Transcript Overview about the European Storm Forecast Experiemnt, ESTO

http://www.estofex.org/
Convective basics and
ESTOFEX
Speaker: Helge Tuschy
http://www.dwd.de/
1
Short vita
 studied Meteorology / Geophysics at the Leopold-Franzens
University of Innsbruck, Austria
 2002, 2007 internship National Weather Service Amarillo, Texas
 2004, internship Storm Prediction Center ( SPC )
 talks: ECSS, ICAM, media …
 forecaster at ESTOFEX / member of ESSL
 Since 2010 working at the DWD (RZ Leipzig, E-Germany)
 favorite sport: baseball and soccer
 favorite food: Italian style
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The outline
 Basics about organized convection
• Overview about ESTOFEX
• Case study (15th August 2008)
• Future of ESTOFEX
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Convective forecast parameters
and signatures
@ EUMETSAT
9-11 km
SBCAPE
MLCAPE
MUCAPE
0-6 km
0-3 km
0-1 km
Lifted Condensation Level (LCL)
0-3 km
Low-level
CAPE
Speed shear
Storm relative helicity
- mixing ratio (0-1 km)
- 0-1 km mean wind streamlines4
- real time T/Td data
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Convective available potential
energy
Surface based (SB) CAPE
 Surface dewpoints / temperatures
 realistic layer depth for thunderstorm
inflow ?
 Magnitude highly! variable in
space and time
Pro:
e.g. winter with thin low-level
moisture
Mean / Mixed layer (ML) CAPE
 Mean/Mixed temperatures / dewpoints
within lowest 50 – 100 hPa
 realistic layer depth for low topped
supercells ?
Pro:
often most reliable parameter
Contra:
in winter often underestimates
true magntiude
Contra: - in summer often way too
high
- decays too fast
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5
Speed shear
a)
b1)
b2)
d)
c)
Cyclonic
rotation
Anticyclonic
rotation
@ Eye on the
Twister
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@ LakeErieWX
Directional shear (helicity)
a)
b)
@ A REVIEW FOR FORECASTERS ON THE
APPLICATION OF HODOGRAPHS TO
FORECASTING SEVERE THUNDERSTORMS
by Charles A. Doswell III
c)
@ Dynamics of tornadic thunderstorms
by Joseph B. Klemp
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Storm relative winds
Storm relative winds
(arrow) and storm relative
helicity (colored area);
here: 1-3 km SRH
180 °
Storm relative helicity
Horiz. Vort.
vector
Thunderstorm motion
e.g. 320° 12 kn
270 °
90 °
15 kt
30 kt
Sfc. To 1 km
(tornadogenesis)
Sfc. To 3 km
(mesocyclones)
0°
3km
H   (V  C)  (kˆ  V 8)dz
z
0
Be careful of composed
parameters
Supercell composite parameter
Significant Tornado Parameter
Energy Helicity Index
Derecho Composite Parameter
(SCP)
(STP)
(EHI)
(DCP)
e.g. highly
fluctuating
STP  (
sbCAPE  2000 sbLCL   SRH 1   6BWD   200 sbCIN 

) 


 
2 2  
1  
1
1500Jkg1 
1500m
100
m
s
20
ms
150
Jkg
 
 
 

