Monsoon likely by June 6th to the Kerala coasts and Pre-Monsoonal activity over interior peninsula to Increase Further
Generally Monsoon reaches the Coasts of Kerala by June-1st. Every year IMD issues a model error of (+) or (-) 4 days. All conditions became favourable during first half of May month. But the Cyclone Roanu sucked up the evolving favourable conditions and finally moved North-east wards and crossed the coast of Bangladesh.
The much awaited pre-monsoon showers failed to materialize well over South Peninsular India due to Roanu. The roanu sucked up the moisture from The South india....Thus making some 5-6 dry days starting from 20th May. But some influence of Arctic Oscillation has made some Thunderstorms...which are associated with good CAPE and possess Flanking Nature...
EQUITORIAL ROSSIBY INFLUENCE AND KELVIN WAVE IMPACT ON THUNDERSTORM BUILD UP-
ROSSIBY WAVE-
KELVIN-PLOT:
INFERENCE-
The Kelvin and rossiby waves are the planetary waves which give good amounts of energy to the cyclone genisis and the building up of Thunderstorms...Here, we have used this one to estimate the rain rate in mm over some period of time...Until the monsoon onset, Some wave action will fetch some good quantum of rain to interior peninsular india with a spilled spell of rain to Coastal india....( Note that it Will be active under the presence of good amounts of Heat).
FORECAST ON ONSET AND DEVELOPMENT OF SOUTH-WEST MONSOONAL WINDS (ANIMATED)-
Observe the GIF once or Twice, we can get an idea how the Monsoon winds strengthen near Kerala coast on 7th June,2016...Once the flow strengthens, the rain starts to penetrate near the Western ghats and cause good amounts of rainfall to the west coast.... The first spell of Monsoon rain to the interiors will be around June 9th or 10th. So interiors should wait.
Madden Julian Oscillation Forecast and its impact on Monsoon onset-
Madden Julian Oscillation (MJO) is related to the good amounts of energy suppliers across the Indian Ocean, Maritime Continent and Parts of Western Pacific Ocean. They are the most necessary thing for Increased quantum of rain or Suppressed amount of rain.
The above Chart shows the Re-appearance of MJO in indian ocean....Favourable Monsoon Progress starts from June 7th and Touch Kerala coast on June 7th....I also assure that it will cover almost upto central Maharastra by June 12th Itself....Such a favourable conditions arising.
MJO ASSOCIATED RAINFALL ANOMALIES OVER THE COUNTRY-
Some Meteorological Organizations like GFS, ECMWF, Ensemble members, UKMET etc conducted several experimental runs and have acquired the following details-
If we go through the Above map, We can get information about the rainfall probabilities corresponding to the MJO phase brewing over the Oceans. The magnitude of Rains depends on the strength possessed by the MJO in terms of amplitude.
WHAT ABOUT THE ENSO???
ENSO- Elnino Southern Oscillation, a key aspect of Monsoon and is daily monitored by BOM( Bureau of Meteorology), Australia. They take the the current values of ENSO and compare with the previous threshold..Finally they submit their thesis and analysis to forecasting centers of GFS, ECMWF....They will again analyze and estimate the further conclusions and give up their forecasts and display them at NOAA site....I can managed to take certain key things from them related to Monsoon.
The above graph tell us that the Elino is almost to dead and the Neutral conditions exists. This will further reach to a greater threshold of Lanina by July-end. The Monsoon flow amplitude is Directly proportional to the ENSO potential added that favourable conditions persist in the Indian ocean.
Climatological probable forecasts from NOAA shows a good bountiful Monsoonal rain with Normal and Above Normal rain at many parts of India....South Peninsula to get Above Normal rainfall.
JUNE-AUGUST FORECAST-
SEPTEMBER-OCTOBER FORECAST-
NOTE- These are taken with respect to initial conditions in the past...This may change time to time....Still then we can conclude a good rain to india with the transition of good amounts of tropical Monsoonal depressions so called "insitu" systems in Bay of Bengal during peak Monsoonal Months.
GFS EXPERIMENTAL RUN-
MONSOON "INSITU" SYSTEMS GENERAL CRITERIA AND ORIGINATION ??-
Monsoon systems originate due to the flow of tropical easterly jet and cross Equatorial current to the South China sea... This will create a pulse and then develop suitable conditions to make it move close to East coast of india. Generally they take place close to Mid-Central Bay of Bengal and move North. They play an important role in giving heavy rainfall during the active monsoonal phase. During break period, the Tibetian High collapses and the Monsoonal flow is affected and moves straight South-West to the foot hills of Himalyas. Western ghats Stop getting rainfall and Interior Peninsula gets some Thunderstorms.
SEA SURFACE TEMPERATURES (LATEST)-
ENSEMBLE LAND RAINFALL SPREAD INDEX-
INFERENCE-
This index tells the Thunderstorm sustains will be good over Land and likely to peak near August and september...We can expect some flood like conditions in the interiors if India....when a active moisture supply by monsoon is expected..
BY
B.SAI PRANEETH
(WOS-TIRUPATI)
