In the summer of 2022, there was a climate anomaly with the highest average temperature and less precipitation since 1961 in China, accompanied by the strongest nationwide high temperature processes (except northeastern China) and a wide range and strong summer drought in the middle and lower reaches of the Yangtze River and Sichuan and Chongqing. For the persistence and extremity of the high temperature and drought event in this summer in China, this paper analyzes the temporal and spatial distribution characteristics and cirulation situation based on the daily maximum temperature and precipitation of 2162 meteorological stations in China from June to August 2022 and the daily reanalysis data of NCEP (National Centers for Environmental Prediction) /NCAR (National Center for Atmospheric Research), which will be of some references for the forecast of summer high temperature and drought with different time scales in southern China. The results show that in the summer of 2022, a total of 48 198 high temperature events occurred in 76.0% of the stations in China, among which 36.6% of the stations experienced 3001 extreme high temperature events. The stations with more than 20 extreme high temperature events all distributed in the Sichuan Basin, and the high temperature situation was more severe this year than the typical high temperature years since the 21st century. The nationwide high temperature process lasted from June 13 to August 30, a total of 79 days, and the strongest high temperature period was from August 11 to 24. According to the comprehensive ranking of high temperature station numbers, duration, intensity and impact range from strong to weak, the order is East China, Central China, southwestern China, northwestern China, North China and South China, among which, the extreme was the most in southwestern China, while there was no high temperature in northeastern China. The spatial and temporal distribution of drought is basically similar to that of high temperature, and the strongest drought period in China was in mid-August. In the summer of 2022, the 500 hPa over the middle and high latitudes of Eurasia showed a “two ridges and one trough” pattern, especially in July and August, the high pressures ridge near the Ural Mountains and the Sea of Okhotsk formed periodic blocking high. The strong subtropical system blocked the active cold air between the two high pressures to the north of 50°N most of the time, resulting in the pattern of “flood in the north and drought in the south” in China. The Iran high at low latitude extended abnormally to the east, and the western Pacific subtropical high was slightly northward and abnormally extended to the west. The air flow in the control area of the high pressure zone formed by the long-term connection of the two high pressures diverged and sank, which continuously blocked the transport of water vapor to the middle latitude, and was not conducive to the precipitation in the Yangtze River basin. At the same time, the south Asia high at high-level was abnormally eastward and moved to the opposite direction of western Pacific subtropical high at mid-level, which superimposed over the range of 80°E-120°E in the middle and late August, resulting in a stable barotropic structure of the high pressure system controlling a wide range of China, and the center was located over Sichuan and Chongqing region, which made Sichuan-Chongqing region become the large value center of high temperature days and the extreme high temperature event times.

Based on the daily minimum temperature and precipitation data from 126 meteorological observation stations in Beijing-Tianjin-Hebei (BTH) region from 1961 to 2017, the spatial and temporal characteristics of occurrence frequency of cold wave, and dry and wet characteristics of regional cold wave were analyzed by using defined discriminant index of dry and wet. The results are as follows: (1) The averageannual frequency of cold wave in BTH was more in the northwest than in the southeast, and 86% of the stations showed a decreasing trend in annual frequency of cold wave. (2) The accumulative occurrence station times of cold wave from 1961 to 2017 showed a significant decreasing trend (P<0.001) with a climate tendency rate of -5.7 station times per year and it mutated in 1983. The accumulative occurrence station times of cold wave from 1961 to 1971 reached a peak, it decreased sharply since 1972. The average accumulative occurrence station times of cold wave from 2007 to 2017 was the lowest in history. (3) The inter-annual variation of occurrence frequency of regional cold wave from 1961 to 2017 showed a decreasing trend with a climate tendency rate of -0.282 per decade. The frequency of regional cold wave was most in winter of 1960s, it was most in autumn and spring of 1970s, it reached the second peak in winter and spring of 2000s, and it was least in three seasons during 2011-2017. The frequency of regional cold wave was most in autumn, followed by winter and it was least in spring; the cold wave was most active in October and November. (4) The dry process was most in regional cold wave processes in BTH. From 2011 to 2017, the dry and wet characteristics of regional cold wave process showed the polarization distribution of dry process and wet process.