 Each parameter has its positive and negative side
 Composed parameters mix those aspects; negative ones
can multiply
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European Storm Forecast Experiment (ESTOFEX) www.estofex.org
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Forecasters of ESTOFEX
Dr. Pieter
Groenemeijer
Dr. Johannes
Dahl
Dr. Oscar van der
Velde
Christoph
Gatzen
Helge Tuschy
Oliver
Schlenczek
Tomas Pucik
Marko
Korosec
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1st outlook of ESTOFEX
VALID 06Z THU 10/10 - 00Z
FRI 11/10 2002
ISSUED: TUE 08/10 23:10Z
FORECASTER: HAVEN
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European Storm Forecast
Experiment (ESTOFEX)
What is ESTOFEX?
An initiative of a team of European meteorologists and students in
meteorology and serves as a platform for exchange of knowledge about
severe convective storms in Europe and elsewhere.
!
ESTOFEX offers a GUIDANCE where organized convection is
forecast. This guidance can be used by local forecast offices for
daily warning preparation.
!
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Which risk of (extremely) severe convective
weather phenomena does ESTOFEX forecast ?
Severe convective weather phenomena:
• tornado (waterspouts)
• hail with a diameter of at least 2.0 cm
• wind gusts with a speed of at least 25 m/s (92 km/h or about 49 knots)
• excessive rainfall of at least 60 mm
Extremely severe convective weather phenomena:
• tornado; (E)F 2 or stronger
• hail with a diameter of at least 5.0 cm
• wind gusts with a speed of at least 33 m/s (119 km/h or about 65 knots)
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The meaning of the level areas
• 41 km radius of a
chosen point
• verification by
EUCLID/ESWD
R = 25 miles
= 41 km
A ~ 5085 km2
Severe wind
gust report
Tornado
report
Large hail
report
Heavy rain
report
Evaluation of ESTOFEX forecasts: Severe thunderstorm forecasts
H.E. Brooks et al.
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Probabilities
Verification of severe and significant severe events (1266 forecasts)
Level areas
% coverage of
severe events
% coverage of
significant severe
events
(svr.[%])
(sig.svr.[%])
Level 0
0.40 %
0.01 %
<5
Level 1
4.90 %
0.80 %
5 – 15
Level 2
14.50 %
2.80 %
>15
Level 3
22.20 %
11.10 %
3–5
>5
Lightning probabilities
Marginal lightning probabilities
15.0 %
Enhanced lightning probabilities
50.0 %
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The meaning of the level areas
1) E.g. probability of 15 % means a 15 % chance for that event to happen
within a radius of 41 km around each point. May seem low, but compared
to climatology, it is significant
2) Level 0
expected probability of severe convection appears insignificant
3) Level 1
most common threat level; low threat of severe weather
4) Level 2
large confidence of severe storm occurrence and slight risk for
extreme severe
5) Level 3
major severe thunderstorm outbreak (e.g. 15th August 2008 )
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How do we prepare our outlooks?
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Wind profiler
Surface data
European radar data
(Meteox and local data)
Soundings:
Real time/model
AVHRR SST
(spout forecast)
ESTOFEX outlook
Lightning data
(EUCLID)
Ensemble
prediction system
(EPS) data from
global models
EUMETSAT
Satellite data [HVIS !]
Model data:
- global models
Climatology
- local / regional models
(e.g. thunderstorm days)
- self-produced outputs for convective
forecasts
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Synopsis
Structure of a Severe Weather Outlook
Short overview
Day 1 or 2 (SWODY 1 or SWODY 2)
- upper level streamline pattern (e.g. trough, ridge, jets)
- low levels (e.g. sig. boundaries, characteristics of the planetary boundary layer quality regarding
moisture, temperature)
- possible: short outline of model credibility (e.g. ensembles, EFIs etc.)
- if necessary: short side notes for significant weather events like a depression with a potential (sub)
tropical character
Discussion
Header
Severe Weather Outlook Day 2 (SWODY 2):
General discussion
Severe Weather Outlook Day 1 (SWODY 1):
Discussions of each area of interest within different paragraphs. The following points are discussed:
- kinematic environment (shear)
- instability
- forcing
- storm mode
- time frame/duration
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Tornado outbreak 15th August
2008 (Poland)
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Pattern recognition !
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Upper levels
White:
isohypse
Green:
isohumid
Yellow:
lapse rates
(2-4 km
AGL)
T
h
Pink arrow:
300 hPa jet
wind
H
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Low levels
White:
isobare
Green:
isohumid
Arrows:
850 hPa jet
wind and
temperature
advection
(colorized)
t
T
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Severe Weather Outlook Day 2: 13th August 2008
SYNOPSIS
upper-level trough shifts to the east over central Europe. […]. At the surface, a quasistationary frontal boundary is still in place, running from the Alpes over CNTRL Poland to W-Russia, […].
Active weather pattern continues as a strong
DISCUSSION
** A major severe-weather event is forecast for parts of central Europe and an outbreak of severe
thunderstorms with tornadoes, damaging wind gusts and significant hail can be expected. **
[…]
35-40 m/s 0-6km bulk shear values over the northern central Mediterranean. During the afternoon and evening hours, shear also increases
significantly E/NE of the Alpes, with 0-6km DLS values of 25-35m/s all the way to N-Poland. […] LL shear of locally up to 20m/s and also
very high SRH values, maximized over Poland, but also augmented all the way down to the N-Adriatic Sea.
Very rich BL moisture and steep mid-level lapse rates along the front result in near 1000 J/kg MLCAPE, with locally higher
MUCAPE values. […] Another interesting point is abundant LL CAPE release along the boundary, which could be a backing
mechanism for tornado development, which has to be monitored in the upcoming model runs.
is prime for tornadoes/a few strong ones/large
hail/a few damaging events included and severe to damaging wind gusts. […]
Forecast soundings from central Italy to Poland indicate that the environment
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Severe weather outlook day 2 (SWODY 2)
Issued: Wed 13 Aug 2008 21:18 Z
Level areas:
13th Aug 2008
Lightning data:
15th Aug 2008
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Severe weather outlook day 1
Issued: Thu 14 Aug 2008 21:16 Z
Issued: Fri 15 Aug 2008 18:09 Z
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Future of ESTOFEX
- More forecasters participating in this experiment, e.g. from the
Mediterranean or E/SE Europe
- Platform for forecasters to discuss realtime / past events
- To bring more meteorological students on board
- Creation of a detailed climatology about European convection
(also push verification of outlooks)
- In the long term future: maybe an institution for European convective
forecasts ?
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Thank you very much for
your attention !
Email: [email protected]
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