|David Reed, Hydrologist In Charge||Vol. 5 No. 1, Autumn 2001||Ethan A. Jolly, Editor|
|Special Issue: Southern Region River Forecast Center’s Technology Transfer Workshop 2001|
|From the HIC|
We are nearing the end of an eventful 2001. We had widespread flooding in the Spring followed by the remnants of Tropical Storm Allison causing major flooding over much of southern Louisiana in early June. The NWS conducted a Services Assessment on TS Allison and LMRFC received many kudos. To quote from the Assessment “The LMRFC provided outstanding service to its customers and partners”. Congratulations on a job well done to the staff at the LMRFC.
During this period, we have been busy on many fronts to implement technology to provide you better products and services. Some of our forecasts are available on a personal digital assistant (PDA) and all should be available soon. Our web presence continues to improve and we have more products that will meet your needs. We continue to implement new forecast techniques to improve our forecasts.
This issue will be devoted to some of those technological advances. LMRFC recently hosted a workshop to transfer technology between the four Southern Region RFCs. At this workshop, our technological advances along with those of the other RFCs were highlighted. Work teams were formed and we will be working together as a region to implement some of the emerging technology to improve services at LMRFC and the other RFCs in SR.
We will do all this and continue to prepare for the coming 2002 flood season. Please let us know if we need to provide additional products and services. We always enjoy hearing from our cooperators and partners.
|Southern Region River Forecast Center’s Technology Transfer Workshop 2001|
During the week of November 5, 2001, representatives from all the Southern Region River Forecast Centers met at the LMRFC to share technological advances and service improvements. The goals of the meeting were:
The LMRFC has been posting PDA formatted pages for the lower Ohio and Mississippi River for several months and is currently working on adding all forecasts in the LMRFC area. The forecasts for the Ohio and Mississippi can be found at http://www.srh.noaa.gov/lmrfc/pda/
The forecasts for the other rivers in the LMRFC will include the latest river stages along with the three to five day forecast. These should be online by the end of the year and will be found by visiting the above URL.
The Lower Mississippi River Forecast Center (LMRFC) collects, processes, and analyses a large amount of data. To keep its users informed, the LMRFC prepares a significant number of products using ArcView/GIS. These products are used internally at LMRFC and within the NWS and may be posted to the LMRFC webpage. Some products prepared using ArcView include:
Some future emphasis will be place on 3D analyst tools and what it may offer as well as the Arc-IMS internet map server. The map server will allow any internet user to create and zoom in on any arcview compatible dataset.
Work Station ETA
The meteorological output from the workstation Eta model has a time step of 6 hours with model output to 60 hours. Output from the workstation Eta includes the following: pressure, temperature, wind, and precipitation. Other meteorological output is available from the workstation Eta model to determine the possibility for heavy rainfall and severe weather.
The workstation Eta has been running at the LMRFC since March 2001. The HAS group uses the information from the model to determine the possibility for heavy rainfall. To determine how well the workstation Eta predicts rainfall, graphical and statistical based verification has recently been established. The graphical verification is run twice a day on a 4 panel display and allows the forecaster to compare observed rainfall to the precipitation from the workstation Eta model, Eta model, and forecasted rainfall from the HAS forecaster. The statistical verification is run once a month and compares the workstation Eta to the observed rainfall estimates from ground instruments and radar derived precipitation. Mean absolute, mean, and root mean square errors have been computed for southeast Louisiana with general trends showing a high rainfall bias for the workstation Eta. Since the statistical sample size is quite small, more months are needed before more definitive results can be completed.
The workstation Eta will continue to run at the LMRFC to help HAS forecasters with heavy rainfall. Future work will include lowering the resolution to 10 km for a smaller domain of the LMRFC area to possibly study sea breeze effects along the Louisiana and Mississippi coast. Verification will continue to be perform to validate benefits from the workstation Eta.
SLOSH and the Interface with DWOPER
DWOPER is the LMRFC river surge model and was developed for a 254 river mile reach along the lower Mississippi River running from Red River Landing to West Pointe ala Hache (WPHL1). River forecasts are prepared for both boundary stations plus the following river locations: Bayou Sara, Baton Rouge, Donaldsonville, Reserve, New Orleans, and Chalmette. The SLOSH surge hydrograph output is used as input to DWOPER at the WPHL1 downstream boundary to allow forecasting of surge heights at the above 8 locations.
Operational action taken by LMRFC is dependent on hurricane status. For a Hurricane Watch (landfall > 24 hours) situation, LIX provides LMRFC forecasters with five possible surge scenarios based on a TPC catalogued set of surge hydrographs for WPHL1. The five possible surge hydrographs are then input at WPHL1 and dynamically routed upstream providing a range of crests at each of the 8 forecast locations along the Mississippi River. These possible crests are issued to LIX for inclusion in the public Hurricane Local Statement product. When a Hurricane Warning is in effect (landfall < 24hours), a single surge hydrograph based on TPC’s best forecasted track is input at Pointe a la Hache, LA and a single crest for each river location is issued by LMRFC using the NEWRVASIL mainstem product.
Storm Surge/SLOSH Interfaces
These surge hydrographs are input directly as downstream boundary conditions to the NWS River Forecast System (NWSRFS), Dynamic Wave Operational (DWOPER) Model for forecasting river crests as the surge wave progresses upstream. The forecast output from the DWOPER model is used as important hydrologic guidance for several points along the lower Mississippi River beginning at West Pointe ala Hache, Louisiana, and upstream 254 river miles to Red River Landing, Louisiana; which includes the New Orleans metropolitan area.
PHP & MySQL
The LMRFC is currently working with PHP and MySQL on several interactive Intranet projects and plans to implement this technology onto the LMRFC web site in the near future. Some uses of this technology for the LMRFC include forecast standardization, custom searches, and inclusion of latest river stages.