Temperatures needed to produce Tucson's thunderstorms are somewhat lower. In general, for Phoenix, the temperature limits for the production of monsoon thunderstorms are 100° to 108☏ with the optimum temperature being about 105☏. It originally was linked to the total amount of water in the atmosphere above the weather station (a precipitable water amount of 1", a quantity thought to be necessary for convective thunderstorm activity). The operational criterion for the onset of "monsoon" conditions used in Arizona is " prolonged (3 consecutive days or more) period of dew points averaging 55☏" or higher." There is nothing magical, however, about 55☏. In addition, strong moisture influx into Arizona is also required. By that, we mean that the thunderstorms are powered by intense surface heating. Monsoon thunderstorms are convective in nature. Consequently, the proper terminology is "monsoon thunderstorms" not "monsoons." The word should be used in the same manner that "summer" is used. Researchers have proposed the Gulf of Mexico and/or the Gulf of California as the source regions but conclusive evidence has so far been elusive.īy the way, the term "monsoons" as in "when the monsoons arrive. The exact source region for the moisture of the Arizona monsoon is unknown. The southerly winds push moisture north-ward from Mexico. These two features combine to create strong southerly flow over Arizona. In addition, the intense heating of the desert creates rising air and surface low pressure (called a thermal low) in the Mohave (L).The movement northward from winter to summer of the huge upper air subtropical high pressure cells, specifically the so-called Bermuda High (H).This wind shift is the result of two meteorological changes: Such a change, together with daytime heating, is the key to the Arizona monsoon. This shift produces a radical change in moisture conditions statewide. Moisture streams northward from the Pacific Ocean and the Gulf of Mexico. As we move into the summer, the winds shift to a southerly or southeasterly direction. During the winter time, the primary wind flow in Arizona is from the west or northwest-from California and Nevada. The Arizona Monsoon is a well-defined meteorological event (technically called a meteorological 'singularity') that occurs during the summer throughout the southwest portion of North America. ![]() This causes air to swirl in from the west, the south and the east-all oceans! The result? HEAVY RAIN! For the summer, the desert of western India heats up and low pressure forms. Again, for India, during the winter dry period, the airflow comes from high pressure to the north-the dry Himalayas and Siberia. In fact, the name "monsoon" is derived from the Arabic word " mausim" which means "season" or "wind-shift". But more fundamentally a 'Monsoon' is linked more to a wind shift rather than precipitation. Actually one of the reasons that India has its more famous monsoon is largely due to the huge Rajasthan Desert in western India.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |