Posted April 13, 2012 Sorry, I'm not buying this. Theres a more logical reason for this. Notices in those obs that the winds were 10 mph gusting to 18. That is PLENTY of wind to mix out that heat coming from that tarmac. This article acts if while the ASOS station had NW winds the tarmac to its west has no/ calm winds. It doesn't work like that. Those NW winds were blowing over that tarmac and mixing out. So what caused the jump? If you have ever looked at a topographical map for the BWI area there is the MD fall line about 3 miles to the west of the airport. Its a fall of 300-600 feet over 2 miles. I've noticed even at my house (which is 9 miles away and in a wooded area) that when the wind blows from the west you get an increased jump in temperatures due to downsloping from the fall line. Thats NOT an ASOS placing problem, it's natural and has been there way before the airport ever existed. Link to comment Share on other sites More sharing options...
Sunny and Warm Posted April 13, 2012 Author Share Posted April 13, 2012 Sorry, I'm not buying this. Theres a more logical reason for this. Notices in those obs that the winds were 10 mph gusting to 18. That is PLENTY of wind to mix out that heat coming from that tarmac. This article acts if while the ASOS station had NW winds the tarmac to its west has no/ calm winds. It doesn't work like that. Those NW winds were blowing over that tarmac and mixing out. So what caused the jump? If you have ever looked at a topological map for the BWI area there is the MD fall line about 3 miles to the west of the airport. Its a fall of 300-600 feet over 2 miles. I've noticed even at my house (which is 9 miles away) that when the wind blows from the west you get an increased jump in temperatures due to downsloping from the fall line. Thats NOT an Airport placing problem, it's natural and has been there way before the airport ever existed. I certainly agree with you on your second paragraph. West winds tend to bring temp jumps in many places. However, I have a hard time seeing a three degree jump for only ten minutes of west wind. As to your first paragraph, it really depends on whether the westerly fetch from the runway is much longer than the northwesterly fetch. I could see small heat island effects. For example, I went jogging the other day and ran by a pond that was much warmer than surrounding areas. The wind was coming from the direction of the pond, and the increased temp and humidity I felt during those 15-20 seconds I jogged by that fetch was remarkable. I could certainly see a three degree rise if jets were steadily upstream to the west versus NW. Link to comment Share on other sites More sharing options...
Ellinwood Posted April 13, 2012 Share Posted April 13, 2012 My thoughts: It's not a "false high." A three degree between hourly temperatures and intra-hour highs are fairly common across the U.S. and the intra-hour highs are usually correct. NBD Link to comment Share on other sites More sharing options...
donsutherland1 Posted April 13, 2012 Share Posted April 13, 2012 I disagree. First, posted hourly readings can miss maximum and minimum temperatures that are set between the hours. Consecutive hourly readings mean little in that context. Second, the distance of the ASOS from the runway and mass of the runway makes it improbable that a single runway could account for a 3-4-degree jump in the temperature. The wind would disperse the narrow area of excess heat well before it had a significant impact on the ASOS. Third, statistical analysis indicates no such problems exist at BWI. The following are some standard deviations (2000-2010) for daily high temperatures: BWI: 18.292° DCA: 17.949° MD Science Center: 18.653° National Arboretum: 18.651° Vienna: 17.095° What happened was that downsloping, not heat from the airport runway led to the brief bounce in BWI's temperature. My confidence in this scenario is very high. Link to comment Share on other sites More sharing options...
mattmfm Posted April 13, 2012 Share Posted April 13, 2012 Erm, not to mention, the rise described could have simply been 59.4 to 61.5, only a 2.1 degree rise between hours. Which, with a change in wind direction, is all too common. What a ridiculous assertion. Link to comment Share on other sites More sharing options...
