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 DestinJeff:


thank you for not using the ubiqutous(?) "hinting at"
your welcome
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Can someone post the parallel GFS? I lost the link.
Member Since: September 2, 2009 Posts: 130 Comments: 21091
Some models are sniffing out a Cape Verde Storm to start developing around the 19th-22cnd E of the Lesser Antillies.
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Off to New Smyrna Beach with my dog children for the morning while the sun is out. Be back later to see how 96L is behaving.
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Quoting IKE:
Kept at 40%...wth? That's 40% and 95L was at zero pct. as it was heading for southern Louisiana.

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT WED JUL 7 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A BROAD AREA OF LOW
PRESSURE LOCATED OFF THE NORTHWESTERN COAST OF THE YUCATAN
PENINSULA REMAIN DISORGANIZED. ENVIRONMENTAL CONDITIONS APPEAR
MARGINALLY CONDUCIVE FOR SOME DEVELOPMENT OF THIS DISTURBANCE AS
IT MOVES WEST-NORTHWESTWARD AT 10 TO 15 MPH. THERE IS A MEDIUM
CHANCE...40 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
BEFORE IT MOVES INLAND OVER MEXICO OR SOUTHERN TEXAS IN A DAY OR
SO.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BROWN
Yeah they actually should've raised it from 40%.
Member Since: September 2, 2009 Posts: 130 Comments: 21091
seems like cycloginisis is really hard to get going this year
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The 00z ECMWF is developing another "Alex-type" tropical system in the Caribbean. The system is first analyzed as a sharply inverted tropical wave at 168 hours approaching Belize and the Yucatan. The system later develops into a strong tropical depression/weak tropical storm in the BOC.

ECMWF 00z 168 hours

Member Since: September 2, 2009 Posts: 130 Comments: 21091
Quoting IKE:


Here's the South America view of the latest ECMWF through day 10, which shows the coast of Africa westward....Link
Im locked out on links here for some reason.
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And here is the current wx feature that's going to make my morning suddenly much less pleasurable than I expected.....



I can hear the thunder in the distance, and it's as dark outside now as it was at 6:00 a.m.
Member Since: October 25, 2005 Posts: 19 Comments: 21484
74. IKE
Quoting scott39:
Goodmorning, Ike have you looked at the long range models, say around the 19th of July, putting a developing TC E of the Lesser Antilles?


Here's the South America view of the latest ECMWF through day 10, which shows the coast of Africa westward....Link
Member Since: June 9, 2005 Posts: 23 Comments: 37858


This has been sitting around for days...
Member Since: October 25, 2005 Posts: 19 Comments: 21484
Quoting BahaHurican:
I know for a fact that it can get to 130+ degrees inside a parked car under those conditions. This is why one never leaves animals or children in a parked car.... the heat could quite literally kill them....


Unfortuneatly people do, because they are stupid.
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A heatwave in 2003 in Europe killed more than 30,000. So far I have read of 1 death in the NE due to the heat, so that puts it into perspective, 1 v 30,000......stay cool if you can......
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Word of the day- Decoupled
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Quoting IKE:
I feel for anyone without an AC in the heat. I can put on enough clothes to get warm in the winter, but I can't take off enough to get cool in the summer.

Try it without an AC in your car...that's real fun! Especially when it's been sitting on asphalt in a parking lot with no shade and you get in it.
I know for a fact that it can get to 130+ degrees inside a parked car under those conditions. This is why one never leaves animals or children in a parked car.... the heat could quite literally kill them....
Member Since: October 25, 2005 Posts: 19 Comments: 21484
Goodmorning, Ike have you looked at the long range models, say around the 19th of July, putting a developing TC E of the Lesser Antilles?
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I was thinking NHC would go up from 40%. Dropsondes from the current recon while not showing an overly moist environment have not shown so far a lot of dry air. May be designated with the Air Force lower level recon this afternoon.
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65. IKE
Quoting GTcooliebai:

lol, oh man i was just about to agree with you. But hey they're the nhc, so this shouldn't come as a surprise.


Good point.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting flibinite:
We all adjust to our normal temperature and humidity situations and locations, blueschipper. Please try to have a little insight into human metabolism and adaptation before you start thumping your chest about yours.
Jo
Especially considering that central air conditioning becomes less and less common farther north, and poor old folks who are most at risk are probably least likely to have any at all. Innocent people will die. Guess some people can't write anything but to showoff their ignorance.
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Quoting IKE:
Kept at 40%...wth?

