Bulletin du jour

# ENSO daily bulletin - 2026-11-04 11:39 UTC

Latest observation: 2026-11-02
  Nino 3.4   +3.36 C   (daily)
  Nino 3     +4.49 C
  Nino 4     +1.51 C
  Nino 1+2   +5.80 C
  Nino 3 - Nino 4  +2.98 C (east-Pacific leaning)
  90-day running mean  +2.99 C (ONI proxy -> very strong El Nino)

  change over 1 week: -0.13 C
  change over 1 month: +0.07 C

Indian Ocean Dipole (DMI, 2026-11-02):
  DMI  +0.74 K -> positive IOD   30-day mean +0.74 K
  west box +1.08 K, east box +0.34 K
  a daily proxy for a monthly published index; quote BoM or NOAA

Subsurface (recharge state):
  mean 20 C isotherm depth    144.4 m   (west 144.9, east 143.8)
  warm water volume           27.62 x1e14 m3  (anom +1.55, short baseline)
  thermocline contrast          1.1 m (west - east; climatology 80-100 m)
     vs record mean           -11.6 m (short baseline)
  volume tilt (west - east)   +1.11 x1e14 m3  (+1.73 of it is box-width geometry, leaving -0.62)

Atlantic genesis windows (ERA5 2026-10-27, 7-day means, about 6 days behind today):
  box             VI      7d   shear     SST   state
  ATL_CARIB    0.098  -0.076    16.4   29.5C   closed (falling)
  ATL_GOM      0.232  +0.122    25.3   27.9C   closed (rising)
  ATL_MDR      0.156  -0.007    22.8   28.9C   closed (falling)
  ENP          0.141  +0.062    16.8   28.9C   closed (rising)
  WNP          0.119  +0.015    13.8   29.1C   closed (rising)
  thresholds and measured skill (IBTrACS 1991-2020, in-sample):
    ATL_CARIB  opens below 0.0750  POD 0.57  FAR 0.67  open 29% of season  genesis 1.96x more likely inside
    ATL_GOM    opens below 0.0600  POD 0.56  FAR 0.53  open 29% of season  genesis 1.94x more likely inside
    ATL_MDR    opens below 0.0925  POD 0.64  FAR 0.38  open 29% of season  genesis 2.21x more likely inside
    ENP        opens below 0.0650  POD 0.47  FAR 0.09  open 29% of season  genesis 1.60x more likely inside
    WNP        opens below 0.0525  POD 0.37  FAR 0.35  open 30% of season  genesis 1.25x more likely inside -- LOW SKILL
      WNP caveat: lift 1.25: the open window carries only a quarter more genesis risk than the west Pacific season as a whole
  shear anomaly baseline: 1991-2020 (20+ years/day)

Relative index, daily proxy (ERA of RONI, 2026-11-02):
  Nino 3.4  +3.36 C  minus tropical mean +1.90 C  = +1.46 C
  scaled to RONI: +2.04 C   90-day mean +2.13 C
  scale 1.395 +/- 0.056 fitted on 14 months -- PROVISIONAL; the quotable RONI is NOAA's, above

NOAA CPC official indices (monthly, 3-month means):
  RONI  +1.97 -> strong El Nino   (ASO 2026) ** the official index since Feb 2026 **
  ONI   +2.46 -> very strong El Nino   (ASO 2026)   traditional
  the +0.49 difference is background tropical warming, which RONI removes

Rainfall seasons (accumulation against the same days of 1991-2020):
  WMO_OND_HOTSPOT   October–December     day 33/92    88.1 mm vs   61.3 normal = 143.6%
  GREATER_HORN      October–December     day 33/92    42.3 mm vs   48.5 normal =  87.1%
  HORN_AFRICA       October–December     day 33/92    70.4 mm vs   57.9 normal = 121.6%
  EAST_AFRICA_EQ    October–December     day 33/92    78.3 mm vs   82.5 normal =  94.9%
  SHABELLE_UPSTREAM October–December     day 33/92    59.9 mm vs   56.1 normal = 106.8%
  JUBBA_UPSTREAM    October–December     day 33/92   115.5 mm vs   86.0 normal = 134.3%
  SOUTHERN_AFRICA   November–March       day 2/151     1.6 mm vs    2.7 normal =  57.6%

Soil moisture (C3S/ESA CCI COMBINED, 0.25 deg, 2026-09-20, 45 days behind):
  AFRICA     0.168 m3/m3     109% of the reference
  SAMERICA   0.227 m3/m3     103% of the reference
  baseline: mean of the accumulated record, +/-15 days around day 263, 16 days from year 2026 -- a short, moving baseline, not a 1991-2020 climatology

