University of Washington: "A cooperative program for the improvement of mesoscale
forecasting for the Pacific Northwest"
Project Objectives and Accomplishments
During the period of this project there has been significant progress in a
number of areas:
- A major area of cooperation has dealt with hydrological prediction. A joint
project, partially supported by the NOAA/NWS SWPI program, is coupling a distributed
hydrological model (DHSVM) with the real-time MM5 run at the UW. The real-time
output from this hydrological modeling is made available to the Seattle NWS
office, where Doug McDonald, service hydrologist, is leading the effort to verify
the hydro forecasts. Under this joint project, the coupled model will be improved
and extended to most rivers draining into Puget Sound. During the past six months
this coupled hydrological work has been extended to six western Washington Rivers.
- Major advances have been made in the area of regional mesoscale modeling and
particularly in real-time regional numerical weather prediction. During 1999
there were major enhancements to the physics and graphics products. MM5 grids
are delivered to the Seattle NWS and can now be viewed on AWIPS. We are now
working on a regional ensemble forecasting system using 5 runs of the MM5 (12-km
resolution) using different operational initializations (eta, avn, mrf, ngm,
- The student volunteer intern program has continued in which undergraduate students
spend 3-10 hours per week at the Seattle forecast office. These students learn
about the forecast process and NWS operations, and assist with a variety of
- University staff and WFO Seattle continue to manage the 915 MHz profiler with
RASS installed at Sand Point. The data stream is being managed by the NWS/UW,
with the data being archived at the UW. There has been a continuous and active
interactive between the UW and NWS regarding the operation and interpretation
of the data from this unit.
- The regional mesoscale database has been further enhanced. Mesoscale maps produced
at the UW are being shipped to the Seattle WFO and printed every three hours.
They are also provided to the NWS in a format that allows animation of a time
sequence of hourly mesoscale maps.
A quality control system for regional data assets has been created and has been
- The COMET graduate fellow, Brett Newkirk, has made excellent progress in the
development of model initialization tools. Available on the web, this software
allows a forecaster to compare a wide range of model forecasts (AVN, Eta, NOGAPS,
ECMWF, MRF, NGM) with all available observational assets over the Pacific. In
addition, quantitative summaries of initialization quality are provided. Brett's
tools are becoming very popular.
- The Seattle NWS office and UW have worked cooperatively on their WEB home pages,
exchanging data and graphics.
Joint planning is taking place for the next Northwest Weather Workshop.
- The Seattle WFO and UW are now working on the analysis of the 12 December 1995
major windstorm event, that was observed with the NOAA P3 during COAST.
Benefits to the University
Some examples include:
- The close relationship with the Seattle WFO has provided students with considerable
exposure to operational forecasting. For example, several students are serving
as volunteer interns at the Seattle WFO, and Brad Colman has lectured on operational
problems to the senior forecasting class.
- The cooperative relationship has made several data sets available to the university
(e.g., 1 km visible satellite data, hydro data).
- The cooperative effort has made possible the acquisition and operational transfer
of the 915 MHz profiler data and Level II WSR-88D data.
- The close association between the NWS and the UW has facilitated the employment
of many UW students in the National Weather Service.
Benefits to the NWS Office
- The NWS continues to utilize Harry Edmon as a systems analyst resource. This
has led to rendering the HP workstations and N-AWIPS more useful, which in turn
has resulted in more accurate forecasts on a number of occasions.
- Once student volunteers become proficient in certain duties, time is freed up
for NWS personnel to work on projects, etc. A new student (Casey Anderson) has
started to redo an important local study that should further refine several
significant forecast parameters needed to improve our lowland precipitation-type
- Daily access to output from the MM5 mesoscale model by NWS forecasters has led
to better understanding of terrain-induced circulations, and hence better forecasts.
The MM5 forecasts have become more reliable and forecasters have become more
familiar with model biases and behavior. This allows a smarter application of
these data and an optimal mix of operational and experimental data streams in
the local forecast process.
- The Atmospheric Science department maintains the mesoscale network observations
archives. This gives NWS more time for studies, etc., since we do not have to
devote resources to the archiving function.
- Free access to the University's data archive is also valuable. This archive
includes microfilm of upper air and surface, all local surface observations
including the non-standard set cooperatively collected, and many full resolution
model grids. Several of this past year's forecaster studies relied upon this
- Through the university-sponsored mesoscale modeling committee, the NWS developed
closer ties with the Puget Sound Air Pollution Control Agency. This recently
led to the NWS refining forecast procedures for conditions conducive to ozone
episodes with direct input from PSAPCA.
Outreach Program related references (publications and presentations)
Chien, F.-C., C. F. Mass, and P. J. Neiman, 1999: An observational and numerical
study of an intense land-falling front along the northwest coast of the U.S.
during COAST IOP2. Submitted to Mon. Wea. Rev.
Mass, C., D. Ovens, M. Albright, and K. Westrick, 1999: Does increasing resolution
always improve forecast skill? Submitted to Bull. Amer. Meteor. Soc.
Westrick, K. and C. Mass, 1999: A coupled hydrometeorological prediction system.
Submitted to Journal of Hydrometeorology.
Colle, B. A. and C. F. Mass, 1999: High-resolution observations and numerical
simulations of easterly gap flow through the Strait of Juan de Fuca on 9-10
December 1995. Accepted in Mon. Wea. Rev.
Colle, B. A. and C. F. Mass, 1999: The 5-9 February 1996 flooding event over
the Pacific Northwest: sensitivity studies and evaluation of the MM5 precipitation
forecasts. Accepted in Mon. Wea. Rev.
Westrick, K., C. Mass, and B. Colle, 1999: Is meteorological radar useful for
quantitative precipitation estimation over the western U.S.? Bull. Amer. Meteor.
Soc., 80, 2289-2298.
Mass, C. and J. Steenburgh, 1999 An Observational and Numerical Study of an
Orographically Trapped Wind Reversal along the West Coast of the U.S. Accepted
in Mon. Wea. Rev.
Colle, B. A., K. J. Westrick, and C. F. Mass, 1999: Evaluation of MM5 and Eta-10
precipitation forecasts over the Pacific Northwest during the cool season .
Weather and Forecasting, 14, 137-154.
Colle, B. A., C. F. Mass and B. F. Smull, 1999: An observational and numerical
study of a cold front interacting with the Olympic Mountains during Coast IOP
5. Mon. Wea. Rev., 127, 1310-1334.