1. Северо-Евразийский
Климатический Центр
Seasonal outlook for JJA 2017 from North Eurasian Climate Center Valentina Khan THIRTEEN SESSION OF THE FORUM ON REGIONAL CLIMATE MONITORING, ASSESSMENT AND PREDICTION FOR ASIA, APRIL 24-26, 2017, BEIJING, CHINA

2. Forecast technology at NEACC

3. THE FORECAST MODELS DISCRIPTION
The Semi-Lagrangian 28-level atmospheric prognostic global model (SL-AV) developed at the Hydrometeorological centre of Russia and the Institute of Numerical Mathematics of the Russian Academy of Sciences is in active operational use. The model has a spatial resolution of lat x lon. Source of atmospheric initial conditions are NCEP Reanalysis 2 (hindcast) / HMC data assimilation system (forecast). Ensemble size for the hindcasts is 10. Ensemble size for the forecast is 20. The forecast ensemble is configured by the original and perturbed (breeding of fast growing modes) analysis fields from the date 2 days prior to current month. Source of ocean initial conditions is Reynolds-Smith OI. SSTs are taken 3 days before the forecast period.
The model of Voeikov Main Geophysical Observatory (MGO) - Т42L14. Ensemble size for the forecast is 10. The forecast ensemble is configured by the original and perturbed analysis fields of the Hydrometeorological centre of Russia. SSTs are taken from the inertial forecasts.
Activities to improve forecast technology
- Implementing CHFP and S2S output standards.
- New snow albedo parameterization in SL-AV, cloudiness retuning.
- Moving from NCEP2 to ERA Interim data for hindcasts.
- More accurate SW and LW radiation parameterization.
- Increased horizontal resolution (0.72°x0.9° lat-lon)

4. NEW PRODUCTS: Sub-seasonal forecast technology
Regime of issuance of forecasts
d0-63: Once a week, 20 members ensemble initialized on 00Z every Wednesday forced py persisted SST anomalies (mean for 2 weeks) from NCEP (Reynolds SST OI v2). Perturbation from a breeding cycle. Re-forecast suite with 10 members spanning 30 years ( ) run in real-time.
Skill scores of sub seasonal forecasts
ELEMENT trsf
EUROPE (10-60, )
RO Q MSE MSSS AC RMS ROC_BN ROC_NO ROC_AN ROC_AG
week1_HMC
week1_MGO
week2_HMC
week2_MGO
week3_HMC
week3_MGO
week4_HMC
week4_MGO
month1_HMC
month1_MGO
month2_HMC
month2_MGO

5. CLIMATE WATCH ADVISORY TEMPERATURE WILL BE SIGNIFICANTLY ABOVE NORMAL
WMO RA VI
WMO RA II
RCC-Network
CLIMATE WATCH ADVISORY
TEMPERATURE WILL BE SIGNIFICANTLY ABOVE NORMAL
The new forecasts (from ) for the next two weeks show a continuation of the above normal temperature for the Siberia and the Far East. The most significant temperature anomalies (up to 8-9˚C) are expected in the North and East of Siberia, and also in the central regions of Yakutia.
WEEKLY DETERMINISTIC FORECASTS OF TEMPERATURE ANOMALIES
(HIDROMETEOROLOGICAL CENTRE OF RUSSIA (SL-AV) and MGO MODEL)
Abnormal cold weather
At a period (from October to March) when the mean daily temperature anomalies are less than 7 °С during the 5 or more days.
Abnormal hot weather
At a period (from April to September) when the mean daily temperature anomalies are more than 7 °С during the 5 or more days.
The dangerous phenomena are the phenomena of weather which intensity, duration and time of occurrence represent threat of a security of people, as well as they can cause significant damage to branches of economy. The list of the typical dangerous phenomena which are used and specified by the local territorial hydrometeorological services of Russia Federation is located on the web site of the Hydrometeorological centre of Russia:

6. The NEACOF has been conducted twice a year at the end of the springtime, in May, (on the base of Internet resources) and at the end of the autumn, in November (physical sessions), with focus on the seasonal prediction for summer and winter respectively.
NEACOF
(English version)
(Russian version)

7. SESONAL FORECAST OUTLOOK
WMO RA VI
WMO RA II
RCC-Network
DRAFT
SESONAL FORECAST OUTLOOK
SUMMER 2017
1. Oceanic Forecasts: Sea Surface Temperature (SST)
2. Atmosphere: General circulation
3. Temperature and precipitation: North Eurasia and areas under consideration
4. Verification
5. Consensus statement