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT WED JUL 7 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A BROAD AREA OF LOW
PRESSURE LOCATED OFF THE NORTHWESTERN COAST OF THE YUCATAN
PENINSULA REMAIN DISORGANIZED. ENVIRONMENTAL CONDITIONS APPEAR
MARGINALLY CONDUCIVE FOR SOME DEVELOPMENT OF THIS DISTURBANCE AS
IT MOVES WEST-NORTHWESTWARD AT 10 TO 15 MPH. THERE IS A MEDIUM
CHANCE...40 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
BEFORE IT MOVES INLAND OVER MEXICO OR SOUTHERN TEXAS IN A DAY OR
SO.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BROWN

lol, oh man i was just about to agree with you. But hey they're the nhc, so this shouldn't come as a surprise.
Member Since: Posts: Comments:
ABNT20 KNHC 071138
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT WED JUL 7 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A BROAD AREA OF LOW
PRESSURE LOCATED OFF THE NORTHWESTERN COAST OF THE YUCATAN
PENINSULA REMAIN DISORGANIZED. ENVIRONMENTAL CONDITIONS APPEAR
MARGINALLY CONDUCIVE FOR SOME DEVELOPMENT OF THIS DISTURBANCE AS
IT MOVES WEST-NORTHWESTWARD AT 10 TO 15 MPH. THERE IS A MEDIUM
CHANCE...40 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
BEFORE IT MOVES INLAND OVER MEXICO OR SOUTHERN TEXAS IN A DAY OR
SO.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BROWN
Member Since: Posts: Comments:
60. IKE
Kept at 40%...wth? That's 40% and 95L was at zero pct. as it was heading for southern Louisiana.

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT WED JUL 7 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A BROAD AREA OF LOW
PRESSURE LOCATED OFF THE NORTHWESTERN COAST OF THE YUCATAN
PENINSULA REMAIN DISORGANIZED. ENVIRONMENTAL CONDITIONS APPEAR
MARGINALLY CONDUCIVE FOR SOME DEVELOPMENT OF THIS DISTURBANCE AS
IT MOVES WEST-NORTHWESTWARD AT 10 TO 15 MPH. THERE IS A MEDIUM
CHANCE...40 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
BEFORE IT MOVES INLAND OVER MEXICO OR SOUTHERN TEXAS IN A DAY OR
SO.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BROWN
Member Since: June 9, 2005 Posts: 23 Comments: 37858
59. IKE
Quoting weathermanwannabe:
Good Morning. It appears that Dr. Masters actually picked a great time to go on vacation.


I agree. Looks like a slow time in the ATL. The pattern there is is similar to an Alex track...into Mexico and the Yucatan.


Quoting GTcooliebai:

I feel ya, been driving w/o a/c in my car and afraid to leave the window down because it might rain the steering wheel gets hot too. Only the other day I let my cousin check it out & found it there was a leak. Also I would hate to be in NYC right now those buildings and the pavement always seems to trap the heat!


Same here. And then when it does rain, the windows in the car fog up...no defroster...you better have 1-2 hand towels in the car to wipe the windows off or you can't see.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
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Quoting cloudy0day:
Good Morning All!

Glad to see 96L is still a sleeper. Maybe if we are all quiet today it will stay that way so the folks in TX/Mexico don't have to deal with more rain.

So long as it's not flooding I prefer the rain rather than the heatwave in the Northeast!
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Quoting IKE:
I feel for anyone without an AC in the heat. I can put on enough clothes to get warm in the winter, but I can't take off enough to get cool in the summer.

Try it without an AC in your car...that's real fun! Especially when it's been sitting on asphalt in a parking lot with no shade and you get in it.

I feel ya, been driving w/o a/c in my car and afraid to leave the window down because it might rain the steering wheel gets hot too. Only the other day I let my cousin check it out & found it there was a leak. Also I would hate to be in NYC right now those buildings and the pavement always seems to trap the heat!
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Good Morning All!

Glad to see 96L is still a sleeper. Maybe if we are all quiet today it will stay that way so the folks in TX/Mexico don't have to deal with more rain.
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Bassis - I think they are called evaps now... At least they are in Arizona.

