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 kinsingmonster:
What does the number eg "96" "91" mean when identifiying the Invest wave?


It's the name the NHC gives them. When the NHC decides that an area of interest or of concern has enough of a chance to develop, they declare it an invest, which is just short for investigation. The first name is 90L, then 91L, then 92L, and so on. Once it gets past 99L, it goes back to 90L. In other basins the letter on the end would be different. East Pacific would be 90E, West Pacific would be 90W, North Indian in the Bay of Bengal would be 90B, North Indian in the Arabian Sea would be 90A, etc.
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What is the stuff off the SE Texas coast? Just rain? Anything from 96 that broke off and sped away? part of 96?
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134. MahFL
Quoting txalwaysprepared:


Do you want them to come to you?


They will go where they go, my desires do not matter.
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I lived in Chicago during the 1995 heat wave. It was very scary. Very few places compared to Florida have air conditioning and the places that did were losing power because of the high demand for electricity. I moved to Florida the following year...where it's actually cooler in the summer. LOL
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What does the number eg "96" "91" mean when identifiying the Invest wave?
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Quoting tkeith:
mornin Hanna, local Mets say we're gonn dry out for a few days....for what it's worth

Man, I hope so. The field next to us is so tall, but too wet to cut. I keep losing my dog in it!
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AOI
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Quoting tkeith:
both...

Oh, and the booms dont work either. I spent 2 years building the new Rigolets Bridge and the currents at the Rigolets are comparative to river currents. I've spent alot of time on Pontchatrain, it makes me physically ill to see this.


same here, tkeith. My parents had a summer home in North Shore Beach off of Hwy 11 for years. Spent many summers as a kid fishing the Rigolets area.
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Man, she's winding up now, ain't she......pffft

Sat
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Quoting tkeith:
both...

Oh, and the booms dont work either. I spent 2 years building the new Rigolets Bridge and the currents at the Rigolets are comparative to river currents. I've spent alot of time on Pontchatrain, it makes me physically ill to see this.

Hey Tkeith. It is so disheartening. I think this is just the beginning, with no end in sight.
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Quoting hurricanehanna:
Good morning all. Finally catching a temporary break from the rain. Looks like 96L will cause more problems for Mexico rain-wise. Hopefully only minimal development - looks like shear will help out.
So is the rain in the GOM coming into LA from the tail end of 95L ?
mornin Hanna, local Mets say we're gonn dry out for a few days....for what it's worth
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Quoting aspectre:

Arctic gold at the end of the 3:00am rainbow.


That's a cool photo > recently I've seen 2 rainbows that have wow'ed me. One stretched clear across our city like you see in a picture book.
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124. IKE
LATCUR = 23.3N LONCUR = 93.3W DIRCUR = 300DEG SPDCUR = 9KT

An Alex track...heading for northern Mexico.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
Oh what a morning in coconut grove, fl. It's raining and dreary ugh I just want to go back to bed.
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Good morning all. Finally catching a temporary break from the rain. Looks like 96L will cause more problems for Mexico rain-wise. Hopefully only minimal development - looks like shear will help out.
So is the rain in the GOM coming into LA from the tail end of 95L ?
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I see recon in 96L and acording to its data we have a 1005mb depression
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Quoting aspectre:
How is crude getting into LakePontchartrain? Storm waves upon high tide overtopping the coast? Or leaving R igolets/etc open for boat traffic instead of blocking the passages?
both...

Oh, and the booms dont work either. I spent 2 years building the new Rigolets Bridge and the currents at the Rigolets are comparative to river currents. I've spent alot of time on Pontchatrain, it makes me physically ill to see this.
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119. IKE
Quoting DestinJeff:


it was a bridging high (atlantic high bridged with high centered over central US). The US high was "out-of-ordinary" for June. So our sample size for 2010 is basically 1, not counting 96L.

I am hesitant to draw comparative conclusions between steering patterns of 2010 with any year just yet.


Look at the latest ECMWF...and where it shows the next potential "mischief"....Link
Member Since: June 9, 2005 Posts: 23 Comments: 37860
Quoting bohonkweatherman:
When I was younger I use to say I want to see a tornado, 10 years ago I was driving home in bad weather and a tornado touched down very close to my car. I don't care to see another tornado. Watch what you wish for.


Exactly. I used to love getting Tropical Storms. They were fun... and Lord knows we've had enough of them around here. But after Hurricane Ike (yes, IKE I still consider him your unrulyjunior) I want to have nothing to do with those things.

But fortunately, this blog, believe it or not, kept me calm in preperations :)
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Quoting aspectre:
How is crude getting into LakePontchartrain? Storm waves upon high tide overtopping the coast? Or leaving Rigolets/etc open for boat traffic instead of blocking the passages?


aspectre, its more a case of rough seas inhibiting booming efforts and the feds putting restrictions on every effort the state makes to block the oil.
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Quoting MahFL:


I want to see Hurricanes.


