Dec 2012 Initial Conditions Summary Forecast maps Forecast Background ENSO update Current State of the global climate SST Forecasts Summary Summary The forecasts call for slightly increased chan ID: 554771
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Slide1
Consolidated Seasonal Rainfall Guidance for Africa Dec 2012 Initial Conditions
Summary
Forecast
maps
Forecast Background
ENSO update
Current State of the global climate
SST
Forecasts
SummarySlide2
Summary
The forecasts call for slightly increased chan
ce for above average rainfall in parts of Tanzania in Jan-Mar, Feb-Apr 2013, and the same for Malawi and Mozambique in Mar-May 2013. There is a slightly increased chance for below average rainfall along coastal Guinea in Feb-Apr 2013.
Neutral
El Nino Southern Oscillation (ENSO) conditions continue to prevail
Sea surface temperatures (SSTs) in the
tropical Atlantic
and the Indian Ocean are
slightly
above normal with a tendency for cooling
SST predictions favor ENSO-neutral and most models do not predict significant departures from climatology in the global tropical oceans
Neutral
ENSO conditions and weak SST anomalies in the tropical south Atlantic and in the Indian Ocean
contribute
to a low confidence in the precipitation forecasts for the coming seasons
.
Additional forecast resources can
be found here:
http://www.cpc.ncep.noaa.gov/products/NMME
/Slide3
Methodology
The
consolidated outlook is subjectively derived from CCA forecasts,
the
NCEP Climate Forecast System (CFS) outlooks, and current state of the global climate system and outlooks. Equal Chance (EC) is indicated where there is no signal in either the CFS or the CCA. EC is also indicated where there is disagreement between the CCA and the CFS.
Seasonal Rainfall Guidance for Africa,
Dec IC, Issued 3 Jan 2013,
Valid Jan-Mar
2013,
Feb-Apr 2013, Mar-May 2013Slide4
Jan-Mar 2013, Zero
Month
Lead
Seasonal Rainfall Guidance for Africa,
Dec IC, Issued 3 Jan 2013, Valid Jan-Mar 2013, Feb-Apr 2013, Mar-May 2013Feb-Apr 2013, One MonthLead
The forecasts call for a slightly elevated chance for above average rainfall to occur
over the
eastern half of Tanzania, northern Mozambique, and Malawi during Jan-Mar 2013.
For
Feb-Apr 2013, there is a slightly increased chance for above average rainfall over northeastern Tanzania, and slightly increased chance for below average rainfall along portions of the Gulf of Guinea coast. For Mar-May 2013, there is a slightly increased chance for above average rainfall over Malawi and northern Mozambique. Climatology is suggested everywhere else.
Mar-May
2013,
Two Months
LeadSlide5
CPC ENSO Update
CPC ENSO
Alert
Status
: Not Active(6 December 2012, next update 10 Jan 2013)Synopsis: ENSO-neutral is favored for Northern Hemisphere winter 2012-13 and into spring 2013. .Slide6
Current State of the Global Ocean
SST
Anomaly and Tendency for
December
2012The change in SST anomalies is negativein the equatorial Pacific, suggesting a decrease in SST
Slightly positive SST
anomalies persisted
over
the central
Indian
Ocean
SST was near
average
across
much of the
Pacific
.
Elevated SST
persisted
locally
off the Angola
coast. Slide7
200hPa
850hPa
Wind Anomaly
Winds were near average over the
central Pacific
.
Anomalous
low-level (850-hPa)
easterly
winds were evident across the western Pacific
Ocean, converging with easterly wind anomalies over the eastern Indian Ocean.
Anomalous upper-level (200
hPa
) winds
were
easterly over the eastern Pacific. Winds were near average over the equatorial Indian Ocean
Ocean
. Slide8
OLR Anomaly, December 2012
Negative OLR anomalies (enhanced convection and precipitation, blue shading) were observed over
eastern Australia and Indonesia with an extension over the central Indian Ocean. Precipitation was also enhanced over southern Africa.
Positive OLR anomalies (suppressed convection and precipitation, red shading) were apparent over eastern Indonesia, Papua New Guinea, and in the central
Pacific. Precipitation was also suppressed over Madagascar and the southwestern Indian Ocean.Slide9
Summary of State of the Global
Ocean in Dec 2012
Neutral ENSO state continued to prevail in December. Equatorial
sea surface temperatures (SST) anomalies were slightly positive across
the far western tropical Pacific Ocean, neutral in the central Pacific, and slightly below normal over the eastern Pacific. Over the past month, SST remained slightly elevated over much of the tropical Indian Ocean. However, no significant departure from Nov SST was seen. SST continued to decrease over the Mozambique Channel, where neutral conditions prevailed. Southwest Indian Ocean SST continued to decrease
In the Atlantic, SST continued to increase
along coastal Angola, but decreased over the south central sector. Tropical north Atlantic continued to be warmer than normal, but a tendency for cooling in the eastern sector was observed in Dec. The same scenario prevailed for subtropical northwestern Atlantic.
Upper-level and lower-level zonal winds were near
average across the central Pacific. Precipitation
was near average across the eastern equatorial Pacific, slightly suppressed over the central and western sectors of the Pacific, and enhanced over the eastern and central Indian Ocean. Thus, confirming that both the atmosphere and ocean indicated ENSO-neutral conditions. Slide10
CPC/IRI Probabilistic ENSO Outlook
(updated 6 Dec 2012)
ENSO-neutral is favored through mid-2013.
CPC ENSO Monitoring TeamSlide11
Pacific Ni
ño 3.4
SST Outlook
Figure provided by the International Research Institute (IRI) for Climate and Society (updated 18 Dec 2012).
Most models predict either persistence or a gradual weakening of current Niño-3.4 values, with ENSO-neutral continuing through the Northern Hemisphere summer 2013.
CPC ENSO Monitoring TeamSlide12
Pacific SST
Outlook: NCEP
CFS.v2
Forecast Issued 30 December 2012
The CFS.v2 ensemble mean (black dashed line) predicts below-average SSTs during N. Hemisphere winter 2012-13.
CPC ENSO Monitoring TeamSlide13
Jan-Mar 2013
Feb-Apr 2013
Mar-May 2013
Apr-Jun 2013
May-Jul 2013
Global SST Outlook: NCEP
CFS.v2
Forecast
Initial Conditions 23 Dec 2012 – 2 Jan 2013
CFS.v2 predicts above normal SST over the northern Indian Ocean and near Australia. Near average conditions are predicted over most areas in the central IO through the spring to early summer season
Additional forecast resources are found here:
http://www.cpc.ncep.noaa.gov/products/NMME/
Caution
: Ocean
areas
with
skill less than 0.3
are shaded in graySlide14
Summary
Neutral El Nino Southern Oscillation (ENSO) conditions continue to prevail
Sea surface temperatures (SSTs) in the Atlantic and the Indian Ocean are also near normal
SST predictions favor ENSO-neutral and most models do not predict significant departures from climatology in the global tropical oceans
Neutral ENSO conditions and weak SST anomalies in the tropical south Atlantic and in the Indian Ocean contribute to a low confidence in the precipitation forecasts for the coming seasons.Additional forecast resources can be found here: http://www.cpc.ncep.noaa.gov/products/NMME/