Workshop Notes
Monday
November 15
Travel Day
Tuesday November 16
Morning Ice
Cover Hydraulics
Note Taker: Brad Temeyer
8:00 - 8:30 am Registration
8:30 - 8:50 am Welcome / Background / Logistics / etc
Larry Rundquist -
Video of ice break up
during breaks
Please fill out workshop
evaluation form.
Please e-mail or fax travel
voucher to Becky Perry when travels return home
8:50 - 9:10 am Status of Action Items Larry Rundquist - NWS AR
For action items, need to identify
a sponsor to follow specific protocol to follow up on partly done action items.
Ice Related Items
·
1. Develop modeling tools to assess the threat
of ice jams. –status to be covered on Tuesday AM.
·
14. Prepare a requirement document to develop
SHEF coding for the new Doppler- has been completed by HADS
·
26. Develop a National Ice Observation Website –
hasn’t really taken off thus far
Ice Related Issues
How do we handle
forecasting increased stage and or/decreased flow during freeze up- in AHAPS,
have the option of turning on comments (ice effected)
How do we forecast the stage in ice freeze up?
The effects of ice on the
interaction of surface and ground water
Does the pressure due to ice cover force water down steam
and how much of the water in the stream does it effect?
Snow data
Frozen Ground
Miscellaneous
Administrative Items
9:10 - 9:25 am Overview of Issues Larry Rundquist - NWS AR
9:25 - 9:45 am Break(up)
9:45 - 10:45 am Ice Formation and Ice Cover Hydraulics Dr. Steven Daly - CRREL
Ice forms in two
environments, turbulent and quiescent water
Ice thickness is
proportional to a coefficient multiplied by the square root of freezing degree
days
Ice thickness information is not available in locations
in and around the
Has not had the opportunity
to take measurements related to Manning’s Equation
River models don’t account
for reduction in flow discharge downstream.
If you can model ice cover,
models will match dynamic effect and will reduce flow
The key is to identify
where the ice forms
You may want to look at
current year’s AFDD graph to evaluate ice jam potential.
10:45 - 11:30 am Measuring Velocity and Streamflow under
Open Water and Ice Cover John
Fulton - USGS
Determine mean vertical
velocity by breaking in to subsections
Max velocity is generally
below the water surface (around 0.3 D, bottom to sfc)
Explored methods to
determine stream flow discharge values
Limits to hand held
measurements under pooled conditions due to lack of velocity
To collect data in ice
conditions, break river into 20 to 25 sections, using an ice rod, place at a specified
depth in each section measure the flow in each drilled hole at specified depth
across river
You can use the same Q
values in the open water and ice season for a specific location to determine
amount of flow.
Stage Flow
To determine pressure, have
gas lines and amount of gas bubbled can be equated to pressure
Lines can be pinched by
ice, thus reporting erroneous flows
Lines can also become
clogged by sediment/debris
Open water records do not
work under ice conditions
ISSUE: If we (the NWS)
reports real time data to the public and the data is affected by ice, how do we
display/convey this information?
