Dr. Jeff Masters' WunderBlog

The Northeast Heatwave

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

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.

Categories: Heat

Permalink | A A A

Top of Page

Reader Comments

Display: 0, 50, 100, 200

Sort: Newest First - Order Posted

Viewing: 351 - 401

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 | 37 — Blog Index

351. help4u 3:25 PM GMT on July 07, 2010
You know the tropics are dead when the talk is anything but tropics.Good day to go christmas shopping.lol Member Since: September 18, 2006 Posts: 0 Comments: 1069

352. cgableshurrycanegal 3:25 PM GMT on July 07, 2010
thanks Dr C for keeping us uptodate some of us are lurkers more than participants :) btw - you should stick YOUR pic in when subbing for Dr M heheheh ;) Member Since: July 12, 2005 Posts: 24 Comments: 211

353. txalwaysprepared 3:25 PM GMT on July 07, 2010
Loving the sound of thunder (we had lots of rain from Alex, but no thunder) Member Since: August 18, 2007 Posts: 0 Comments: 1642

354. angiest 3:27 PM GMT on July 07, 2010
Quoting help4u: You know the tropics are dead when the talk is anything but tropics.Good day to go christmas shopping.lol Erg, don't get me started. I am already seeing Christmas decorations in stores. Member Since: August 26, 2006 Posts: 16 Comments: 4757

355. LoneStarWeather 3:28 PM GMT on July 07, 2010
Quoting txalwaysprepared: Loving the sound of thunder (we had lots of rain from Alex, but no thunder) We had an awesome storm in Richmond, TX yesterday evening about 7. Lots of lightning and thunder and a flood advisory. It just doesn't get any better than that! Member Since: September 8, 2001 Posts: 0 Comments: 391

356. tropicfreak 3:28 PM GMT on July 07, 2010
Quoting watchingnva: i dont understand how they can have severe air quality alerts and ozone alerts, and all this...but not put an advisory out...lol...maybe bc weve already had like 7-10 days of 100+ days here this summer that they think we are use to it:))...and my family and i were the smart ones who when to the beach on monday...and the river in downtown richmond yesterday...never again going to belle isle on a 100+ days...the boulders were scorching...you could fry an egg on them if you wanted to, and there are freaking river rocks with rapids around them...lol...too hot...dry heat i dont usually have a problem with...but 103-105 with a dewpoint higher than 65...no thank you...lol I'm pretty surprised as well. No one in VA is under an advisory except for a few counties in N VA near DC. Member Since: September 2, 2006 Posts: 110 Comments: 6564

357. Daveg 3:29 PM GMT on July 07, 2010
Wow... 96L sure didn't move much over night. Still barely off land. Trying to get her act together... AVN Color Imagery Loop I guess the day shall tell. Member Since: September 23, 2005 Posts: 0 Comments: 426

358. OneDay 3:30 PM GMT on July 07, 2010
We caught the last storm of the evening last night in Spring at about 10:30. Picked up a quick 1 inch and 1 clap of thunder before daytime heating lost out. I suspect we'll get a good deal more today and tomorrow... Member Since: July 13, 2005 Posts: 35 Comments: 929

359. muddertracker 3:31 PM GMT on July 07, 2010
Quoting ElConando: Wade and Bosh to Miami!!!! Erm I mean hows 96L? Isn't it amazing what a trip to south beach will do? Member Since: August 16, 2007 Posts: 1 Comments: 2093

360. tropicfreak 3:31 PM GMT on July 07, 2010
Quoting angiest: Erg, don't get me started. I am already seeing Christmas decorations in stores. Oh hush. Here many kids in Richmond including myself just started summer 2-3 weeks ago, we will start school the day after labor day. At Target, they already have "Back to School Savings". We just started summer!!!!!!!!!!!! Member Since: September 2, 2006 Posts: 110 Comments: 6564

361. Neapolitan 3:36 PM GMT on July 07, 2010
Quoting atmoaggie: Want to never be overly hot again? Had a job one summer at Texas A&M tending to cotton fields. All work by hand, no machines. Weeks of ~100 F and just under 70F dewpoints and out in it 10 hours a day. Try it and no amount of hot will actually bother you ever again... 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... :-) Member Since: November 8, 2009 Posts: 4 Comments: 11138