donsutherland1 Posted April 13, 2012 Share Posted April 13, 2012 Justin Berk posted a response on the blog stating: If +3 degrees is not such a big deal in these conditions, consider that these conditions of prevailing wind and afternoon sun occur more than 50% of the year. Doing some crude estimates, 1/2 the days and 1/2 the daily temperature extremes would results in +.75F higher results over the course of a year (on average). Let's take a look at the data (2000-10 to cover the common period for all three stations): Mean annual high temperature at Beltsville: 65.76° Mean annual high temperature at BWI: 65.76° Mean annual high temperature at Maryland Science Center: 66.59° Standard deviation in daily high temperatures: Beltsville: 18.259° BWI: 18.292° Maryland Science Center: 18.653° The statistical data suggests that it is improbable that BWI's temperature record is flawed. In other words, it is extremely unlikely that the bounce in temperature at BWI has anything to do with the integrity of BWI's data record. Nearby BWI and Beltsville have almost identical high temperatures (BWI's average high was 0.007° warmer than Beltsville's and its standard deviation was 0.033° larger than Beltsville's). Were runway-enhanced heat causing a problem, these near identical results would not exist. For all intents and purposes, these proximate locations have statistically almost identical data, as one would expect if the data were correct. P.S. There's greater variability between New York City's Central Park and La Guardia Airport (Average high temperature difference of 0.598° and 0.179° difference in standard deviation) than between Beltsville and BWI. Link to comment Share on other sites More sharing options...
WxUSAF Posted April 14, 2012 Share Posted April 14, 2012 Excellent work, Don. Link to comment Share on other sites More sharing options...
donsutherland1 Posted April 14, 2012 Share Posted April 14, 2012 Thanks WxUSAF. Link to comment Share on other sites More sharing options...
donsutherland1 Posted April 14, 2012 Share Posted April 14, 2012 A quick update: I just read Jason Samenow's piece in the Post's Capital Weather Gang section. He attributed the temporary rise to the sun breaking out from the clouds. I had not realized that it had been mostly cloudy except for a few breaks during the critical hour in question. His explanation makes a lot of sense. Ironically, a similar thing happened at NYC's Central Park the same day. The highest hourly reading was listed at 59°. The maximum temperature was 61°. For Central Park, I know firsthand that there had been intervals of clouds and sun during the period when the temperature peaked. Statistically, I also looked at average low temperatures between BWI and Beltsville (2000-10). The figures were very close: BWI: 45.96°/Standard Deviation of 16.880°; Beltsville: 45.73°/Standard 'Deviation of 16.987°. The almost identical figures also strongly argue against flawed siting at BWI. Link to comment Share on other sites More sharing options...
Scuddz Posted April 14, 2012 Share Posted April 14, 2012 Justin Berk is an idiot Link to comment Share on other sites More sharing options...
usedtobe Posted April 14, 2012 Share Posted April 14, 2012 Don, good stuff. I lifted your post and put it in the remarks section of Jason's CWG posting. I noticed I made some typos in the attribution, I apologize and hope everyone can figure out they quote marks should have been included at the end of the post. Wes Link to comment Share on other sites More sharing options...
donsutherland1 Posted April 14, 2012 Share Posted April 14, 2012 Don, good stuff. I lifted your post and put it in the remarks section of Jason's CWG posting. I noticed I made some typos in the attribution, I apologize and hope everyone can figure out they quote marks should have been included at the end of the post. Wes Thank you very much, Wes. Link to comment Share on other sites More sharing options...
mattmfm Posted April 16, 2012 Share Posted April 16, 2012 “There’s no way a jump of 3-4 degrees occurred and then fell back down between obs,” he added. For a supposed rare occurrence, DCA high temperature today was 3 degrees higher than hourly observations. Link to comment Share on other sites More sharing options...
Ellinwood Posted April 16, 2012 Share Posted April 16, 2012 He just won't give it up... http://www.examiner....cid=db_articles Sidenote: He's been forecasting for Baltimore for 15 years... why is he bringing this up now? Link to comment Share on other sites More sharing options...
