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The
Desert Research Institute (DRI) has contributed new expertise in the
area of numerical weather forecasting—a method of predicting weather
conditions by numerically solving the fundamental equations of atmospheric
dynamics and thermodynamics. The behavior of weather phenomena then
can be illustrated by various types of statistical and graphical analyses
and representations. Darko Koracin, principal investigator for the
DRI’s Atmospheric and Dispersion Modeling (ADIM) program, led
the research project that culminated in a real-time atmospheric forecasting
system using Mesoscale Model 5 (MM5). Details about DRI’s ADIM
program, products, research, projects, and publications can be reviewed
at http://www.adim.dri.edu. Dr. Koracin recently
explained the unique characteristics of this MM5 system in an interview
for NBC-TV Channel 4 in Reno, Nevada, which can be seen at http://www.dri.edu/Home/Features/clips/MM5_Chnl4.wmv .
(This is a large file and takes several minutes to download from a
28.8 phone modem, so please be patient.)DRI researchers applied their
recently developed operational version of the MM5 atmospheric forecasting
system to the West Coast of the United States, Nevada, and California.
This project was funded by the California Department of Boating and
Waterways and produced a state-of-the-art, real-time atmospheric forecasting
system to support shipping and boating operations on the West Coast.
The MM5 forecasting system operates from a cluster of computers having
13 nodes (26 processors), and in February 2004, the system began continuous
operation with atmospheric forecasts posted in real time on DRI’s
public web site at http://www.adim.dri.edu/Projects/CalBoat/jsp/index.html.
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DRI’s MM5 modeling system was designed
to resolve regional and mesoscale weather on the West Coast and, in particular,
along the California coast. Mesoscale implies horizontal scales of weather
processes on the order of a few kilometers to several hundred kilometers
and time scales of a few hours to one day or so. The capability to analyze
and visualize weather phenomena in this range is central to solving problems
and determining the validity of theories and models relating to weather
and climate. DRI computer technicians Domagoj Podnar and Travis McCord
were instrumental in designing and setting up the computer system as well
as the graphical displays for the Internet. Illustrations of forecasting
results for the three model domains, which include the western United States,
California and Nevada, and southern California, can be viewed at http://www.adim.dri.edu/Projects/CalBoat/jsp/index.html.
The coarse grid has a horizontal resolution of 27 km and encompasses most
of the eastern Pacific Ocean and western United States. The inner grid,
which has a horizontal resolution of 9 km, covers California, while the
innermost grid having a resolution of 3 km focuses on the Santa Barbara
Channel and Los Angeles Basin. Twenty-six-hour forecasts are updated on
a 12-hour schedule and displayed on the DRI ADIM web site. The 26-hour
period includes the actual model run time as well as delays in waiting
on input files and pre-and post-processing times.
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Setup of the three MM5 modeling
domains having horizontal resolutions of 27 km (D01), 9 km (D02),
and 3 km (D03). |
Although the California Department of Boating
and Waterways was interested primarily in surface-wind forecasts, the modeling
system also provides comprehensive information on other simulated meteorological
parameters including temperature, humidity, barometric pressure, and precipitation
in terms of horizontal cross-sections (two-dimensional slices of data representing
meteorological parameters at a certain time) and vertical soundings (meteorological
parameters such as wind and temperature as a function of height through
various atmospheric levels at a certain location and time). Time series
(meteorological parameters such as winds and temperature as a function
of time at a certain location) of simulated winds and temperatures from
buoy stations along the California coast are part of the forecasting system.
Other useful applications for atmospheric forecasting results include real-time
forecasting, specifically for the West Coast; air-quality studies; regional
transport; wind energy studies; opportunities to couple atmospheric forecasting
results with oceanic models and hydrological models; and cloud-seeding
simulations.The DRI web site also allows interactive access to the National
Oceanic Atmospheric Administration’s National Data Buoy Center (NDBC)
to evaluate the model using data collected at buoy stations. By moving
backward in time by one or more days, one can generate comparison plots
for the simulated temperature and wind speed with data from the California
buoys. All model forecasts are saved on electronic media and represent
a valuable resource for a wide range of research and application studies.
This modeling database is expected to be used as essential input for improved
predictions of wind-generated ocean waves.Real-time forecast results are
posted on the web site twice daily at 9:30 am and pm local standard time
(one hour earlier than daylight savings time) for simulations initialized
with data from the global observational network collected every day at
0000 UTC (coordinated universal time, formerly known as Greenwich Mean
Time) and 1200 UTC, respectively. These forecasting results provide the
following categories of information:
- Surface winds, barometric pressure, and temperature—the main
modeling results for the three domains.
- Precipitation, upper-level winds, and vertical soundings for the
three domains.
- Time series for wind speed, wind direction, and temperature from
selected NDBC buoy stations.
- Verification of past forecasts with measured wind speed, wind direction,
and temperature data gathered from the 21 NDBC buoy stations.
The following charts are examples of the
most recent ADIM MM5 forecasting results and provide real-time atmospheric
conditions for the three modeling domains—the coarse grid (western
United States), inner grid (California and Nevada), and innermost grid
(southern California). Click
on Chart 1 to initiate the most recent forecast images for Domain 1. Click on Chart 2 and Chart
3 for animated representations of forecasts for Domain 2 and Domain
3, respectively, which include the full 26-hour simulation period with
wind barbs (full barb equals 10 knots), sea-level pressure given as labeled
contours, and temperature correlated with the color bar.
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CHART 1
Surface winds, sea-level pressure, and temperature for the coarse
grid—Domain
1, which includes most of the western United States—as forecasted by MM5
for 14 hours. |
CHART 2
Surface winds, sea-level pressure, and temperature in the inner
grid—Domain
2, which includes California and Nevada—as forecasted by MM5 for 14 hours. |
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CHART 3
Surface winds, sea-level pressure, and temperature for the innermost
grid—Domain
3, which includes the Santa Barbara Channel and the Los Angeles basin—as
forecasted by MM5 for 14 hours. |
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