This Drought Workshop was held April 25-27, 2002 at the National Climatic Data Center in Asheville, North Carolina, U.S.A. The workshop had two goals:
The North America drought discussion was a follow-up to a November 14-16, 2001 "Troika" meeting of representatives from the U.S., Canada, and Mexico. The November Troika meeting discussed the need to establish a near-real time climate extremes monitoring system and assessment of trends as a partnership between the three countries. The results of that meeting included:
The international participants included:
To accomplish these goals, the April workshop agenda was divided into three parts:
Some of the speakers provided digital files of their presentations. These files can be accessed on the agenda page.
NCDC hosted the 2nd annual Drought Monitor Forum which featured an excellent agenda and which was well attended as more than 48 people from Mexico, Canada and the United States attended the 3 day conference. A summary of the discussions held, and the recommendations made, are detailed below.
In addition, Friday was set aside for Troika meetings involving scientists from Canada, Mexico and the U.S. to discuss drought issues and investigate the logistics and feasability of producing a monitoring team that would put together a monthly Drought Monitor product for North America.
Highlights of Thursday's speaker presentations, as recorded by the note-takers:
Covered the general "making of the DM" logistics/timeline that the DM authors undertake each week. Emphasized that the effort would not be doable were it not for the cooperation between the agencies and the NDMC along with the essential input that comes from the local experts in the field.
1994-formal regional drought policy efforts began.
-provided information to users
"Triggers" for issuing Drought Statements: Annual precipitation deficiency of 15% or more OR 6-months at 15% or more OR D1 or greater on the Drought Monitor for areas in their region.
* RFC's issue bi-weekly drought/water resource guidance
* AHPS probabilistic streamflow forecasts
* drought declaration status map
* provide local value-added information
ACTION: Would like to see NWS hydrological information center on Drought Monitor web site along w/ any relevant local products
Went over layout of South Carolina's Drought Response Act (1985)
Logistics of how they monitor and coordinate response to drought in the state.
Amended the Drought Act in 2000
-criteria set to river basin and NOT climate division
-use of MULTIPLE indicators of which the Drought Monitor is one (others: PDSI, SPI, streamflow, aquifer levels, etc.)
Drought response levels: Incipient/ Moderate/Severe/Extreme....these are "general" statewide level designations (ex. so an extreme hydro/incipient agricultural drought would average out to a moderate designation for the state)
-this causes problems
-use DM A, W, F to differentiate
-calculate their own bi-weekly SPI on the 15th and 30th of each month
**PROS and CONS from survey of people working with the S.C. drought coordinator:
Potential impacts this year in Oklahoma: winter wheat...major.
Streamflow, water management and fire are right there as well.
A strong Mesonet system allows for quality real-time monitoring and generation of derived products to aid them in monitoring drought.
Contrary to popular belief, a lot of the Mesonet data/products are free!
They are working on providing a rolling 30, 60, 90, 180 day SPI product as well (w/ NDMC contributions).
**DM is a good product....keep open the communication lines with the local experts!
As the DM has become increasingly popular and accepted....the expectations have risen for the product!
Talked about the work of the N.C. state climate office and Mesonet/soil moisture network and soil moisture estimates (critical for better forecasting!).
Emphasized the idea of re-scaling the DM and enhancing it at regional, state, or local levels. What scale does the DM represent? Who is the audience? Is it applicable for our town? Is it static?
* An expectation may be that the DM should tell us what to expect next.
* Media and the public take the DM as the "final word"
* Should we have 1 or 2 products for short and long-term drought?
* Do we need a similar (more detailed) state level product?
* How can the DM be used efficiently for local decision making?
* Can we project future conditions/forecasts onto the DM?
* Could the DM methodology be used to create a higher resolution DM (supplement w/ Mesonet data)?
* Need to develop local scale soil moisture information (and national!)
***The DM community needs to develop some recommendations that will address soil moisture monitoring standards and efforts at all levels! (probes, depths, etc.)
DM could serve as a model for an Expert System (decision support system)
* July of 1998 seems to be the origin of the current drought
* Data are collected from the TVA, National Parks and Forests. UT Dept. Ag (experimental farms), TEMA, and Tennessee Department of Agriculture.
* They then put their "spin" on all that comes in before sending it on to the DM author that week
* Primary focus is on "Hydro" droughts
* TVA Drought Definition: Combination of streamflows, reservoir levels, etc. are insufficient to meet demands.
