Transcript Predecessor Rain Events Ahead of TC Ike and TC Lowell on 11–14 September 2008 Lance F.

Predecessor Rain Events Ahead of TC Ike
and TC Lowell on 11–14 September 2008
Lance F. Bosart, Thomas J. Galarneau, Jr.,
Jason M. Cordeira, and Benjamin J. Moore
Department of Atmospheric and Environmental Sciences
University at Albany, SUNY
Albany, NY 12222
11th Annual Northeast Regional Operational Workshop
Albany, NY
4–5 November 2009
Motivation
• Predecessor Rain Events (PREs) are high-impact
weather events that can result in significant
inland flooding
• High-impact PREs occurred with TS Erin (18–19
Aug 2007), TC Ike (12–13 Sep 2008), and TC Rita
(24–26 Sep 2005)
• PREs represent a big forecast challenge for
models and humans alike
• Dynamics and thermodynamics governing PREs
need to be better understood
TS Erin PRE 18–19 Aug 2007
Example of High-Impact Nature of PREs
Photo from Minneapolis Star Tribune
Photo from NWS La Crosse, WI
Outline
• Brief synopsis of PRE/TC relationships
• Synoptic overview of Lowell/Ike PREs
– Rainfall and satellite signatures
– Upper-air analyses
– Precipitable water (PW) and sounding analysis
• Regional perspective
– Ike moisture, PRE, and downstream jet
– Trajectory analysis
– Cross section analysis
• Summary
Predecessor Rain Events (PREs)
•
•
•
•
•
Coherent area of rain displaced poleward of TC
Moisture transport from TC toward PRE
Event duration ~ 12 h
Maximum rainfall rates typically ≥ 100 mm (24 h)1
Time lag between PRE and TC passage ~ 36 h
Bosart and Carr (1978) conceptual
model of antecedent rainfall
for TC Agnes (1972)
Detailed study of PREs in Cote (2007) and
Galarneau et al. (2009, submitted to MWR)
Data: 2.5 NCEP–NCAR Reanalysis
200 hPa h mean (dam) and anomaly (σ),
mean wind (kt), and TC tracks
8–14 September 2008
15
= 00Z position
14
11
10
9
13
8
7
12 1110
TS Lowell
9
8
7
TC Ike
- 1. Lubbock, TX (LBB), 11 Sept, 198.1 mm
- broke all-time 24-h rainfall record of 147.8 mm set on 18–19 Oct 1983
- 2. Wichita, KS (ICT), 12 Sept, 261.9 mm
- broke all-time 24-h rainfall record of 165.6 mm set on 8 Jun 1923
- 3. Chicago, IL (ORD), 13 Sept, 168.7 mm
- broke all-time daily rainfall record of 164.8 mm set on 14 Aug 1987
3
2
1
Ending 1200 UTC
14 Sep 2008
http://nmq.ou.edu/
72-h Quantitative Precipitation Estimates (inches)
Ike tropical moisture
arrives by 06 UTC
PRE
ORD
L
L
Ike
Ike
ORD rainfall in 6-h periods:
00–06 UTC 13  5.1 mm
06–12 UTC 13  75.4 mm
12–18 UTC 13  72.6 mm
18–00 UTC 13  19.8 mm
00Z/13
12Z/13
WSR-88D base reflectivity mosaic
PRE
PRE
L
L
Ike
Ike
Source: NCAR case-selection archive
06Z/13
18Z/13
ORD
Ike
Ike
ORD rainfall in 6-h periods:
00–06 UTC 14  1.3 mm
06–12 UTC 14  5.6 mm
12–18 UTC 14  25.7 mm
18–00 UTC 14  5.3 mm
06Z/14
15Z/14
WSR-88D base reflectivity mosaic
Ike
Ike
Source: NCAR case-selection archive
12Z/14
18Z/14
Infrared Satellite Imagery
1200 UTC 9 September 2008
1200 UTC 10 September 2008
source: http://adds.aviationweather.gov
Infrared Satellite Imagery
1200 UTC 11 September 2008
1200 UTC 12 September 2008
source: http://adds.aviationweather.gov
