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 weatherspawn:


Thanks, I just figured that out. I'm actually a programmer/web developer by trade, I just wasn't sure what markup the blog used. I've got it now though!
'Same line of work here. Welcome to the blog.
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Reedzone, 96L just has to fight off dry air. It has already formed a surface circulation. I wouldn't call it pathetic.
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Quoting Drakoen:
96L has acquired a closed surface low.



true,although its broad and asymetrical,elongated N to S...
Member Since: October 5, 2007 Posts: 20 Comments: 4970
96L still has about 24-36 hours before making landfall
Member Since: October 28, 2006 Posts: 57 Comments: 30355
Quoting LightningCharmer:
The area south of it north of Hispaniola has caught my untrained eye as well.


Yep, this is the tropical wave that everybody was looking to develop lol. However, it's merging with the giant low, this may help the low acquire Subtropical characteristics since the wave is fully warm cored.
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Yeah Reedzone this non tropical upper level low looks interesting. Some of the models try to develop a weak surface low as it gets picked up and swept out to sea over the weekend.

Link
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If anything has a chance for "Bonnie", it would be the NON-TROPICAL low off the East Coast. These things can take advantage of the warm waters this time of year. 96L is just very disorganized, yellow circle by 2 p.m. if this continues to look pathetic. Though a yellow circle is possible with the Ocean Storm as the wave merges with the system, this will help it become more warm cored (hybrid) since the wave is totally warm cored.
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Quoting reedzone:
A bigger look at the NON-TROPICAL low, starting to detatch from the front.

The area south of it north of Hispaniola has caught my untrained eye as well.
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Quoting Drakoen:
NHC cancelled the recon for today but a NOAA G-IV will be conducting research on the system at 1730z
Well with that buoy data we still have surface obs supporting a circulation. Would like to see that west wind a little stronger though.
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Quoting StormW:


Drak, about where I posted earlier today, 23.3N;93,3W?


23.5N 93.4W
Member Since: October 28, 2006 Posts: 57 Comments: 30355
Heavy rain now moving into HGX:

at 1118 am CDT...National Weather Service Doppler radar indicated
an area of very heavy rain falling across northern Galveston County.
Rainfall rates up to 2.5 inches per hour have been observed. With
the ground still moist from last weeks rains...some of this water
will run off to produce minor street and feeder Road flooding. This
precipitation will be moving into southern Harris County.
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NHC cancelled the recon for today but a NOAA G-IV will be conducting research on the system at 1730z
Member Since: October 28, 2006 Posts: 57 Comments: 30355
Quoting Chicklit:
Hi Weatherspawn,
In case you don't already know, if you click "link" above the message portion, and accept whatever that thing says on top of the page, then you can paste the link right into your message.


Thanks, I just figured that out. I'm actually a programmer/web developer by trade, I just wasn't sure what markup the blog used. I've got it now though!
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Quoting StormW:


Drak, about where I posted earlier today, 23.3N;93,3W?


doesn't that severely limit the amount of time 96L has to develop? Or are we still looking at about 36-48 hours?
Member Since: March 10, 2010 Posts: 1 Comments: 7589
Really? Where?
Floater - Infrared Channel 2 Loop
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Quoting hurricane47:
Don't give up on 96L. Some indications that the clouds are beginning to consolidate once again.
Don't you know that "patience is a virtue" except, on this blog!
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A bigger look at the NON-TROPICAL low, starting to detatch from the front.

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Just saw post below, nevermind. NHC might up the chances to red at 2 now.
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Buoy 42055

