Title: UNSTABLE The UNderstanding Severe Thunderstorms and Alberta Boundary Layers Experiment
1UNSTABLEThe UNderstanding Severe Thunderstorms
and Alberta Boundary Layers Experiment
Project Overview NWC / NSSL Seminar Series NOAA
Hazardous Weather Testbed Spring Experiment
- Neil Taylor1, Dave Sills2, John Hanesiak3, Jason
Milbrandt4 - 1 Hydrometeorology and Arctic Lab, Environment
Canada (EC) - 2 Cloud Physics and Severe Weather Research
Section, EC - 3 Centre for Earth Observation Science,
University of Manitoba - 4 NWP Research Section, EC
2Outline
- Rationale
- Socioeconomic Issues
- Forecast Challenges
- Environment Canada Mandate
- Project Goals and Deliverables
- UNSTABLE Science Questions
- Preliminary Experimental Design
- Summary
3PASPC Areas of Responsibility
PASPC-EDM
4Severe Wx on Canadian Prairies1984 2006
Averages
Event Type Alberta Saskatchewan Manitoba Average for Prairies
Tornado 13 14 9 36
Hail 39 33 25 97
Wind 12 20 13 45
Rain 10 7 8 25
All Events 74 75 55 203
5What is UNSTABLE?
- Field experiment in summer 2008 over the Alberta
foothills designed to improve understanding of
processes important for convective initiation
(CI) and severe thunderstorm development - better understanding ? better watches/warnings
- Focus on
- ABL water vapour and convergence boundaries
- Land surface processes (sensible / latent heat
flux) - High-resolution NWP as a forecasting tool
- 3-week IOP July 2008
- Both observational and modeling components
- Led by Environment Canada in collaboration with
Canadian Universities and the private sector - International participation welcome!
6Rationale Socio-economic Impacts
7Rationale Socio-economic Impacts
8RationaleSocio-economic Impacts
9RationaleSocio-economic Impacts
- Frequent (Severe) Thunderstorms People More
People Busy Airports Potential Human and
Economic Loss - Since 1980 gt 2B and gt 40 lives lost in AB due to
severe thunderstorms - Improved understanding of processes leading to
severe storms ? better warnings ? mitigate
impacts of severe weather on Canadians
10Rationale AB Severe Wx Forecast Challenges
- AB Forecasters face uncertainty with respect to
- ABL structure and evolution (especially vertical
water vapour profiles in ABL) - Role and importance of mesoscale boundaries /
circulations in foothills (dryline?) - Land surface ABL interactions (sensible /
latent heat fluxes) in foothills and upstream - Conceptual models for CI
- Compounded by
- Inadequate observation network to resolve the
above - NWP performance with respect to above
11RationaleObs. Network
Hourly SFC observations available to PASPC
forecasters
- Large void of real-time surface observations over
the Alberta foothills - Foothills a known genesis region for severe
thunderstorms
12(No Transcript)
13Albert Thunderstorm Research
- Rich history dating back to Albert Hail Studies
(ALHAS) and Alberta Hail Project (AHP) - Later research largely focused on synoptic-scale
and upper-air processes - Conceptual models for Alberta severe weather
outbreaks established by Strong (1986) and Smith
and Yau (1993) - Capping lid, underrunning ABL moisture and
mountain-plain circulation - Little to no focus on ABL convergence boundaries
14Conceptual Model (Strong 1986)
15Conceptual Model (Strong 1986)
16Conceptual Model (Smith and Yau 1993)
Similar to model proposed by Strong (1986) but
with more focus on MP Circulation
17SFC Analysis (Smith and Yau 1993)SFC Td and Wind
Vectors
1600
1800
Shallow and capped ABL
Shallow and capped ABL
ABL Depth gt 800m
18RationaleSevere Wx Forecast Challenges
- Dryline-like convergence boundary has been
observed and measured in recent years - Appears to form mainly in response to subsidence
and mixing in lee of Rocky Mountains - Bulges observed in response to mixing of momentum
to the surface - Does this boundary conform to accepted conceptual
model (e.g., Ziegler and Rasmussen 1998)? - Has been sampled with mobile observations in
terms of humidity (mixing ratio) but not with
wind measurements - Existing observational network far too coarse
(100km between SFC stations!)
19Rationale The Dryline?
