Dr. Jeff Masters' WunderBlog

The Northeast Heatwave

Posted by: Dr. Jeff Masters, 09:08 GMT le 07 juillet 2010

Hi, Dr. Rob Carver, filling in for Jeff while he's on vacation.

The most significant weather event in the US on July 6, 2010 didn't show up on any radar. The geostationary satellites didn't see it in their constant watch over the Earth's atmosphere. Instead, the tale of this event was told by the thermometers, because the heatwave in the Northeast was the most significant event for July 6, and it will likely be the most important weather story for July 7.

The heat wave covers Pennsylvania to Maine, but Tuesday's worst was centered over New York City. All six of the stations used by the New York NWS office for climate reports (Central Park, La Guardia, JFK, Islip, Bridgeport, and Newark) set or tied the daily high temperature record. Newark and Central Park both reached 103 degrees F.

How unusual is this heat wave?
Figures 1 and 2 show how warm the highs and lows are compared to 30 year averages. Unless you were at the Great Lakes, the Midwest and Northeast have highs well above normal, with 10-15+ degree F differences over the coastal cities of the Northeast. Using my gridded temperature data, the low for New York City was 6 degrees F above normal, which should happen 30% of the time (1.1 standard deviations away from normal). The high was roughly 20 degrees above normal, which should happen only 0.29% of the time (3.04 standard deviations away from normal). This is an unusually strong heat wave.

Why it's hot
Basically, it's because there is "the Bull of a high pressure ridge [over the NE US]" to quote the Mount Holly NWS office forecast discussion. The large ridge of high pressure is forcing air to slowly descend across the Northeast, preventing clouds from forming. Without no clouds and plenty of daylight, the Sun heats the ground which then heats the air.

When will it cool down?
That's an excellent question. A trough of low pressure off the coast will bring onshore winds to the Tri-State area and MA by Thursday, so they should cool down a bit. The southern part of the heat wave, DC and Philadelphia, will have to wait for a cold front to arrive from the Great Lakes sometime Saturday to get relief.

Population affected
As Figure 3 shows, heat advisories covered most of the urban areas of the northeastern US. By my calculations, over 32 million people were under a heat advisory. Different offices have different guidelines for heat advisories. The NWS office responsible for New York issues a heat advisory if the heat index will be above 95 deg. F for two or more days or if the index will be above 100 deg. F for any length of time.

Fig.1 Plot of the difference between maximum temperature (the high for the day) and average maximum temperature in degrees F for July 6.

Fig.2 Plot of the difference between minimum temperature (the low for the day) and average minimum temperature in degrees F for July 6.

Fig.3 Plot of the active heat advisories across the northeastern US for July 6.

Heatwave impacts
The predominant impact from heat waves is increased mortality. CDC estimates that over 8,000 people died during heat waves from 1979 to 2003. That's more than all of the deaths due to lightning, flooding, tornadoes, hurricanes, and earthquakes. The elderly, sick, poor, and very young face the worst of the effects of the heat. Wikipedia has an interesting article describing the Chicago Heat Wave of 1995, a modern heat wave with a large number of fatalities due to the heat.

Heatwave coping strategies
The Centers for Disease Control have some tips for dealing with the heat. In summary, drink plenty of water, spend time in air-conditioned buildings, and wear light-colored clothing.

Is this heat wave due to global warming?
Ah, the $64,000 question. In the absence of detailed analysis, it's hard to specify the exact cause for this heat wave, from a meteorological or climatological view point. However, events like this are consistent with research showing that heat waves are more likely with
global warming. I like the metaphor of loaded dice, global warming is not specifically responsible for any heat wave, but it will make them happen more often.

Tropics
My thinking on Invest 96L is unchanged from this blog entry. In summary, I believe that 96L has a <50 % chance becoming a tropical cyclone before it makes landfall. If it does so, it will likely be near the coast when that happens. In any event though, the winds and waves it generates will likely disrupt oil spill recovery efforts. Also, I would expect a broad area of showers and 20+ mph winds will affect the Gulf coast somewhere from south Texas to Louisiana.

Next update
I'll have an update this afternoon to talk about the tropics.