Do you want them to come to you?
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You can really see the high pressure building more and more into the NE GOM!! that will make sure 96L stays wnw... ok I feel better now - - think we got one more day of these tropical rains and then thursday things could start to dry out!!!! my freaking grass is 18" tall!!!
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EXTENDED FORECAST...
THE TROPICAL WAVE LOCATED OVER THE EASTERN CARIBBEAN SEA IS STILL
FORECAST BY THE LONG RANGE MODELS TO MOVE WEST TO NORTHWEST AND
CLIP SOUTH FLORIDA ON FRIDAY. THIS WILL ALLOW FOR SOME TROPICAL
MOISTURE TO WORK BACK INTO THE AREA. SO HAVE KEPT THE POPS IN THE
CHANCE OR SCATTERED RANGE AT THIS TIME OVER SOUTH FLORIDA WITH THE
HIGHEST POPS OVER THE INLAND AREAS ON FRIDAY.

Miami NWS Discussion
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113. MahFL
Seems to be a coc that just is coming of the Yucatan coast.
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640

WHXX01 KWBC 071243

CHGHUR

TROPICAL CYCLONE GUIDANCE MESSAGE

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

1243 UTC WED JUL 7 2010



DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.

PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE

AND SUBTROPICAL CYCLONE INFORMATION.



ATLANTIC OBJECTIVE AIDS FOR



DISTURBANCE INVEST (AL962010) 20100707 1200 UTC



...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...

100707 1200 100708 0000 100708 1200 100709 0000



LAT LON LAT LON LAT LON LAT LON

BAMS 23.3N 93.3W 24.3N 95.4W 25.2N 97.4W 25.9N 99.2W

BAMD 23.3N 93.3W 24.0N 95.2W 24.6N 97.2W 25.2N 99.1W

BAMM 23.3N 93.3W 24.2N 95.3W 25.0N 97.3W 25.8N 99.2W

LBAR 23.3N 93.3W 24.5N 95.2W 25.9N 97.3W 27.6N 99.5W

SHIP 25KTS 28KTS 33KTS 38KTS

DSHP 25KTS 28KTS 33KTS 28KTS



...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...

100709 1200 100710 1200 100711 1200 100712 1200



LAT LON LAT LON LAT LON LAT LON

BAMS 26.5N 101.0W 27.2N 104.7W 28.0N 107.9W 28.1N 110.0W

BAMD 25.5N 101.0W 26.1N 105.4W 27.3N 109.7W 27.7N 113.4W

BAMM 26.4N 101.0W 27.3N 104.9W 28.3N 108.4W 28.4N 111.0W

LBAR 29.2N 101.2W 32.6N 102.3W 34.5N 99.7W 35.6N 93.4W

SHIP 43KTS 55KTS 58KTS 52KTS

DSHP 27KTS 27KTS 27KTS 27KTS



...INITIAL CONDITIONS...

LATCUR = 23.3N LONCUR = 93.3W DIRCUR = 300DEG SPDCUR = 9KT

LATM12 = 22.5N LONM12 = 91.6W DIRM12 = 300DEG SPDM12 = 9KT

LATM24 = 21.3N LONM24 = 89.5W

WNDCUR = 25KT RMAXWD = 90NM WNDM12 = 25KT

CENPRS = 1006MB OUTPRS = 1009MB OUTRAD = 225NM SDEPTH = M

RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM



$$

NNNN
Member Since: July 15, 2006 Posts: 175 Comments: 54858
How is crude getting into LakePontchartrain? Storm waves upon high tide overtopping the coast? Or leaving Rigolets/etc open for boat traffic instead of blocking the passages?
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When I was younger I use to say I want to see a tornado, 10 years ago I was driving home in bad weather and a tornado touched down very close to my car. I don't care to see another tornado. Watch what you wish for.
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Quoting DestinJeff:
I just want the seas to calm down. Emerald coast isn't used to rough seas for extended periods like we have seen.


We'll be in your neck of the woods on Saturday for a week. I hope they calm down too. I hear the beach calling me.
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WOCN11 CWTO 071001
Humidex advisory
Updated by Environment Canada Ontario region.
6:01 AM EDT Wednesday 7 July 2010.