donsutherland1 Posted April 16, 2012 Share Posted April 16, 2012 He just won't give it up... http://www.examiner....cid=db_articles Sidenote: He's been forecasting for Baltimore for 15 years... why is he bringing this up now? The better approach would have been for him to step back and recognize that his comments were an overreaction to the kind of bounce in temperatures that is actually fairly common and not unique to BWI. Also, it seems that he is trying to make this an issue of climate change. He stated, "My motives are already questioned by Global Warming promoters..." As far as I can tell, this issue has been strictly about the integrity of BWI's records. Ironically, on the same day BWI recorded its 3° between hours fluctuation, Central Park also had a 2° fluctuation. Maybe the heat from 5th Avenue is to blame? Science is about testing of hypotheses not proclaiming such hypotheses findings absent of testing. The statistical analysis makes it impossible to reach Mr. Berk's conclusion, much less with a 90% or 95% level of confidence. In a bid to side-step the the lack of statistical support for his hypothesis, he questions the siting of the Maryland Science Center thermometer. Beltsville has an even closer match to BWI. Moreover, Weatherbug stations do not receive the kind of quality control to which ASOS stations are subjected. Finally, if one looks at NWS-Sterling records, BWI's highest temperature in July 2010 was 105° on July 6, not 106°. In the end, the objective data suggests that BWI offers a good temperature record. Subjective opinion might disagree, but it is the concrete objective data that matters. As a result, I highly doubt that NCDC will reduce the high temperature for the day in question. Link to comment Share on other sites More sharing options...
chris87 Posted April 16, 2012 Share Posted April 16, 2012 He just won't give it up... http://www.examiner....cid=db_articles Sidenote: He's been forecasting for Baltimore for 15 years... why is he bringing this up now? He shows a complete lack of any understanding of how a convective boundary layer works.... Here is an example of 30-s 2-meter temperature from a sensor in Huntsville, AL, one can see how large variability can be in the CBL (on short time scales) as eddy updrafts and downdrafts pass over the sensor site....I think if Mr. Berk was provided the time series of 2-meter temperature which has 30-sec or 1-min temporal resolution from just about any site in the US...he'd change his tune quickly. http://vortex.nsstc....rface/t_dpt.png Link to comment Share on other sites More sharing options...
usedtobe Posted April 16, 2012 Share Posted April 16, 2012 He shows a complete lack of any understanding of how a convective boundary layer works.... Here is an example of 30-s 2-meter temperature from a sensor in Huntsville, AL, one can see how large variability can be in the CBL (on short time scales) as eddy updrafts and downdrafts pass over the sensor site....I think if Mr. Berk was provided the time series of 2-meter temperature which has 30-sec or 1-min temporal resolution from just about any site in the US...he'd change his tune quickly. http://vortex.nsstc....rface/t_dpt.png Either that or a political agenda since stats for BWi and Beltsville and the Bowie Science Center don't support his allegations and his blog has been discussed here and elsewhere pretty with many arguing against his claims. At the very least it shows sloppiness on his part as it would have been easy to check BWI averages and standard deviations versus other nearby stations like Don Southerland did. The similarities in the data for BWi and Beltsville should have made him rethink his claim. That he continues to march to his own tune makes me wonder about having an agenda. Even with the 30 second data that you show, I wonder whether he would be willing to change his tune. Link to comment Share on other sites More sharing options...
WxUSAF Posted April 17, 2012 Share Posted April 17, 2012 Of course he has an agenda. At least this claim is slightly less foolish than JB's (the original) claim that CO2 is not a well-mixed gas in the troposphere Link to comment Share on other sites More sharing options...
donsutherland1 Posted April 17, 2012 Share Posted April 17, 2012 Another example of how between hours readings can fluctuate dramatically from the hourly reports. Today's data is from Boston. Both hourly reports showed a temperature of 84° (2:54 pm and 3:54 pm). However, at 3:04 pm, the mercury reached 87°, breaking the daily high temperature record of 84°, which was set in 2003. In sum, there's nothing unusual about what happened at BWI. Furthermore, there's no statistical evidence that the BWI temperature data is flawed. Statistically, the data matches up extremely well with nearby stations. Link to comment Share on other sites More sharing options...
CapitalClimate Posted April 19, 2012 Share Posted April 19, 2012 Mr. Berk has a long and distinguished career of illogical and irrational denial of climate change. Link to comment Share on other sites More sharing options...
CapitalClimate Posted April 19, 2012 Share Posted April 19, 2012 Justin Berk is an idiot But he teaches at Villa Julie Finishing School College. Link to comment Share on other sites More sharing options...
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