Based on 2-meter temperature data from the second generation monthly dynamic extended range forecast (DERF2.0) model, observational temperature data at 69 weather stations in Gansu Province, reanalysis data of NCEP/DOE and sea surface temperature data of NOAA，the forecast errors of January temperature in Gansu Province by DERF2.0 model from 1992 to 2013 and their relationship with external forcing were analyzed. The results are as follows: (1) The simulated effects of January temperature by DERF2.0 model in eastern Yellow River of Gansu (known as Hedong for short) were better than that in most regions of western Yellow River of Gansu (known as Hexi for short), especially  in Gannan, Linxia, Lanzhou, Dingxi, Pingliang and Qingyang, the average errors between forecast and observation were small and stable, and the linear tendency rates of forecasted temperature in January were consistent with observation from 1992 to 2013, while the average errors were bigger and unstable in most regions of Hexi, and the change trends of forecasted temperature were contrary to actual observation. (2) Although the model could well reflect the inter-annual variation and spatial distribution pattern of January temperature in Gansu, the abnormal centers and values of temperature change were significantly different from the observation. (3) The EOF1 of error field reflected consistent overestimate or underestimate to  January temperature, the EOF2 presented an opposite distribution pattern in Hedong and Hexi, while the EOF3 appeared a reverse phase distribution pattern in Gannan Plateau and other parts of Gansu Province. (4) The main modes of forecast error field were significantly correlated with circulation and sea surface temperature (SST) in key areas, which indicated that the response of model to circulation and SST anomalies was deficient. Therefore, it was partially possible to reduce forecast errors of January temperature in Gansu by adjusting the response ability of DERF2.0 model to circulation and SST in key areas.

Based on precipitation from 280 meterological stations in west China and NCEP reanalysis data of OLR，the relationship between autumn precipitation anomaly and OLR in western China was analyzed using EOF，correlation analysis method．The main results are as follows:(1)The high value area of autumn OLR corresponded to the low value area of autumn precipitation，and the autumn OLR and precipitation had the remarkable opposite tendency，which indicated the increase((reduction)of autumn OLR would cause the reduction(increase)of autumn precipitation;(2)There was a large remarkable inverse correlative region between autumn OLR and precipitation in west China，especially in northwest and southeast area of west China，and in September inverse correlative area was biggest;(3)By the EOF analysis，the autumn OLR was most sensitive in the southern Xinjiang basin and northeast of Qinghai plateau，in Septemper the abnormal increase(decrease)of the autumn OLR in Turpan of Xingjiang，the autumn precipitation in southwest Xinjiang，north region of Qinghai plateau，Gannan plateau and middle Gansu was more(few)，but in the Tibet and western Sichuan plateau was few(more);In October the autumn OLR’s abnormity in west Inner Mongolia Xinjiang would resulted in remarkable inverse change of autumn precipitation in Xinjiang，north Shaanxi，north Sichuan and west Guangxi;In November the autumn OLR’s abnormity in Taklimakan desert would resulted in remarkable oppositive change of autumn precipitation in Shaanxi．The influence of OLR abnormity in sensitive area on autumn precipitation was maily in December of last year，April to June and August;(4)The low value center of OLR over the Qinghai－Tibet Plateau moved to southeast from winter to summer．In September the plateau OLR low value ascension was propitious to increase of precipitation in Tibet Plateau but decrease in the northeast side of the plateau．In October，the low value ascension of OLR was in favor of precipitation increase(reduction)in the plateau(middle Hexi Corridor)．In November both autumn OLR and autumn precipitation had no obvious correlation．The influence of OLR abnormity on autumn precipitation was maily in January，March and June．

Through comparison of the evaluation of climate prediction operation for Gansu，Qinghai，Shaanxi and Ningxia in 2009 by the
old and new evaluation methods respectively，for precipitation and temperature，it has been found that both the average annual score
and the maximum score by the old method were systematic higher about 15% than that by the new method，but the minimum score by
the old method was systematic lower than that by the new method in most cases． It was relatively higher probability to reach full mark
for the maximum sore by the old method especially to temperature prediction，and less probability by the new method． A zero score was
high probability by the old method when the prediction was opposite to the fact，but 20 points by the new method at least． The new evaluation
method for climate prediction was more rigorous than not only the old method，but also the evaluation method for weather forecast．

The new generation of "the synthetical system of operation and service on the northwest drought monitoring and fore
is a synthetical system of operation service which has good physical foundation，stronger monitoring,  prcdicting,and
service abilities, higher automation degree and local characteristic of the northwest region.  Relying on the short一term weather
forecasting, this system gathers the weather information collecting,  processing and information saving for an integral whole,
and takes full advantage of the Internet technique and previous systems, data and information，takes up the systems and pro-
ductions of the other sul〕一special subjects in the item，so that it saves the great capacity of computer space，avoids many rc-
pcated labor, and it brings into play the positive function in the usually monitoring and forecasting service in recent years.

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Giwing temperature ,precipitation ,lowest temperature and raindays over Cransu province in May 2002. Analysis of unconventionality of subaltern tropic high pressure for phases.position and intensity of polar swirl.and vapor and cold atmosphere conditions.Calculating correlation with precipitation and SST in the Pacific over Cransuprovince in May ,and compare with portent signal in representative similitude years.