* Regional overview of the Tennessee Reservoir/River System and impacts of the 1998-2002 drought was given
* DM can help TVA w/ drought education and awareness, especially on the issue of "hydro" vs. "ag"
* objective water table and soil moisture conditions are needed
* would TVA stream/rain data help the DM?
Impact disconnects w/ drought in the Midwest 1999-2000
The issue is not just "short" vs. "long" term, but more so the TYPES and TIMING of drought.
Fundamental issue of defining drought
Problems w/ PDSI.....especially in the West
Need to better utilize daily near- or real-time data for the U.S. and the globe!
Utah really can't use the DM as it is now
Need to get off of the climate division analysis
Move to pixels/grids and interpolate using real-time station data
Why does the CIA monitor? ..... Food security issues lead to unstable nations being toppled
Many issues: Flood control/hydropower/recreation/fish+wildlife (environmental)/water supply
Need to be careful about artificial drawdowns!
Drought management plan is ESSENTIAL for each reservoir.
How COE Monitors:
Drought Monitor/PDSI/Rainfall/Normalized Stream Flow/Soil Moisture/Guide Curves
**Can an index be developed (that all stakeholders can understand) to assist in the decision making process?
**Drought Awareness and Response:
---- weekly conference calls
---- monthly face to face
---- coordinated press releases (all need to be on the same page w/ 1 voice)
North Carolina went through a revision of its Drought Assessment and Response Plan (May 2001). It is a DUAL SYSTEM in that is addresses both assessment and response. Would like to implement a DM like system for the state, including the use of a higher resolution state DM map.
Highly endorsed the DM
Implemented 2 pilot projects in the southern region (NWS)
First Prototype: Drought Information Statements (DIS) (TX and FL) w/ plans to implement region-wide this year (2002)
PDSI "moderate" is the trigger to prepare the DISs
Report on any hydro, fire or ag impacts taking place. There is a synopsis, response/actions, water use restrictions and a hydro/met outlook.
Second Prototype: New graphical product depicting % of normal rainfall. Several RFC's using PRISM data sets to generate % normal rainfall info for various time durations using Multi-Sensor precipitation estimates.
AHPS---- Advanced Hydrologic Prediction Services
- new hydro info/products through new science/tools
- inclusion of probability info on future stage/flows
The new Objective Blend of Drought Indicators (OBDI) methodology was discussed. The OBDI is an attempt at quantifying and in aiding the subjective DM judgements.
2 blends (short- and long-term) and a Unified.
-- first investigated all available indicators on a WEEKLY basis
-- what goes in and what weight to give them was done by trial and error and feedback from the authors of the DM
* Expressed as a percentile specific to location and time of year
* MUST have history (accurate percentile assessment)
* Have come up w/ a temporary fix/procedure to account for the Climate Division precipitation data problems in parts of the west
* Are using weekly values from daily precip. from gridded analysis (including SNOTEL)
**Depict final result of each of the 3 blends as a percentile based on that blend's history for ALL months in the history
** Need for a national groundwater/data assessment product
** Well levels are NOT currently incorporated into the OBDI or DM (directly)
** Correlations (levels to months) varied by time of year and from station to station
** Strongest relationship was found between 5 and 10 months (precip vs. well levels)
** Sample size as small as 17 was used for some well-precip correlations
** Hopeful that a precipitation proxy for groundwater can be determined
Would like to see an objective high-resolution monitoring of drought take place using radar
-- a more objective assessment
-- Get the DM to a HIGHER RESOLUTION
DEOS (Delaware Environmental Observation System)
Development of a high-resolution weather data system (decision support system-DSS)
- real-time operational weather info-system
- 4x4 km grid w/ a full suite of variables
- also used as an analysis tool (for historical context)
- observed/derived suite of products
- water balance (budget) model incorporated
- use digital precip array
- remove bias between reflectivity to rate (adjustment algorithms)
Seasonal Drought Outlook overview and methodology discussed
FUTURE: verify/archive/legend/show forecast tools used/PMD-technical discussion/research/multi-regression drought forecast models
Discussed background and goals, 2001 Troika (U.S., Canada, Mexico) meeting.
Objectives: Assessment/monitoring of "extremes/trends", monitoring drought across the North American continent is the first step.
Can a DM concept be applied to N. America?
Can we monitor it near real-time on a consistent basis and are the data available for this?
Lay framework for action steps to get North America Drought Monitor going.