Dryline observed with and without mobile
observations (Hill 2006)
Drylines and severe storm tracks from summer 2000
Dryline transect (Strong)
Taylor (2004)
20RationaleEcoclimate Regions and ET
21Rationale EC Results Management Framework
- All of EC structured according to Outcome Project
Plans (OPPs) everything we do has an associated
OPP - UNSTABLE addresses 10 OPPs related to
- Monitoring atmospheric conditions
- Weather prediction
- Understanding, detection, and prediction of
severe and high-impact weather - Understanding the water cycle
- Improved weather warnings, forecasts, and warning
preparedness - Aviation weather services
22UNSTABLE Goals
- To improve understanding of atmospheric processes
(especially in ABL) prior to and during CI and
severe thunderstorm development - To improve accuracy and lead time for severe
thunderstorm watches and warnings - To assess utility of GEM-LAM-2.5 to resolve
physical processes over AB Foothills and ability
to provide useful guidance for CI and severe
thunderstorm forecasts - To refine existing conceptual models describing
CI and severe thunderstorm development over AB
and the Western Prairies
23UNSTABLE Deliverables
- Unique and high-resolution dataset of
measurements from various platforms including
surface, upper-air, and vertical profiles of
atmospheric characteristics - Peer-reviewed articles, presentations / posters
at conferences and workshops - Presentations / reference material targeting
forecasters at SPCs with operational application - Through Research Support Desk (RSD) direct
knowledge transfer to operational meteorologists
in real time prior to and during high-impact
weather events
24UNSTABLE Science Questions
- ABL Processes (Taylor/Sills Environment Canada)
- 1. What are the contributions of ABL processes to
the initiation of deep moist convection and the
development of severe thunderstorms in the
Alberta Foothills? - Land Surface ABL Interactions (Hanesiak U of
Manitoba) - 2. What are the contributions of surface
processes to the initiation of deep moist
convection and the development of severe
thunderstorms in the Alberta Foothills? - Numerical Weather Prediction (Milbrandt
Environment Canada) - 3. To what extent can high-resolution NWP models
contribute to forecasting the initiation and
development of severe thunderstorms originating
in the Alberta Foothills?
25Science Question 1 ABL Processes
- What is ABL evolution especially wrt water vapour
prior to and during CI? - What is role and importance of mesoscale
convergence boundaries and circulations
associated with CI? - How are they influenced by terrain and
synoptic-scale processes? - How do they affect storms (motion, intensity,
morphology)? - What is 4D characterization of the dryline and
importance for CI? - Which storms become severe and why? How related
to boundaries associated with CI? - Are conceptual models adequate?
- How improve observational network to aid
forecasters?
26Science Question 2 Land Surface ABL
Interactions
- Influence of wet / dry areas on CI and storm
evolution via agrometeorological model? - Can we resolve gradients in water vapour and
mesoscale circulations (e.g., land breezes)
across wet / dry areas? - If so how do they influence CI and storm
evolution? - What are heat fluxes over the region wrt wet /
dry areas and how influence temperature /
humidity stratification? tentative - How does background flow modify gradients /
circulations associated with wet / dry areas? - Can ET contributions to ABL column water vapour
be quantified? tentative - How can observational network be improved to
address the above?
27Science Question 3 Numerical Weather Prediction
- What constitutes a successful high-resolution
simulation? - How can we quantify the models ability to
simulate observed convection? - Can the atmospheric state be classified a priori
as predictable or non-predictable in terms of
recommended use of the GEM-LAM-2.5 run to guide
the forecast? - How realistic are simulated storm structures and
microphysical fields? - How realistic is the evolution of the boundary
layer and surface processes in the foothills
regions? - Can deficiencies in physical parameterizations be
identified? - What would be the effect of performing a
subsequent nest to a higher-resolution (e.g.
1-km) grid driven from the 2.5-km run? - Can an ensemble of high-resolution runs improve
the prediction of convective initiation? - Can a high-resolution analysis using the
additional observations improve the numerical
prediction of CI and subsequent storm development?
28Experimental Design Domain
- Study area designed to include existing SFC and
radar stations given climatological CI and
thunderstorm activity - Primary domain defined by supplementary mesonet
and FCA stations main focus for mobile
measurements - Secondary domain to include FCA and other
stations still deploy mobile measurements for
interesting cases
Red Deer
Banff
Calgary
29For Comparison
30What is Needed to Resolve ABL and Other Processes
Related to CI?
N
31Supplemental Instrumentation
15 Station Configuration
- Fixed
- Mesonet stations (10-20)
- 2 radiosondes
- Tethersonde
- 2 WV radiometers
- Profiling radiometer (H2O profile)
- GPS PW sensors
- Eddy Correlation Flux Tower(s)?
- Additional Profiling Radiometer (T, RH)?
- Mobile
- AMMOS / Strong Mobile (T, P, RH)
- MARS (PW, SFC wx, profile wind, T, RH)
- 3 radiosondes
- Aircraft
- Photography
Locations of fixed radiometers, GPS sensors,
tethersonde to be determined
32ATMOS SFC Mesonet Stations
Automated Transportable Meteorological
Observation System
33EC AMMOS Mobile Mesonet Unit
Automated Mobile Meteorological Observation System
34How Will the AMMOS be Used?