Wind Direction (WDIR): W ( 260 deg true )
Wind Speed (WSPD): 5.8 kts
Wind Gust (GST): 7.8 kts
Wave Height (WVHT): 1.6 ft
Dominant Wave Period (DPD): 6 sec
Average Period (APD): 4.9 sec
Mean Wave Direction (MWD): ENE ( 64 deg true )
Atmospheric Pressure (PRES): 29.78 in
Pressure Tendency (PTDY): 0.03 in ( Rising )
Air Temperature (ATMP): 81.9 F
Water Temperature (WTMP): 82.6 F
Dew Point (DEWP): 75.9 F
Heat Index (HEAT): 89.1 F
Member Since: October 28, 2006 Posts: 57 Comments: 30355
Hi Weatherspawn,
In case you don't already know, if you click "link" above the message portion, and accept whatever that thing says on top of the page, then you can paste the link right into your message.
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Don't give up on 96L. Some indications that the clouds are beginning to consolidate once again.
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Well it's been the same here in Kent county Delaware. Rain to the west, north and south.....keep getting missed. Maybe late Saturday or early Sunday we may finally see some much needed down pours.
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96L has acquired a closed surface low.
Member Since: October 28, 2006 Posts: 57 Comments: 30355
NON-TROPICAL low invest area, may get tagged if it continues to organize, very large, a large Ocean Storm for right now, it seems to be absorbing the wave to the southeast.

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96L does have very low wind shear going for it. With a possible surface circulation developing, it might be able to take advantage of it.
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Hi there. I've been a lurker at this site for a few years now and I figured I'd finally become a member to help pay for some of that bandwidth I've used during that time.

Here is a shot of some of the tropical moisture moving onshore from Invest 96L.

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Quoting atmoaggie:
Ugh. That reminds me of the times we had to spray pesticides in the greenhouses...full Tyvek suit. Bring a change of clothes, and wring the sweat out of whatever you had on...

No way would I do that full time.

Worked in a restaurant's kitchen once that fits the bill, too. A place that had a poorly functioning exhaust system. Looked down at the meat thermometer in the apron pocket...130 F. Pretty sure that OSHA never visited...and more than a little nasty when every cook is dripping...
The roof story reminds me of my days teaching junior high phys. ed. classes. I had a student whom I knew was very smart but couldn't stay out of trouble.

One day while some workers were on the roof of the school slinging hot tar I told him if he didn't get his act together then he was going to end up on that roof one day.

Forward to about 15 years, I saw him in a bar one night and he bought me a beer. He is married with kids and a good job. I asked him if he remembered what I said to him about the roofing job. He said yes, but that I really didn't have to tell him that because his dad OWNED a roofing company! We got a big laugh out of that one.
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I swear I will not get suckered into these Cape Verde waves for another month/month and a half. They are shotless.
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Quoting Drakoen:
There is evidence based on satellite imagery that a surface circulation is trying to form with 96L on the northern edge of the convection.


I've been watching that as well. I'm sure Pat and a few others are watching it too.
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This microwave pass also suggests that 96L is trying to form a surface circulation. The system still has the chance to become a tropical cyclone prior to landfall.

Member Since: October 28, 2006 Posts: 57 Comments: 30355
Quoting Daveg:
Well, 96L may have lost the blogs attention, but I'll be watching. I bet it makes at least TD status before landfall (I know, not exciting).

At the very least, it means a ton of rain for the Texas coast and South and Central Texas.

Yep. and for once, we don't need it.
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ALBANY, NY

WNYT TV - Menands, Albany, New York (PWS)
Updated: 6 sec ago
Haze
93.0 F
Haze
Humidity: 50%
Dew Point: 71 F
Wind: 1.0 mph Variable
Wind Gust: 3.0 mph
Pressure: 30.01 in (Falling)
Heat Index: 101 F


EAST OF HOPEWELL, VA

JAMES RIVER VA US (MADIS)
Temperature: 101 F
Dew Point: 73 F
Humidity: 42%
Heat Index: 106 F
Wind: WNW at 3mph

to the west in colonial hieghts -

Mount Pleasant, Colonial Heights, Virginia (PWS)
Updated: 10 sec ago
Partly Cloudy
98.4 F
Partly Cloudy
Humidity: 38%
Dew Point: 68 F
Wind: 10.0 mph
Wind Gust: 10.0 mph
Pressure: 29.99 in (Falling)
Heat Index: 104 F

still not understanding the criteria needed for a heat advisory...lol...anyways....time to go get a cold drink...lol
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Quoting StormW:
Visible satellite loop imagery indicates the center of 96L may be further north, and coincides with the ATCF site near 23.3N;93.3W


Hi > would this change the anticipated track?
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At this point I don't know if we are dealing with remnant moisture from 95L or early moisture from 96L, but my neighbors off to the east have this:

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAKE CHARLES LA
1108 AM CDT WED JUL 7 2010

THE NATIONAL WEATHER SERVICE IN LAKE CHARLES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
SOUTHEASTERN HARDIN COUNTY IN SOUTHEAST TEXAS...
THIS INCLUDES THE CITY OF LUMBERTON...
NORTH CENTRAL JEFFERSON COUNTY IN SOUTHEAST TEXAS...
THIS INCLUDES THE CITY OF BEAUMONT...