River stage, Amazon (DAHITI altimetry, vs each station's own seasonal cycle):
  AMAZON_OBIDOS          -1.14 m below seasonal (-1.4 sd) — lower than this 10% of the time in its own record; record low -1.80 m (2023-07-21)   [2026-09-24, 41d old, 90 obs]
  PURUS_LABREA           -0.83 m below seasonal (-0.5 sd) — lower than this 33% of the time in its own record; record low -4.05 m (2023-11-28)   [2026-10-23, 12d old, 166 obs]
  SOLIMOES_TABATINGA     -0.72 m below seasonal (-0.4 sd) — lower than this 32% of the time in its own record; record low -4.28 m (2024-10-29)   [2026-10-25, 10d old, 218 obs]
  TAPAJOS_SANTAREM       -0.43 m below seasonal (-0.9 sd) — lower than this 10% of the time in its own record; record low -1.25 m (2024-06-30)   [2026-09-18, 47d old, 100 obs]
  MADEIRA_PVELHO         -0.20 m below seasonal (-0.1 sd) — lower than this 41% of the time in its own record; record low -3.84 m (2024-01-19)   [2026-10-16, 19d old, 230 obs]
  NEGRO_MANAUS           +0.89 m above seasonal (+0.4 sd) — lower than this 76% of the time in its own record; record low -5.04 m (2024-09-30)   [2026-10-21, 14d old, 104 obs]
  a departure inside about one standard deviation is ordinary: these stations sit there most of the time. An event is a value well outside that AND sustained across successive revisits, which are 2-4 weeks apart.
  El Nino's Amazon signature, integrated over the catchment and lagged by the routing time

River stage, Horn (DAHITI altimetry, vs each station's own seasonal cycle):
  SHABELLE_BULOBURTE     -2.21 m below seasonal (-1.2 sd) — lower than this 6% of the time in its own record; record low -3.73 m (2025-11-30)   [2026-09-13, 52d old, 90 obs]
  SHABELLE_BELETWEYNE    -1.88 m below seasonal (-1.2 sd) — lower than this 7% of the time in its own record; record low -2.59 m (2025-11-30)   [2026-10-04, 31d old, 91 obs]
  SHABELLE_JOWHAR        -1.84 m below seasonal (-1.4 sd) — lower than this 4% of the time in its own record; record low -3.20 m (2025-11-25)   [2026-09-13, 52d old, 52 obs]
  JUBBA_BAARDHEERE       -1.29 m below seasonal (-1.3 sd) — lower than this 7% of the time in its own record; record low -2.58 m (2019-04-21)   [2026-10-08, 27d old, 135 obs]
  JUBBA_DOOLOW           -0.92 m below seasonal (-1.1 sd) — lower than this 5% of the time in its own record; record low -1.94 m (2022-04-15)   [2026-09-21, 44d old, 96 obs]
  a departure inside about one standard deviation is ordinary: these stations sit there most of the time. An event is a value well outside that AND sustained across successive revisits, which are 2-4 weeks apart.
  context for the Deyr season, NOT a flood trigger: satellite altimetry revisits these reaches every 7-17 days, while a riverine flood warning needs hours. The operational trigger is FAO-SWALIM's FRRIMS in-situ gauge network at these same towns

  levels are elevations above the EGM2008 geoid: comparable with each station's own history, not between stations
  @AMAZON_OBIDOS -1.9296 -55.5142 AMAZON Amazon Obidos mainstem
  @JUBBA_BAARDHEERE 2.0604 42.2429 HORN Jubba Baardheere tributary
  @JUBBA_DOOLOW 4.1287 42.2352 HORN Jubba Doolow tributary
  @MADEIRA_PVELHO -8.6328 -63.8418 AMAZON Madeira Porto Velho tributary
  @NEGRO_MANAUS -3.3040 -60.0674 AMAZON Negro Manaus mainstem
  @PURUS_LABREA -7.1471 -64.6423 AMAZON Purus Labrea tributary
  @SHABELLE_BELETWEYNE 4.7113 45.2127 HORN Shabelle Belet Weyne tributary
  @SHABELLE_BULOBURTE 3.9470 45.5294 HORN Shabelle Bulo Burte tributary
  @SHABELLE_JOWHAR 3.0215 45.5064 HORN Shabelle Jowhar tributary
  @SOLIMOES_TABATINGA -4.3772 -69.7923 AMAZON Solimoes Tabatinga mainstem
  @TAPAJOS_SANTAREM -2.1417 -54.5321 AMAZON Tapajos Santarem mainstem

