The Northeast Heatwave

By: Dr. Jeff Masters , 9:08 AM GMT on July 07, 2010

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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.

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Quoting reedzone:
Over the past few hours, it seems that the structure is starting to improve fast.. Got my crow defrosting for tomorrow.


LMAO. Takes a real man to eat crow! Impressive.
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1286. Patrap
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Looks less organized than it was a couple of hours ago and not nearly the man that 95L was. I expect 96L to go poof overnight but the effects will still be the same for Texas and MX.
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Quoting Daveg:
Well it ain't purty... but it is starting to effect more and more of the gulf...



That it has. It prevented me from going offshore to work today. Im now in a holding pattern onshore waiting and watching.
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Quoting StormW:


Because the process that causes lightning in a thunderstorm, is due to mostly the effect of vertical winds in the thunderstorm.

In a tropical cyclone, the winds are traveling mostly horizontal. Now, some very intense hurricanes have had lightning near the eyewall.

Here's a good article on it:

NASA



I think this may be the article StormW meant to link:

http://www.nasa.gov/mission_pages/hurricanes/archives/2006/hurricane_lightning.html


( his link went to his previous image... I have done that also)
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Ut-oh...pine hole eye??? :)
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1279. Levi32
Convection with 96L is still being limited in intensity at least partially by Alex's cool SST wake, which is a big factor here.



Member Since: November 24, 2005 Posts: 628 Comments: 26455
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1277. Patrap
RAW: NASA Hurricane Jimena Lightning

Courtesy NASA and accuweather.com


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1275. Dakster
Quoting Patrap:

New Lightning Tech Could Help Hurricane Tracking & Preparation
By Joe Pappalardo



October 1, 2009 12:00 AM

Tallying lightning strikes from thousands of miles away may be the key to measuring the strength of hurricanes before they get close to land. "There have been big advances in predicting where hurricanes will go," says Kirt Squires, the co-author of a recent paper studying lightning patterns in hurricanes. "But ways to determine how strong they will be are still lagging."
29diggsdigg

Currently, the only way to get real-time information on wind speed inside the eye wall is to send in an airplane. But stronger winds produce more lightning, so measuring the frequency of lightning is a good way to track the strength of a hurricane, Squires says. Very low frequency radio signatures of strikes can be picked up from thousands of miles away with commercially available detectors as those signals bounce between the ground and the ionosphere.

The reason high winds cause lightning has to do with the way ice and hail move inside the eye wall. As the frozen water particles rise and fall, they lose electrons, which collect at the bottom of a cloud, producing a negative charge that causes lightning. Squires and University of Hawaii researchers report similar patterns of lightning during the life cycles of recent hurricanes, forming a potential base line for a detector that can determine wind speed without the risk of hurricane flights.­­


VERY interesting article. Now has anyone tested it out to see?
Member Since: March 10, 2006 Posts: 0 Comments: 9737
Thanks Pat, Karen, Storm, and Charmer great info!!
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1273. Levi32
Quoting bigdoge3:
Hey StormW or Levi what are the latest coordinates? Thanks.


Official 18z coordinates were 23.8N, 93.6W. On current satellite imagery I have it near 24N, 94.1W, but it is hard to get an exact fix due to all the cloud-cover.
Member Since: November 24, 2005 Posts: 628 Comments: 26455
It's always sureal (neat in a way) that with tropical weather it can be raining as hard as it can possibly rain... with virtually no thunder and lightning..

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Quoting TxMarc71:
I have always wondered....

Does anyone (Pat, StormW) know why there is much much less electrical activity (thunder and lightning) associated with tropical systems than say your average summer storm??


Lightning is caused by static charges being built up between two different kinds of ice -- graupel (ice pellets) and snow. This static transfer tends to build up differential charges between them, as sharp-pointed surfaces more readily give up electrons than smooth surfaces. The snow is blown aloft easier while the graupel tends to fall more readily, thus separating the charges. Lightning results.

Hurricanes, being warm-cored systems, produce very little ice, and thus have little charge separation,
and thus, lightning.
Member Since: September 7, 2007 Posts: 1 Comments: 937
Quoting HurricaneSwirl:


That's the chance you'll get that cookie..


What kind of cookies ?
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1267. Patrap
Happy Birthday Ringo Starr

A Beatle turns 70.

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Quoting TxMarc71:
I have always wondered....

Does anyone (Pat, StormW) know why there is much much less electrical activity (thunder and lightning) associated with tropical systems than say your average summer storm??
In short there is limited vertical exchange of air, water droplets, ice and water vapor in tropical systems which is necessary for lightning. I'm sure one of the experts here can elaborate.
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Quoting OracleDeAtlantis:


"The usually dry Santa Catarina river that runs through the centre of Monterrey turned into a raging torrent, flooding major highways and paralysing Mexico's third-biggest city."


the image in the link looks more like earthquake damage rather than hurricane.
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After looking at the organization over the last hour, I'd say 60% for now.
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1263. Patrap

New Lightning Tech Could Help Hurricane Tracking & Preparation
By Joe Pappalardo



October 1, 2009 12:00 AM

Tallying lightning strikes from thousands of miles away may be the key to measuring the strength of hurricanes before they get close to land. "There have been big advances in predicting where hurricanes will go," says Kirt Squires, the co-author of a recent paper studying lightning patterns in hurricanes. "But ways to determine how strong they will be are still lagging."
29diggsdigg

Currently, the only way to get real-time information on wind speed inside the eye wall is to send in an airplane. But stronger winds produce more lightning, so measuring the frequency of lightning is a good way to track the strength of a hurricane, Squires says. Very low frequency radio signatures of strikes can be picked up from thousands of miles away with commercially available detectors as those signals bounce between the ground and the ionosphere.

The reason high winds cause lightning has to do with the way ice and hail move inside the eye wall. As the frozen water particles rise and fall, they lose electrons, which collect at the bottom of a cloud, producing a negative charge that causes lightning. Squires and University of Hawaii researchers report similar patterns of lightning during the life cycles of recent hurricanes, forming a potential base line for a detector that can determine wind speed without the risk of hurricane flights.­­
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Quoting HurricaneSwirl:


That's the chance you'll get that cookie..


NICE!!! lol
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Quoting Hurricanes101:


only if you spell it right lol, j/k


did we figure out when the next recon flight would be?


Schedule fix 12Z (8 AM) tomorrow morning.
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Quoting HurricaneSwirl:


That's the chance you'll get that cookie..


LMAO
Member Since: March 10, 2010 Posts: 1 Comments: 7233
Quoting Hardcoreweather2010:


2%


That's the chance you'll get that cookie..
Member Since: July 7, 2008 Posts: 2 Comments: 3237
Quoting reedzone:
Over the past few hours, it seems that the structure is starting to improve fast.. Got my crow defrosting for tomorrow.


Might wanna chuck it in the microwave in case it becomes Bonnie tonight lol jk, it wont.
Member Since: July 7, 2008 Posts: 2 Comments: 3237
Quoting MiamiHurricanes09:
What percentage will the NHC give 96L of tropical cyclone formation in the next 48 hours on the 8PM TWO?

The person that guesses correctly gets a cookie. Lol.

By the way I went with a 70% chance.


2%
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I have always wondered....

Does anyone (Pat, StormW) know why there is much much less electrical activity (thunder and lightning) associated with tropical systems than say your average summer storm??
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Hey StormW or Levi what are the latest coordinates? Thanks.
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Over the past few hours, it seems that the structure is starting to improve fast.. Got my crow defrosting for tomorrow.
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Quoting CJC111:
Hi Storm, does the tropical funnle come with a small umbrella?


only if you spell it right lol, j/k


did we figure out when the next recon flight would be?
Member Since: March 10, 2010 Posts: 1 Comments: 7233
1249. CJC111
Hi Storm, does the tropical funnle come with a small umbrella?
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I will say 73% chance

oh wait they don't break it down that far yet? oh right that will be next season lol

I am on the fence, I guess it depends on how well organized they see it, I could see them going anywhere from 60-80%, but if I had to guess I would say 60%
Member Since: March 10, 2010 Posts: 1 Comments: 7233
Quoting MiamiHurricanes09:
What percentage will the NHC give 96L of tropical cyclone formation in the next 48 hours on the 8PM TWO?

The person that guesses correctly gets a cookie.

By the way I went with a 70% chance.


60% chance.

That cookie will be MINE!

Although 70% chance is what it SHOULD be.
Member Since: July 7, 2008 Posts: 2 Comments: 3237
1246. OneDay
Quoting Patrap:
Gulf Of Mexico - Water Vapor Loop


So much for the dry air in the W GOM...
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1244. Patrap
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Oy -- does every storm this year have to try to spin up the entire Gulf? :P
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1242. oakland
Keeper- Where is that data from?
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I'll be conservative and say 60%.
Member Since: July 8, 2005 Posts: 259 Comments: 23013
What percentage will the NHC give 96L of tropical cyclone formation in the next 48 hours on the 8PM TWO?

The person that guesses correctly gets a cookie. Lol.

By the way I went with a 70% chance.
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1239. Patrap
Gulf Of Mexico - Water Vapor Loop
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1238. KEEPEROFTHEGATE (Mod)


ALERT ATCF MIL 96X XXX 100707180000
2010070718
23.8 266.4
26.1 261.2
100
23.8 266.4
072100
1007072000
2
WTNT01 KNGU 072000
SUBJ/TROPICAL CYCLONE FORMATION ALERT 072000Z JUL 10//
RMKS/1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
100 NM EITHER SIDE OF A LINE FROM 23.8N 93.6W TO 26.1N 98.8W
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNING AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 20 TO 25 KNOTS. METSAT
IMAGERY AT 071930Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 23.8N 93.6W. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 13
KNOTS.
2. REMARKS: A BROAD AREA OF LOW PRESSURE LOCATED JUST WEST OF THE
YUCATAN PENINSULA TRACKS WEST-NORTHWEST TOWARDS THE NORTHEAST COAST
OF MEXICO. THE LATEST METSAT IMAGERY INDICATES INCREASED CONVECTION,
WHICH IS INDICATIVE OF STRENGTHENING. INCREASED SEA SURFACE TEMPERATURES
IN THE REGION AND LIGHT UPPER LEVEL WIND SHEAR WILL PROVIDE FAVORABLE
CONDITIONS FOR TROPICAL CYCLONE DEVELOPMENT.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED
BY 082000Z.//
9610070306 159N 760W 25
9610070312 162N 775W 25
9610070318 150N 799W 25
9610070400 154N 808W 25
9610070406 157N 816W 25
9610070412 160N 822W 30
9610070418 164N 826W 30
9610070500 168N 831W 30
9610070506 174N 837W 30
9610070512 182N 846W 30
9610070518 188N 853W 30
9610070600 197N 868W 30
9610070606 205N 881W 30
9610070612 213N 895W 30
9610070618 220N 907W 25
9610070700 224N 916W 25
9610070706 228N 924W 25
9610070712 232N 930W 25
9610070718 238N 936W 30

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1237. Patrap
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About JeffMasters

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.