Second warmest March on record; will La Niña be gone by hurricane season?
March 2008 was the 2nd warmest March for the the globe on record, according to statistics released by the National Climatic Data Center. Over the Northern Hemisphere, and over all of the globe's land areas, March 2008 was the warmest March in the 128-year global record. Only the presence of a moderately strong La Niña event that cooled ocean waters in the central and eastern equatorial Pacific prevented March 2008 from surpassing March 2002 as the warmest March on record. March broke a string of three straight months when the globe did not record a top ten warmest month ever. Between February 2006 and November 2007, the globe set top ten monthly warm temperature records for 22 straight months.
Figure 1. Departure of temperature from average (the anomaly) for March of 2008, the second warmest March on record for the globe. While the U.S. recorded slightly below average temperatures, much of Asia and Europe saw remarkably warm temperatures. Image credit: National Climatic Data Center.
How much cooling did La Niña give to the globe in March?
La Niña is a periodic cooling of the Equatorial waters of the Eastern Pacific that occurs every 3-7 years. The cooling is due to a natural cycle of anomalous winds from the east that act to push surface waters away from the coast of South America, allowing cold water from deep in the ocean to rise to the surface to replace the surface waters blown to the west. These cool waters often cause a noticeable drop in global temperatures. Conversely, when the opposite phenomena occurs--an El Niño event, which brings anomalously warm Sea Surface Temperatures (SSTs) to the Equatorial Eastern Pacific, enough heat is added to the atmosphere that global temperatures warm significantly. According to Trenberth et al. (2002), a typical El Niño event increases global temperatures by about 0.1°C. Exceptional El Niño events, such as occurred in 1997-1998 and 1982-1983, increase global temperatures by up to 0.2°C. El Niño events heat the atmosphere by causing changes in cloudiness and atmospheric circulation, and through direct radiation of heat from the ocean to the atmosphere. There is a lag of 3-6 months between the time an El Niño event occurs and the time the atmosphere heats in response. Similarly, when a La Niña event occurs, heat is drawn out of the atmosphere and the oceans are recharged with heat. Global temperatures cool, again with a lag of 3-6 months. The correlation between global temperature anomalies and El Niño/La Niña temperature anomalies can be plainly seen in Figure 2. Note that the correlation is not perfect--there are some El Niño/La Niña events that do not affect the global temperature much. For example, global temperatures did not cool much during the strong 1988-1989 La Niña event. Therefore, it is a good bet--but not certain one--that had we not had a strong La Niña event this winter, March 2008 would have been the warmest March on record, since it missed the record by only 0.04°C.
Figure 2. Comparison of temperature anomalies in the equatorial Pacific Ocean bounded by a box between 5°S, 5°N, 120°W, and 180°W (the Niño 3.4 region) and global temperatures for 1950-1998. Means for 1950-1976 and 1977-1998 (horizontal lines) are shown separately to highlight a climate shift that occurred in 1976/1977. The reasons for this shift are unknown. Note that when an El Niño event occurs, the globe tends to warm by about 0.1°C, and when a La Niña event occurs, the globe tends to cool. Image credit: American Geophysical Union's Journal of Geophysical Research.
Warmest month ever stats
It is interesting to compare what the phase of El Niño/La Niña was during each of the 12 record warmest months the globe has recorded. If we adjust for the 3-6 month lag between an El Niño/La Niña event and the monthly global temperature records, it turns out that nine of the twelve monthly records were set when an El Niño event occurred during the 3-6 month period prior to the record. Considering that climatologically El Niño conditions are present only about 25% of the time, El Niño has a major impact on when record global warmth will occur. The warmest year on record, 1998, occurred during the strongest El Niño of the past century. The table below compares the 12 monthly global temperature records with the temperature in the Niño 3.4 region (a 3-month average centered four months before the record was set). El Niño events, which occur when the Niño 3.4 index is greater than 0.4°C, are marked with an "E".
Record......Niño 3.4 index
-----------------------------
Jan 2007 +0.7 E
Feb 1998 +1.7 E
Mar 2002 -0.1
Apr 1998 +2.5 E
May 1998 +2.3 E
Jun 2005 +0.5 E
Jul 1998 +1.4 E
Aug 1998 +1.1 E
Sep 2005 +0.5 E
Oct 2003 +0.0
Nov 2004 +0.7 E
Dec 2003 +0.4
Figure 3. A La Niña event exists when ocean surface temperatures in the equatorial Pacific Ocean bounded by a box between 5°S, 5°N, 120°W, and 180°W (the Niño 3.4 region) are cooler than 0.4°C below average (based on means from 1971-2000). La Niña events between 0.5°C and 0.9°C are referred to as weak, 1.0°C and 1.4°C are moderate, and 1.5°C or cooler, strong. The winter of 2007-2008 saw strong La Niña conditions, but this has weakened to a moderate event in March. Image credit: NOAA Climate Prediction Center.
