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WFO TULSA HYDROLOGY |
The National Weather Service (NWS) has responsibility for the issuance of river forecasts and flood
warnings. The NWS Tulsa office has hydrologic responsibility for over 30 forecast points
on streams covering an area of eastern
Oklahoma and northwest Arkansas.
To issue these river forecasts, local NWS offices rely upon forecast guidance generated by a regional
NWS River Forecast Center (RFC). The RFCs use complex hydrologic computer models
to forecast rivers. NWS Tulsa is serviced by two RFCs, the co-located Arkansas-Red Basin River Forecast
Center (ABRFC) and the Lower Mississippi River Forecast Center
(LMRFC) in Slidell, Louisiana. |
DATA (RIVER STAGES AND LAKE LEVELS) |
Most of the forecast points in the NWS Tulsa area have telemetered river gage equipment. The U.S.
Geological Survey (USGS) and the U.S. Army Corps of Engineers (COE) own and/or maintain the vast
majority of these river gages. The Oklahoma
City District USGS and the Little Rock
District USGS maintain websites which provide real-time river stage data and flow information. The
Tulsa District COE maintains a website which also provides
real-time river stage data and reservoir information, including lake levels and dam releases.
(Beaver Lake information is available from the
Little Rock District COE.)
The USGS and COE operate most of their stream gages on a cooperative basis with other Federal, state,
and local agencies that fund individual gaging stations for agency-specific projects or regulatory
needs. Reductions in stream gaging program funds may require the closure of some stations. For more
information, see the USGS fact sheets,
"Stream Gaging and Flood Forecasting, a Partnership of the USGS and the NWS" and
"Streamflow Information for the Nation." |
DATA (PRECIPITATION) |
Precipitation data is vital to river forecasting. Local NWS offices must supply their umbrella RFCs
with precipitation data to input into their computer models. The ABRFC
precipitation gage data and the
LMRFC precipitation gage data is blended with precipitation estimates from a network of WSR-88D
radars to produce cumulative precipitation maps. The hydrometeorologist at each RFC will quality
control both data sources and produce a final ABRFC
precipitation map and LMRFC
precipitation map. This processed data is one of the main inputs into the RFC's hydrologic model. |
FORECASTS (PRECIPITATION) |
In the past, river forecasts were made strictly on the basis of rainfall which had occurred. Today,
river forecasts incorporate quantitative precipitation forecasts (QPF) into the hydrologic model,
as well. This has led to more accurate river forecasts, especially in the fall and winter months,
when areal rainfall tends to be more uniform. The
ABRFC QPF and the LMRFC QPF can
both be seen on their respective homepages. |
FORECASTS (RIVER STAGES) |
The forecasts of river stages is generated by complex computer models at the RFCs which incorporate
many factors beyond the ones discussed above. The local WFOs receive these river stage forecasts
from the RFCs and generate public products under several headings:
(1) River Flood Warning � an initial product warning interests that a river is forecast to rise above
flood stage.
(2) River Flood Statement � a followup product which updates a River Flood Warning.
(3) River Flood Outlook - a product which notes where potential flooding will occur...only if a
24-hour precipitation forecast verifies.
The products listed above are generated by the Tulsa WFO in a text format. It often includes
statements of the impact that a forecasted crest will have on the immediate surrounding area.
For users who do not need the additional textual information, the ABRFC flood forecasts and daily forecasts for
selected stations available in a graphical form. In a text format, the
LMRFC forecasts available also for selected points.
The following table lists most of the forecast points for WFO Tulsa and links to current stages and
flood forecasts (if applicable). |
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AHPS (Advanced Hydrologic Prediction Service) |
The NWS is in the process of enhancing the way which river forecast
information is presented. The Advanced Hydrologic Prediction Service
(AHPS) will provide the user with not only more information, but will
display the information in a user-friendly graphical manner.
WFO Tulsa has several river forecast points with new AHPS capabilities. Here was the information statement.
Please visit the WFO Tulsa AHPS webpage.
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