Issues: data/tools/common periods of record/QC/near real-time production/logistics
Went over Canada's National Agroclimate Information Services
* Seeing many of the same climate trends that we are seeing in the U.S. and Mexico
* Seeing less variability in wheat yields
Feed supplies/Fire/Desertification (Environmental Degradation)/Water Supply
* 180 stations providing data on a near real-time network (Canada's Met. Service- MSC)
* 1 km grid interpolation from the 180 sites using ArcView and ARC IMS software
60-80% of norm ppt = moderate drought OR equal or less than the 10th percentile
< 60% = severe drought
* in 2001, 45% of prairie livestock farms faced drought
* water shortages in surface water supply (dugouts) for farmers widespread
* seasonal climate predictions are very important for management decisions
* soil moisture (% capacity) 76% of crop land is at 50% of capacity this spring
* seeing some growth in Mesonets
* no soil moisture/temp networks in place though. They are starting a 15 site prototype in Alberta this year
* weekly NDVI
* climate profiles/drought definitions by ecoregions (terrestrial ecozones, ecodistricts)/modified PDSI/SPI?
* establish a Canada Drought Centre in Regina, SK -- could partner with U.S. and Mexico (Drought Research Center, Chihuahua, Mexico) in a North America Drought Network.
No current operational drought monitoring activities at SMN. They prepare special reports when needed.
* Until now, not utilizing indices but are looking into PDSI and SPI
* Subjective criteria varies for drought
* Suite of precipitation anomaly maps
National Commission for Disaster Prevention:
- More than one standard deviation from monthly rainfall avg. (only applied May-November)
- Transboundary water issue is important (Rio Grande). Illustrates need for common climate products and seamless integration across borders. Analysis needed by cooperating into the 21st century.
-- incorporate indices into analysis year round
-- identify climate stations w/ suitable data for near real-time data
-- develop strategy plan to monitor regionally and nationally. There are 13 regions in the National Water Commission (NWC) administration.
NCDC Drought Monitoring Activities
- Part of NCDC's State of the Climate reporting
- Monthly and seasonal textual/graphical web-based reports
- Comprehensive review of previous month's drought conditions throughout the US
- A National summary and more detailed regional reviews
- Also includes separate pages containing pertinent drought indices
- Drought monitoring assessments are also included in the broader annual climate assessments.. BAMS and the WMO Annual Statement on the Climate
A Global Drought Preparedness Network
-- a virtual network of networks by forming regional drought preparedness networks
-- share information and lessons learned in order to help reduce the impacts of drought
-- INFO: policy/planning methodologies/stakeholder involvement/climate and drought indices/EWS/triggers/impact and vulnerability assessment methodologies/water supply issues/agronomic practices/mitigation and response actions
-- organize and conduct regional workshops and longer-term training on these issues
-- North America, South America, Sub-Sahara Africa, Mediterranean, West Asia, Australia and Pacific, Eastern and Central Europe
-- Specifically for North America:
* identify the principal regional/national institutions and stakeholders
* who can organize a launching workshop for this regional network?
* what is the scope, objectives and activities of the N.Am. network?
* what are the potential sources of financial support?
* who can work w/ the NDMC/IDIC in the development of a regional network/web site?
* Approximately 150 sites w/ precip/temp through 1998, back to the 1920's, some as early as 1895; most Canadian stations are along the U.S. border
* PDSI analysis in Canada and North America (continental patterns of PDSI )
* Basically, trend has been statistically significant to a wetter regime
* Year to year spatial PDSI match well at the U.S./Canada border
Warm season droughts in the Central U.S. (April-September)
- CCA for 4 regions on the Plains
- ENSO/drought connections
- PDO/drought connections
- add to inter- and intra-seasonal rainfall variation
PDSI/Precip frequency (# of days with precip greater than or equal to 2.5mm)/ Dry days (D = number of days where region's 21-day average precip significantly below the climatological normal)/ dry day runs
PCA based (principle components)
** 20 out of 94 years saw drought in MULTIPLE regions
Pacific Decadal Oscillation (PDO)....in the cold (negative) phase now
Warm season droughts split 50-50% between PDO phases. The character of the droughts do differ depending on the phase though.
Paleo climate: Interannual to Centennial scale variability
Value of Paleo: Placing current conditions in historical context (NOT assessing current status)
Paleo = pre-instrumental proxy data (tree rings, pollen, ice and sediment cores, historical documents, fauna, coral, insects, boreholes)
Now part of NCDC but still located at Boulder, CO. They are the World Data Center for Paleoclimatology
** Customers: climate research community/educators/media/public
** A lot of work in paleoclimate reconstructions and modeled results
Paleo PDSI grids to expand for all of North America for drought reconstructions is planned
**Reconstructing streamflow (Connie Woodhouse)
- duration and severity of low flow events
**Snow water equivalents reconstructed to help in determining flows
PRODUCTS ON THE WEB: slide sets/climate time line information tool
Tom Karl: sees monitoring as a way to get to the point of making trend analysis.
