The Northeast Heatwave

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

Share this Blog
3
+

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.

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1587 - 1537

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37Blog Index

Quoting jamesrainier:


What does LO stand for?


Low.

Other abbreviations they use:

DB=Disturbance
WV=Wave
TD=Tropical Depression
TS=Tropical Storm
HU=Hurricane
Member Since: July 7, 2008 Posts: 2 Comments: 3237
Quoting zoomiami:
Hi Storm-- sure you could tell a lot of stories of places without AC -- military was never one to see to all the creature comforts.

By highlighting that area are you indicating that you believe it is a TD?

I spent my childhood growing up in Army housing and we only had AC when we got down in Alabama. In Illinois we had to put in our own window units. The day my dad bought a cheap one and put in my room is one of the most memorable days of my life.
Member Since: Posts: Comments:
Wind shifted to the NNE this morning here in S. Tex. I knew then the low was getting deeper and closer. Have had some passing showers today. Skeeters are loving it!!
Member Since: Posts: Comments:
Quoting jamesrainier:


What does LO stand for?
Low.
Member Since: Posts: Comments:
SAB up to 1.5. Let's see what the TAFB and CIRA show.
Member Since: Posts: Comments:
Quoting KarenRei:
I just now noticed -- TS-strength winds on the northeast side:



Time: 21:36:00Z
Coordinates: 25.7667N 90.4167W
Acft. Static Air Press: 638.8 mb (~ 18.86 inHg)
Acft. Geopotential Hgt: 3,915 meters (~ 12,844 feet)
Extrap. Sfc. Press: 1008.1 mb (~ 29.77 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 136° at 35 knots (From the SE at ~ 40.2 mph)
Air Temp: 5.7°C (~ 42.3°F)
Dew Pt: 5.7°C (~ 42.3°F)
Peak (10s) Flt. Lvl. Wind: 37 knots (~ 42.5 mph)
SFMR Peak (10s) Sfc. Wind: 36 knots (~ 41.4 mph)
SFMR Rain Rate: 10 mm/hr (~ 0.39 in/hr)
(*) Denotes suspect data


Pretty far from the COC, but then again, the COC on this storm is quite large currently.


They might make this directly to TS Bonnie if this is the case.
Member Since: Posts: Comments:
Thanks Drak & Levi -- makes sense (I guess)
Member Since: Posts: Comments:
Quoting HurricaneSwirl:
AL, 96, 2010070800, , BEST, 0, 235N, 938W, 30, 1005, LO, 34, NEQ, 0, 0, 0, 0, 1009, 200, 65, 0, 0, L, 0, , 0, 0, INVEST, D,

Those are the major changes in this ATCF update..


What does LO stand for?
Member Since: Posts: Comments:
1578. IKE
96L..looped.
Member Since: Posts: Comments:
96L moving towards the NW between 18z and 00z ATCF coordinate fixes.
Member Since: Posts: Comments:
1576. Levi32
Quoting zoomiami:
Drak - thanks. One question I had the other day, that sad to say I've forgotten. Why is that an area will get the circle with a percentage of development, but not get an invest category?


Invests have no required criteria and are a completely subjective declaration. Forecasters can declare an invest whenever they feel that they want to investigate a disturbance and run model forecasts on it.
Member Since: Posts: Comments:
07/2345 UTC 23.8N 93.6W T1.5/1.5
Member Since: July 7, 2008 Posts: 2 Comments: 3237
Quoting IKE:
Updated image....0015UTC...



your pic shows me 96L now has excellent structure
Member Since: Posts: Comments:
1573. Drakoen
Quoting zoomiami:
Drak - thanks. One question I had the other day, that sad to say I've forgotten. Why is that an area will get the circle with a percentage of development, but not get an invest category?


Whether or not something gets invest status is completely up to the forecaster. Invest status allows the forecaster to get additional information on a system such as computer models.
Member Since: Posts: Comments:
I just now noticed -- TS-strength winds on the northeast side:



Time: 21:36:00Z
Coordinates: 25.7667N 90.4167W
Acft. Static Air Press: 638.8 mb (~ 18.86 inHg)
Acft. Geopotential Hgt: 3,915 meters (~ 12,844 feet)
Extrap. Sfc. Press: 1008.1 mb (~ 29.77 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 136° at 35 knots (From the SE at ~ 40.2 mph)
Air Temp: 5.7°C (~ 42.3°F)
Dew Pt: 5.7°C (~ 42.3°F)
Peak (10s) Flt. Lvl. Wind: 37 knots (~ 42.5 mph)
SFMR Peak (10s) Sfc. Wind: 36 knots (~ 41.4 mph)
SFMR Rain Rate: 10 mm/hr (~ 0.39 in/hr)
(*) Denotes suspect data


Pretty far from the COC, but then again, the COC on this storm is quite large currently.
Member Since: Posts: Comments:
1571. IKE
Updated image....0015UTC...