362. LoneStarWeather 3:37 PM GMT on July 07, 2010
Wow, this blog is "deader" than 96L! Member Since: September 8, 2001 Posts: 0 Comments: 391

363. muddertracker 3:37 PM GMT on July 07, 2010
whiskey tango foxtrot? Member Since: August 16, 2007 Posts: 1 Comments: 2093

364. watchingnva 3:38 PM GMT on July 07, 2010
Quoting HurricaneSwirl: Lol I don't understand it either. But you better be used to it today as this is gonna be the worst of it for you guys. Then it's our turn come thursday :(, although we're still only forecast to hit 101-102, which is still a nice couple of degrees cooler than what you're getting today so im fine :) Man and on the topic of scorching boulders I remember going to Jekyll island last year during a heat wave that brought heat indexes up to around 120 degrees.. I literally burnt my feet on the sand, and I thought the water would cool me down. It didn't :( yea....i really wish we could get a couple fronts coming through like we had last wed/thurs...dropped it into the mid 80s with dewpoints in the 50's...it was nice...too bad it couldnt last...knowing how things have been so far this summer...its gonna be in the mid 90's with higher humidity through early next week...then we will go 3-4 days back above 100...seems like the trend weve had the last month or so... Member Since: September 7, 2005 Posts: 3 Comments: 1310

365. angiest 3:38 PM GMT on July 07, 2010
Quoting LoneStarWeather: We had an awesome storm in Richmond, TX yesterday evening about 7. Lots of lightning and thunder and a flood advisory. It just doesn't get any better than that! We caught the edge of that storm in Katy. I grew up outside of Dallas. People down here just don't really know what a thunderstorm is. ;) Member Since: August 26, 2006 Posts: 16 Comments: 4757

366. Daveg 3:39 PM GMT on July 07, 2010
Quoting LoneStarWeather: Wow, this blog is "deader" than 96L! Not anywhere near dead. Member Since: September 23, 2005 Posts: 0 Comments: 426

367. help4u 3:41 PM GMT on July 07, 2010
Is this the home shopping blog?lol! Member Since: September 18, 2006 Posts: 0 Comments: 1069

368. watchingnva 3:41 PM GMT on July 07, 2010
Quoting tropicfreak: Morning watch!! Today will be our last day in the triple digits! Wohoo!! true...but 92-98 with dewpoints of 73+ is really gonna feel that much better? lol... and i know we have a chance of rain through the weekend...but wanna bet we dont get a drop right around here...itll rain west, north and east...but fall apart if it heads this way...lol...thats what it has been doing the last 2 months...is our luck gonna change?...lol Member Since: September 7, 2005 Posts: 3 Comments: 1310

369. OneDay 3:44 PM GMT on July 07, 2010
It's kind of like early '05...check out Dr. M's blog archives from early that season. There were posts with 2 and 6 and 21 comments. Member Since: July 13, 2005 Posts: 35 Comments: 929

370. help4u 3:45 PM GMT on July 07, 2010
2005 had 4 named storms by now. Member Since: September 18, 2006 Posts: 0 Comments: 1069

371. Drakoen 3:46 PM GMT on July 07, 2010
I see 96L has grown less organize as it failed to take advantage of the diurnal maximum this morning. The storm ended up doing what the ECMWF forecasted which was for the mid level center to decouple to the north and leave the surface center trailing WNW. A buoy south of the system is reporting winds out of the ENE at this time suggesting that 96L does not have a closed circulation. In addition, visible satellite loops show outflow boundaries denoting collapsing thunderstorms llikely due to dry air west of the system. Member Since: October 28, 2006 Posts: 57 Comments: 29010

372. StadiumEffect 3:46 PM GMT on July 07, 2010
Link Two interesting features are approaching the Lesser Antilles. Visible sat. shows decent cyclonic turning with both waves and this also shows on the most recent vorticity maps. Convection seems to be increasing with both, although drier air in the vacinity may keep heavy thunderstorms under check for a while. These will have to be watched over the next few days....

