World Meteorological Organization Symposium on Nowcasting - WMO
World Meteorological Organization Symposium on Nowcasting - WMO
World Meteorological Organization Symposium on Nowcasting - WMO
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development of the Maintenance Decisi<strong>on</strong> Support System (MDSS) in 2001. MDSS provides<br />
a single platform, which blends existing road and weather data sources with numerical<br />
weather and road c<strong>on</strong>diti<strong>on</strong> models in order to provide a display of the diagnostic and<br />
prognostic state of the atmosphere and roadway (with emphasis <strong>on</strong> the 1- to 48-hour time<br />
period) as well as a decisi<strong>on</strong>-support tool for roadway maintenance treatment opti<strong>on</strong>s. In the<br />
past, the system has been used mainly for strategic purposes 12-24 hours prior to a storm’s<br />
arrival in order to prepare the maintenance vehicles and schedule pers<strong>on</strong>nel. However,<br />
during the 2008–2009 winter seas<strong>on</strong>, MDSS has been modified and applied for use over<br />
Denver Internati<strong>on</strong>al Airport (DIA), including all six runways and the main arterials leading into<br />
the airport. The users at DIA want to utilize MDSS for strategic decisi<strong>on</strong>-making but also have<br />
a need for a more accurate tactical (0-6 hours) comp<strong>on</strong>ent to the system. Currently, MDSS<br />
uses three numerical weather models, model output statistics from two models, and various<br />
pavement and weather–related surface observati<strong>on</strong>s in order to generate both weather and<br />
road surface forecasts. In order to address the short-term forecasting needs, radar data<br />
assimilati<strong>on</strong> and/or high resoluti<strong>on</strong> mesoscale numerical weather models are being assessed<br />
for possible inclusi<strong>on</strong> into MDSS. Additi<strong>on</strong>ally, a n<strong>on</strong>-wintertime MDSS is also being<br />
developed that may also require the additi<strong>on</strong> of other nowcasting capabilities, such as<br />
lightning data and radar storm-tracking (e.g. TITAN).The objective of this presentati<strong>on</strong> is to<br />
provide an overview of the present and future capabilities of the MDSS system as they relate<br />
to the diagnoses and short-term forecasting of weather that may impact the roadway/runway<br />
maintenance operati<strong>on</strong>s for various decisi<strong>on</strong>-makers.<br />
P1.12<br />
The Design and Implementati<strong>on</strong> of B08FDP Data Support System<br />
WANG Yubin[1], YU D<strong>on</strong>gchang[1], SU Debin[1], ZHOU Haiguang[2], ZHOU Y<strong>on</strong>g[3],<br />
LIANG Feng[1]<br />
[1] Beijing <str<strong>on</strong>g>Meteorological</str<strong>on</strong>g> Bureau, Beijing, China;[2] Chinese Academy of <str<strong>on</strong>g>Meteorological</str<strong>on</strong>g><br />
Sciences, Beijing, China;[3] Nati<strong>on</strong>al <str<strong>on</strong>g>Meteorological</str<strong>on</strong>g> Informati<strong>on</strong> Center, Beijing, China<br />
For 2008 Olympic weather service, there were eight nowcasting systems operated in<br />
B08FDP (WWRP/Beijing 2008 Forecast Dem<strong>on</strong>strati<strong>on</strong> Project). In this paper the data<br />
envir<strong>on</strong>ment requirement from the B08FDP participants has been analyzed, which includes<br />
data acquisiti<strong>on</strong>, transmissi<strong>on</strong>, disseminati<strong>on</strong>, m<strong>on</strong>itoring and the data formats. Within the<br />
given domain of the mesoscale observati<strong>on</strong> network, a GPS timer was setup to synchr<strong>on</strong>ize<br />
the data acquisiti<strong>on</strong> and computer timer. The File Alterati<strong>on</strong> M<strong>on</strong>itor (FAM) system based <strong>on</strong><br />
the inotify (a Linux kernel subsystem that provides file system event notificati<strong>on</strong>) was used to<br />
guarantee the data transmissi<strong>on</strong> timeliness and the realtime synchr<strong>on</strong>izati<strong>on</strong> technology for<br />
Doppler radars was used <strong>on</strong> the Doppler radar operati<strong>on</strong>. For supplying a comm<strong>on</strong> data<br />
interface for all FDP participants, XML, NetCDF that c<strong>on</strong>formed to the internati<strong>on</strong>al rule has<br />
been setup for all systems. For a better support to very short range forecasting systems, the<br />
Hi-MAPS (High-resoluti<strong>on</strong> Mesoscale data Acquiring and Pre-processing System) was<br />
