Consolidated Seasonal Rainfall Guidance for Global Tropics, September 2016 Initial Conditions

Consolidated Seasonal Rainfall Guidance for
Global Tropics, September 2016 Initial Conditions
Issued 9 September 2016
• Forecast Background
– ENSO update
– Current State of the global climate
– SST Forecasts
• Regional Rainfall Forecast maps
• Summary
CPC ENSO Update
• CPC ENSO Alert System Status: Not Active
• Synopsis: ENSO-Neutral conditions are slightly
favored (between 55-60%) during the upcoming
Northern Hemisphere fall and winter 2016-17.
(Updated on 8 September 2016)
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory
/index.shtml
Current State of the Global Ocean,
Positive SST
anomalies persisted
across eastern
Indian Ocean.
SST tendency was
negative over the
western Indian
Ocean.
Last Four Weeks
Tropical SSTs were
above average near
the Maritime
Continent and the
Atlantic Ocean.
Equatorial SSTs were
near or below average
in the east-central and
eastern Pacific Ocean.
Equatorial SST
anomalies decreased
east of the International
Date Line, and
increased across parts
of the eastern Pacific,
and equatorial Atlantic .
Current State of the Global Ocean
Last Week
Weekly SST Anomaly 28 August – 3 September 2016 and
Tendency for 28 Aug – 3 Sep 2016 minus 24 – 30 August 2016
Tropical SSTs were
above average in the
western Pacific.
Positive SST anomalies
Equatorial SSTs were
persisted across the
below average in the
central and eastern
east-central and
Indian Ocean. SST was
eastern Pacific, and
below average over the
equatorial Atlantic
western Indian Ocean.
Ocean.
Changes in equatorial
SST anomalies were
positive over the
Western Indian
Ocean.
SST anomalies
decreased in the
equatorial central
pacific, and
increased across
equatorial eastern
Pacific, and
equatorial Atlantic.
Nino region SST departures
The latest weekly SST departures
Niño 4 :
Niño 4 = -0.1ºC
Niño 3 = -0.3ºC
Niño 3.4 = -0.7ºC
Niño 3
Niño 1+2 = 0.3ºC
Niño 1+2
Eq. Subsurface temperature
Anomalies
During the last two months, negative
subsurface temperatures weakened, but
0.9ºC
extended to the surface in the east-central
Pacific Ocean.
0.9ºC
0.5ºC
OLR Anomaly, August 2016
Negative OLR anomalies (enhanced convection and precipitation, blue shading) was observed
over parts of the Sahel and the Greater Horn of Africa, and equatorial eastern Indian Ocean,
portions of the Maritime Continent region, including Australia.
Precipitation was suppressed (orange-red shading) over portions of the Lake Victoria region
equatorial western Indian Ocean, India, and equatorial western and central Pacific.
Low Level 850 mb Wind Anomaly
At 850-hPa level, westerly anomalies were observed across the eastern Indian Ocean and
equatorial Atlantic Ocean.
Upper Level 200 mb Wind Anomaly
Upper-level (200-hPa) westerly wind anomalies prevailed across equatorial Indian Ocean
and the central Pacific.
Evolution of Indian Ocean SST Indices
Negative Indian Ocean Dipole (IOD) condition persisted in August and early September.
The latest weekly index, as of 4 September 2016, is -0.91°C.
Summary of State of the Global Climate in August 2016
• ENSO-neutral conditions were observed during the past month.
• Near-to-below average surface temperatures (SST) was observed
across the east-central and eastern Pacific Ocean.
• Positive SST anomalies persisted across the eastern Indian Ocean.
Negative Indian Ocean Dipole (IOD) persisted in August and early
September 2016.
• Elevated precipitation was observed over parts of the Sahel and the
Greater Horn of Africa, and equatorial eastern Indian Ocean,
portions of the Maritime Continent region, including Australia.
• Precipitation deficits were present over portions of the Lake
Victoria region equatorial western Indian Ocean, India, and
equatorial western and central Pacific.
IRI/CPC NINO3.4 Forecast Plume
Source: International Research Institute (IRI) for
Climate and Society (updated 16 June 2016).
Season
ASO 2016
SON 2016
OND 2016
NDJ 2016
DJF 2016
JFM 2017
FMA 2017
MAM 2017
AMJ 2017
La Niña
48%
43%
41%
40%
39%
36%
30%
26%
22%
Neutral
52%
57%
58%
57%
57%
56%
57%
57%
58%
El Niño
0%
0%
1%
3%
4%
8%
13%
17%
20%
- Most multi-model averages indicate a borderline or a weak La Niña starting during the Northern Hemisphere fall
and persisting through winter 2016-17.
- .
CFS.v2 Global SST Outlook: Skill Masked
(September 2016 Initial Conditions)
Oct - Dec 2016
Nov 2016 - Jan 2017
CFSv2 model
forecasts suggest
ENSO-Neutral
condition through the
northern hemisphere
winter.