Categories: Heat

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851. angiest 20:02 GMT le 07 juillet 2010
Quoting lhwhelk: 96L. 95L is what hit us last week, bringing 5" of rain on Wed, Thurs, & Fri to Lake Jackson. So far today, just 1" here. No, last week was Alex. 95L was a couple of days ago (though I am not convinced all the moisture has left). Member Since: 26 août 2006 Posts: 16 Comments: 4766

852. AllBoardedUp 20:02 GMT le 07 juillet 2010
Quoting IKE: 96L. Thanks, and that ain't good for us. Looks no end in sight, whether it develops, or not! Member Since: 25 juillet 2008 Posts: 0 Comments: 585

853. KarenRei 20:02 GMT le 07 juillet 2010
For those curious as to what the track and intensity of this storm means to the people of the Rio Grande: the current river forecast peak for Laredo is ~38 feet. If the river crests six feet lower than that: THE LOWEST BUSINESSES NEAR THE RIVER FLOOD IN DOWNTOWN LAREDO. RUNOFF DOWN FROM CHACON AND ZACATE CREEKS ADD TO THE RIO GRANDE RIVER BACKFLOW...AND CAN FLOOD HOMES ALONG THESE CREEKS. STREETS AND BRIDGES ARE FLOODED AND ARE EXTREMELY DANGEROUS TO TRAFFIC If the river crests six feet higher than that: MASSIVE RESIDENTIAL AND COMMERCIAL FLOODING OCCURS. NEAR THE RIVER...AND ALONG CHACON AND ZACATE CREEKS...FLOODING CAN BE LIFE THREATENING...AS THE RIO GRANDE RIVER BACKS THEM UP. THE SEWAGE PLANT IS UNDER SEVERAL FEET OF WATER. THE INTERNATIONAL BRIDGE FLOOR FLOOR FLOODS...AND LIVESTOCK ARE CUT OFF AND POTENTIALLY DROWNED IN THE FLOOD PLAIN...ABOVE EAGLE PASS TO FALCON RESERVOIR So what this storm does is very relevant, even if it never becomes super-windy. Member Since: 7 septembre 2007 Posts: 1 Comments: 934

855. MiamiHurricanes09 20:03 GMT le 07 juillet 2010
Quoting Hurricanes101: It can be both, he said no TD tonight Last I checked, none of us said that either lol He was continuously saying that it isn't going to develop and that everyone is hyping it. Now he changed his mind. Oh well. CIMSS 18:00 UTC 850mb vorticity product. Member Since: 2 septembre 2009 Posts: 129 Comments: 20002

856. kelley9 20:03 GMT le 07 juillet 2010
Quoting btwntx08: really looks good to me lol I say we send in a boat. Got plenty of 'em out that way these days, ya know? ;) Member Since: 24 juillet 2007 Posts: 0 Comments: 24

857. StormChaser81 20:03 GMT le 07 juillet 2010
Quoting atmoaggie: Even the NOAA crews? (pretty sure they are not) Most of all NOAA crew where military and now work for NOAA, which falls under federal. Atleast thats what I've been told could be wrong. Member Since: 11 août 2008 Posts: 0 Comments: 2315

859. AllBoardedUp 20:04 GMT le 07 juillet 2010
Quoting OracleDeAtlantis: I've never seen so many crybaby wannabe whiners over 95L not being classified as tropical. Hey! We resent that! We're not whiners! LOL Member Since: 25 juillet 2008 Posts: 0 Comments: 585

860. atmoaggie 20:04 GMT le 07 juillet 2010
Quoting OracleDeAtlantis: I've never seen so many [snip] over 95L not being classified as tropical. ??? Was the tone there really necessary? Member Since: 16 août 2007 Posts: 6 Comments: 12461

861. txalwaysprepared 20:04 GMT le 07 juillet 2010
Quoting AllBoardedUp: Thanks, and that ain't good for us. Looks no end in sight, whether it develops, or not! I got 2 inches so far today -- that's on top of the 10 last week from Alex. Member Since: 18 août 2007 Posts: 0 Comments: 1642