* UNTIL 500 PM CDT

* AT 1055 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED
VERY HEAVY RAINS LOCATED OVER BEAUMONT EXTENDING NORTH INTO
LUMBERTON. RADAR ESTIMATES AND GAUGE REPORTS INDICATE 3 TO 5
INCHES OF RAIN HAS FALLEN THIS MORNING IN AND AROUND BEAUMONT IN
THE PAST FEW HOURS. ADDITIONAL HEAVY RAINS OF 1 TO 3 INCHES ARE
EXPECTED INTO THIS AFTERNOON
AND WILL PRODUCE ADDITIONAL FLOODING.



* SOME DRAINAGES THAT WILL BE PRONE TO FLOODING FROM THIS RAINFALL
ARE...WILLOW MARSH BAYOU. IN ADDITION STREETS IN NORTHERN BEAUMONT
WILL LIKELY BECOME IMPASSABLE FOR A TIME.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.
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There is evidence based on satellite imagery that a surface circulation is trying to form with 96L on the northern edge of the convection.
Member Since: October 28, 2006 Posts: 57 Comments: 30355
Heh, I'm in a 2% tornado risk again.
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395. Daveg
Well, 96L may have lost the blogs attention, but I'll be watching. I bet it makes at least TD status before landfall (I know, not exciting).

At the very least, it means a ton of rain for the Texas coast and South and Central Texas.
Member Since: September 23, 2005 Posts: 0 Comments: 426
Quoting Neapolitan:


I may have you beat: I worked for a Miami-area roofing company as a hot mopper, which basically consisted of standing on a pitched or flat roof in the middle of the summer heat and humidity while slinging around buckets full of 650-degree bitumenous asphalt...all while wearing full-length protective coveralls. Yeah, that job was a real hoot... :-)
Ugh. That reminds me of the times we had to spray pesticides in the greenhouses...full Tyvek suit. Bring a change of clothes, and wring the sweat out of whatever you had on...

No way would I do that full time.

Worked in a restaurant's kitchen once that fits the bill, too. A place that had a poorly functioning exhaust system. Looked down at the meat thermometer in the apron pocket...130 F. Pretty sure that OSHA never visited...and more than a little nasty when every cook is dripping...
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I see not much is going on today....96L just isn't able to get itself together...
Member Since: July 2, 2009 Posts: 0 Comments: 2811
sitting at 100 at noon...yay...
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Quoting FLdewey:
Since it's so slow... here is an interesting study about rainbows:

It's worth a look. ;-)

Rainbow study


Study about rainbows, Ya right, its a guy crying he's so happy about rainbows. You got my hopes up for a crazy rainbow hugger. =(
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Quoting NRAamy:
POLO!!!
Where?
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Quoting SQUAWK:
Gotta do it....

MARCO!!!!!
Where?
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Quoting CoopsWife:


ROFL - Same here in Central VaBeach - the storms roll over the airport (west of me) and up Great Neck Rd (east of me). I can see the clouds - even the rain trails, and get not a single drop.


lmao...i can imagine watching the radar down in your area...especially the last 2 weeks were you had a ton of rain to you east and north.....but it kinda rotated around and to the coast...


lol.

lately around here...anything that is heading our way from the west/northwest either fizzles coming over the mountains...gets started too late, so that when the sun goes down they are gone...or just plain dies as its coming into the western parts of the richmond metro area...its been ridiculous...lol



i live halfway between the d in Richmond and the w in Waverly...near Hopewell...this is what its been like so for the last 2 months...we've had less here than Richmond has officially recorded, and that's freaking sad...lol....please rain this week!!!...lol
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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.

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