An El Niño by hurricane season?
Presence of El Niño conditions usually causes enhanced levels of wind shear over the Atlantic, reducing hurricane activity, so it would be nice to see an El Niño this Fall. The strong La Niña event we had over the past winter has weakened considerably in the past two months, and is now classified as a moderate event, according to the latest El Niño discussion issued by NOAA's Climate Prediction Center. There is some hope that an El Niño will develop by hurricane season. Two of the long-range computer models are now calling for an El Niño to develop by hurricane season (Figure 4), and none of them were calling for El Niño last month. However, there is probably not time for a full-fledged El Niño event to develop, and it is expected that we will have weak La Niña or neutral conditions this hurricane season. Since reliable El Niño records began in 1950, there has never been a switch over to El Niño by hurricane season from a La Niña as strong as the one we have now. Columbia University's International Research Institute is predicting that neutral El Niño conditions are most likely for the coming hurricane season (57% chance), with a 20% chance of an El Niño, and 23% chance of a La Niña. This is pretty much what climatology says--on average, we experience El Niño conditions 25% of the time and La Niña conditions 25% of the time.
Figure 4. Computer model forecasts of El Niño/La Niña made in April. The forecasts that go above the red line at +0.5°C denote El Niño conditions; -0.5°C to +0.5°C denote neutral conditions, and below -0.5°C denote La Niña conditions. Image credit: Columbia University's IRI.
References
Trenberth, K. E., J. M. Caron, D. P. Stepaniak, and S. Worley, >Evolution of El Niño, Southern Oscillation and global atmospheric surface temperatures", J. Geophys. Res., 107(D8), 4065, doi:10.1029/2000JD000298, 2002.
I'll be in Orlando next week for the American Meteorological Society's bi-annual hurricane conference, and plan to make some quick posts during the week to update everyone on the latest hurricane research. I may make one more post before then.
Jeff Masters
Reader Comments
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Joe Bastardi's Early 2008 Hurricane Forecast!
AccuWeather.com Hurricane Center meteorologists, led by Chief Long-Range and Hurricane Forecaster Joe Bastardi, have released a preliminary hurricane season forecast for 2008. They believe the waning La Niña conditions and a continued warm water cycle in the Atlantic Basin will be the two defining factors influencing the 2008 hurricane season, causing the number of storms to be slightly above average but, more importantly, increasing the chance for U.S. landfalling storms.
"The warming is not uniform across the entire Atlantic. In some areas where hurricanes normally form - the central and eastern tropical Atlantic - ocean water temperatures are near or below normal. This should limit the number of storms, so we do not expect a near record high number like in the 2005 season. However, considering other factors, the number of storms should be slightly higher than historical averages", said Bastardi. "The warmest waters relative to normal will be in the northern areas of the Atlantic, especially toward the North American continent. This could potentially increase the threat of major landfalls to the U.S. coast."
"In determining areas of elevated potential for landfall, we try to understand where the spread of storm tracks will center - but even within this spread, storms can 'bunch', creating discrete areas of increased risk," Bastardi said. Last season, the spread of the storms shifted southwest with one such bunch in the northern Caribbean. "This year, early indications show that the spread will move north and east with a target closer to the Southeast U.S."
Bastardi and the AccuWeather.com Hurricane Center are looking at 1950, 1996, and 1999 as a few of the years showing similar weather characteristics to our current large-scale patterns. In October of 1950, Hurricane King tracked through the Caribbean making landfall on the Southeast coast of Florida. In 1995, Hurricanes Connie and Diane hit North Carolina. During the 1999 hurricane season, Floyd and Dennis made landfall in September on the North Carolina coast.
Bastardi will provide more details and insight at the AccuWeather.com Hurricane Summit on May 12, 2008 in Houston, TX.
According to the continued positive anomalies west of Africa and this paper we should see a very active season.
Interesting stuff there Sullivan. Thanks
An exceedingly hot, windy, dry day here today. 91 f, 55 % hum , heat index 96 !
Fire weather......
Hey IKE, are you woecasting ? LOL
LOL....getting the itch for the season. Curious as to how it plays out. They usually follow patterns...
This Dryseason has been a peculiar one for us here at 11n 61w. Its been relatively wet, cool, lots of overcast days. No Dust at all yet, for the first time in years. SST around here still anom.low, thanks to the above. But I expect that to change pretty fast in the next couple weeks, although the surface winds are 15 mph still.
