EL NINO SUMMER?

[Texaspirate11]

From HGX NWS DISCO March 18th:

http://www.srh.noaa.gov/graphicast.php?site=hgx&gc=2


El Niño is a disruption of the ocean-atmosphere system in the Tropical Pacific having important consequences for weather and climate around the globe. During El Niño, the jetstream is oriented from west to east across the southern portion of the United States, making the southern region more susceptible to severe weather outbreaks during the fall, winter and spring seasons. In addition during the summer months and more specifically for hurricane season across the tropical Atlantic, the stronger winds in the upper atmosphere increase the total vertical wind shear which is detrimental to the formation of hurricanes. There tend to be fewer Atlantic hurricanes during El Niño because of this expanded area of high vertical wind shear. During El Niño fewer hurricanes and major hurricanes develop in the deep Tropics from African easterly waves. The chances for the continental U.S. and the Caribbean Islands to experience a hurricane increase substantially during La Niña, and decrease during El Niño. For more information on the El Nino forecast http://www2.ucar.edu/atmosnews/features ... or-la-nada

[BlueJay]

I have been watching (but not necessarily fully understanding) Ptarmigan's ENSO reports on his on-going thread. It would seem that an El Niño summer would be a good thing for us if there is less hurricane activity. (?)

[Texaspirate11]

Blue Jay - generally EL NINO's inhibit cane development as the HGX NWS states.
But I wouldn't let your guard down - Andrew came under one and so did the 1900 storm,
depending how strong the EL NINO is and when it comes into being.

But overall, it may be too "boring" a summer for some

[BlueJay]

I will be continuously watchful! Boring is good for a Texas summer.

[jeff]

Warm ENSO years tend to favor early season development which can be in the Gulf of Mexico. Middle to late season tends to be disrupted by El Nino. Roughly 10% of TX annual rainfall comes from TX landfalls...and since there have been almost no threats to the state since 2011 that is one reason why it has been dry...not the only reason...just one of many.

[BlueJay]

Was Allison, the tropical storm of June 2001, a product of a warm ENSO year?

[srainhoutx]

Since the models some time rush transitions in cycles, 1958 Hurricane Ellen (Cat 2) dropped a maximum rainfall of 13.06 inches at Sholes Field in Galveston. Even a weak El Nino is no guarantee of a quite season.

[Texaspirate11]

Thank you, always interesting on this wx forum!!!!!

[Stormrider]

Hurricane Alicia (1983) was also a storm that formed during an El Nino year. A homebrew system that caught a lot of people off guard due to its rapid development.

[BlueJay]

I lived on the 20th floor of the Houston House in downtown during Alicia in 1983 and listened to crashing glass all night. But we took measures to protect the large glass sliding door and other window so they were fine. Downtown was hit pretty badly.

[Ptarmigan]

Was Allison, the tropical storm of June 2001, a product of a warm ENSO year?

It was Neutral by June 2001. The winter of 2000-2001 was a weak La Nina.

Since the models some time rush transitions in cycles, 1958 Hurricane Ellen (Cat 2) dropped a maximum rainfall of 13.06 inches at Sholes Field in Galveston. Even a weak El Nino is no guarantee of a quite season.

1957 had Hurricane Audrey make landfall on the Texas/Louisiana border and that was an El Nino season. Some active hurricane season occurred in an El Nino season like 1969 and 2004.

Blue Jay - generally EL NINO's inhibit cane development as the HGX NWS states.
But I wouldn't let your guard down - Andrew came under one and so did the 1900 storm,
depending how strong the EL NINO is and when it comes into being.

But overall, it may be too "boring" a summer for some

1900 and 1983 had a dying El Nino.

[Ptarmigan]

Warm ENSO years tend to favor early season development which can be in the Gulf of Mexico. Middle to late season tends to be disrupted by El Nino. Roughly 10% of TX annual rainfall comes from TX landfalls...and since there have been almost no threats to the state since 2011 that is one reason why it has been dry...not the only reason...just one of many.

El Nino Summers can be wide ranging. They can be hot and dry or cool or wet. Some El Nino summers were quite dry, while others are wet.

If El Nino summers are hot and dry, the consolation prize is that Fall and Winter are cooler and wetter.

[BlueJay]

As Mr. Spock would say "Fascinating". (a most respectful nod to wxdata)

I'm afraid all of this information is way over my head, but it sounds like a 2014 El Nino Summer may not indicate what type of weather we will have except that we need to continue to be aware and be prepared the best we can. (Which is always good advice.)

[Andrew]

Summer may be a little quick on the draw. Models have been having issues over the last couple of years on predicting the right ENSO. We are seeing some evidence in the pacific that would support El Nino but it may not be until late summer that conditions arise from it. Hopefully an El Nino situation would help drought conditions across the area, especially next fall. A lot of times we see a relatively active sub tropical jet associated with these conditions. Of course though with any large scale weather system the details are key. Overall though definitely a positive trend.

[Ptarmigan]

Sub-surface is warming rapidly.

[Andrew]

Also good news that the 300m deep water is drifting east pretty quickly. Nice to see anomalies in the .5 to 1 range.

[Portastorm]

Let us not forget that El Nino autumns can produce some amazing amounts of rainfall in Texas not only from regular weather systems but from Eastern Pacific tropical cyclones which landfall in Mexico and quickly roll into the southwestern/south central USA. Here's hoping that Nino verifies.

[wxman57]

Note that the 1983 hurricane season went from El Nino (+0.6C) in May/June/July to La Nina (-0.8C) for August/September/October. Neutral conditions prevailed (-0.2C) when Alicia struck, quickly shifting to La Nina. Betsy of 1965 would be a good example of a big impact in a relatively inactive El Nino season.

http://www.cpc.ncep.noaa.gov/products/a ... ears.shtml

[Ptarmigan]

Note that the 1983 hurricane season went from El Nino (+0.6C) in May/June/July to La Nina (-0.8C) for August/September/October. Neutral conditions prevailed (-0.2C) when Alicia struck, quickly shifting to La Nina. Betsy of 1965 would be a good example of a big impact in a relatively inactive El Nino season.

http://www.cpc.ncep.noaa.gov/products/a ... ears.shtml

The winter of 1983-1984 was a weak La Nina. Yet that winter was quite cold and on top of it, the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) were strong positive. The East Pacific Oscillation (EPO) was strong negative. It shows that EPO has much of an impact on winter than NAO and AO.

As for 1983 Atlantic Hurricane Season being inactive, the ambient pressure was higher, air was drier, and lot of wind shear despite La Nina. I would guess the impact of the El Nino was still there despite it fading. The West Pacific Typhoon Season was not as active in 1983, while East Pacific was very active.

I notice when there is a strong El Nino, it goes into La Nina like in 1973, 1983, and 1998. I wonder why that happens.

[Ptarmigan]

Let us not forget that El Nino autumns can produce some amazing amounts of rainfall in Texas not only from regular weather systems but from Eastern Pacific tropical cyclones which landfall in Mexico and quickly roll into the southwestern/south central USA. Here's hoping that Nino verifies.

Some of the biggest fall floods happen in El Nino like 1994 and 2002. There have also been big rain events in El Nino winters like 1982 and 1991.