862. extreme236 20:05 GMT le 07 juillet 2010
I'd rather keep an eye on 96L which has a very good chance to develop into a cyclone in the short term rather than a weak non-tropical low that most likely will not develop in the short couple day window it has. Member Since: 2 août 2007 Posts: 19 Comments: 19234

863. Drakoen 20:05 GMT le 07 juillet 2010
Lots of low level convergence associated with 96L as well Member Since: 28 octobre 2006 Posts: 57 Comments: 29012

864. PtownBryan 20:06 GMT le 07 juillet 2010
Quoting louisianaweatherguy: yeah Rita hit the LA/TX border... Ike pretty hit Houston head on, right? Ike did go just east of downtown. I know, I live south of downtown in a city called Pearland...the eye went to our east and we never had calm winds except before Ike started and when he decided to leave like 10 hours later! lol. Crazy how the second half of the storm was worse than the first part. If Ike would have hit my county(brazoria) instead of Glaveston county, Galveston would have been in far worse shape and it was bad enough just taking the direct hit, less dirty part! Member Since: 5 juillet 2010 Posts: 0 Comments: 170

865. NttyGrtty 20:06 GMT le 07 juillet 2010
Quoting kelley9: Agreed. Been a "watcher" for many years, (I'm asperger's and kinda anti-social) but finally decided to join the blogging masses, so I kinda already know who to avoid, who's alright and who's talking out of their... um, behind. Ya know? Yep, I do... Member Since: 11 février 2010 Posts: 0 Comments: 666

866. StormChaser81 20:06 GMT le 07 juillet 2010
Hurricane hunter missions: In the United States, the Air Force, Navy, and NOAA units have all participated in this mission. Member Since: 11 août 2008 Posts: 0 Comments: 2315

867. leo305 20:06 GMT le 07 juillet 2010
96L is looking better on satellite.. it feels as if it's beginning to concentrate the convection on a spin Member Since: 17 avril 2010 Posts: 0 Comments: 1752

868. atmoaggie 20:06 GMT le 07 juillet 2010
Quoting extreme236: I'd rather keep an eye on 96L which has a very good chance to develop into a cyclone in the short term rather than a weak non-tropical low that most likely will not develop in the short couple day window it has. ??? whiskey tango foxtrot? I think you just described the same system twice... Member Since: 16 août 2007 Posts: 6 Comments: 12461

869. extreme236 20:06 GMT le 07 juillet 2010
Next week's most likely focus will be in the area shaded red on the map. Perhaps if this CV storm starts to begin to take shape late in the week that could be of interest as well. Member Since: 2 août 2007 Posts: 19 Comments: 19234

870. lhwhelk 20:07 GMT le 07 juillet 2010
Quoting angiest: No, last week was Alex. 95L was a couple of days ago . True. My bad. They're coming thick and fast this year. But please, no more Katrina's, Rita's, or Ike's--except the blogger, of course! Member Since: 26 août 2008 Posts: 0 Comments: 58

871. MiamiHurricanes09 20:07 GMT le 07 juillet 2010
Quoting extreme236: I'd rather keep an eye on 96L which has a very good chance to develop into a cyclone in the short term rather than a weak non-tropical low that most likely will not develop in the short couple day window it has. Agree. Short-term focus is on 96L, once this system is gone we focus on the non-tropical low by the Bahamas. From what I'm seeing 96L will become Bonnie, but will likely not exceed the 40mph threshold. Then again, it doesn't have much time over water so we aren't going to see a strong system. Member Since: 2 septembre 2009 Posts: 129 Comments: 20002

872. extreme236 20:07 GMT le 07 juillet 2010
Quoting atmoaggie: ??? whiskey tango foxtrot? I think you just described the same system twice... No I was talking about 96L and then the "Reed Low" lol Member Since: 2 août 2007 Posts: 19 Comments: 19234