Collect data at 1 s intervals Measure gradients
across boundaries (met and land use) Fill in
holes in mesonet as needed
35University of Manitoba Instrumentation
36University of Manitoba Mobile Atmospheric
Research System (MARS)
37Pursuing Funding for Aircraft
National Research Council Canada Twin Otter (T,
Td, SFC T, 3-axis wind acceleration, vertical
fluxes, radiation)
Also investigating use of UAVs but limited
expertise within Environment Canada
WMI King Air w/ AIMMS-20 Instrument Package (T,
P, RH, 3-axis wind acceleration)
38Instrumentation Deployment
- Fixed mesonet (grid and line siting
configuration) takes advantage of existing
stations and climatologically favoured regions
for CI and severe storms (includes
high-resolution lines of mesonet stations) - Two fixed sounding locations near and upstream
(at low-levels) of foothills catch moist
advection and pre-storm ABL - Fixed tethersonde, WV radiometers, GPS PW
sensors, profiling radiometer(?) in primary study
area near expected CI regions - Mobile surface platforms to be deployed on
intensive observation days to obtain
four-dimensional characteristics of ABL and upper
troposphere - Deployment to target mesoscale boundaries and
favoured CI regions within study area(s) - Bookend AMMOS (and Strongs) mobile mesonet
with mobile radiosondes - Attempt to place MARS near to, and east of,
observed boundaries (thermal, moisture, wind
profiles) - Supplement ground-based observations with
aircraft stepped traverses and circuits
Details of deployment will appear in UNSTABLE
field plan
39Experimental Design Duration and IOP
- UNSTABLE Study Period
- 1 June to 31 August 2008
- Fixed mesonet stations to be deployed prior to
June 1st 2008 - Mobile instrumentation / communications tests in
15 June to 31 June window - Intensive Observation Period
- Tentatively 9 July to 31 July (23 days)
contingent on field participation, expendables, - UNSTABLE Operations Plan to be developed this
fall / winter
40Timeline and Milestones
Date Event
Summer 2006 Test of ATMOS and AMMOS
27-29 September 2006 Preliminary Mesonet Site Selection
March 2007 UNSTABLE website and leads for science questions 2 and 3
6 April 2007 Draft Science Plan distributed and posted
18-19 April 2007 First UNSTABLE Science Workshop
Spring / Summer 2007 Finalize Science Plan
2-4 May 2007 Mesonet Site Selection
31 May 2007 Presentations at 41st CMOS Congress
18 June 13 July 2007 BAQS-Met field use of ATMOS, AMMOS, tethersonde
1 Sept 13 Nov 2007 Develop UNSTABLE Field Plan
27 Nov 2007 UNSTABLE Field Plan workshop
29 Feb 2008 UNSTABLE Field Plan finalized
31 Mar 2008 Finalize all land-use agreements
12-31 May 2008 Deploy fixed mesonet stations
1 June 31 Aug 2008 UNSTABLE Study Period
9-31 July 2008 UNSTABLE IOP
1-19 Sept 2008 Remove mesonet stations, etc.
22 Sept 2008 Begin data QC
Fall 2008 UNSTABLE article for CMOS / BAMS
Funding Requests
41Principal Investigators
- Neil Taylor, HAL, EC
- Science Question 1 Co-Lead, Project Manager
- Dave Sills, CPSWRS, EC
- Science Question 1 Co-Lead
- John Hanesiak, CEOS, U of Manitoba
- Science Question 2 Lead
- Jason Milbrandt, RPN, EC
- Science Question 3 Lead
- Pat McCarthy, PASPC, EC
- PASPC Severe Weather Program Supervisor
- Geoff Strong, Adjunct Professor, U of Alberta
- Craig Smith, Climate Research Division, EC
42Collaborators
UNSTABLE is a collaborative project with National
and Provincial Government, Canadian University,
and Private Sector participation
43Summary
- Potential for future human and economic loss in
Alberta due summer severe storms is increasing - Accuracy and lead-time of convective watches and
warnings needs to be maximized to mitigate
impacts of summer severe weather - Severe weather forecast challenges wrt ABL water
vapour, convergence boundaries, and land surface
processes are compounded by - inadequate observations
- need for updated conceptual models
- sometimes questionable model performance
44Summary
- Field experiment being designed to investigate
ABL processes significant for CI and severe storm
development over the Alberta foothills (summer
2008) - Efforts to transfer results to SPC operations
with aim to improve watches / warnings - UNSTABLE to include both observational and
modeling components - targeted, high-resolution fixed and mobile
surface and upper-air observations - 2.5 km configuration of CMC GEM LAM
- Science questions and plan drafted in process
of refining science questions and instrumentation
/ measurement strategies
45Thank You!
- Neil.Taylor_at_ec.gc.ca
- (780) 951-8636