11:30 am - 1:00 pm Lunch
Afternoon Ice
Jams
Note Taker: Rob Shedd
1:00 - 2:00 pm Ice Jam Formation and Release Dr. Steven Daly - CRREL
Ice jam flooding is
typically upstream of jam – although downstream flooding can occur, typically
when another jam forms
Critical points for nws
reports for ice jam database – river, city, location, nearest gage, lat/lon,
type of jam (breakup, freezeup, midwinter), damages ($, water intakes),
articles
Advice on dealing with ice
jams – some material on CRREL web, need knowledge of flow thru channel – survey
before ice forms
Ice Jam database can handle
all types of reports, including ice cover reports, however, they need to be
labeled clearly in order to handle analysis appropriately
2:00 - 2:45 pm River Ice Jam Flood Forecasting Research
Dr. Faye Hicks -
More details at www.riverice.ca
Public domain models –
river1d, river2d
RADARSAT imagery generally
available daily In some locations (every few days in other locations). 8m
footprint fine resolution (32m is standard resolution)
Model parameterization
-
river1d – manning’s n; ice accumulation
characteristics
-
river2d – topo information but less other
parameters required
2:45 - 3:15 pm Break(up)
3:15 - 4:00 pm Application of Fuzzy-Logic to River
Ice Jam Flood Forecasting Chandra
Mahabir -
4:00 - 4:15 pm Remote Sensing of Ice Cover Larry Rundquist - APRFC
Aerial reconnaissance (paid
for by AK Emergency Services) coincident with breakup time
Corps looked into RadarSat
but cost and scheduling made it impractical
4:15 - 4:40 pm Reduction of River Flows During
Freeze-up Brian Connelly - NCRFC
Ice bite typically occurs
within 2 days of cold snap
4:40 - 5:00 pm Tuesday Wrapup / Action Items Larry Rundquist - NWS AR
Few river ice projects have
come thru for AHPS funding
Wednesday November 17
Morning Ice
Cover Hydraulics/Ice Jams
Note Taker: Paula Cognitore
8:00 - 8:15 am Overview of Issues Larry Rundquist - NWS AR
8:15 - 8:30 am Collection of Spotter Data Using Web
Entry Form Robert Shedd - NERFC
Training if Ice Observers:
Types, Estimate of Thickness w/o going out on it
NERFC has trained, but have
not collected data – security issues
USGS gages/forecast
locations - joint funding to bring in webcam USGS does leg work
NCRFC – USGS fills out a
form at site visits
USGS – get discharge
measurement notes, mostly hand written notes – check on status of getting this
information out electronically (John Fulton – USGS)
National form, central website, national
database - national effort
SHEF encoding
Look at Fire Weather Form
How many observations would
we have nationally?
Tapping into Severe Weather
Spotters
Adding option to include
pictures
8:30 - 9:00 am Status of Threshold Ice Jam Model
Project Dr. Steven Daly - CRREL
Next to “hind cast” for
accuracy, looking at rivers that didn’t freeze?
Probability – ice jams
Just need to do write-up
9:00 - 9:20 am Status of Incorporating Ice into NWS
Hydraulic Models Janice Sylvestre - NWS
HL
9:20 - 9:30 am Selection of Breakout Session Topics Larry Rundquist - NWS AR
Webpage/Data Collection
Form - Don Cline
Ice Jam Modeling – where do
we go from here - Brian Connelly
See Excel sheet for Action
Items
9:30 - 9:50 am Break(up)
9:50 - 10:00 am Travel Weather Briefing Jim Keeney - NWS CR
9:50 - 11:00 am Breakout Sessions
11:00 - 11:20 am Breakout Session Reports Team Leaders
11:30 am - 1:00 pm Lunch
Afternoon Snow
Data
Note Taker: Ray Fukunaga
1:00 - 1:20 pm Overview of Issues Larry Rundquist - NWS AR
Sep 05 Workshop on River
Ice by CRREL
1:20 - 2:20 pm SNOTEL, Snow Course, and SCAN Network
Description and Status Tony Tolsdorf -
NRCS
What does future hold for
SCAN (soil moisture sensors)?
Will be
increasing number of sites. Ask local
office for possible new locations
Why are there a lot of
sensors near some locations?
Result of local people asking for
sensors. Cost of new locations depends
on local data collection office.
Reference made to white paper as developed from last conference.
2:20 - 2:40 pm A Simple and Inexpensive Method for
Measuring Snow Water Equivalent James
LaRosa - WFO
No
comments or questions
2:40 - 3:00 pm Preliminary Results from an Automated
Snow Depth Sensor Study Mark Walton -
WFO Grand Rapids MI
How many sensors would DOT
want?
Current work is more of a
proof of concept. Do not know how many DOT would like.
Without snow fences data
would not be real uniform
Sensor cost? $5-600 for Judd
sensors
Media and forecasters
really liked the snowfall rates inferred from the data
Data not yet being used
operationally. Proof of concept study
for now.
Larry Rundquist
Review of 2002 CRHW Snow
related action items
3:00 - 3:20 pm Break(up)
3:20 - 4:30 pm National Snow Analysis and SNODAS Snow
Modeling Don Cline and Carrie Olheiser -
NOHRSC
SWE and snow depths are
really what are used in data assimilation
Estimates of AESC are
important from field offices and is being used
Any observed precip used?
