Past IEM Features tagged: elnino
La Niña Fall
22 Nov 2022 05:30 AMThe persistent La Niña continues to create weather troubles over much of the US with the ongoing drought being difficult to break. With just a few days left in the fall season of September, October, and November, it is a good time to check in on the relationship between the El Niño index and fall season average temperatures and precipitation. Since the impact of El Niño is not instantaneous, the plot compares the August value with the subsequent fall season totals for Iowa. The relationship is not necessarily direct nor strong during the fall season, but general trend is for La Niña falls to be drier and a bit warmer than average.
Voting:
Good: 8
Bad: 0
Tags: elnino
Fall Season and El Nino
30 Nov 2020 05:36 AMWith today being the last day of a fall season encompassing the months of September, October, and November, it is a good time to look at summary stats in comparison to the El Nino 3.4 Index as shown by the featured chart. The left panel presents the yearly combination of average temperature and precipitation for Iowa with the color of the dots representing the August El Nino 3.4 Index value. The two right panels present the direct comparison between the index and the Iowa value. The 2020 value for Iowa comes in close to average for both temperature and precipitation. The La Nina condition this fall is still developing and stronger influences for our weather may be more likely toward later in the cold season.
Voting:
Good: 11
Bad: 0
Tags: elnino
Developing La Nina
30 Oct 2020 05:35 AMThe featured chart presents the combination of monthly average temperature departures for Des Moines along with the El Nino 3.4 index value. The La Nina (negative El Nino index) condition continues to strength with some further strengthening expected this winter season before a transition next year to possible El Nino. So what does this index over the equatorial Pacific Ocean have to do with Iowa's weather? Well sometimes a lot and other times not so much! The index covers a very important region of the planet that drives large scale transport of heat, moisture, and energy. The strength of the influence of this index on our weather depends on the time of year and many other things. The chart shows a clear influence from the "Godzilla El Nino" back in 2015 leading to many months of warmer than average temperatures, but other periods the influence is more nuanced. La Nina's impact for Iowa during winter months is not too strong, but favors wetter and cooler conditions than average. With October coming in cooler than average, we shall see what the rest of the cool season months have in store.
Voting:
Good: 13
Bad: 0
Tags: elnino
El Nino and Winter Weather
26 Oct 2017 05:32 AMNOAA recently released their winter season forecast. For Iowa, the forecast called for about average temperatures and slightly above normal precipitation. One of the many tools used to make this forecast is the current and forecasted El Nino index. The La Nina conditions have taken a bit longer than expected to develop and the index currently still has a ways to go before getting to La Nina state. Anyway, the featured plot combines the El Nino index along with three month averaged temperatures and precipitation. The two right hand side plots provide the direct comparison and a simple linear fit. Of course, there is no magic bullet here with strong correlations to predict the upcoming winter season. The weather forecast though is more definite over the near term with chances of snow arriving for the weekend!
Voting:
Good: 6
Bad: 2
Tags: elnino
Godzilla El Nino
19 Oct 2015 05:36 AMMuch is currently being made about the very strong El Nino, which some have labelled as a "Godzilla El Nino". The concern is the impact of this on our upcoming winter season. The relationship between Iowa's weather and the El Nino is not simple as it takes time for its effects to be felt, if at all. The featured chart displays a monthly time series of El Nino 3.4 index and average Iowa monthly temperature departures. The current El Nino is the strongest since 1997.
Voting:
Good: 22
Bad: 14
Abstain: 5
Tags: elnino
El Niño Impact?
25 Aug 2015 05:22 AMThe strengthening El Niño over the Pacific Ocean is currently generating many headlines as the current forecasts have the strength reaching levels not seen before since records began in 1950. In fact, one forecaster referred to this situation as a "Godzilla El Niño." The featured chart looks at the combination of August Southern Oscillation Index (SOI) and September plus October average temperature and total precipitation for Iowa. The color of the dots represent the SOI index. The relationship shown is not clear cut. You can generate this chart online and compare the SOI value from some number of trailing months to a summary number of months of your choice.
Voting:
Good: 23
Bad: 7
Abstain: 1
Tags: elnino
Recent Monthly Departures
02 Oct 2013 05:45 AMThe featured chart displays the combination of recent monthly precipitation departures for Ames along with the monthly El Nino 3.4 index value. Many scientists believe that the El Nino index, which determines if we are in La Nina or El Nino condition, is correlated with longer timescale temperature and precipitation in the United States and elsewhere. The chart nicely shows the drought periods of the past two years and the wet periods of 2008 and 2010. This October looks to turn wet for the rest of the week with showers arriving late this evening.
Voting:
Good: 77
Bad: 9
Tags: elnino