Look at this effort from the perspective of the users (what tools will be useful). Users may include:
Want a central collection point for all of the data. NCDC could play this role (NCDC's infrastructure is set up to handle this. Val Swail - Canada not easily set up for this now. Miguel Cortez - agrees that NCDC be the collection point.). Maybe we could distribute the computation of the various parameters.
Will want to distribute to all of the Troika members/participants all of the data that are collected and all of the parameters that are computed.
Make this data and output visible for all users to see (e.g., web page).
Created 3 teams: Data, Products and Display, Authors and Communications
Team members were discussed both at the April workshop and subsequently. Team leader is Richard Heim of NCDC.
Products and Display Team:
Team members were discussed both at the April workshop and subsequently. Team leader is Jay Lawrimore of NCDC.
Authors and Communication Team:
Team members were discussed both at the April workshop and subsequently. Team co-leaders are Brad Rippey and David Miskus of the NOAA-USDA Joint Agricultural Weather Facility (JAWF).
The composition of all 3 teams will undergo further definition as additional team members are identified later.
NOTE: NCDC will set up 3 TEAM and one general North American DM list server groups.
Will want English, French, & Spanish versions of the North America DM. English is the common language. Canada will translate to French, Mexico will translate to Spanish.
The local/state/provincial drought products would continue to be made. This North America Drought Monitor product would not replace these local/state/provincial products.
The Drought Monitor will describe current conditions and put it into a historical perspective, but may also want to include a subsidiary drought product something along the line of a projection (what the drought is expected to do in the near future).
September-October 2002 is the time frame for the author group to get together.
Val Swail - in Canada, Agrifood Canada will lead and MSC will work with Agrifood
Get the 2001 North American Drought Assessment done for the WMO & National Assessments, and use that to get us started doing a monthly North American Drought Monitor.
Outreach - joint international press release on the 2001 drought assessment & launching of the North America Drought Monitor, coordinated press release in all 3 countries (i.e., via the public affairs agencies in each country).
(Decisions/Recommendations/Summary are indicated in bold red italics after each agenda item)
Administrative Issues, Technical Issues, & Discussion Items:
8:40-9:00 a.m. * Resolve difference between weekly and monthly Palmer Index
NCDC run the monthly Palmer program several times each month (i.e., each week), using current month values (revised weekly) computed from
[last month (thru day X+1)] to [this month (thru day X)]
as the current monthly value.
R.Tinker & D.Lecomte will initiate contact with T.Heddinghaus re this with contact to be passed on to NCDC later. Run this in parallel test mode for a while with current weekly Palmer indices continued to be computed.
* Resolve issue of consistency/agreement in calculation of the SPI (Pearson III vs Gamma)
Agreed to convert to Pearson III for monthly for all groups (NCDC, WRCC, NDMC, etc.). K.Redmond needs to make it a higher priority.
9:00-9:20 a.m. * Clarify the protocol for responding to inquiries to the Drought Monitor authors. Who will answer these inquiries? Should this be the job of the back-up author each week? Should all authors see the questions, or just the author and back-up?
Should all authors see the questions - yes.
Forward special questions to appropriate group. Tell emailer that their email will be answered after the Drought Monitor is completed for that week (put this on the DMon web page).
* Clarify the timing of the final draft, the "near final", and the "final, final" DM maps. Make sure that all authors are on the same page as to when Kim and Deb need these maps and when they will be posted. For example, if a map is changed early Thursday morning, it may have to be re-posted to the web site if Kim and Deb have already done the preparation and posting for that week.
The last/final draft of the map on COB Wednesday will be the final final draft ... no changes to map after that (any last minute map changes can be made on next week's map). But we can change the text on Thursday morning before the final release date if necessary (for things like outlook or other changes).
* Clarify the listserve web site and emphasize that the authors themselves can point new members to the listserve to join.
* Creation of a vision-impaired friendly version of the DM website.
* Creation of a vision-impaired friendly version of the DM map.
* How to successfully deal with the voluminous weekly email.
