why is nature playing April Fools?

Today in class we saw how the 3 dominant conditions impact our weather. these three conditions form our weather and bring us different weather storms at different times in the seasons. the first condition is moderate La Nina conditions which is a coupled ocean-atmosphere phenomenon similar to El Nino.During a period of La Niña, the sea surface temperature across the equatorial Eastern Central Pacific Ocean will be lower than normal by 0.5 °C. In the United States, an episode of La Niña is defined as a period of at least 5 months.
The second condition is the strong polar circulation. which is the large-scale movement of air, and put together with the smaller ocean circulation, the means by which heat is distributed on the surface of earth.
the third and final one is the divided north American jet stream. these is the maps that show us where the weather is going to hit the hardest.
when you get these weather conditions they change your climate. When we see these types of conditions they effect how our plant and food preservation. We are seeing right now that out fruit and vegetable life's are hit hard in the summer down south because there isn't enough weather and moisture there for them to grow. this is related to drought because here isn't enough water there to soften the land so they can grow food for them selfs. if the ground is hard and has no water source how d you expect them to grow food, have plants, or trees for shade or anything else at that matter?

(1) http://en.wikipedia.org/wiki/La_Ni%C3%B1a
(2) http://en.wikipedia.org/wiki/Atmospheric_circulation