Agricultural stress (FAO ASIS, 1 km dekadal, ASIS.VHI-D.2026-10-D3):
  SHABELLE_UPSTREAM VHI 0.37  mild stress         (expects wet, 95% of the box carries data)
  JUBBA_UPSTREAM    VHI 0.41  no drought stress   (expects wet, 98% of the box carries data)
  NE_BRAZIL         VHI 0.45  no drought stress   (expects dry, 57% of the box carries data)
  EAST_AFRICA_EQ    VHI 0.47  no drought stress   (expects wet, 56% of the box carries data)
  HORN_AFRICA       VHI 0.48  no drought stress   (expects wet, 52% of the box carries data)
  PERU_COAST        VHI 0.49  no drought stress   (expects wet, 43% of the box carries data)
  WMO_OND_HOTSPOT   VHI 0.52  no drought stress   (expects wet, 57% of the box carries data)
  GREATER_HORN      VHI 0.52  no drought stress   (expects wet, 62% of the box carries data)
  ALTIPLANO         VHI 0.55  no drought stress   (expects dry, 73% of the box carries data)
  SOUTHERN_AFRICA   VHI 0.65  no drought stress   (expects dry, 77% of the box carries data)
  VHI is FAO's composite of vegetation and temperature condition, normalised at each pixel against 1984-present

Vegetation health against its own record (FAO ASIS province means, same dekad every year):
  MARITIME_SE_ASIA  VHI 0.42  rank 5 of 43 from the driest  |  -0.05 vs the median of 11 past El Nino years
  DRY_CORRIDOR      VHI 0.47  rank 5 of 43 from the driest  |  -0.02 vs the median of 11 past El Nino years
  NE_BRAZIL         VHI 0.37  rank 6 of 43 from the driest  |  -0.05 vs the median of 11 past El Nino years
  MEKONG            VHI 0.45  rank 9 of 43 from the driest  |  -0.01 vs the median of 11 past El Nino years
  ALTIPLANO         VHI 0.48  rank 20 of 43 from the driest  |  +0.01 vs the median of 11 past El Nino years
  CARIBBEAN         VHI 0.55  rank 21 of 43 from the driest  |  +0.05 vs the median of 11 past El Nino years
  EAST_AFRICA_EQ    VHI 0.52  rank 25 of 43 from the driest  |  +0.05 vs the median of 11 past El Nino years
  PERU_COAST        VHI 0.48  rank 28 of 43 from the driest  |  +0.05 vs the median of 11 past El Nino years
  SAHEL_EAST        VHI 0.55  rank 28 of 43 from the driest  |  +0.04 vs the median of 11 past El Nino years
  HORN_AFRICA       VHI 0.54  rank 31 of 43 from the driest  |  +0.10 vs the median of 11 past El Nino years
  SAHEL_WEST        VHI 0.58  rank 33 of 43 from the driest  |  +0.05 vs the median of 11 past El Nino years
  WMO_OND_HOTSPOT   VHI 0.55  rank 37 of 43 from the driest  |  +0.09 vs the median of 11 past El Nino years
  SOUTH_ASIA        VHI 0.62  rank 37 of 43 from the driest  |  +0.12 vs the median of 11 past El Nino years
  SOUTHERN_AFRICA_COUNTRIES VHI 0.60  rank 43 of 43 from the driest  |  +0.11 vs the median of 11 past El Nino years
  a rank, not a percentile: ~43 samples support one and not the other
  the El Nino comparison is FAO's own method: what previous cycles did over the same ground, not all years together

Tropical cyclones: none active (NHC)

Tropical cyclones worldwide (4 in the IBTrACS active file, every basin):
  In-Fa        WP  peak 128 kt  23.1N  139.3E  2026-10-23 to 2026-11-03 (85 fixes)
  Arnab        NI  peak 119 kt  20.1N   82.1E  2026-10-26 to 2026-10-29 (27 fixes)
  Vance        EP  peak 100 kt  22.6N  107.8W  2026-10-18 to 2026-10-30 (91 fixes)
  Murasu       NI  peak  84 kt  15.5N   80.3E  2026-11-01 to 2026-11-03 (17 fixes)
  peak is the highest one-minute wind recorded so far, not the current one; the track carries the whole history
  tracks current to 2026-11-03T00:00 (1.5 days old)

