Based on 0 cm and 20 cm monthly average ground temperature and air temperature from 68 meteorological stations in Zhejiang Province from 1951 to 2018, and the annual average temperature for one hundred years at Hangzhou and Wenzhou stations, the 0 cm and 20 cm annual average ground temperature in Zhejiang Province from 1905 to 2018 were established by using the method of global correction of local station observations (GAoSV). The spatialtemporal characteristics of ground temperature at a century scale were analyzed through Morlet wavelet analysis, MK test and other climatic statistical diagnosis methods. The results are as follows: (1) The climate tendency rate of 0 cm and 20 cm ground temperature in Zhejiang was 0.2 ℃·（10 a）-1 (P＜0.05) from 1905 to 2018. The highest, lowest and average value was 20.5,16.5 and 18.6 ℃ at a depth of  0 cm, and 19.9, 16.1 and 18.1 ℃ at a depth of 20 cm, respectively. (2) Under the background of climate warming, the ground temperature in Zhejiang Province experienced a “coldwarm” climate evolution, and the ground temperature was lower before the mid1990s and higher after that. Two obvious rising stages were during 1905-1925 and 1991-2018, respectively. (3) The spatial distribution of 0 cm and 20 cm annual average ground temperature in Zhejiang Province showed the same spatial distribution characteristics with low in the north and high in the south. The high value areas were distributed in Wencheng, Longquan, Lishui and the south of Wenling, while the low value areas were distributed in Anji, Xiaoshan, Deqing, Huzhou, Changxing. (4) Obvious oscillation periods of 2-6 years, 6-8 years and 16-20 years in different periods were detected through analyzing annual average ground temperature of 0 cm and 20 cm in Zhejiang Province from 1905 to 2018, and the abrupt point occurred around 1986.

A provincial drought situation occurred in autumn 2019 in Zhejiang, especially in the central and western part of Zhejiang Province. Precipitation in autumn 2019 broke the least record in history, and the temperature anomaly was 1.5 ℃ at most of stations. Based on observation data of precipitation and temperature from 67 normal stations in Zhejiang Province and the NCEP-NCAR reanalysis data, the drought causes over Zhejiang Province in 2019 were analyzed systemically. Such severe autumn drought was directly caused by continuous less precipitation and high temperature. The main part of the polar vortex on 500 hPa was located in the Western Hemisphere, thus cold air intensity over Asia was relatively weak, furthermore, the East Asia trough position was eastward and northward, which was hard to cause the cold air to affect Zhejiang. The more intensive of western Pacific subtropical high (WPSH) and associated northward location of the ridge line and westward advance of the westward ridge point, the abnormal high pressure over South Asia, distinct downdraft over Zhejiang, the narrower-span and slower updraft of Hadley Cell and subsequent weaker northward transport of weaker vapor, stronger moisture divergence in the mid-lower troposphere worked together to bring about the typical drought climate in Zhejiang in autumn 2019.
Key words: drought; atmospheric circulation; western Pacific subtropical high; cause

There was a peculiarly strong heat-wave event in May 2018 in Zhejiang Province. The extreme maximum temperature (EMT) in most areas was higher than 36 ℃ and in a few regions it could reach 40 ℃. The EMT and high-temperature days (NHD) in many stations broke historical record. The accumulated station-high-temperature days and effective accumulated high temperature both ranked the first in observational record. Based on daily observations at 66 normal stations in Zhejiang Province, NCEP/NCAR reanalysis data, and circulation indices of western Pacific subtropical high (WPSH) provided by National Climate Center, a diagnostic analysis was conducted to illustrate the large-scale circulation cause for such extreme high-temperature event. The results indicate that an enhanced, northward and westward western-distributed WPSH, which accompanied by eastward-march of the south-Asia high, was the direct reason for such extreme heat-wave event. Under the control of WPSH, broad anticyclonic horizontal wind anomaly formed in the region of southeast China-northwest Pacific on 850 hPa, and downward flow prevailed over Zhejiang region. During 14-18 of May 2018, positive anomaly of short-wave radiation flux and the subsident air worked together to intensify the extremity of prominent heat-wave. The change of intensity and location of WPSH was intimately linked with tropical and middle-latitude circulation. More supervital convection in Marine Continent, tropical middle Pacific and north Indian Ocean, weakened convective activity in south China Sea, decreased typhoon in tropical western Pacific acted jointly to enhance WPSH, while in mid-latitude, northward-placed westerly jet on 200 hPa made for stable maintenance of WPSH.

Recently，frequent occurrence of extreme weather and climate events had caused serious impacts on people s production and livelihood，so the extended － range weather forecast attracted more and more attention． With the national spread and promotion of the low － frequency synoptic chart，extended － range synoptic processes forecast was developing vigorously throughout the country． To better satisfy the service need of synoptic processes forecast，an on － line displaying system associated with the extended － range synoptic processes forecast was developed in Zhejiang Climate Center． In this paper，the design philosophy，detailed structure，and the thoughts of future improvement and optimization were introduced extensively． The on － line displaying system included two columns，i． e． ，the heavy rainfall processes and the intensive air － temperature reduction processes based on different objects of forecast． The column of heavy rainfall processes consisted of the figure comparing between forecast and the actual state，forecast document，table of dynamic scores，table of brief description of the realistic observation，and table of detailed description of the realistic observation． The contents of intensive air － temperature reduction processes column were similar to that of the heavy rainfall processes，but the table of dynamic scores was omitted． In the future，the system will receive more improvement and optimization through designing more suitable indices and establishing the marking scheme for intensive air － temperature reduction processes and expanding the components of extended-range synoptic processes forecast．