Member Since: Posts: Comments:
Quoting cccidojr1:
somehow, I knew this thing was gonna get going at the last minute.. I know u experts r probably thinking it doesnt have time to be a cane but I have this gut feeling it will be at least a category 1. from past canes what warrants mandatory evacuations ? man the clouds here in corpus christi looks ominous !!


try not to use those words: "gut feeling"
Member Since: Posts: Comments:
They might a little while to see any start of impressive convection, it'll probably have high enough winds to be classified Bonnie by then too.
Member Since: July 7, 2008 Posts: 2 Comments: 3237
1567. IKE
That's got to be frightening experiencing an earthquake. Never went through one here in Florida. Apparently it wasn't a serious one...from what I've read on here.
Member Since: Posts: Comments:
Quoting WatchingThisOne:


Nope different spot.

I know it's a different spot but is it the same fault line. btw 1560 - a 5.9 is big as far as I'm concerned. At least it felt that way to me!
Member Since: Posts: Comments:
AL, 96, 2010070800, , BEST, 0, 235N, 938W, 30, 1005, LO, 34, NEQ, 0, 0, 0, 0, 1009, 200, 65, 0, 0, L, 0, , 0, 0, INVEST, D,

Those are the major changes in this ATCF update..
Member Since: July 7, 2008 Posts: 2 Comments: 3237
Quoting RobertM320:


But you know, MH09, Hardcore's got a point. When everyone along the LA/MS coast was watching 95L, we were told to stop wasting time, it wasn't anything. Well, other than the actual breadth of the storm, 96L's pressure is no lower, winds are no higher, and circulation is no more closed than 95L's was, and yet everyone's in a tizzy.....not arguing here, just making a legitimate point.
I completely understand especially considering the oil spill recovery efforts. But 96L is more organized that 95L and warrants our attention, 95L is the past, and now we have to look at the future.
Member Since: Posts: Comments:
Drak - thanks. One question I had the other day, that sad to say I've forgotten. Why is that an area will get the circle with a percentage of development, but not get an invest category?
Member Since: Posts: Comments:
Quoting melwerle:
I'm wondering if it's the same fault as the easter quake. And I certainly hope that's not a foreshock. Looks like it's going to be a long night.


Nope different spot.
Member Since: Posts: Comments:
Hi Storm-- sure you could tell a lot of stories of places without AC -- military was never one to see to all the creature comforts.

By highlighting that area are you indicating that you believe it is a TD?
Member Since: Posts: Comments:
1560. 900MB
Quoting AstroHurricane001:
Earthquake in California:



5.9 is not a biggie, but very active down there lately and this one is further North than the last series, hopefully not a foreshock!
Member Since: Posts: Comments:
1559. IKE
Quoting MiamiHurricanes09:
I would expect a renumber at any time...


I'm holding my breath.
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
You are only looking at convection. There are a lot of things in favor of that percentage, and if the convection was good than 96L would be a TD.

Ditto.. I had just got on and looked at the Visible only when I said TD@8:00
Organization was good, vertically integrated as Levi has been waiting for all day, nice circulation.
Of course when I saw the convection afterwards I said $#@!$..
Member Since: Posts: Comments:
80%...hmmmm
Member Since: Posts: Comments:
Quoting btwntx08:
if it upgraded at 11 then more than likely we will see bonnie out this


I'm almost sure this will be at least TS Bonnie by landfall..
Member Since: Posts: Comments:
Quoting Drakoen:


96L is pretty much on the verge of becoming a tropical depression
I would expect a renumber at any time...
Member Since: Posts: Comments:
1554. Drakoen
Quoting zoomiami:
Drak - with a closed low doesn't that make it a TD?

Hi everyone - forgot my manners, was a little riled by the ignorance of no AC etc. Its amazing how many people think the way they live is the only way to live.





96L is pretty much on the verge of becoming a tropical depression
Member Since: Posts: Comments:
1553. IKE
248NM Brownsville radar....

Member Since: Posts: Comments:
Quoting Houstonia:


I'm watching the USGS site and see nothing other than a 2.7 for the L.A. area.

There was this - yesterday or very early today: MAP 5.4 2010/07/07 23:53:33 33.417 -116.483 11.7 SOUTHERN CALIFORNIA


Trust me it was now :-)

2010 July 07 23:53:33 UTC

mag 5.4

Here's the USGS link again

Cali quake
Member Since: Posts: Comments:
1549. Drakoen
Quoting GeoffreyWPB:


Hi Drak...Could you please post the link to that page? Mine got lost in the clutter. Thanks!


