10°N
20°N
30°N
EQUATOR 0°
HIMALAYA
W. GHATS
ARAVALLI
ARAKAN YOMA
TROPICAL EASTERLY JET (≈150 hPa, easterly)
SUBTROPICAL WESTERLY JET (withdraws N in summer)
SOMALI JET
SE TRADES → cross equator
ARABIAN SEA BRANCH
deflected N along Ghats
Narmada–Tapi gap
parallel to Aravalli — no lift → Thar dry
BAY OF BENGAL BRANCH
trapped by Khasi funnel
up the Ganga valley — rain ↓ westward
branches merge over NW plains
RETREAT from NW (mid-Sep)
withdrawal sweeps SE by Oct
NE MONSOON — offshore, dry
re-charged over Bay → Coromandel rain
L
MONSOON
TROUGH
H
MASCARENE
HIGH ↓SE
H
HIGH re-builds
L
BoB lows /
cyclones
Mawsynram
~11,870 mm
Mahabaleshwar
~625 cm
Pune
~70 cm
Chennai
NE-monsoon fed
Jaisalmer
~16 cm
Kolkata
~160 cm
Delhi
~80 cm
ITCZ & Monsoon Trough
Mascarene High
Somali / Findlater Jet
Arabian Sea Branch
Western Ghats — Orographic Rain & Rain-Shadow
Bay of Bengal Branch
Khasi Hills — Mawsynram Funnel
Thar & the Aravalli Parallelism
Tibetan Plateau & Tibetan High
Tropical Easterly Jet (TEJ)
Subtropical Westerly Jet & Onset Trigger
Break in the Monsoon
NE / Retreating Monsoon — Coromandel
ENSO & Indian Ocean Dipole
3D Conceptual Masterclass · Survey of India layout
Indian
Monsoon
System
Mains Analytical · process & vectors
Packaging…
PRELIMS CORE
MAINS ANALYTICAL
Season
0.99×
Schematic key
Arabian vector
Bay vector
Somali / cross-equatorial
Withdrawal vector
NE monsoon vector
Tropical Easterly Jet
Subtropical Westerly Jet
L / H pressure cells
Vertical cross-section
· how to draw it
S ◂ Equator
Himalaya ▸ N
↑ altitude (hPa)
Indian Ocean
Peninsula
Tibet
H
Mascarene
moist SW surface current
deep convection (ITCZ / trough)
H
Tibetan High (aloft)
Tropical Easterly Jet ≈150 hPa
STWJ jumps N
subsidence
150
500
1000
Withdrawal
Sep – Oct
Retreat from NW · October heat · clear skies
Trough collapses; high pressure re-builds over the north.
01 · Mar – May
Pre-Monsoon
02 · ~1 June
Onset / Burst
03 · Jul – Aug
Established
04 · Sep – Oct
Withdrawal
05 · Oct – Dec
NE / Retreating
Tweaks
✕
Theme
Indigo Night
Monsoon Teal
Chalkboard
Ink on Paper
Context HUD layout
Bottom sheet
Compact
Side dock
Map labels
Station names & rainfall