Genesis detector, out of sample (2026-08-31 to 2026-10-27, 58 days):
  ATL_CARIB  POD none yet (fitted 0.57)   FAR none yet (fitted 0.67)
  ATL_GOM    POD      0/1 (fitted 0.56)   FAR      2/2 (fitted 0.53)
      missed: Isaias
  ATL_MDR    POD      0/1 (fitted 0.64)   FAR none yet (fitted 0.38)
      missed: Gonzalo
  ENP        POD      3/5 (fitted 0.47)   FAR      0/1 (fitted 0.09)
      missed: Simon, Trudy
  WNP        POD none yet (fitted 0.37)   FAR      2/2 (fitted 0.35)
  rates are withheld below 8 events and the counts shown instead: a handful cannot estimate a rate, and the fitted column rests on thirty seasons
  scored as the calibration scores -- a genesis counts as caught inside a window or within 2 days of it closing
  the record ends where ERA5 does, about six days back, so a storm that formed this week is not scored yet

Tropical cyclones of 2026 so far (IBTrACS, through 2026-11-03):
  102 named systems, 45 reached hurricane force (64 kt), 32 major (96 kt); 2 still going
  by basin: EP 24, NA 10, NI 3, SI 20, SP 13, WP 32
  strongest so far: Champi (WP) at 159 kt
  counts are of systems that reached the archive, not of landfalls, and a season is not over until it is over

Nino 3.4 seasonal forecast (C3S multi-model, initialised 2026-10-01, anomaly vs each model's own hindcast climatology):
    centre        L1  L2  L3  L4  L5  L6
    cmcc          +3.47  +3.91  +4.19  +4.30  +4.00  +3.49
    dwd           +3.90  +4.17  +4.54  +4.63  +4.49  +4.16
    eccc          +3.83  +4.42  +4.41  +4.10  +3.63  +3.07
    ecmwf         +3.58  +3.99  +4.18  +4.11  +3.83  +3.47
    jma           +3.54  +3.88  +4.01  +3.97  +3.75  +3.19
    meteo_france  +3.81  +4.13  +4.20  +3.84  +2.99  +1.96
    ncep          +3.20  +3.44  +3.37  +2.78  +2.38  +1.90
    ukmo          +3.43  +3.65  +3.60  +3.40  +2.89  +2.19
    --------------------------------------------
    multi-model   +3.59  +3.95  +4.06  +3.89  +3.49  +2.93
    spread (sd)    0.24   0.31   0.40   0.57   0.69   0.82
  anomalies are corrected for each model's mean drift but NOT for its variance: seasonal systems over-amplify Nino 3.4 at long lead, so these are not calibrated amplitudes
  these are other centres' forecasts, reported not issued; this pipeline's own predictions are graded separately
Standing predictions (issued before the outcome, graded after):
  [2026-09-19] discharge_onset: verify after 2027-07-16
  [2026-09-19] centroid_migration: verify after 2027-01-17

Sources:
  sst   ok (2026-10-25 -> 2026-11-03)
  olr   ok (2026-10-22 -> 2026-11-03)
  sla   ok (2026-10-26 -> 2026-11-03)
  wind  ok (2026-10-26 -> 2026-11-03)
  d20   ok (2026-10-26 -> 2026-11-03)
  iod   ok (2026-10-26 -> 2026-11-03)
  wwv_pmel ok
  tc_windows ATL_CARIB=closed, ATL_GOM=closed, ATL_MDR=closed, ENP=closed, WNP=closed
  official RONI +1.97 (ASO 2026), ONI +2.46, gap +0.49
  roni_proxy rel +1.46, scaled +2.04 (scale 1.40 on 14 mo)
  impacts ok (2026-11-02, 7 of 10 regions inside their season)
  soil_moisture ok (2026-09-20, 45d behind, 20 days cached)
  seasonal ok (2026-10-01, 8 centres)
  sst_map ok (2026-11-02, 52 frames)
  monsoon ok (WEST_AFRICA 2026-07-15, SOUTH_ASIA 2026-06-21)
  genesis_score ok (ATL_GOM 0/1, ATL_MDR 0/1, ENP 3/5)
  storms_global ok (4 worldwide)
  season_tracks ok (102 storms in 2026, 2 active)
  storms ok (0 active, 0 features)
  asis  ok (ASIS.VHI-D.2026-10-D3, 10 regions)
  rivers ok (11 of 11 stations)
  wwv_check agree (r=+0.99, offset 24.37)
  consistency ok (14 checks)
  interpretation ok
  forecast 0 issued, 0 graded