They don't work in humid SFL.
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Quoting pfdfirefighter:
after loking at the water vapor loop, it looks like all the moisture Louisiana got is going back to the E pacific. Doesnt look like 96i is gonna do much the ULL to the west HIGH to the north and the ULL east of FLA. is just pull it apart.

2 words DRY AIR
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50. IKE
I feel for anyone without an AC in the heat. I can put on enough clothes to get warm in the winter, but I can't take off enough to get cool in the summer.

Try it without an AC in your car...that's real fun! Especially when it's been sitting on asphalt in a parking lot with no shade and you get in it.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting bohonkweatherman:
I feel for any part of the World that has terrible heat and I hate Summer here in Texas. Last Summer we had 70 days of 100 to 110 with no signs of rain. I wish I was wealthy and could live somewhere cool during the Summer and come here the rest of the year. This Summer the temps are down due to quite a bit of rain but the heat indexes are sky high. How many people don't have A.C. in the northeast? Good morning to all and stay cool.


it's the elderly I fear for. Do they still have swamp coolers out west. I was amazed when I was a child in Utah the first time I saw one
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after loking at the water vapor loop, it looks like all the moisture Louisiana got is going back to the E pacific. Doesnt look like 96i is gonna do much the ULL to the west HIGH to the north and the ULL east of FLA. is just pull it apart.
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Today's ENSO forecast from the Aussies....La Nina on the way:

Trend towards La Niña continues.
Issued on Wednesday 7 July 2010 | Product Code IDCKGEWWOO

Sea surface temperatures in the central equatorial Pacific have continued to cool over the past fortnight, and hence the tropical Pacific is now generally cooler than average east of the date-line. Below the surface, temperatures also remain significantly cooler than average, with some areas more than 4°C cooler than normal. Trade winds in the western Pacific remain stronger than normal and cloudiness near the date-line continues to be suppressed. These indicators, together with the Southern Oscillation Index (SOI), which has been positive since April, are consistent with the developing stages of a La Niña event.

The majority of climate models surveyed by the Bureau suggest current patterns and trends will continue, with a significant likelihood of further ocean cooling beyond La Niña thresholds before the end of the southern winter.

Historically, about 35 to 40% of El Niño events (such as occurred in 2009/10) are followed by a La Niña within the same year. The combination of current trends and model outlooks suggest the chance of a La Niña in 2010 is now clearly more likely than not.
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I feel for any part of the World that has terrible heat and I hate Summer here in Texas. Last Summer we had 70 days of 100 to 110 with no signs of rain. I wish I was wealthy and could live somewhere cool during the Summer and come here the rest of the year. This Summer the temps are down due to quite a bit of rain but the heat indexes are sky high. How many people don't have A.C. in the northeast? Good morning to all and stay cool.
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Good Morning. It appears that Dr. Masters actually picked a great time to go on vacation.
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44. IKE
I'll go w/30% on the next TWO. I'd go w/20% but I doubt the NHC lowers it that much....

Member Since: June 9, 2005 Posts: 23 Comments: 37858
It seems that invests/tropical waves or whatever they are are sneaky this year especially when approaching the gulf coast...Lets just hope that 96L keeps looking "sick" and we get no surprises. I truly don't think Brownsville(tx coast) or Mexico would appreciate any "tricks" fromm 96L.
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Good Morning Wunderblog... I hope the NE cools down a little. They seem to curse the heat as much I curse the snow and bitter cold.

Aspectre - Nice shot of a rainbow... Did you get the pot of gold?
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41. IKE
Parallel 6Z GFS through July 23rd....yawn.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Good morning...

Glad to see 96L is not making progress.
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95L looked better than 96L ever will NEXT!!!!
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38. IKE
Inland Florida panhandle and this goes on for 3-4 months w/humidity.


Thursday
Mostly sunny. Highs around 100. Northeast winds around 5 mph shifting to the south in the afternoon.

Thursday Night
Partly cloudy. Lows 71 to 74. Southwest winds around 5 mph in the evening becoming light.

Friday
Partly cloudy. A 20 percent chance of showers and thunderstorms in the afternoon. Highs around 97. South winds 5 to 10 mph.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Good Morning Storm, Good and a wonderful morning to you all. Here in Dover, NH we had readings of 99 deg. with a dew point at 70-71. Were already at 93% humidity and dew point of 71 and 72 deg and expecting low 90's today. That down right nasty in any climate. Lots of water to consume
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.