8. SEA SURFACE TEMPERATURE (SST)
OCEANIC FORECASTS
SEA SURFACE TEMPERATURE (SST)
OUTLOOK
In the Indian Ocean: the most significant SST anomalies (positive and negative) are found in the southern hemisphere. Several centers predict weakl positive SST anomalies in the vicinity of the South East Asia. It can cause the summer monsoon circulation weakening. In the Pacific Ocean: Most of models predict warmer than normal conditions in the equatorial latitudes. Accoding to the IRI/CPC probabilistic forecast the probabilities for La Nina, neutral and El Nino conditions (using -0.5C and 0.5C thresholds) over the coming JJA season are: 2%, 32% and 66 %. According forecasts of CPC, significant positive anomalies of SST are expected in modlatitudes.. Colder than normal conditions are predicted in the high latitudes. It can result in an activation of cyclones in the north of Russian Far East. North Atlantic: The tripole is the principal mode of SST variability in the North Atlantic (see picture). According to the forecasts of WMO, it is characterized by negative anomalies in the central part of the area. There are significant positive SST anomalies in the Gulf Stream and the NEO. Increasing temperature contrasts can lead to an exacerbation of atmospheric fronts and increased cyclonic activity . This means that the zonal transport of air mass is more intensive than it is necessary under the climate.
According to the forecasts of most centers the significant positive SST anomalies are expected in the Norwegian and Barents Seas at high latitudes of the North Atlantic. These anomalies are characterized by high stability. Significant positive SST anomalies that persist for a long time may result in a further reduction in the area of ice cover in the Arctic (see below).

9. INDICES OCSILLATION FORECASTS
HYDROMETEOROLOGICAL CENTRE OF RUSSIA (SL-AV)
INDEX
MAY – JULY
MAY
JUNY
JULY
MAY-JULY EA
-0,24
-0,42
-0,48
-0,35 WA
0,21
-0,03
-0,13
0,49 EU
1,42
0,71
0,58
1,71 WP
0,84
0,51
0,40
0,83
PNA
0,22
0,66
0,38
0,52
NAO
-1,09
-1,72
0,02
-1,32
POL
0,93
0,19
-0,72
0,44
East Atlantic (EA), West Atlantic (WA), Eurasian (EU), west Pacific (WP), Pacific-North American (PNA) oscillations (Wallace J. M., Gutzler D.S. Teleconnections in the geopotential height field during the Northern Hemisphere winter. – Mon. Wea. Rev., 1981, vol. 109, pp ).
North Atlantic (NAO), Polac (POL) oscillations (Climate Prediction Centre of USA).

10. NORTH ATLANTIC OSCILLATION SUMMER COMPOSITE MAPS
Negative phase
(NAO< -0.49), T2m anomaly
Negative phase
(NAO< -0.49), H-500
Negative phase
(NAO< -0.49), PR
The NAO index is characterized by negative values, which means the positive geopotential anomalies in the Icelandi region and negative in the Azores region. According to forecasts of NAO, negative air temperature anomalies are more likely in the north of Europe, and positive air temperature anomalies are more likely in the south of Europe and in the Middle East in summer.

11. EURASIAN OSCILLATION (EU) COMPOSITE MAPS ANOMALY
SUMMER
Positive phase
(EU>0.46), H-500
Positive phase
(EU>0.46), T2m
Positive phase
(EU>0.46)
The meridional forms of atmospheric circulation are expected to prevail during the summer over most of Northern Eurasia. Significant positive values ​​of the EU index are associated with positive air temperature anomalies over most of Siberia and below the negative anomalies in the north of Europe. Negative precipitation anomalies are expected in Siberia, positive precipitation anomalies are expected in the north of Europe.

12. National Snow and Ice Data Centre, Boulder, CO
ARCTIC SEA ICE EXTENT
National Snow and Ice Data Centre, Boulder, CO
Sea-Ice extension in Arctic in March Significant positive SST anomalies that persist for a long time resulted in a further reduction in the area of ice cover in the Arctic.
Arctic Sea Ice Extent (% from mean).
Planetary frontal zone will tend to be northward and less intensive

13. ANOMALIES OF AIR TEMPERATURE AND PRECIPITATION
PROBABILISTIC FORECASTS
HIDROMETCENTRE OF RUSSIA (SL-AV) И MGO
May - July 2017
May - July 2017
The forecast is issued on March 2017

14. THE PROBABILISTIC FORECASTS OF AIR TEMPERATURE
TOKYO CLIMATE CENTRE
APCC
The forecast is issued on April 2016
Forecast issued on March 2017

15. LC MMELRF-WMO Lead Centre for MME LRF
PRECIPITATION
LC MMELRF-WMO Lead Centre for MME LRF
June - August 2017
Composite map
Models:
Montreal
Melbourne
Forecast is issued on April 2017

16. Consensus forecast from empirical models
June July 2017
August 2017

17. Draft seasonal forecasts over south CIS in JJA 2017
Precipitation B N
A/N
Air temperature A N
B/NN

18. COMPARISON OF CONSENSUS SEASONAL FORECASTS WITH OBSERVATION AIR TEMPERATURE DJF 2016-2017
FORECASTED
OBSERVED
+AO, + NAO, + WP
Weak Siberian High, cyclonic activity in the southeast Asia
Snow cover was above normal
Sea ice extent in the Arctic region was below normal

19. Climate services to support forestry agency
FOREST FIRE DANGER OUTLOOK FOR UPCOMING SUMMER
June July 2017
August 2017

20. Thank you for attention!