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A MULTISCALE ANALYSISOF A HEAVY RAINFALL EVENT
OVER LAKE MICHIGAN
Jason M. CordeiraDEPARTMENT OF ATMOSPHERIC AND ENVIRONMENTAL SCIENCES
UNIVERSITY AT ALBANY, STATE UNIVERSITY OF NEW YORK
NROW XIIIWednesday 2 November 2011
Nicholas D. MetzDEPARTMENT OF GEOSCIENCE
HOBART AND WILLIAM SMITH COLLEGES
OBJECTIVES
• To investigate far-upstream precursors to heavy rainfall events (HREs) in the Great Lakes region
• To investigate the possible role of Lake Michigan (LM) on difficult to predict HREs in the Great Lakes region
OUTLINE
• Motivation
• Radar overview
• Far-upstream precursors
• Synoptic-scale and mesoscale analysis
• WRF simulation
OUTLINE
• Motivation
• Radar Overview
• Far-upstream precursors
• Synoptic-scale and mesoscale analysis
• WRF simulation
MOTIVATION – PRECIPITATION TOTALS
• 48-h precipitation totals >150 mm (>6 in) over LM
• 48-h precipitation totals ~100 mm (~4 in) over northern Indiana
image source: http://nmq.ou.edu
48-h precipitation totals ending 0000 UTC 2 July 2011
• Valparaiso, IN– 91.7 mm precipitation on 1 July 2011– 100.8 mm precipitation in 24-h period ending 0000 UTC 2 July 2011– 30-d precipitation ending 0000 UTC 1 July 2011: 87.4 mm– 30-d precipitation ending 0000 UTC 2 July 2011: 188.2 mm– 1-in-5-yr event (http://hdsc.nws.noaa.gov/hdsc/pfds/)
image source: http://nmq.ou.edu
24-h precipitation totals ending 0000 UTC 1 July 2011
24-h precipitation totals ending 0000 UTC 2 July 2011
MOTIVATION – PRECIPITATION TOTALS
• Severe weather confined to Chicago region overnight 30 June to 1 July 2011
• Subsequent severe weather event over MN, WI, IA, SD late on 1 July 2011
image source: http://www.spc.noaa.gov
30 June 2011 Storm Reports 1 July 2011 Storm Reports
MOTIVATION – SEVERE WEATHER
image courtesy ABC-7 Chicago
MOTIVATION – NAM (WRF-NMM) QPFArea-averaged accumulated precipitation (28 June forecasts)
Area-averaged domain:
NC
EP
4-k
m s
tage
IV
NAM (WRF-NMM)
MOTIVATION – NAM (WRF-NMM) QPFArea-averaged accumulated precipitation (29 June forecasts)
NC
EP
4-k
m s
tage
IVN
AM
(W
RF
-NM
M)
Area-averaged domain:
MOTIVATION – NAM (WRF-NMM) QPFArea-averaged accumulated precipitation (29 June forecasts)
NC
EP
4-k
m s
tage
IVN
AM
(W
RF
-NM
M)
Area-averaged domain:
Forecasts largely miss 1800 UTC 30 June to 0600 UTC 1 July precipitation
OUTLINE
• Motivation
• Radar overview– 1800 UTC 30 June – 0600 UTC 1 July 2011
• Far-upstream precursors
• Synoptic-scale and mesoscale analysis
• WRF simulation
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
1200 UTC 30 June
image source: http://locust.mmm.ucar.edu/
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
1300 UTC 30 June
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
1400 UTC 30 June
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
1500 UTC 30 June
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
1600 UTC 30 June
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
1700 UTC 30 June
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
1800 UTC 30 June
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
1900 UTC 30 June
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
2000 UTC 30 June