874. txalwaysprepared 20:07 GMT le 07 juillet 2010
Quoting PtownBryan: Ike did go just east of downtown. I know, I live south of downtown in a city called Pearland...the eye went to our east and we never had calm winds except before Ike started and when he decided to leave like 10 hours later! lol. Crazy how the second half of the storm was worse than the first part. If Ike would have hit my county(brazoria) instead of Glaveston county, Galveston would have been in far worse shape and it was bad enough just taking the direct hit, less dirty part! Yep. We rode the west side of the eye for a good bit. And the back side of the storm was much worse. I never expected that!! Member Since: 18 août 2007 Posts: 0 Comments: 1642

876. PtownBryan 20:08 GMT le 07 juillet 2010
Quoting btwntx08: i think we will get a weak 40-45 ts out of this I think that is a pretty good guess. And it starts raining harder as I say that LOL. Member Since: 5 juillet 2010 Posts: 0 Comments: 170

877. extreme236 20:08 GMT le 07 juillet 2010
Quoting MiamiHurricanes09: Agree. Short-term focus is on 96L, once this system is gone we focus on the non-tropical low by the Bahamas. From what I'm seeing 96L will become Bonnie, but will likely not exceed the 40mph threshold. Then again, it doesn't have much time over water so we aren't going to see a strong system. Agreed. Probably similar intensity to what TS Erin was (One good analogy Reed used for this). Member Since: 2 août 2007 Posts: 19 Comments: 19234

878. atmoaggie 20:08 GMT le 07 juillet 2010
Quoting StormChaser81: Most of all NOAA crew where military and now work for NOAA, which falls under federal. Atleast thats what I've been told could be wrong. Yep. I know of one that went from AF HH to NOAA just a year or 2 ago. Member Since: 16 août 2007 Posts: 6 Comments: 12461

881. ElConando 20:09 GMT le 07 juillet 2010
Quoting StormW: Well, right now, until I get updated steering for tonight, there are 2 possible scenarios...it continues SSW, and crosses into FL., or it continues SSW, stalls, does a semi-cyclonic loop, and heads back out to sea. The wave in the Bahamas may cross into Florida? Member Since: 6 septembre 2009 Posts: 2 Comments: 3709

882. PtownBryan 20:09 GMT le 07 juillet 2010
Quoting txalwaysprepared: Yep. We rode the west side of the eye for a good bit. And the back side of the storm was much worse. I never expected that!! Me either. I know that at 3 or 4 am I wanted to get a little rest...as I lay in the recliner...I sit up and say..this ain't normal! lol. No sleep for me until about 8 or 9 that morning...I was so tired I slept in the heat and didn't care how much I sweated! Member Since: 5 juillet 2010 Posts: 0 Comments: 170

883. KarenRei 20:10 GMT le 07 juillet 2010
Quoting PtownBryan: I think that is a pretty good guess. And it starts raining harder as I say that LOL. Yep -- she's going to be a rain machine. Not Alex's caliber, but more than I think most people are expecting. Member Since: 7 septembre 2007 Posts: 1 Comments: 934

884. extreme236 20:10 GMT le 07 juillet 2010
The CPC forecast in the green circle labled as "4" shows a high chance for rainfall in these areas, suggesting the potential for some type of disturbances (whether or not they are or become tropical cyclones) to be around. Member Since: 2 août 2007 Posts: 19 Comments: 19234

885. atmoaggie 20:10 GMT le 07 juillet 2010
Quoting extreme236: No I was talking about 96L and then the "Reed Low" lol Hokay. Since 95L went inland, I wasn't aware there was much of anything else, besides 96L, to look at...but I have been fairly busy, lately. And, here I go to busy-land, L8R, y'all. Member Since: 16 août 2007 Posts: 6 Comments: 12461

886. MiamiHurricanes09 20:10 GMT le 07 juillet 2010
Quoting extreme236: Agreed. Probably similar intensity to what TS Erin was (One good analogy Reed used for this). That's a really good example as far as intensity and track goes. Member Since: 2 septembre 2009 Posts: 129 Comments: 20002

887. sebastianflorida 20:12 GMT le 07 juillet 2010
Quoting StormW: Well, right now, until I get updated steering for tonight, there are 2 possible scenarios...it continues SSW, and crosses into FL., or it continues SSW, stalls, does a semi-cyclonic loop, and heads back out to sea. Hopefully not a loop thing like Jeanne in 04. Thanks Member Since: 5 août 2007 Posts: 0 Comments: 513