Humidex advisory continued for..
City of Toronto
Windsor - Essex - Chatham-Kent
Sarnia - Lambton
Elgin
London - Middlesex
Simcoe - Delhi - Norfolk
Dunnville - Caledonia - Haldimand
Oxford - Brant
Niagara
City of Hamilton
Halton - Peel
York - Durham
Huron - Perth
Waterloo - Wellington
Dufferin - Innisfil
Grey - Bruce
Barrie - Orillia - Midland
Belleville - Quinte - Northumberland
Kingston - Prince Edward
Peterborough - Kawartha Lakes
Stirling - Tweed - South Frontenac
Bancroft - Bon Echo Park
Brockville - Leeds and Grenville
City of Ottawa
Gatineau
Prescott and Russell
Cornwall - Morrisburg
Smiths Falls - Lanark - Sharbot Lake
Parry Sound - Muskoka
Haliburton
Renfrew - Pembroke - Barry's Bay
Algonquin
Burk's Falls - Bayfield Inlet.

..Hot, hazy and humid weather continues..

The hot..Hazy and humid conditions are expected to continue for most
of Southern Ontario through Thursday. Temperatures will reach the
Low to mid 30S across the district with humidex values in the low
40S each afternoon.

Some local relief will be in areas near the shorelines of the great
Lakes..Where the cooler water will help to moderate the daytime
temperatures somewhat. In addition areas that receive isolated
showers or a thunderstorm may experience temporary relief from the
heat.

The hot hazy and humid weather will come to an end on Friday..As a
cold front is forecast to move through with a cooler and less humid
airmass in its wake.

This is an advisory that high humidex values are expected in these
Regions. Monitor weather conditions..Listen for updated statements.

END/OSPC


latest special statements
Member Since: July 15, 2006 Posts: 175 Comments: 54858
Good morning 96L...

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Quoting MahFL:


I want to see Hurricanes.


No you don't, sounds like you've never faced losing your home, dealing with insurance companies and trying to rebuild.
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What a mess...



96L is likely to end up being only a rain storm. And that may not be good news depending on where it lands.
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102. MahFL
Quoting rmbjoe1954:


i believe as StormW indicated yesterday that conditions will change soon enough that would allow more favorable conditions to grow these storms in the CAtl. It's all about climatology. Then we'd wish it wouldn't be so.


I want to see Hurricanes.
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101. IKE
Quoting DestinJeff:


was it an atlantic high that protected U.S. from Alex or was it a CONUS high?

2007's Dean and Felix were steered by the atlantic high, which currently does protect the U.S. but I can't remember what June and July setup was in 2007.


I don't remember....I remember a trough/cold front coming into the SE USA. Maybe the high behind the trough/cold front.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
Quoting scott39:
I hope that at least lasts thru August1
I meant all the way thru August!
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Quoting IKE:


From what I've seen of the ECMWF it's been doing a great job after what it showed with 90L slamming in the Carolina's, which didn't happen.

What the current pattern on the ECMWF shows is...Yucatan and Mexico. USA looks protected by a strong Atlantic high....similar to 2007.


i believe as StormW indicated yesterday that conditions will change soon enough that would allow more favorable conditions to grow these storms in the CAtl. It's all about climatology. Then we'd wish it wouldn't be so.
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Quoting IKE:


I would say southern and SW GOM....right now...similar to....



I hope that at least lasts thru August1
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97. IKE
Quoting scott39:
Looks like the high pattern for July, rolls possible TCs mostly into the GOM. IMO


I would say southern and SW GOM....right now...similar to....



Member Since: June 9, 2005 Posts: 23 Comments: 37860
Quoting IKE:


From what I've seen of the ECMWF it's been doing a great job after what it showed with 90L slamming in the Carolina's, which didn't happen.

What the current pattern on the ECMWF shows is...Yucatan and Mexico. USA looks protected by a strong Atlantic high....similar to 2007.
Looks like the high pattern for July, rolls possible TCs mostly into the GOM. IMO
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Quoting DestinJeff:
Long range models are equally as unreliable in forecasting non-development as they are in forecasting development.
Granted, It was just an observation, we will definitely have to get closer to Mid to latter July to be concerned!
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93. IKE
Quoting DestinJeff:
Long range models are equally as unreliable in forecasting non-development as they are in forecasting development.


From what I've seen of the ECMWF it's been doing a great job after what it showed with 90L slamming in the Carolina's, which didn't happen.

What the current pattern on the ECMWF shows is...Yucatan and Mexico. USA looks protected by a strong Atlantic high....similar to 2007.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
Quoting DestinJeff:


Thar she blows.
Lol, thank you. I've gotta go, later all.
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Sorry about the double-post.
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Quoting mcluvincane:
seems like cycloginisis is really hard to get going this year


Not really because of the lack of storms in June and July......Alex caused a lot of deaths due to it's large effects and hurricane status; it was an anomonly for June (a "gift" if you will).
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88. IKE
Quoting MiamiHurricanes09:
Yeah they actually should've raised it from 40%.


Member Since: June 9, 2005 Posts: 23 Comments: 37860

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About

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