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
2100 UTC 30 June
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
2200 UTC 30 June
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
2300 UTC 30 June
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
0000 UTC 1 July
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
0100 UTC 1 July
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
0200 UTC 1 July
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
0300 UTC 1 July
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
0400 UTC 1 July
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
0500 UTC 1 July
image source: http://locust.mmm.ucar.edu/
RADAR OVERVIEW – 30 JUNE–1 JULY 2011
0600 UTC 1 July
RADAR SUMMARY – 30 JUNE–1 JULY 2011System 1
×××××
System 2 System 3 System 417
18
19
20
21
22
23
00
01
0201
02
03
000102
03
04
03
0405
Convection features four quasi-linear systems:
• System 1: 1700 UTC 30 June to 2100 UTC 30 June 2011
• System 2: 2200 UTC 30 June to 0300 UTC 1 July 2011 – evolves into two right-moving supercells (×)
• System 3: 0000 UTC 1 July to 0400 UTC 1 July 2011
• System 4: 0300 UTC 1 July to 0500 UTC 1 July 2011
OUTLINE
• Motivation
• Radar overview
• Far-upstream precursors
• Synoptic-scale and mesoscale analysis
• WRF simulation
FAR-UPSTREAM PRECURSORS
• The evolution of the large-scale flow over North America is often influenced by variability in the large-scale flow over North Pacific
• Variability in the large-scale flow over North Pacific is often influenced by tropical cyclones
FAR-UPSTREAM PRECURSORS
Tropical Storm Haima (18–25 June 2011) Tropical Storm Meari (22–27 June 2011)
image source: http://agora.ex.nii.ac.jp/digital-typhoon/index.html.en
• The evolution of the large-scale flow over North America is often influenced by variability in the large-scale flow over North Pacific
• Variability in the large-scale flow over North Pacific is often influenced by tropical cyclones
• What is the influence of tropical storms Haima and Meari on the evolution of the large-scale flow over North America?
Meari Haima
0000 UTC 22 June 2011Precipitable water (mm; shade), 850-hPa rel. vor. (10−4 s−1; white), DT wind speed (m s−1; black), and 700-hPa wind (knots; barbs)
FAR-UPSTREAM PRECURSORS
H
M
source: 0.5° NCEP–GFS
0000 UTC 24 June 2011Precipitable water (mm; shade), 850-hPa rel. vor. (10−4 s−1; white), DT wind speed (m s−1; black), and 700-hPa wind (knots; barbs)
FAR-UPSTREAM PRECURSORS
H M
source: 0.5° NCEP–GFS
0000 UTC 24 June 2011Precipitable water (mm; shade), 850-hPa rel. vor. (10−4 s−1; white), DT wind speed (m s−1; black), 300–200-hPa PV (PVU; thin black), and 250-hPa irrotational wind (m s−1; vectors)
FAR-UPSTREAM PRECURSORS
H M
source: 0.5° NCEP–GFS
10 m s−1
0000 UTC 26 June 2011Precipitable water (mm; shade), 850-hPa rel. vor. (10−4 s−1; white), DT wind speed (m s−1; black), and 700-hPa wind (knots; barbs)
FAR-UPSTREAM PRECURSORS
M
source: 0.5° NCEP–GFS
0000 UTC 26 June 2011DT potential temperature (K; shade), DT wind speed (m s−1; black), DT wind (knots; barbs), and 850-hPa rel. vor. (10−4 s−1; white)
FAR-UPSTREAM PRECURSORS
M
source: 0.5° NCEP–GFS
0000 UTC 26 June 2011DT potential temperature (K; shade), DT wind speed (m s−1; black), DT wind (knots; barbs), and 850-hPa rel. vor. (10−4 s−1; white)