373. CoopsWife 3:47 PM GMT on July 07, 2010
Quoting watchingnva: true...but 92-98 with dewpoints of 73+ is really gonna feel that much better? lol... and i know we have a chance of rain through the weekend...but wanna bet we dont get a drop right around here...itll rain west, north and east...but fall apart if it heads this way...lol...thats what it has been doing the last 2 months...is our luck gonna change?...lol 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. Member Since: June 19, 2006 Posts: 63 Comments: 4167

374. OneDay 3:48 PM GMT on July 07, 2010
sorry, I was trying to quote post #362. The blog's like early '05, not the season (at least I hope not. :-/ Member Since: July 13, 2005 Posts: 35 Comments: 929

375. help4u 3:50 PM GMT on July 07, 2010
I see. Member Since: September 18, 2006 Posts: 0 Comments: 1069

376. mcluvincane 3:51 PM GMT on July 07, 2010
Zzzzzzzzzzzzzzz Member Since: June 2, 2010 Posts: 0 Comments: 1315

378. help4u 3:55 PM GMT on July 07, 2010
Tick ,Tock,Tick,Tock. Member Since: September 18, 2006 Posts: 0 Comments: 1069

380. help4u 3:56 PM GMT on July 07, 2010
RIP tropics for next couple weeks. Member Since: September 18, 2006 Posts: 0 Comments: 1069

381. cctxshirl 3:57 PM GMT on July 07, 2010
Quoting DestinJeff: RIP 96L Quoting DestinJeff: RIP 96L that's just what I was thinking. Member Since: July 15, 2005 Posts: 25 Comments: 316

382. reedzone 3:57 PM GMT on July 07, 2010
I give 96L a 10% chance for development before it makes landfall somewhere in Texas. However, the NHC might want to take more notice to the NON-TROPICAL low near Bermuda, could gain some Subtropical characteristics since it's sitting there in the warm waters. I give this a 30% for SUBtropical development. The waves coming off Africa continued to get sheared as they past 40W. I don't expect shear to decrease until after 200 hours or so as the EURO suggests something may try to get going by 240 hours. Member Since: July 1, 2008 Posts: 13 Comments: 7247

383. SQUAWK 3:57 PM GMT on July 07, 2010
Gotta do it.... MARCO!!!!! Member Since: December 9, 2008 Posts: 0 Comments: 2497

384. Daveg 3:58 PM GMT on July 07, 2010
LOL... I think all the deadcasters are going to be sadly mistaken. No, I really don't think it will become a hurricane, but 96L is far from dead. Member Since: September 23, 2005 Posts: 0 Comments: 426

386. NRAamy 3:59 PM GMT on July 07, 2010
POLO!!! Member Since: January 24, 2007 Posts: 315 Comments: 31937

388. watchingnva 4:00 PM GMT on July 07, 2010
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 Member Since: September 7, 2005 Posts: 3 Comments: 1310

389. AllBoardedUp 4:00 PM GMT on July 07, 2010
Quoting SQUAWK: Gotta do it.... MARCO!!!!! Where? Member Since: July 25, 2008 Posts: 0 Comments: 585

390. AllBoardedUp 4:00 PM GMT on July 07, 2010
Quoting NRAamy: POLO!!! Where? Member Since: July 25, 2008 Posts: 0 Comments: 585

391. StormChaser81 4:01 PM GMT on July 07, 2010
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. =( Member Since: August 11, 2008 Posts: 0 Comments: 2315

392. watchingnva 4:03 PM GMT on July 07, 2010
sitting at 100 at noon...yay... Member Since: September 7, 2005 Posts: 3 Comments: 1310

393. TexasHurricane 4:04 PM GMT on July 07, 2010
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

394. atmoaggie 4:09 PM GMT on July 07, 2010
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... Member Since: August 16, 2007 Posts: 6 Comments: 12461

395. Daveg 4:09 PM GMT on July 07, 2010
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

396. angiest 4:11 PM GMT on July 07, 2010
Heh, I'm in a 2% tornado risk again. Member Since: August 26, 2006 Posts: 16 Comments: 4757

398. Drakoen 4:12 PM GMT on July 07, 2010
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: 29010

399. angiest 4:13 PM GMT on July 07, 2010
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. Member Since: August 26, 2006 Posts: 16 Comments: 4757

400. AustinTXWeather 4:13 PM GMT on July 07, 2010
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? Member Since: September 13, 2008 Posts: 0 Comments: 241

401. watchingnva 4:15 PM GMT on July 07, 2010
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 Member Since: September 7, 2005 Posts: 3 Comments: 1310

Viewing: 351 - 401

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 | 37 — Blog Index

Top of Page

New Comment

Community Standards Policy 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.

About JeffMasters