Creating a separate listserver for drought research topics would probably not work. Instead, send an email to the current Drought Monitor general listserver saying something like, "To help the Drought Monitor authors more efficiently sort this list's email, please add the following tag to email discussing subjects other than providing input to the current weekly Drought Monitor: DM*COMMENT." Or, authors will just have to be more selective in reading the list email. We really did not resolve this issue.
9:20-9:40 a.m. * Identify issues relevant to drought monitoring in the western U.S. (e.g., the use of reservoir data & SWSI) to bring up for discussion at the Portland, OR May drought gathering
Wish List for SWSI:
Wish List for Reservoir Data:
* Identify issues relevant to drought monitoring in the southwestern U.S. (e.g., when does a desert have drought?) to bring up for discussion at a future drought gathering in the Southwest
It is possible to have a meteorological drought in a desert, but a hydro drought is another matter if the reservoirs are full. Need to define what a drought is; define the difference between drought and aridity; look at hydrology of the area (e.g. snow in the mountains) in determining the definition. Build consensus with the users in these areas, including politicians. Need to get SWSI computed for the southwestern states. Let each state's experts determine their definition of drought using tools such as SWSI.
9:40-10:00 a.m. * "Do we lead in the political decision process or follow?"
Lead intelligently as defined by science. Work with the politicians in the gray areas of science.
* Computation of the percent area in the Drought Monitor categories and other GIS matters
Ultimate goal is to take the DM to a higher resolution.... to the point where one would have the national map in its current form and then they could click to go down to more regional-scaled drought maps and finally down to state-level detailed maps or state Drought Monitors. This cooperative effort would be coordinated between the current Drought Monitor partners as well as the regional climate centers and the state climate offices.
* Terminology (should D1 be called "First Level Drought" or just plain "Drought" instead of "Moderate Drought"?)
No need to change terminology.
10:30-11:00 a.m. * Labeling, Interpretation, & Consistency. Examples:
Can there be a D0 (W), (A), or (F)?
D3(W) - does it imply no D1 or D2 Ag or Fire?
If an area is D3(F), is it automatically D2(A,W) unless stated otherwise?
If an area is D3(W), but also D0(A,F), should it be labeled D3(W) or an average D2(W)? (In other words: If an area has different severities of short- & long-term drought, do we show the most severe of these on the map or an "average"?)
Should we label multiple impacts with different D levels in a given area? No. But add a note to the map key for the user to read the text for different level multiple impacts.
Should we eliminate the Fire impact? No consensus, so keep it in. A lot of discussion of the fire labeling issue in general.
* When is a drought really over? When the blended indicators say so? When some of the indicators say so? When all of the indicators say so?
11:00-11:30 * Do we need two separate Drought Monitor maps (a weekly map for short-term drought & a monthly map for long-term drought)? More than two maps?
The general feeling was we do need two maps, at least two, one for short-term drought and one for long-term drought.
Frank Richards (NWS Office of Climate, Water & Weather Resources) offered to attempt to create a long-term (hydro) drought monitoring map (he is willing to go to the RFC's to try to make this happen). It would be called a "Water Resource Assessment", not a drought assessment. It would be created on a monthly basis by NWS hydro personnel in Washington DC from input from the 13 RFCs, COE, BLM, USDA/NRCS, etc., so there would be, in effect, a new/auxiliary set of (monthly) authors added to our nation's drought monitoring effort. This Water Resource Assessment would have a 5-scale category depiction similar to the Drought Monitor categories, be created in a GIS environment, be released on the Thursday that follows the 10th business day of each month. The input indicators would vary with RFC region, but would generally include: streamflow, well data, reservoir obs, SWSI, and multi-month precipitation. The dialog for the Water Resource Assessment product would occur on the same listserver as the Drought Monitor discussions.
The Drought Monitor authors responded very favorably to this.
* If depicting short- & long-term drought on one map: Again, do we average the two blends of indicators, or show the worst of the two on the one map?
On the current 4-panel experimental blends map product, change the bottom right panel map from the CPC modeled soil moisture depiction to a new map: a map that shows the worst Dx of the short and long-term blends.
Continue to depict the short and long-term blend maps as the top two panel maps. Change the weights on the long-term blend to:
The unified blend map (bottom left panel map) shall be generated as before except it can't get worse than the worst Dx of the short or long-term blend.
The published manually-created Drought Monitor map is a blend in our head (where each author emphasizes what he/she thinks is the most significant that week?).
If you have questions or need additional information on the June North American Drought Monitor Forum workshop, contact:Richard Heim