FAR-UPSTREAM PRECURSORS
Shifted domain
source: 0.5° NCEP–GFS
0000 UTC 28 June 2011DT potential temperature (K; shade), DT wind speed (m s−1; black), DT wind (knots; barbs), and 850-hPa rel. vor. (10−4 s−1; white)
FAR-UPSTREAM PRECURSORS
source: 0.5° NCEP–GFS
0000 UTC 30 June 2011DT potential temperature (K; shade), DT wind speed (m s−1; black), DT wind (knots; barbs), and 850-hPa rel. vor. (10−4 s−1; white)
FAR-UPSTREAM PRECURSORS
source: 0.5° NCEP–GFS
0000 UTC 30 June 2011DT potential temperature (K; shade), DT wind speed (m s−1; black), DT wind (knots; barbs), and 850-hPa rel. vor. (10−4 s−1; white)
FAR-UPSTREAM PRECURSORS
source: 0.5° NCEP–GFS
0000 UTC 30 June 2011700–500-hPa lapse rate (K km−1; shade), 700–500-hPa wind (knots; barbs), and 200-hPa geo. height (dam; black)
FAR-UPSTREAM PRECURSORS
DTθsource: 0.5° NCEP–GFS
FAR-UPSTREAM PRECURSORS
40°–50°N
20 June–10 July 2011700–500-hPa lapse rate (K km−1; shade), 250-hPa meridional wind anomaly (every 10 m s−1; red/blue contours), and 250-hPa zonal wind speed (every 5 m s−1 starting at 30; dash)
source: 0.5° NCEP–GFS
20 June–10 July 2011700–500-hPa lapse rate (K km−1; shade), 250-hPa meridional wind anomaly (every 10 m s−1; red/blue contours), and 250-hPa zonal wind speed (every 5 m s−1 starting at 30; dash)
FAR-UPSTREAM PRECURSORS
40°–50°N
“PRE”
OUTLINE
• Motivation
• Radar overview
• Far-upstream precursors
• Synoptic-scale and mesoscale analysis
• WRF simulation
SYNOPTIC-SCALE AND MESOSCALE ANALYSIS
1800 UTC 30 June 2011250-hPa geo. height (dam; solid) and wind speed (m s−1; shade), and 850-hPa wind (knots; barbs)
source: RUC 20-km
Low-level
jet
SYNOPTIC-SCALE AND MESOSCALE ANALYSIS
1800 UTC 30 June 20111000–500-hPa thick (dam; dash), SLP (hPa; solid), 925-hPa mixing ratio (g kg−1; shade), and 10-m wind (knots; barbs)
source: RUC 20-km
SYNOPTIC-SCALE AND MESOSCALE ANALYSIS
1800 UTC 30 June 2011Most-unstable CAPE (J kg−1; shade) and 0-to-6-km shear (knots; barbs)
source: RUC 20-km
SYNOPTIC-SCALE AND MESOSCALE ANALYSIS
1800 UTC 30 June 2011Manual surface analysis: temperature (°C; red), mixing ratio (g kg−1; green), and SLP (hPa; black)Base reflectivity (dBZ; shaded)
warm
front
SYNOPTIC-SCALE AND MESOSCALE ANALYSIS
1800 UTC 30 June 2011Manual surface analysis: temperature (°C; red), mixing ratio (g kg−1; green), and SLP (hPa; black)Base reflectivity (dBZ; shaded)
W E
SYNOPTIC-SCALE AND MESOSCALE ANALYSIS
1800 UTC 30 June 2011Cross sectional potential temperature (K; gray), mixing ratio (g kg−1; shaded), wind (knots), and horizontal temperature advection (K d−1; dashed every 10 K d−1)
W ELMWIMN MI
6 9 12 15 18 g kg−1
source: RUC 20-km
Pres
sure
(hP
a)
SYNOPTIC-SCALE AND MESOSCALE ANALYSIS
0000 UTC 1 July 20111000–500-hPa thick (dam; dash), SLP (hPa; solid), 925-hPa mixing ratio (g kg−1; shade), and 10-m wind (knots; barbs)
source: RUC 20-km
SYNOPTIC-SCALE AND MESOSCALE ANALYSIS
0000 UTC 1 July 2011Most-unstable CAPE (J kg−1; shade) and 0-to-6-km shear (knots; barbs)
source: RUC 20-km
SYNOPTIC-SCALE AND MESOSCALE ANALYSIS
0000 UTC 1 July 2011University of Wyoming Sounding
SYNOPTIC-SCALE AND MESOSCALE ANALYSIS
