About Jeff Masters
Cat 6 lead authors: WU cofounder Dr. Jeff Masters (right), who flew w/NOAA Hurricane Hunters 1986-1990, & WU meteorologist Bob Henson, @bhensonweather
July 2012: hottest month in U.S. history
By: Dr. Jeff Masters , 7:16 PM GMT on August 10, 2012
During the 1930s, a series of epic heat waves gripped the U.S., drying up the soil in an unprecedented drought that brought about the great Dust Bowl. The most intense heat hit during July 1936, which set a record for hottest month in U.S. history that stood for 76 years. That iconic record has now fallen, bested by 0.2°F during July 2012, which is now the hottest month in U.S. history, said NOAA's National Climatic Data Center (NCDC) this week. So far in 2012, we've had the warmest March on record, 3rd warmest April, 2nd warmest May, and warmest July. These remarkably warm months have helped push temperatures in the contiguous U.S. to the warmest on record for the year-to-date period of January - July, and for the 12-month period August 2011 - July 2012. Twenty-four states were record warm for that 12-month period, and an additional twenty states were top-ten warm. The past fourteen months have featured America's 2nd warmest summer (in 2011), 4th warmest winter, and warmest spring. The summer of 2012 is on pace to be a top-five warmest summer on record, and could beat the summer of 1936 as the warmest summer in U.S. history.
Figure 1. When the temperature peaked at an all-time high of 108° in Minneapolis, Minnesota on July 14, 1936, the want-ad staff at the 'St. Paul Daily News' was provided with 400 pounds of ice and two electric fans to cool the air in the press room. Photo from the Minnesota Historical Society.
Figure 2. Year-to-date temperature, by month, for 2012 (red), compared to the other 117 years on record for the contiguous U.S., with the five ultimately warmest years (orange) and five ultimately coolest years (blue) noted. The 2012 data are still preliminary. The year-to-date period of January - July was the warmest on record by a huge margin--1.0°F. Image credit: NOAA/NCDC.
Figure 3. For the fourth consecutive month, a new U.S. record for hottest 12-month period was set in July 2012. Five of the top-ten warmest 12-month periods in the contiguous U.S. since 1895 have occurred since April 2011. Image credit: NOAA/NCDC.
Most extreme January - July period on record
NOAA's U.S. Climate Extremes Index (CEI), which tracks the percentage area of the contiguous U.S. experiencing top-10% and bottom-10% extremes in temperature, precipitation, and drought, was 46% during the year-to-date January - July period. This is the highest value since CEI record-keeping began in 1910, and more than twice the average value. Remarkably, 83% of the contiguous U.S. had maximum temperatures that were in the warmest 10% historically during the first seven months of 2012, and 74% of the U.S. of the U.S. had warm minimum temperatures in the top 10%. The percentage area of the U.S. experiencing top-10% drought conditions was 20%, which was the 16th greatest since 1910. Extremes in 1-day heavy precipitation events were the 24th greatest in the 103-year record.
Figure 4. NOAA's U.S. Climate Extremes Index (CEI) for January - July shows that 2012 has had the most extreme first seven months of the year on record, with 46% of the contiguous U.S. experiencing top-10% extreme weather.
Little change to the U.S. drought during the past week
The great U.S. drought of 2012 remained about the same size and intensity over the past week, said NOAA in their weekly U.S. Drought Monitor report issued Thursday, August 9. The area of the contiguous U.S. covered by drought dropped slightly, from 63% to 62%, and the area covered by severe or greater drought stayed constant at 46%. The area of the country in the worst drought categories (extreme to exceptional drought) doubled from 10 percent last month to 22 percent this month. The extreme dryness and excessive heat devastated crops and livestock from the Great Plains to Midwest. During July, the area of the U.S. covered by moderate or greater drought was 57%, ranking as the 5th largest drought in U.S. history:
1) Jul 1934, 80%
2) Dec 1939, 60%
3) Jul 1954, 60%
4) Dec 1956, 58%
5) Jul 2012, 57%
Video 1. This is Not Cool: Peter Sinclair's July 2012 video from the Yale Forum on Climate Change and the Media couples historical footage with contemporary clips and news segments. In one of the latter, for instance, NBC anchor Brian Williams opens the network’s flagship news program with the words: “It’s now official. We are living in one of the worst droughts of the past 100 years.” NASA scientist James Hansen is featured testifying about risks of “extreme droughts” in the nation’s breadbasket, and I'm featured in a few clips talking about the drought of 2012.
I'll have a new post by noon Saturday.
Wunderground's weather historian Christopher C. Burt has a post looking back at the great Heat Wave of July 1936.
Jeff Masters
The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.
Reader Comments
Category 6™
1645. hurrtracker1994
1644. Tribucanes
1643. sar2401
Why do you think no one listened to you? Several of us have been saying something similar as well. So far, at least, WU isn't giving out gold stars for correct guesses. Now, the real trick is to be right on track and intensity when we get a major. That's a lot tougher than predicting lousy looking storms aren't going to do much.
1642. AussieStorm
It's on roids. GFS is best after cyclonesis. NOGAPS is good at predicting Cyclonesis.
1640. RTSplayer
Stick a fork in it baby, it's done.
LOL.
...at least for now anyway. Probably take a day or two to reorganize, if it ever does at all.
1639. AussieStorm
you mean... TD-07... I have been saying it also.
1638. sar2401
That's why most of us don't believe the SHIPS model this year. :)
1637. AussieStorm
Open-wave???