Cant venture any predictions at this stage........
If you notice, His reason for stating that the hurricane season will be limited to a certain amount of storms is that SST's are below average, The way SST's have been warming up lately, i wouldnt be surprised to see ABOVE average temps by the season start. Joe bastardi in my opinion doesent know what he is talking about, Last season he said Florida would be the bull's eye of storms. We didnt get anything. I think the current forecast will hold, and yes the U.S. is at higher risk for a landfall.
Action: | Ignore User
Yes, This is exactly why i dont value his opinion at all.
456, I'm just looking at your photo of Frigate Bay beach. Thinking that I should call my nephew there and tell him I am coming to visit for a week or so. Looks good !
Yeah..it is...ur always welcome in SK anytime. Nevis also has some excellent beaches. Nevis is our sister island.
Actually, he has been harassing me for 2 yrs to come. Says its lovely. Enjoy it, and good luck for the coming season.
edit ok
I agree with u....There is evidence that SSTs are warming quickly...In 15 days, the 26 degree isotherm moved 1 degree northward and in some places like the northern caribbean it moved 2-3 degrees. Also the TCHP has increase alot in the Northwest Caribbean around Jamaica and Cuba, the area that favors TC development the most anywhere in the Atlantic basin.
SSTs yesterday
SSTs 15 days previous to yesterday
Mar 25
Great 456. I'll call the nephew, ask him to send a ticket ! Nothing ventured, nothing gained, as they say.
Actually, he has been harassing me for 2 yrs to come. Says its lovely. Enjoy it, and good luck for the coming season.
Good luck to u guys too even tho trinidad isnt really prone to TC they do come too close to comfort.
Still getting the blog page when I click modify.
333. IKE 11:39 AM EDT on April 25, 2008
Not that anyone cares or should...but I just paid my $5 membership to WU! Also...I've made 7653 posts on here...and, I did stay at a Holiday-Inn Express last night.
Yeah, I also did the former, about 4 weeks ago. Almost as good as a Holiday Inn Express . . .
Getting warmer...
In defense of Joe B. Joe is a highly skilled forecaster who is wrong from time to time. Please, let all the forecasters who can claim otherwise throw the first stone. Forecasting can be a pretty humbling experience. I for one value his input just as I value many of the comments and personas on this site
Thankyou.
Its always great to here what other great minds have to say in the tropical weather field.Atleast thats the way i feel.
SSTs are a major factor.
Hey Drak....I don't disagree with you at all; What I am pointing out is that warm SST's during the Summer are usually a "given", and probably one of the most constant benchmarks for storm development every Season/Summer....Given that constant, and from the ground/ocean up so to speak, then we look at persistence, convection, shear, dust, moisture......With dry air, dusty air, and higher shear values, being potential storm killers in spite of favorable SSTs......
Afternoon all.
333. IKE 11:39 AM EDT on April 25, 2008
Not that anyone cares or should...but I just paid my $5 membership to WU! Also...I've made 7653 posts on here...and, I did stay at a Holiday-Inn Express last night.
Yeah, I also did the former, about 4 weeks ago. Almost as good as a Holiday Inn Express . . .
I guess I'm grandfathered in...I think it costs $10 now.....really...what can you do with $5.00 anymore...buy one gallon of gas!
BahaHurican 2:11 PM CDT on April 25, 2008
Afternoon all.
333. IKE 11:39 AM EDT on April 25, 2008
Not that anyone cares or should...but I just paid my $5 membership to WU! Also...I've made 7653 posts on here...and, I did stay at a Holiday-Inn Express last night.
Yeah, I also did the former, about 4 weeks ago. Almost as good as a Holiday Inn Express . . .
I guess I'm grandfathered in...I think it costs $10 now.....really...what can you do with $5.00 anymore...buy one gallon of gas!
LOL. Maybe that will be the case by the end of 2008!
Or sooner, if a cat 3 makes it into the GOM this summer/fall.....
Thats true. And it only takes one.
Or sooner, if a cat 3 makes it into the GOM this summer/fall.....
I don't think anyone wants to know how much prices would get in that case lol
Hey Ike; nice to see you around, hope all is well with you (with the exception of gas prices and the heat)...I've been around the Big Bend from Tallahassee to Bonifay over the past few days (in Marianna Florida right now) and the heat is really kicking....Although, there is some rain coming (as you know) and it's been pretty cloudy and a little drizzly in some parts (it was drizzing in Chipley when I was there an hour ago)..........
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