It is being looked at. Stage IV data is
used.
Corrections are made only
if there is enough data that we are confident with the quality of the data
Text data is available as
well as graphical data
Would like the list of
recommendations presented to other regions.
List of recommendations was well received by the Eastern Region
4:30 - 5:00 pm Wednesday Wrapup / Action Items Larry Rundquist - NWS AR
Any concerns that snow
depth and SWE is being short-changed in the COOP modernization effort. Ken Crawford is aware of this issue (Tom
Carroll)
Thursday November 18
Morning Snow Melt Forecasting
Note Taker: Sherrie Hebert
8:00 - 8:15 am Overview of Issues Larry Rundquist - NWS AR
8:15 - 9:00 am Operational Use of NWSRFS in
Forecasting Snowmelt Andrea Holz - NCRFC
9:00 - 9:20 am Use of Meteorological Model
Temperatures in NWSRFS Larry
Rundquist - APRFC
No comments.
9:20 - 9:40 am Use of ESP for Snow Parameters Larry Rundquist - APRFC
9:40 - 10:00 am Break(up)
10:00 - 10:15 am Computation of Snow Depth in NWSRFS Mike Smith - NWS HL
10:15 - 10:45 am SNODAS Physical Verification Don Cline - NOHRSC
10:45 - 11:15 am SNODAS RFC Verification Tom Carroll - NOHRSC
11:15 - 11:30 am SNODAS RFC Verification Robert Shedd - NERFC
11:30 am - 1:00 pm Lunch
Afternoon Snow
Data / Melt Forecasting
Note Taker: Thomas Hawley
1:00 - 1:20 pm Production of Snowfall and Snow Depth
Maps for Web Mike Lukes - WFO Grand Forks
ND
1. Is this used as a tool to cut down on media
calls after a snow event? Yes.
2. Do the mets use this for verification
purposes? They can but need a lat and lon to enter data.
3. ERH is developing a similar tool to plot
and analyze snowfall to help handle media inquiries. They use “false” NWSLI’s
to plot the data. (Peter G.)
ADD-IN Brian Connelly
talked about the maps NCRFC produces.
1:20 - 1:40 pm Cold Season Processes Research and Development
Mike Smith - NWS HL
1. When will DMIP2 start?
(Peter G.) Last quarter of FY05.
2. Peter asked Tom C. if
they were thinking of using any of the NDFD variables for use in snow modeling.
Tom said they technically could but that some variables they use are not
available in NDFD such as solar radiation.
Andrea Holz spoke about
some improvements that would be nice to see in SNOW-17 such as a six hour
timestep in the JAVA display as well as being able to turn off tolerance and
auto updating so SWE and areal coverage would display in the JAVA window.
This started a lot of talk
about requirements procedures. Ken King mentioned that there is currently a
list of about 500 requirements for SNOW 17 and if we came up with another 20
they would just be added to the list and who knows when they would be seen in
the model. He suggested coming up with just a handful of must have changes and
these may get more attention.
Peter Gabrielsen mentioned
the possibility of forming a Cold Regions Hydrology Theme Team that could come
up with a list of requirements related to cold regions hydrology. This seems to
have support at the regional and possibly national level. Team may include
CRREL, USGS, and NOHRCS as well as RFC and some WFO representation. An example
of a requirement for this team could be the development of a national snow map
that could be navigated from RFC to RFC or even HSA to HSA.
Larry polled the RFC’s
about how they handle the lack of diurnal variability in the NWSRFS. Two said
it was not an issue for them and one said it was an issue.
1:40 - 2:20 pm Group Discussion of R&D Approach
2:20 - 2:30 pm Selection of Breakout Session Topics Larry Rundquist -
Three breakout groups
NOHRSC
will host map and hopes to have something up and running by March 2005. They
will experiment with zooming and user defined time periods.
Where
did the requirement for everyday at 18z come from for SWE at WFO’s?
Requirement
may now be for 06Z and 18Z.
Consistency
of measurements. Make sure observers taking measurements in same representative
area.
Get NWSLI’s for all sites for SHEF
encoding.