1635. sar2401
It's just an M1 X class flare. They happen at least several times a year, and should occur more frequently through 2013 as we approach a sunspot maxima. We ham radio operators look forward to these flares to give us some rare long distance communications on the upper frequency bands.
1634. FLASPOTTER
1633. SLU
1632. AussieStorm
1630. SLU
Yep i realised that. Should be deactivated at 11am or the NHC might hold on to it for precautionary reasons until it clears the islands
1629. weathermanwannabe
Looking ahead a little bit, and with the exception of TD7 and back to watching the models again, I could not tell you when/when the next system will spin up. Need to remind folks that the rise to the "peak" period is just starting and we will get several more storms between now and October.
As far as the Cape Verde season is concerned (and 80% of all Atlantic hurricanes in any given season form from CV waves), it was off to an earlier start than usual this year but we have seen Ernesto (in the Caribbean) and TD7 fizzle and struggle. The better route to go, rather than hype or downcast this season, is to analize what just happened with both systems.
Essentially, conditions in the Central Atlantic have not been "perfect" for these two systems because most other factors being equal, the dry air over the Central Atlantic, and most importantly, the forward speed of both systems in the Central Atlantic and Eastern-Central Caribbean (average speed of over 20 mph for both systems) did not allow them to stack up a well defined lower level circulation in spite of favorable SST's and moderate wind sheer.
The real question then is; Was this just normal July-Early August climatology factors working against both systems which will get better going into the next several weeks, or, is this going to be the general pattern (dry air and excessive forward speed due to stronger than average trade winds) over the next several weeks?
Climatology says that conditions will become more favorable (in the Central Atlantic and Caribbean) over the next several weeks and with all of the other factors going into the favorable mode, we need to keep a close eye on dry air issues and whether the trade winds slow down.
Also, assuming that the CV season started early, it would not be unreasonable to assume that the "closer to home" period might start a little early too in the Western Caribbean, Gulf, and Eastern Seaboard from frontal remnants due to the Fall like trofs and fronts which have arrived early as well.
My point is, Mother Nature might be a little ahead of the normal schedule this year so we also have to keep a real close eye on the next arrival of the MJO in the Atlantic basin from West to East.
1628. kmanislander
1627. Msdrown
I agree, doesn't look bad but I'm going to leave and check it out. Be back later hopefully with some info. Before I go I'll try to find that informative post from early this morning and repost it.
1626. Grothar
LOL
1625. Msdrown
Not a big cat lover but have been around them a few times and the more playfull types are always getting themselves into these sits. Not sure how that is mean, not trying to anger you.
1624. SouthDadeFish
TRMM recently made a nice pass, but TD 7 remains poorly organized. Here is the 37 GHz color, which shows little, if anything, in the way of banding:
And here is the 85 GHz Horizontal, which also shows a disorganized storm:
Not only is it disorganized, but there is very little convection. This disorganized pattern is being confirmed be recon.
1623. Astrometeor
Don't worry, I won't get political. Just saying.
1622. kmanislander
1621. hydrus
1619. SSideBrac
Although not "low Level Flying" per se - it probably makes a nice change for them and IMHO they thoroughly deserve a "perk" now and again
1618. Astrometeor
Alright, I checked the website.
1. That was from the 5th.
2. They used unprecedented NOT TRUE.
A. Quebec blackout
B. Carrington Event
3. I am very aware of the dangers of a CME impacting the Earth.
1617. Msdrown
Same thing as usual. They are in a very siesmic area. They have at least one big one routinely but it is usually in remote areas not like this. Or you could get political and something went wrong with there nuke projects.
1616. kmanislander
20 knots max but all in all not too bad. TD7 is really struggling and so is the HH in trying to pin down a center.
1615. Tazmanian
1614. Msdrown
At least the H/H and this little guy are working it hard you have to give them that. Again Too Funny.
1613. Tazmanian
so ture
1612. Progster
Yes, maybe. The CMC solution is broadly similar to the 00Z ECMWF ensemble and 00Z NOGAPS deterministic runs, although the latter two take it further NW and kill it in colder waters.
1611. AussieStorm
Taz, I'm sure the cat is fine.
1610. MAweatherboy1
We had an M class flare this morning... Not sure if it produced a CME.
I think Pat posted this pic last night... Nothing too unusual about it:
1609. barbados246
Hey Juliet it can be so confusing reading everyones thoughts and still not sure what will happen but i guess thats life and we just have to wait on mother nature to take her course. Its such a lovely day outside its hard to believe we are going to have a rain far less a TD.
1608. AussieStorm
Who, What, Where, Why, When????
1607. Drakoen
1606. Tazmanian
i dont find that photo vary funny in fac i call that mean too a cat plzs dont re post it
1605. kmanislander
I don't pay any attention to that anymore. Way off
1604. Astrometeor
Actually that is Ernesto. Or at least what's left of him.
1603. RTSplayer
Ugh...
this thing needs to be backed up to an older version. It's horribly over-rating storms this year. It's off by like 10mb and 10mph or more...
1602. Saltydogbwi1
could this be the weak center echo?
1601. GeorgiaStormz
1600. AussieStorm
Shhhhh don't say that. wunderkidcayman will get upset.
Just Joking dude. How is the beautiful Cayman Islands Today?
1599. hydrus
1598. Astrometeor
Looked at the USGS page on that too. Wonder what's going on over there...
1597. Msdrown
Yea, that proves my point, check the date upper left and the time upper right. This was yesterdays and I checked it periodically through the day and it never changed.
1596. kmanislander