Infrared Satellite Imagery
1200 UTC 13 September 2008
1215 UTC 14 September 2008
source: http://adds.aviationweather.gov
SLP, 1000–500 hPa Thickness, 250 hPa Wind
I = TC Ike
L = TC Lowell
1200 UTC 8 September
I
L
1200 UTC 9 September
L
I
SLP (solid contours every 2 hPa), 1000–500 hPa thickness (red dashed contours every 3 dam)
and 250 hPa wind speed (shaded in m s−1)
SLP, 1000–500 hPa Thickness, 250 hPa Wind
1200 UTC 10 September
L
I
I = TC Ike
L = TC Lowell
1200 UTC 11 September
L
I
SLP (solid contours every 2 hPa), 1000–500 hPa thickness (red dashed contours every 3 dam)
and 250 hPa wind speed (shaded in m s−1)
SLP, 1000–500 hPa Thickness, 250 hPa Wind
1200 UTC 12 September
I
I = TC Ike
L = TC Lowell
1200 UTC 13 September
I
SLP (solid contours every 2 hPa), 1000–500 hPa thickness (red dashed contours every 3 dam)
and 250 hPa wind speed (shaded in m s−1)
SLP, 1000–500 hPa Thickness, 250 hPa Wind
0000 UTC 14 September
I
I = TC Ike
L = TC Lowell
1200 UTC 14 September
I
SLP (solid contours every 2 hPa), 1000–500 hPa thickness (red dashed contours every 3 dam)
and 250 hPa wind speed (shaded in m s−1)
DT Analysis and Low-Level Frontogenesis
DT pressure (shaded in hPa),
DT–850 hPa wind shear (barbs in kt),
925–850 hPa ζ (contours every 2.0×10−5 s−1)
850 hPa h (solid contours every 2 dam)
wind (barbs in kt),
θ (dashed contours every 2 K),
frontogenesis [shaded in K (100 km)−1 (3 h)−1]
I
I
I = TC Ike
1200 UTC 12 September 2008
DT Analysis and Low-Level Frontogenesis
DT pressure (shaded in hPa),
DT–850 hPa wind shear (barbs in kt),
925–850 hPa ζ (contours every 2.0×10−5 s−1)
850 hPa h (solid contours every 2 dam)
wind (barbs in kt),
θ (dashed contours every 2 K),
frontogenesis [shaded in K (100 km)−1 (3 h)−1]
I
I
I = TC Ike
1200 UTC 13 September 2008
DT Analysis and Low-Level Frontogenesis
DT pressure (shaded in hPa),
DT–850 hPa wind shear (barbs in kt),
925–850 hPa ζ (contours every 2.0×10−5 s−1)
850 hPa h (solid contours every 2 dam)
wind (barbs in kt),
θ (dashed contours every 2 K),
frontogenesis [shaded in K (100 km)−1 (3 h)−1]
I
I
I = TC Ike
1200 UTC 14 September 2008
PW (shaded; mm), 250-hPa HGHT (black; dam),
700-hPa WND (kt), and 925–850-hPa REL VOR (magenta;
every 0.5 x 10-4 s-1)
PW above 700 hPa only
1200 UTC 11 Sep 2008
Total PW
Total Precipitable Water Flux [mm m s−1]
9−10 Sep
11−12 Sep
50 mm m s−1
8
Data: 0.5 NCEP–GFS analyses
13−14 Sep
16 24 32 40 48 56 64 72 80 mm m s−1
EPZ Santa Teresa
DRT Del Rio
00Z 11 Sep
12Z 10 Sep
MAF Midland
12Z 10 Sep
Source: http://weather.uwyo.edu/upperair/sounding.html
TOP Topeka
DVN Davenport
12Z 12 Sep
12Z 13 Sep
ILX Lincoln
12Z 13 Sep
Source: http://weather.uwyo.edu/upperair/sounding.html
0000 UTC 13 September 2008
1200 UTC 13 September 2008
PRE
L
L
Ike
Ike
56 mm
925 hPa h (dam)
925 hPa56
emm
(K)
200 hPa wind speed (m s1)
250 hPa h (dam), 700 hPa  (105 s1)
precipitable water (mm), 850–500 hPa mean wind (m s1)
Data: 0.5 NCEP–GFS analyses
700 hPa h (dam), 700 hPa wind (m s1)
700 hPa ascent (103 hPa s1)
900–400 hPa relative humidity (%)
925 hPa h (dam), 925 hPa wind (m s1)
