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

Forecast technology at NEACC

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 1.125 lat x 1.40625 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)

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 (1981-2010) run in real-time. Skill scores of sub seasonal forecasts ELEMENT trsf EUROPE (10-60, 35 - 70) RO Q MSE MSSS AC RMS ROC_BN ROC_NO ROC_AN ROC_AG week1_HMC 0.79 2.40 8.52 -0.15 0.58 2.92 0.83 0.62 0.73 0.73 week1_MGO 0.78 0.79 3.71 0.50 0.71 1.93 0.60 0.68 0.74 0.67 -------------------------------------------------------------------------------------------------------------------------------------------------------- week2_HMC 0.05 2.68 8.80 -1.66 0.32 2.97 0.53 0.47 0.53 0.51 week2_MGO 0.34 0.65 3.47 -0.05 0.34 1.86 0.73 0.60 0.75 0.69 week3_HMC 0.32 4.97 11.85 -0.95 0.28 3.44 0.34 0.49 0.51 0.45 week3_MGO 0.16 1.63 5.83 0.04 0.27 2.41 0.37 0.58 0.61 0.52 week4_HMC 0.58 4.27 10.76 -0.78 0.41 3.28 0.41 0.48 0.50 0.46 week4_MGO 0.20 1.46 5.97 0.01 0.22 2.44 0.48 0.54 0.54 0.52 --------------------------------------------------------------------------------------------------------------------------------------------------------- month1_HMC 0.60 4.84 5.96 -0.82 0.58 2.44 0.49 0.49 0.48 0.49 month1_MGO 0.56 1.18 2.12 0.35 0.60 1.46 0.71 0.61 0.69 0.67 month2_HMC 0.51 7.42 8.88 -2.70 0.48 2.98 0.45 0.51 0.45 0.47 month2_MGO 0.46 0.93 1.62 0.33 0.61 1.27 0.62 0.57 0.68 0.62

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 22.03.2017) 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: http://meteoinfo.ru/hazards-definitions http://neacc.meteoinfo.ru

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 http://neacc.meteoinfo.ru/neacc/north-eurasian-climate-outlook-forum (English version) http://seakc.meteoinfo.ru/about-centre/-neacof (Russian version)

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 http://neacc.meteoinfo.ru

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). http://neacc.meteoinfo.ru

INDICES OCSILLATION FORECASTS HYDROMETEOROLOGICAL CENTRE OF RUSSIA (SL-AV) INDEX MAY – JULY 2017 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. 784-812). North Atlantic (NAO), Polac (POL) oscillations (Climate Prediction Centre of USA). http://neacc.meteoinfo.ru

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. http://neacc.meteoinfo.ru

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. http://neacc.meteoinfo.ru

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 2017. 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 1981-2010 mean). Planetary frontal zone will tend to be northward and less intensive http://nsidc.org/data/seaice_index/

ANOMALIES OF AIR TEMPERATURE AND PRECIPITATION PROBABILISTIC FORECASTS HIDROMETCENTRE OF RUSSIA (SL-AV) И MGO May - July 2017 May - July 2017 http://neacc.meteoinfo.ru The forecast is issued on March 2017

THE PROBABILISTIC FORECASTS OF AIR TEMPERATURE TOKYO CLIMATE CENTRE APCC The forecast is issued on April 2016 Forecast issued on March 2017 http://www.apcc21.org/eng/service/6mon/ps/japcc030703.jsp http://ds.data.jma.go.jp/tcc/tcc/products/model/index.html

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 https://www.wmolc.org/

Consensus forecast from empirical models June 2017 July 2017 August 2017

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

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

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

Thank you for attention!