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™
1495. msphar
1494. LargoFl
1493. aislinnpaps
Horrible! My thoughts and prayers to everyone affected.
1492. ryang
1491. pottery
LOL, but we don't get Hurricanes like you do......
1490. LargoFl
1489. LargoFl
1488. Msdrown
1487. Dragod66
1486. gordydunnot
1485. LargoFl
1484. washingtonian115
1483. pottery
This shows the fast run-off. Last year, Maraval
Took friends wall, gate, 3' of water at 20 mph through the house.
1482. Msdrown
Good morning Largo, It sure seems like this one is going to get squireling.
1481. LargoFl
1480. hydrus
1479. kmanislander
1478. gordydunnot
1477. wunderkidcayman
1476. hydrus
Category 4 hurricane (SSHS)
Duration October 14 – October 28
Intensity 150 mph (240 km/h) (1-min), 934 mbar (hPa)
WIKI..
On October 14 a tropical storm developed in the southwest Caribbean Sea. It moved northward, becoming a major hurricane on October 20 before crossing Cuba and southeast Florida.
Striking Cuba with winds up to 145 mph (230 km/h),[8] the hurricane caused catastrophic damage and a large loss of life. Several small towns in the storm's path were completely destroyed and damage estimates exceeded $100 million ($1.3 billion 2012 USD)
It then headed northeastward, and strengthened into a Category 4 before hitting Bermuda on October 22. While weather forecasters knew of the storm's approach on Bermuda, it covered the thousand miles from the Bahamas to Bermuda so rapidly it apparently struck with few warning signs aside from heavy swells. On the 21 October, with the eye of the storm still 700 miles from Bermuda, weather forecasts from the US called for it to strike the island on the following morning with gale force. The Arabis class sloop HMS Valerian, based at the HMD Bermuda, was returning from providing hurricane relief in the Bahamas and was overtaken by the storm shortly before she could make harbour. Unable to enter through Bermuda's reefline, she fought the storm for more than five hours before she was sunk with the loss of eighty-five men. The British merchant ship the Eastway was also sunk near Bermuda. Although the Valerian's commanding officer, Commander Usher, reported that there was no sign of a major storm at 08:00, when his ship was in sight of Bermuda, and when the British Army meteorologists at Prospect Camp measured the wind at 28 mph. By 10:00, the winds had reached 95 mph. When the centre of the storm passed over Bermuda at noon, the winds dropped to 8 mph, then increased to 114 mph, whereupon the Army took down its anemometer to protect it. The Royal Naval Dockyard was being hammered severely and never took its anemometer down. It measured 138 mph at 13:00 (about the same time the Valerian went down), before the wind destroyed it.
The storm became extratropical on October 23.
1475. kmanislander
1474. gordydunnot
1473. ryang
1472. LargoFl
WTNT22 KNHC 110833
TCMAT2
TROPICAL DEPRESSION SEVEN FORECAST/ADVISORY NUMBER 7
NWS NATIONAL HURRICANE CENTER MIAMI FL AL072012
0900 UTC SAT AUG 11 2012
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...
NONE.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT...
A TROPICAL STORM WATCH IS IN EFFECT FOR...
* GUADELOUPE AND MARTINIQUE
* DOMINICA
* ST. LUCIA
* BARBADOS
* ST. VINCENT AND THE GRENADINES
A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...IN THIS CASE IN 12 TO 24 HOURS.
TROPICAL DEPRESSION CENTER LOCATED NEAR 14.0N 56.1W AT 11/0900Z
POSITION ACCURATE WITHIN 30 NM
PRESENT MOVEMENT TOWARD THE WEST OR 275 DEGREES AT 21 KT
ESTIMATED MINIMUM CENTRAL PRESSURE 1009 MB
MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.
REPEAT...CENTER LOCATED NEAR 14.0N 56.1W AT 11/0900Z
AT 11/0600Z CENTER WAS LOCATED NEAR 13.9N 55.1W
FORECAST VALID 11/1800Z 14.2N 59.4W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 40NE 0SE 0SW 40NW.
FORECAST VALID 12/0600Z 14.4N 63.5W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 40NE 0SE 0SW 40NW.
FORECAST VALID 12/1800Z 14.6N 67.6W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 40NE 0SE 0SW 40NW.
FORECAST VALID 13/0600Z...DISSIPATED
REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 14.0N 56.1W
NEXT ADVISORY AT 11/1500Z
$$
FORECASTER BEVEN
1471. VR46L
Good Morning Wash , Not so sure on 93l ever developing,
But have to admit there are 2 nice, but small waves getting ready soon to come on to the Atlantic .But the first one will have a major battle with SAL if its to make it ...JMO
1470. pottery
1469. wunderkidcayman
hmm they got the HH coordinates
hmm SHIPS still has it geting stronger on the second half of the run
1468. LargoFl
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
714 AM CDT SAT AUG 11 2012
THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A
* FLASH FLOOD WARNING FOR...
ST. JOHN THE BAPTIST PARISH IN SOUTHEAST LOUISIANA...
THIS INCLUDES THE CITIES OF...RESERVE...LAPLACE...
* UNTIL 915 AM CDT
* AT 709 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED
FLASH FLOODING IS POSSIBLE FROM A THUNDERSTORM OVER THE WARNED
AREA.
* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO EDGARD
PRECAUTIONARY/PREPAREDNESS ACTIONS...
RADAR ESTIMATES THAT JUST UNDER 2 INCHES OF RAIN HAS ALREADY FALLEN
AND AN ADDITIONAL 2 TO 3 INCHES ARE POSSIBLE IN THE WARNED AREA.
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.
LAT...LON 2990 9066 2995 9067 3016 9064 3018 9043
3007 9041 3001 9054 3000 9054 3000 9055
2996 9054 2990 9055
CAB
1467. LargoFl
1466. kmanislander
That pressure would be rounded to 1011 mbs which is high for a TD. Let's see if they find anything lower.
1465. hydrus
1464. LargoFl
1463. kmanislander
Flash flooding is always a big problem with mountainous terrain
1462. wunderkidcayman
maybe is better than ernesto in the winds
maybe well if ernesto can enter the caribeean deal with the bad environment and work its way up why can't TD 7 it sure looks better than Ernesto did at this location interms of those W winds
by the way the lowest pressure found in the system from takeoff till now is 1010.9mb
1461. pottery
The quick run-off is the problem in those valleys.
Overbuilding on the hillsides and too much pavement has exacerbated that.
1460. LargoFl
1459. SLU
WHXX01 KWBC 111236
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS NATIONAL HURRICANE CENTER MIAMI FL
1236 UTC SAT AUG 11 2012
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
TROPICAL CYCLONE SEVEN (AL072012) 20120811 1200 UTC
...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
120811 1200 120812 0000 120812 1200 120813 0000
LAT LON LAT LON LAT LON LAT LON
BAMS 13.3N 57.9W 14.0N 62.1W 14.6N 66.4W 15.2N 70.8W
BAMD 13.3N 57.9W 14.0N 60.3W 14.8N 62.5W 15.6N 64.6W
BAMM 13.3N 57.9W 13.9N 60.9W 14.5N 63.8W 15.1N 66.5W
LBAR 13.3N 57.9W 13.8N 61.6W 14.4N 65.1W 15.2N 68.5W
SHIP 30KTS 31KTS 33KTS 37KTS
DSHP 30KTS 31KTS 33KTS 37KTS
...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
120813 1200 120814 1200 120815 1200 120816 1200
LAT LON LAT LON LAT LON LAT LON
BAMS 15.5N 75.4W 15.9N 83.5W 16.5N 90.1W 17.8N 94.9W
BAMD 16.2N 66.6W 17.2N 70.5W 17.8N 74.6W 18.3N 78.9W
BAMM 15.7N 69.4W 16.9N 75.1W 18.0N 80.9W 19.3N 86.6W
LBAR 16.2N 71.7W 18.7N 77.6W 20.9N 81.3W 19.5N 75.0W
SHIP 42KTS 55KTS 68KTS 74KTS
DSHP 42KTS 55KTS 68KTS 74KTS
...INITIAL CONDITIONS...
LATCUR = 13.3N LONCUR = 57.9W DIRCUR = 270DEG SPDCUR = 23KT
LATM12 = 13.7N LONM12 = 53.2W DIRM12 = 269DEG SPDM12 = 23KT
LATM24 = 13.6N LONM24 = 48.6W
WNDCUR = 30KT RMAXWD = 80NM WNDM12 = 30KT
CENPRS = 1008MB OUTPRS = 1012MB OUTRAD = 100NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM
$$
NNNN
1458. washingtonian115
1457. kmanislander
That's not good at all. We had close to 2 inches since midnight but it all runs off quickly here except for a few very low lying areas
1456. LargoFl
1455. wunderkidcayman
we need to wait for HH to fly E and NE to determine if it is a TS yet
1454. pottery
Trinidad, 11n 61w
Serious flooding in Maraval, Diego Martin, Woodbrook and other areas overnight.
Cars swept away, homes flooded, bridges out.
Looks like about 3" rainfall, but in those areas (the floors of big valleys/catchment areas with steep hillsides) the result of 3" can be disaster.
1453. kmanislander
A whole page of them now but pressure of 1012 mbs. Not a good sign.
1452. LargoFl
1451. stormpetrol
1450. wunderkidcayman
1449. kmanislander
They would be weak with the system in the shape it's in plus the fast forward speed
1448. SLU
1447. GeorgiaStormz
1446. kmanislander
1445. stormpetrol
Coordinates: 13.1667N 57.8667W
Acft. Static Air Press: 977.0 mb (~ 28.85 inHg)
Acft. Geopotential Hgt: 309 meters (~ 1,014 feet)
Extrap. Sfc. Press: 1012.1 mb (~ 29.89 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 267° at 8 knots (From the W at ~ 9.2 mph)
Air Temp: 23.0°C* (~ 73.4°F*)
Dew Pt: 23.0°C* (~ 73.4°F*)
Peak (10s) Flt. Lvl. Wind: 9 knots (~ 10.3 mph)
SFMR Peak (10s) Sfc. Wind: 5 knots (~ 5.8 mph)
SFMR Rain Rate: 3 mm/hr (~ 0.12 in/hr)
(*) Denotes suspect data
WE still got a TD.