889. wunderkidcayman 20:12 GMT le 07 juillet 2010
HEY GUYS GUESS WHAT JUST HAPPEN TO ME I WAS GIVING A FRIEND OF MINE A WEATHER REPORT SHE IS A HAIR DRESSER AND SHE HAD THE PHONE ON SPEAKER SO EVERYONE COULD HEAR AND THIS GUY THAT HEARD IT CAME UP AND SPOKE TO ME ON THE PHONE HE IS THE DIRECTOR OF CITN/WESTSTAR OUR TV/NEWS NETWORK HERE IN CAYMAN AND HE ASKED ME TO MEET WITH HIM SO THIS IS JUST GREAT Member Since: 13 juin 2009 Posts: 2 Comments: 5997

890. extreme236 20:13 GMT le 07 juillet 2010
2007's Tropical Storm Erin nearing landfall: Member Since: 2 août 2007 Posts: 19 Comments: 19234

891. AllBoardedUp 20:13 GMT le 07 juillet 2010
As saturated as the ground is here all along the Texas coast it won't take a whole lot of wind to do some tree damage. I'm not talking limbs, but trees falling over. Member Since: 25 juillet 2008 Posts: 0 Comments: 585

892. watchingnva 20:13 GMT le 07 juillet 2010
JAMES RIVER (MADIS) Updated: 8 sec ago Scattered Clouds 105.4 �F Scattered Clouds Humidity: 37% Dew Point: 69 �F Wind: 0.0 mph Wind Gust: 1.1 mph Pressure: 29.93 in (Falling) Heat Index: 112 �F my ac is too old for this...lol... Member Since: 7 septembre 2005 Posts: 3 Comments: 1310

893. extreme236 20:13 GMT le 07 juillet 2010
Quoting wunderkidcayman: HEY GUYS GUESS WHAT JUST HAPPEN TO ME I WAS GIVING A FRIEND OF MINE A WEATHER REPORT SHE IS A HAIR DRESSER AND SHE HAD THE PHONE ON SPEAKER SO EVERYONE COULD HEAR AND THIS GUY THAT HEARD IT CAME UP AND SPOKE TO ME ON THE PHONE HE IS THE DIRECTOR OF CITN/WESTSTAR OUR TV/NEWS NETWORK HERE IN CAYMAN AND HE ASKED ME TO MEET WITH HIM SO THIS IS JUST GREAT GOTTA LOVE THAT CAPS LOCK BUTTON, HUH? Member Since: 2 août 2007 Posts: 19 Comments: 19234

895. KarenRei 20:13 GMT le 07 juillet 2010
(snip) Member Since: 7 septembre 2007 Posts: 1 Comments: 934

897. ElConando 20:14 GMT le 07 juillet 2010
Quoting MiamiHurricanes09: That's a really good example as far as intensity and track goes. Hopefully it won't re intensify over land. Member Since: 6 septembre 2009 Posts: 2 Comments: 3709

898. FLWeatherFreak91 20:14 GMT le 07 juillet 2010
Quoting KarenRei: Oh great... thanks, ECMWF: 2010's goal is apparently to wash Laredo and Brownsville off the map. This is from last Friday. Member Since: 1 décembre 2006 Posts: 2 Comments: 3516

899. extreme236 20:15 GMT le 07 juillet 2010
Looks like the tropics could be active next week...and I'm gonna miss most of it being on vacation next week. Member Since: 2 août 2007 Posts: 19 Comments: 19234

900. MiamiHurricanes09 20:15 GMT le 07 juillet 2010
. Member Since: 2 septembre 2009 Posts: 129 Comments: 20002

901. angiest 20:15 GMT le 07 juillet 2010
Quoting KarenRei: Oh great... thanks, ECMWF: 2010's goal is apparently to wash Laredo and Brownsville off the map. That forecast is most of a week old now. It looks wrong on the intensity but the location is fairly good, it would appear. Member Since: 26 août 2006 Posts: 16 Comments: 4766

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