April 2012: Earth's 5th warmest on record
April 2012 was the globe's 5th warmest April on record, according to the National Oceanic and Atmospheric Administration's National Climatic Data Center (NCDC). NASA rated April 2012 as the 4th warmest April on record. April 2012 global land temperatures were the 2nd warmest on record, and the Northern Hemisphere land surface temperature was 1.74°C (3.13°F) above the 20th century average, marking the warmest April since records began in 1880. Global ocean temperatures were the 11th warmest on record, and April 2012 was the 427th consecutive month with ocean temperatures warmer than the 20th century average. The last time the ocean temperatures were below average was September 1976. The increase in global temperatures relative to average compared to March 2012 (16th warmest March on record) was due, in part, to warming waters in the Eastern Pacific, due to the La Niña event that ended in April. Global satellite-measured temperatures for the lowest 8 km of the atmosphere were 6th or 4th warmest in the 34-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH). April temperatures in the stratosphere were the 1st to 4th coldest on record. We expect cold temperatures there due to the greenhouse effect and to destruction of ozone due to CFC pollution. Northern Hemisphere snow cover during April was 4th smallest in the 46-year record. Wunderground's weather historian, Christopher C. Burt, has a comprehensive post on the notable weather events of April in his April 2012 Global Weather Extremes Summary. Notably, national heat records (for warmest April temperature on record) occurred in the United States (a tie), Germany, Austria, Poland, Belarus, Lithuania, Moldova, Hungry, Croatia, Ukraine, and Slovakia as well as the cities of Moscow and Munich.
Figure 1. Departure of temperature from average for April 2012. The most notable extremes were the warmth observed across Russia, the United States, Alaska, and parts of the Middle East and eastern Europe. There were no land areas with large-scale cold conditions of note. Image credit: National Climatic Data Center (NCDC) .
La Niña officially ends
According to NOAA's Climate Prediction Center (CPC), La Niña conditions are no longer present in the equatorial Pacific, where sea surface temperatures were approximately average as of May 13. The threshold for a La Niña is for these temperatures to be 0.5°C below average or cooler. CPC forecasts that neutral conditions will persist though the summer, with a 41% chance of an El Niño event developing in time for the August - September - October peak of hurricane season. El Niño conditions tend to decrease Atlantic hurricane activity, by increasing wind shear over the tropical Atlantic.
Figure 2. Arctic sea ice extent in 2012 (blue line) compared to the average (thick grey line.) The record low year of 2007 (dashed green line) is also shown. Arctic sea ice was near average during April, but has fallen well below average during the first half of May. Image credit: National Snow and Ice Data Center (NSIDC).
April Arctic sea ice extent near average
Arctic sea ice extent was near average in April 2012, the 17th lowest (18th greatest) extent in the 35-year satellite record, according to the National Snow and Ice Data Center (NSIDC). This was the largest April Arctic sea ice extent since 2001. However, ice in the Arctic is increasingly young, thin ice, which will make it easy for this year's ice to melt away to near-record low levels this summer, if warmer than average weather occurs in the Arctic.
Figure 2. Mt. St. Helens in Washington State erupting on May 18, 1980. Image credit: USGS.
Anniversary of the eruption of Mt. St. Helens
Today is the 32nd anniversary of the May 18th, 1980 eruption of Mt. St. Helens in Washington State. To mark the occasion, NASA has put together a cool Landsat satellite time lapse of 32 years of regrowth of surrounding forest. The USGS has an extensive informational site on the eruption.
Video 1. In Grand Isle, Louisiana last week, a large waterspout came ashore as an EF-1 tornado. The tornado ripped the roof off of the house across the street from this videographer, who should have taken shelter instead of filming the destruction. There's one 4-letter word in the video. Thanks go to Andrew Freedman of Climate Central for posting this.
Have a great weekend, everyone! I'll be back Sunday or Monday with a new post.
Jeff Masters
Reader Comments
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Newly formed 93L is looking very good.
Carnival Pride
Operator: Carnival Cruise Lines
Last reported at 2012-May-19 11:00 UTC. Time now 2012-May-19 13:31 UTC.
Position N 32°06' W 077°48'.
Wind from 320 at 30 knots
Waves 2.5 meters (8 feet), 15 second period
Barometer 1011.0 mb
Air temperature 23.0 ° C
Visibility: greater than 5.4 NM
Dewpoint 20.0 ° C
Water temperature 27.0 ° C
http://www.sailwx.info/shiptrack/shipposition.pht ml?call=H3VU
hey look its Andrea
Oh, we have a developing subtropical storm off the coast, no wonder.
Looks VERY nice. Unlike 92L, it should continue to fire deep convection.
Already looks like a Tropical Depression... Best looking feature so far this year.
I don't see much development of the system in the Western Caribbean. Even with the pressure drops, the shear should remain quite high.
With an upward pulse in the MJO by the end of the month, it will be more likely to see development in the Caribbean at the end of May.
Good morning
Although the 850 vort and low level convergence have both improved there is only an extremely small area of low shear immediately close to the coast and to the SW of where the low is located. Overhead the conditions are still too hostile for this to develop in the near term.
however shear should die down in a larger area within 12-24 hours if not started yet
Hi Gro,
I agree. The high in the Epac to the South of Nicaragua is shearing the GOH low and this, combined with the shear to the North, is preventing development there. If 93L retrogrades to the SW it too will add to shear by creating South Westerly flow aloft over the GOM and the NW Caribbean.
Yo! Kman! Yes, that is what it looks like. You never stay on long enough for us to give you a hey!
"Alberto"
right that center blob near 16.8N 86.7W is expanding the blob to the east near 16.5N 83.5W is also expanding and also moving towards that center blob
A) Low chance (<30%)
B) Medium chance (30-50%)
C) High chance (>50%)
D) Subtropical depression/storm designation
I say B.
(clearing throat)...
Ahem....
No thank you, please
Whoops. Thanks for noticing that.
Knowing the NHC, yeah, B.
Yep. Looks more like a big rain maker.
Hey, kman.
LOL. I will be on for a bit this morning. There hasn't been a lot of action out there so far but the Caribbean may spin up something in the next couple of weeks if shear dies down.
B.
What, did you think I was only here for comedy relief?? :) Morning, nc.
changed sorry about that made an error with the obs I was looking at some obs that was from 4am the area has 1010mb
B.
Wish I had my laptop...
HI there, a little rain overnight and this morning with passing showers on the cards all day by the looks of things. We've had a fairly wet dry season, in fact no real dry season this year to speak of so moisture levels are fairly high early in the season. The image below is a good indicator of this. If this continues we could see an early start to the season in the Caribbean.
LOL..You dont ever post your blog link in this forum...I didnt know you were doing them..will be sure visit there now and good morning to you too!
I think they will be a bit conservative and go with A
Hey my man, some action to start watching :-)
The high in the Epac has retrograded to the West since yesterday and if it moves out of the way might open the door some for the GOH low to try something but the NHC are calling for it to dissipate. An early season teaser.
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