RFC’s
are using SNODAS very differently. Some using SNODAS very much others not at
all.
Should
continue with verification study. Rob Shedd said should be fairly simple to
continue with a rain plus melt comparison of the SNODAS and SNOW-17 in NWSRFS.
2:30 - 2:50 pm Break(up)
2:50 - 4:10 pm Breakout Sessions
4:10 - 4:40 pm Breakout Session Reports Team Leaders
4:40 - 5:00 pm Thursday Wrapup / Action Items Larry Rundquist - NWS AR
Friday November 19
Morning Frozen
Ground Modeling
Note Taker: Scott Dummer
8:00 - 8:15 am Overview of Issues Larry Rundquist - NWS AR
8:15 - 8:40 am Frost Depth Gauges Brian Hahn - WFO
Is there a SHEF PE for
reporting frozen ground? Yes the SHEF Code Param. It is GD.
SHEF code for Frost Depth
Thawed is GT. Both are reported to the
nearest inch.
What’s the deepest frost
depth you have measured? Typical in WI
is between 18”- 4’. Once in
The highest reading from an
observer a measurement of 50” was reported.
Are soil type observations
taken when these gages are installed?
Yes.
Are observation pictures
taken of the gage surroundings? Sometimes, but that is a good idea. The RFC would be interested in this.
Do we want to have all WFOs
in northern climates install gauges?
How do the soil temp gauges
and frost depth gauges compare with each other?
How do the observations
compare with the grave digger network?
The grave diggers tend to over-estimate in MI.
May be beneficial to
compare the highway department’s gauge right next to the NWS gauges in the same
conditions for comparison.
8:40 - 9:00 am Operational Use of Frozen Ground
Capabilities of NWSRFS Brian Connelly -
NCRFC
Does the RFC assume that
32F temp reading is frozen ground? Yes.
At what soil depth does the
RFC turn back on the interflow valve?
How about the lower soil zones?
This is actually modeled, not physically based. It is a gradual process. The frost data is used qualitatively.
A comparison between frozen
ground indices and frost depth for various soils is needed.
Do moist soils near the
surface contribute to inaccurate SNOWDAS data? The NOHRSC has methods for
subtracting out this effect. They fly in
the late fall to come up with a subtraction map.
Frost depth is
qualitatively used to adjust the frost params in the model.
9:00 - 9:20 am Discussion of Frozen Ground Modeling
RFCs are interested in
looking into how NCRFC qualitatively uses frost depth. If they see a benefit they will work with the
regions to promote the use of frost depth gages at WFOs at least.
9:20 - 9:30 am Session Wrapup / Action Items Larry Rundquist - NWS AR
9:30 - 9:40 am Travel Weather Briefing Jim Keeney - NWS CR
9:40 - 10:00 am Break(up)
10:00 - 11:00 am Workshop Wrap Up / Final Action Items Larry Rundquist - NWS AR
11:00 am Adjourn
Afternoon Travel
Ice-Related Issues
! Interpretation of stage data during freezeup and ice cover
! Lack of data on ice cover and ice characteristics
! Ice thickness observation network development/safety issues
! Forecasting increased stage and/or decreased flow during
freezeup
! Forecast stage verification during freezeup
! The effects of ice on the interaction of surface and
groundwater
! Modeling of ice thickness growth and decay
! Forecasting occurrence, timing, and severity of ice jams
Snow Data and Snowmelt Issues
! How to maximize SWE data available to forecasters
! Collection of accurate SWE data
! Use of wind shields on NWS precipitation gauges
! MAT computational scheme in NWSRFS
! Lack of high elevation temperature data
! Forecasting diurnal fluctuation in flow/stage
! Use of snow depth observations in NWSRFS
! Use of SNODAS information in NWSRFS
! Use of SNODAS output as a snowmelt hazard alert tool
! Limitations of SNOW-17 to account for variability in energy
balance
! IFP displays of more snow parameters
! Lack of national guidelines on minimum and optimum data
requirements
Frozen Ground Issues
! Lack of information on distribution and characteristics of
frozen ground
! Impact of frozen ground on runoff characteristics
! Use of frozen ground data and techniques in NWSRFS