Dec 2016 - Feb 2017
Jan - Mar 2017
NMME Global SST Outlook: Skill Masked
(September 2016 Initial Conditions)
Oct - Dec 2016
Nov 2016 - Jan 2017
NMME model
forecasts suggest
ENSO-Neutral
condition through the
northern hemisphere
winter.
Dec 2016 - Feb 2017
Jan - Mar 2017
IOD Outlook (source: Australian Bureau of Meteorology)
The latest IOD
model outlooks
suggest the IOD is
likely to return to
neutral values by
the end of the
northern
hemisphere fall.
Rainfall Guidance, Africa: NMME, Precipitation Probability Forecasts,
(01 – 08 September 2016 IC) Gray shade indicates indicate dry
Oct – Dec 2016
Nov 2016 – Jan 2017
Dec 2016 – Feb 2017
Jan – Mar 2017
climatological mask
The forecasts call for a slight
to moderate tilt in the odds to
favor below-average rainfall
over portions of the Central
and East Africa during the
northern hemisphere fall and
winter. In contrast, there is a
slight to moderate tilt in the
odds to favor above-average
rainfall over Southern Africa
and parts of the Gulf of
Guinea region through the
northern hemisphere winter
and early spring.
Individual model forecasts can be found
here:
http://www.cpc.ncep.noaa.gov/products/i
nternational/nmme/nmme.shtml
Rainfall Guidance, Maritime Continent: NMME, Precipitation Probability Forecasts,
(01 – 08 September 2016 IC)
Oct – Dec 2016
Dec 2016 – Feb 2017
Nov 2016 – Jan 2017
Jan – Mar 2017
Gray shade indicates indicate dry
climatological mask
The forecasts call for a
slight to moderate tilt in the
odds to favor aboveaverage rainfall over many
places in the Maritime
Continent, including
Australia. In contrast, there
is a slight to moderate tilt in
the odds to favor belowaverage rainfall over parts
of Indonesia and Malaysia.
Individual model forecasts can be found
here:
http://www.cpc.ncep.noaa.gov/products/i
nternational/nmme/nmme.shtml
Rainfall Guidance, CAM and Caribbean: NMME, Precipitation Probability Forecasts,
(01 – 08 September 2016 IC)
Oct – Dec 2016
Nov 2016 – Jan 2017
Gray shade indicates indicate dry
climatological mask
The forecasts call for a
slight tilt in the odds to
favor above-average
rainfall over much of
Central America and the
Caribbean.
Dec 2016 – Feb 2017
Jan – Mar 2017
Individual model forecasts can be found
here:
http://www.cpc.ncep.noaa.gov/products/i
nternational/nmme/nmme.shtml
Rainfall Guidance, South America: NMME, Precipitation Probability Forecasts,
(01 – 08 September 2016 IC)
Oct – Dec 2016
Dec 2016 – Feb 2017
Nov 2016 – Jan 2017
Jan – Mar 2017
Gray shade indicates indicate dry
climatological mask
The forecasts call for a slight
tilt in the odds to favor above
average rainfall over many
places across the northern
and central portions of South
America. In contrast, there is
a slight to moderate tilt in the
odds to favor below-average
rainfall along the northern
end of South America,
southern Brazil, Uruguay,
and southern Chile.
Individual model forecasts can be found
here:
http://www.cpc.ncep.noaa.gov/products/i
nternational/nmme/nmme.shtml
Rainfall Guidance, Central Asia: Precipitation Probability Forecasts,
(01 – 08 September 2016 IC)
Oct – Dec 2016
Nov 2016 – Jan 2017
Gray shade indicates indicate dry
climatological mask
The forecasts call for a
slight to moderate tilt in the
odds to favor below
average rainfall over
portions of Afghanistan and
the neighboring areas
during the northern
hemisphere winter.
Dec 2016 – Feb 2017
Jan – Mar 2017
Individual model forecasts can be found
here:
http://www.cpc.ncep.noaa.gov/products/i
nternational/nmme/nmme.shtml
Summary
•
•
ENSO-neutral conditions were observed during the past month.
Near-to-below average surface temperatures (SST) was observed across the eastcentral and eastern Pacific Ocean.
• ENSO-Neutral conditions are slightly favored (between 55-60%) during the
upcoming Northern Hemisphere fall and winter 2016-17.
• NMME forecasts through the northern hemisphere spring 2017 favor belowaverage rainfall over Central and East Africa. In contrast NMME favors aboveaverage precipitation for portions Southern Africa, the Maritime Continent, many
places in South America.
Additional forecast resources can be found here:
http://www.cpc.ncep.noaa.gov/products/international/index.shtml
http://www.cpc.ncep.noaa.gov/products/international/nmme/nmme.shtml
http://origin.cpc.ncep.noaa.gov/products/people/wwang/cfsv2fcst/