Link
Member Since: Posts: Comments:
Quoting HaboobsRsweet:

yea 95L barely looked like a thunderstorm. It was a said excuse for an invest. I think 96L could easily make TD status tonight but I just dont think it has the time to get to Bonnie...it will be close and could go either way. def leaning towards it having near zero chance for hurricane.


95L seriously looked like a subtropical Tracy.
Member Since: Posts: Comments:
Houston, do we have a problem with "Bonnie to be" that lies over the ocean, 96L is moving NW, From La/tx to tx/mx borders has to be on alert imo.
Member Since: Posts: Comments:
Quoting Hurricanes101:


LOL poor horse


Please stop beating the dead horse in the buttocks or crotch, can't tell which one, and continue the tropical discussion.
Member Since: Posts: Comments:
Quoting AstroHurricane001:
Earthquake in California:



About 50 miles SE of me ... funny it didn't feel stronger ... I'm much closer than OC or San Diego. Mebbe I'm getting jaded after so long in SoCal. If stuff isn't flying around, it "ain't bad."
Member Since: Posts: Comments:


Quoting zoomiami:


That's ridiculous - tons of people don't have AC - I grew up in a house without ac and managed to survive.


Thats exactly my point (without knowing how old you are).. but in this day and age everyone should have an A/C.. or at least a place that they can go for a cool refuge
i.e. - church, mall, grocery store, sit in car?

My main point is, regardless of where you live, summer heat is very hard on those that are already very old or very sick..

National news never reports heat related deaths that occur here (SE TEXAS) EVERY EVERY EVERY SUMMER on the NE coast?? its silly... its summer.. its gets hot... its hard on some people regardless of the logistics of the situation...
Member Since: Posts: Comments:
Quoting cccidojr1:
somehow, I knew this thing was gonna get going at the last minute.. I know u experts r probably thinking it doesnt have time to be a cane but I have this gut feeling it will be at least a category 1. from past canes what warrants mandatory evacuations ? man the clouds here in corpus christi looks ominous !!


I have had just a trace of rain here in Corpus, sun is bright right now where I live.
I dont think there would be a mandatory evac for a Cat 1 but I could be wrong. Maybe out on the island
Member Since: Posts: Comments:
Drak - with a closed low doesn't that make it a TD?

Hi everyone - forgot my manners, was a little riled by the ignorance of no AC etc. Its amazing how many people think the way they live is the only way to live.



Member Since: Posts: Comments:
Hunters have found a very broad low at the mid levels with a minimum extrapolated surface pressure of 1002.3 (unless I missed some that are even lower). Reminds me of Alex (albeit this storm doesn't have nearly as long before land as Alex did at this point in his development).

Time: 23:19:30Z
Coordinates: 22.7833N 94.85W
Acft. Static Air Press: 639.6 mb (~ 18.89 inHg)
Acft. Geopotential Hgt: 3,871 meters (~ 12,700 feet)
Extrap. Sfc. Press: 1002.3 mb (~ 29.60 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 340%uFFFD at 3 knots (From the NNW at ~ 3.4 mph) Air Temp:
7.0%uFFFDC (~ 44.6%uFFFDF) Dew Pt:
7.0%uFFFDC (~ 44.6%uFFFDF) Peak (10s) Flt. Lvl. Wind:
5 knots (~ 5.8 mph) SFMR Peak (10s) Sfc. Wind:
34 knots* (~ 39.1 mph*) SFMR Rain Rate:
20 mm/hr* (~ 0.79 in/hr*) (*) Denotes suspect data


That's a typical pressure for a TS.
Member Since: Posts: Comments:
Quoting Drakoen:
AL, 96, 2010070800, , BEST, 0, 235N, 938W, 30, 1005,


Hi Drak...Could you please post the link to that page? Mine got lost in the clutter. Thanks!
Member Since: Posts: Comments:
hi guys, hope everyone is good.

my girlfriend just called me from palm springs, they felt the earthquake she said it lasted about 30 seconds with a jerking motion. the condo she is staying in has a little damage with outside tiles that came off.
Member Since: Posts: Comments:
Quoting Drakoen:
AL, 96, 2010070800, , BEST, 0, 235N, 938W, 30, 1005,
It's no longer a disturbance and now classified as a "low". Pressure went down a couple of millibars and winds are at 35mph.
Member Since: Posts: Comments:
Hope everyone is ok who were near the earthquake.
Member Since: Posts: Comments:

Viewing: 1587 - 1537

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37Blog Index

Top of Page

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.

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron