I received an email recently asking: When the El Nino pattern ends how long before we experience the reverse pattern, La Nino in addition does this mean a return to normal rain and temperatures?
I want to first explain briefly what the two weather patterns are, keep in mind this definition is very brief and I am not an expert on the subject. But do find it interesting and it reminds me of how fragile the line between sustainable weather and destructive weather can be. El Nino is a large body of warmer than normal water in the Eastern Pacific. This area is about 1 1/2 times the size of the United States. Yes, much larger than what is generally understood. It begins when every three to five years the Tropical Trade winds abate and warm water normally found near Australia spreads outward along the equator in the Pacific. Sometimes when the El Nino is strong the warm water reaches as far as Ecuador and Peru.
On the other side La Nina, which is typically stronger during our Winter season, is also much less understood. I always found it easier to have a basic undertanding for El Nino & La Nina, is that having any other weather pattern than normal will bring extremes to what is normal weather for that area.
El Nino increases rain producing clouds for most but also increase the Tropical Trade Winds along the Atlantic Ocean suppressing the formation of Hurricanes.
La Nina weather pattern typically last one to two years. you might remember the 1988 Mid-West Drought. Also the lighter winds are more favorable for Hurricane formation in the Atlantic. 1992 researchers says that a strong El Nino was present. That year in August Hurricane Andrew made landfall first in South Florida then here in Acadiana. Andrew….an A storm in August yes, fewer storms but it only takes one to make the season devastating. Interesting to know also that Hurricane Andrew before making landfall in South Florida almost weakened to just rain. As it moved a little north and out of the hostile winds it strengthened to the record Category 5 storm.
What generally follows El Nino is the return to normal water temperatures and weather pattern. Not always going from La Nina to El Nino. Yes, we do have normal weather patterns. The research is getting much better now so telling one pattern from the other is closer than ever. In the past 20 years the have been just three La Nina’s and seven El Nino weather patterns.
During an El Nino the energy from the warmer water is pressed high in the atmosphere and directed with pressure eastward where it settles over the Tropical Atlantic and the release of energy tends to choke the formation of Tropical Storms which are very weak in the beginning stage.
The Earth is always trying to balance and for that we get the movement of storms and transfers of energy.
Only changes to the on-going forecast are that the computer models are trending a little slower on the arrival of rain and storms Friday. A vigorous frontal trough will approach by midday Friday with showers and storms likely anytime from the morning through the early afternoon hours with a shield of rain likely behind the front Friday afternoon into the early evening hours. Rain total projections remain in the 1-2″ range for most of Acadiana Friday. As Dave mentioned earlier, it appears that any severe weather threat will be confined to Texas but there could be some healthy storms running ahead of the cold front in Acadiana but instability remains questionable while upper level winds remain healthy but should be weakening as the system moves over Louisiana. Although our highs on Friday will likely be in the mid-upper 60s temperatures will likely drop sharply by late Friday afternoon into Friday evening with lows Saturday morning dipping into the upper 30s with wind chills likely 10 degrees colder. Winter-time temperatures are likely this weekend with highs not making it out of the 40s Saturday and barely reaching the lower 50s Sunday while lows Sunday and Monday mornings will likely be near the freezing mark. Milder temperatures will return for next week but an active El Nino enhanced sub-tropical jet-stream will likely make for plenty of cloud cover and occasional rain chances starting late Monday and continuing for much of the week.
After another nice day Wednesday Acadiana will see more clouds and breezy conditions for Thursday with showers and storms likely by Friday morning. High pressure edging to the east mid-week will allow for a mild return flow from the Gulf. This should allow for milder temperatures Wednesday night with the chance of some fog formation by Thursday morning. A storm system building over Texas Thursday will make for breezy and rather warm conditions for Acadiana. Highs Thursday should top out in the mid-70s. It appears that our rain chances will stay slight at best Thursday, but rain and storms will be building eastward into Acadiana by Friday morning. This storm system should be a national headline-maker with hefty snow and ice on the northern flank and the threat of severe weather farther south across the Texas Hill Country. Any severe weather dynamics with this storm system should weaken as the area of surface low pressure moves into the Bayou State Friday…but we’ll keep an eye on things just in case. The storms could be on the hefty side. As a result I would expect rain totals to be in the one to two range for most of the area. Following Friday’s wet weather a shot of winter-like temperatures will return Friday night through the weekend. Temperatures should drop sharply Friday afternoon/evening with highs suppressed to near 50 Saturday and Sunday under mostly sunny skies. Overnight lows may drop into the lower 30s with a light freeze/frost likely for Sunday morning. Next week looks rather unsettled with an active sub-tropical jet overhead keeping plenty of clouds and occasional rain in the forecast Monday through at least Wednesday.
Our seasonably pleasant weather will continue through Tuesday and part of Wednesday but a storm system promises wet weather forAcadiana later this week and a chill for the weekend. High pressure will slide just to our east Tuesday allowing for sunny and mild conditions. A light return flow from the Gulf will initiate Tuesday evening allowing for the possibility of some patchy fog by Wednesday morning. Mostly cloudy skies will develop for Wednesday ahead of a vigorous/progressive storm system. Our temperatures will likely rise into the upper 60s Wednesday and should be in the low-mid 70s with breezy conditions under mostly cloudy skies for Thursday. Showers and storms will develop late Thursday and should arrive here Thursday night with lingering cold rain persisting through the first part of Friday. Rain totals will be in the neighborhood of about an inch to possibly two. Temperatures will drop from the 70s Thursday into the lower 50s Friday. A dry winter chill will return to Acadiana this weekend with highs confined to the low-mid 50s while lows drop into the 30s. A light freeze/frosty conditions will be quite possible by Sunday morning.
Our gorgeous spring-like weather will continue for our Friday with lots of sunshine. Highs will likely be in the low-mid 70s so it will be a little cooler as compared to the upper 70s we saw Thursday. The next weather-maker will approach Acadiana Saturday allowing for the possibility of fog to develop Friday night with southerly winds ushering in Gulf moisture and higher dew points. Like Wednesday’s weather system there will be a fairly good chance of scattered showers and a few embedded thunderstorms. There may be a slight severe weather risk but per today’s models phasing of any severe weather parameters should occur well to our north, but once again upper level wind profiles may be condusive for and isolated severe storm or two so we’ll keep on eye on it just in 
case. Highs Saturday should stay in the balmy low-mid 70s. Skies should become partly to mostly sunny Sunday with cooler highs topping out in the mid-60s. A secondary surge of chilly air should move in for early next week bringing our highs down into the mid-upper 50s while lows dip into the mid-30s. Skies should stay mostly sunny Monday through Wednesday of next week with showers and storms returning for Thursday and perhaps colder over-running rains for Friday. The storm system late next week could bring freezing (or near freezing) night-time temperatures back to the area for next weekend.
An interesting weather pattern continues to evolve Wednesday for Acadiana as a vigorous upper level disturbance should ignite storms here Wednesday afternoon into the evening hours. The 
This week will be characterized by milder, spring-like conditions with stormy weather for Wednesday and then possibly again late Saturday. In the near term, dense sea fog may form later this evening across the coastal areas and will migrate northward through morning. Dense fog advisories may be issued for portions of Acadiana later tonight. After a foggy start tomorrow Acadiana will see mostly cloudy and mild conditions. Highs will be dictated by the amount and thickness of the cloud cover and by a few possible intervals of sun; upper 60s to near 70 would be a good call at this point. There may be a few embedded isolated sprinkles in the cloud cover tomorrow but the real action will start Wednesday. A rather potent upper level 
disturbance will initiate a warm frontal boundary/trough across the area Wednesday which will likely produce thunderstorms across the Acadiana. Upper level wind profiles, instability and orientation of the sub-tropical jet stream will favor a significant risk of severe weather, but lower level instability and a surface focal points may be lacking. The 
The Earths plates are in motion always and the balance is attempted with sudden movement of that plate occurs. We know this as an Earthquake. So the main quake occurs and the movement afterwards is the plates readjusting to the new postion. The earthquake that struck in Hatti occured along the Noth American Plate and Carribbean Plate, which recently has seen an increase in activity. After Shocks occur imediatly after the main shock and can continue for several week later. 