developed and operated in Beijing <str<strong>on</strong>g>Meteorological</str<strong>on</strong>g> Bureau. It showed that it has been running<br />
successfully and can provide an efficient data envir<strong>on</strong>ment for B08FDP participants<br />
throughout the dem<strong>on</strong>strati<strong>on</strong> period.<br />
2.6<br />
The forecaster role in operati<strong>on</strong>al <strong>Nowcasting</strong> over complex terrain P1.13<br />
Storm Series Algorithms in the GRAPES-SWIFT<br />
Paolo Ambrosetti [1] Alessandro Hering [1]<br />
[1] MeteoSwiss, CH-6605 Locarno (Switzerland) Hu Sheng, Liang Qiaoqian, Wang Ying, Zeng Qin, Feng Yer<strong>on</strong>g<br />
Guangd<strong>on</strong>g <str<strong>on</strong>g>Meteorological</str<strong>on</strong>g> Bureau, China<br />
<strong>Nowcasting</strong> addresses not <strong>on</strong>ly “severe weather” events, but more and more all kinds of<br />
significant weather changes at local level impacting people and goods. Many weather related<br />
decisi<strong>on</strong>s with ec<strong>on</strong>omic and life protecti<strong>on</strong> c<strong>on</strong>sequences are very often deterministic,<br />
therefore requiring a high accuracy and a great time/space resoluti<strong>on</strong>. These requirements<br />
are mostly satisfied <strong>on</strong>ly at 0-3 hour time range. Particularly in complex terrain like the Alps,<br />
operati<strong>on</strong>al forecasters are under stress dealing with str<strong>on</strong>g meteorological gradients<br />
observed both in space and time. These are usually poor resolved by numerical models,<br />
therefore heuristic nowcasting techniques are necessary. Depending from the parameter or<br />
weather phenomena gridded or object approaches are better suitable. For heavy<br />
thunderstorms the object techniques have dem<strong>on</strong>strated great capability, but the early phase<br />
is usually missed. For road maintenance weather a gridded approach is mostly better suited,<br />
like the snow limit altitude. A blending of the results of the two approaches is mostly left to the<br />
forecaster. The rapid updating of the data, typically 5 minutes, represents a challenge for the<br />
humans, because most of the time there is no relevant or significant change. So the early<br />
phase of the significant change can be easily missed, loosing precious time. To cope with this<br />
problem a high degree of automati<strong>on</strong> has to be introduced. This should assure a very high<br />
probability of detecti<strong>on</strong> (POD) of significant, relevant changes. The experience shows that the<br />
side effect is an also high false alarm ratio (FAR), unacceptable for the end users. The role of<br />
The storm series algorithms in the SWIFT, including storm cell identificati<strong>on</strong>, storm<br />
c<strong>on</strong>vecti<strong>on</strong> assessment, storm tracking and storm positi<strong>on</strong> forecast, are discussed. Storm cell<br />
identificati<strong>on</strong> algorithm tests the intensity and c<strong>on</strong>tinuity of the objective echoes by multipleprescribed<br />
thresholds to build 3-D storms.It uses multiple reflectivity thresholds, newly<br />
designs the techniques of cell nucleus extracti<strong>on</strong> and close-spaced storms processing, and<br />
therefore is capable of identifying embedded cells in multi-cellular storms. The str<strong>on</strong>g area<br />
comp<strong>on</strong>ents at a l<strong>on</strong>g distance are saved as 2-D storms.By using the fuzzy logic technique, a<br />
c<strong>on</strong>vecti<strong>on</strong> index of a storm is obtained. A set of features of storm morphology are combined<br />
to describe c<strong>on</strong>vective characteristics of storm cells, and every feature is given a weight. The<br />
likelihood values that the features match with the c<strong>on</strong>vective characteristics of storm cells are<br />
calculated in the fuzzy logic engine. The c<strong>on</strong>vecti<strong>on</strong> index is the weighted average of all the<br />
likelihood values, and signs the c<strong>on</strong>vective strength of a storm instantly. Storm cells identified<br />
in two c<strong>on</strong>secutive volume scan are associated temporally to determine the cell tracking. The<br />
distance between the centroid of each cell detected in the current volume scan and each of<br />
the first-guess locati<strong>on</strong> is calculated to check distance correlati<strong>on</strong>. Those similar storms with<br />
distance correlati<strong>on</strong> are matched.The moti<strong>on</strong> vector for each storm is computed by using the<br />
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