925 hPa e (K)
200 hPa wind speed (m s1)
PRE
H
Ike
Ike
1200 UTC 13 September 2008
Data: 0.5 NCEP–GFS analyses
H
Surface Observations and
Base Reflectivity (dBZ)
MN
SD
WI
IA
NE
SD
NE
MN
WI
IA
IL
KS
MO
0002 UTC 13 Sep 2008
IL
KS
MO
0600 UTC 13 Sep 2008
http://www.atmos.albany.edu/student/cordeira/WEB/GFS_ARCHIVE/
72-h Backward Air Parcel Trajectories
LBB: 00Z / 12 Sep
10
20
30
ICT: 12Z / 12 Sep
40 dBZ
Backward trajectories released from latitude
and longitude of station every 100 hPa
Circles represent 00Z locations
Data: 0.5 NCEP–GFS analyses
hPa
t − 72h position of IKE
t − 72h position of LOWELL
72-h Backward Air Parcel Trajectories
TOP: 18Z / 12 Sep
10
20
30
CHI: 12Z / 13 Sep
40 dBZ
Backward trajectories released from latitude
and longitude of station every 100 hPa
Circles represent 00Z locations
Data: 0.5 NCEP–GFS analyses
hPa
t − 72h position of IKE
t − 72h position of LOWELL
A
B
Potential vorticity (PVU), θ (K), wind (kt)
A
B
Relative humidity (%), θ (K), and
upward vertical motion (10−3 hPa s−1)
A
0600 UTC 12 September
69
Source: NCAR case-selection archive
B
Data: 0.5 NCEP–GFS analyses
A
B
Potential vorticity (PVU), θ (K), wind (kt)
A
A
B
Frontogenesis [K (100 km)−1 (3 h)−1], θ (K), and
upward vertical motion (10−3 hPa s−1)
1200 UTC 12 September
Source:
NCAR case-selection archive
69
B
Data: 0.5 NCEP–GFS analyses
Cross Section Analysis
1200 UTC 13 Sep
Potential vorticity (PVU), tangential circulation vectors,
potential temperature (K)
C
Pressure (hPa)
D
0.5°x0.5°
NCEP GFS
analysis
10 cm
s−1
C
PVU
D
10 m s−1
Cross Section Analysis
1200 UTC 14 Sep
Potential vorticity (PVU), tangential circulation vectors,
potential temperature (K)
C
Pressure (hPa)
D
0.5°x0.5°
NCEP GFS
analysis
10 cm
s−1
C
PVU
D
10 m s−1
Cross Section Analysis
1200 UTC 13 Sep
Mixing ratio (g kg−1), wind speed (kts), tangential circulation
vectors, potential temperature (K)
C
Pressure (hPa)
D
0.5°x0.5°
NCEP GFS
analysis
10 cm
s−1
C
g kg−1
kts
D
10 m s−1
Cross Section Analysis
1200 UTC 14 Sep
Mixing ratio (g kg−1), wind speed (kts), tangential circulation
vectors, potential temperature (K)
C
Pressure (hPa)
D
0.5°x0.5°
NCEP GFS
analysis
10 cm
s−1
C
g kg−1
kts
D
10 m s−1
Cross Section Analysis
1200 UTC 13 Sep
Petterssen frontogenesis (K (100 km)−1 (3 h)−1), upward vertical
velocity (μb s−1), potential temperature (K)
C
Pressure (hPa)
D
0.5°x0.5°
NCEP GFS
analysis
C
K (100 km)−1 (3 h)−1
D
Cross Section Analysis
1200 UTC 14 Sep
Petterssen frontogenesis (K (100 km)−1 (3 h)−1), upward vertical
velocity (μb s−1), potential temperature (K)
C
Pressure (hPa)
D
0.5°x0.5°
NCEP GFS
analysis
C
K (100 km)−1 (3 h)−1
D
Summary of TC Ike/Lowell PREs
• PREs fed off deep moisture from Ike and
middle- and upper-level moisture from Lowell
• PREs occurred along low-level baroclinic zones
well poleward of Ike and Lowell
• PREs were best defined where intense
frontogenetical forcing was concentrated
• PREs were driven by deep ascent in
equatorward jet-entrance regions
• Downstream jet strengthened considerably
due to PRE- and Ike-driven diabatic heating