0000 UTC 1 July 2011Manual surface analysis: temperature (°C; red), mixing ratio (g kg−1; green), and SLP (hPa; black)Base reflectivity (dBZ; shaded)
warm front
SYNOPTIC-SCALE AND MESOSCALE ANALYSIS
0000 UTC 1 July 2011Manual surface analysis: temperature (°C; red), mixing ratio (g kg−1; green), and SLP (hPa; black)Base reflectivity (dBZ; shaded)
W E
SYNOPTIC-SCALE AND MESOSCALE ANALYSIS
0000 UTC 1 July 2011Cross sectional potential temperature (K; gray), mixing ratio (g kg−1; shaded), wind (knots), and horizontal temperature advection (K d−1; dashed every 10 K d−1)
W ELMWIMN MI
6 9 12 15 18 g kg−1
source: RUC 20-km
Pres
sure
(hP
a)
SYNOPTIC-SCALE AND MESOSCALE ANALYSIS
Pres
sure
(hP
a)
Temperature (°C)
1800 UTC 30 June 2011 0000 UTC 1 July 2011
source: RUC 20-kmRUC soundings
SYNOPTIC-SCALE AND MESOSCALE ANALYSIS
Pres
sure
(hP
a)1800 UTC 30 June 2011
0000 UTC 1 July 2011MAUL?
• Moist-Absolutely Unstable Layer (MAUL) criterion satisfied in RUC sounding at 0000 UTC 1 July 2011 (dewpoint depression <1°C and Δθe/Δz<0)
• MAULs are maintained in regions of strong mesoscale dynamic ascent in the presence of weak convective instability (Bryan and Fritsch 2000)
OUTLINE
• Motivation
• Radar Overview
• Far-upstream precursors
• Synoptic-scale and mesoscale analysis
• WRF simulation
WRF SIMULATION
4-km WRF-ARW simulation initialized at 1200 UTC 30 June 2011
• 4-km WRF-ARW simulation for 1200 UTC 30 Jun–1200 UTC 1 Jul 2011
• Initialized with and without LM (LM and No-LM, respectively)
• Physics: WSM-6; Cumulus: explicit; Surface: thermal diffusion
Initialized with LM Initialized without LM
LM grid points replaced with sub-surface and surface characteristics of Wisconsin grid point
LM (control) No-LM
WRF SIMULATION AND COMPARISON
12-h forecast verifying 0000 UTC 1 July 2011Simulated reflectivity (dBZ; shaded), 2-m pot. temp. (K; contours); and 10-m wind (knots; barbs)
LM (control) No-LM
Observed: NAM 12-h simulated reflectivity: HRRR 12-h simulated reflectivity:
• 30 June–1 July 2011 convective event associated with 24-h precipitation totals >100 mm over western Great Lakes region
• Rossby wave train amplification and dispersion associated with western North Pacific tropical cyclones Meari and Haima produced favorable environmental conditions for convection and heavy precipitation over the western Great Lakes region
• Elevated convection developed along a north-south oriented surface baroclinic zone (warm front) at the nose the low-level jet and in the presence of strong WAA, deep-tropospheric moisture, enhanced midtropospheric static instability, and moist absolute instability
SUMMARY 1
• Convection developed along the shorelines of LM where the LM “cold dome” and strong horizontal temperature gradients may have favored enhanced local ascent and organized convection, respectively
• Influence of LM on convective development was likely secondary to the synoptic and mesoscale environment
• WRF initialized with and without LM at 1200 UTC 30 June 2011 failed to produce the elevated convective event between 1800 UTC and 0600 UTC 1 July 2011
SUMMARY 2
HRES
Annual frequency of warm season 24-h precipitation events >25 mmData source: Unified Precipitation Dataset (UPD) May–October 1984–2003