A M ULTISCALE A NALYSIS OF A H EAVY R AINFALL E VENT OVER L AKE M ICHIGAN Jason M. Cordeira D EPARTMENT OF A TMOSPHERIC AND E NVIRONMENTAL S CIENCES U NIVERSITY AT A LBANY, S TATE U NIVERSITY OF N EW Y ORK NROW XIII Wednesday 2 November 2011 Nicholas D. Metz DEPARTMENT OF GEOSCIENCE HOBART AND WILLIAM SMITH COLLEGES

O BJECTIVES 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

O UTLINE Motivation Radar overview Far-upstream precursors Synoptic-scale and mesoscale analysis WRF simulation

O UTLINE 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: 48-h precipitation totals ending 0000 UTC 2 July 2011

Valparaiso, IN – 91.7 mm precipitation on 1 July 2011 – 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: mm – 1-in-5-yr event ( image source: 24-h precipitation totals ending 0000 UTC 1 July 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: 30 June 2011 Storm Reports 1 July 2011 Storm Reports MOTIVATION – SEVERE WEATHER image courtesy ABC-7 Chicago

MOTIVATION – NAM (WRF-NMM) QPF Area-averaged accumulated precipitation (28 June forecasts) Area-averaged domain: NCEP 4-km stage IV NAM (WRF-NMM)

MOTIVATION – NAM (WRF-NMM) QPF Area-averaged accumulated precipitation (29 June forecasts) NCEP 4-km stage IV NAM (WRF-NMM) Area-averaged domain:

MOTIVATION – NAM (WRF-NMM) QPF Area-averaged accumulated precipitation (29 June forecasts) NCEP 4-km stage IV NAM (WRF-NMM) Area-averaged domain: Forecasts largely miss 1800 UTC 30 June to 0600 UTC 1 July precipitation

O UTLINE 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 UTC 30 June image source:

RADAR OVERVIEW – 30 JUNE–1 JULY UTC 30 June

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 30 June

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 30 June

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 30 June

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 30 June

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 30 June

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 30 June

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 30 June

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 30 June

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 30 June

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 30 June

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 1 July

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 1 July

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 1 July

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 1 July

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 1 July

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 1 July

image source: RADAR OVERVIEW – 30 JUNE–1 JULY UTC 1 July

RADAR SUMMARY – 30 JUNE–1 JULY 2011 System 1 × × × × × System 2System 3System 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

O UTLINE Motivation Radar overview Far-upstream precursors Synoptic-scale and mesoscale analysis WRF simulation

F AR - 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

F AR - UPSTREAM PRECURSORS Tropical Storm Haima (18–25 June 2011)Tropical Storm Meari (22–27 June 2011) image source: 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 2011 Precipitable 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) F AR - UPSTREAM PRECURSORS H M source: 0.5° NCEP–GFS

0000 UTC 24 June 2011 Precipitable 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) F AR - UPSTREAM PRECURSORS H M source: 0.5° NCEP–GFS

0000 UTC 24 June 2011 Precipitable 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) F AR - UPSTREAM PRECURSORS H M source: 0.5° NCEP–GFS 10 m s −1

0000 UTC 26 June 2011 Precipitable 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) F AR - UPSTREAM PRECURSORS M source: 0.5° NCEP–GFS

0000 UTC 26 June 2011 DT 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) F AR - UPSTREAM PRECURSORS M source: 0.5° NCEP–GFS

0000 UTC 26 June 2011 DT 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) F AR - UPSTREAM PRECURSORS Shifted domain source: 0.5° NCEP–GFS

0000 UTC 28 June 2011 DT 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) F AR - UPSTREAM PRECURSORS source: 0.5° NCEP–GFS

0000 UTC 30 June 2011 DT 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) F AR - UPSTREAM PRECURSORS source: 0.5° NCEP–GFS

0000 UTC 30 June 2011 DT 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) F AR - UPSTREAM PRECURSORS source: 0.5° NCEP–GFS

0000 UTC 30 June –500-hPa lapse rate (K km −1 ; shade), 700–500-hPa wind (knots; barbs), and 200-hPa geo. height (dam; black) F AR - UPSTREAM PRECURSORS DTθ source: 0.5° NCEP–GFS

F AR - UPSTREAM P RECURSORS 40°–50°N 20 June–10 July –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 –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) F AR - UPSTREAM P RECURSORS 40°–50°N “PRE”

O UTLINE Motivation Radar overview Far-upstream precursors Synoptic-scale and mesoscale analysis WRF simulation

SYNOPTIC-SCALE AND MESOSCALE ANALYSIS 1800 UTC 30 June 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

S YNOPTIC - SCALE AND MESOSCALE ANALYSIS 1800 UTC 30 June –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

S YNOPTIC - SCALE AND MESOSCALE ANALYSIS 1800 UTC 30 June 2011 Most-unstable CAPE (J kg −1 ; shade) and 0-to-6-km shear (knots; barbs) source: RUC 20-km

S YNOPTIC - SCALE AND MESOSCALE ANALYSIS 1800 UTC 30 June 2011 Manual surface analysis: temperature (°C; red), mixing ratio (g kg −1 ; green), and SLP (hPa; black) Base reflectivity (dBZ; shaded) warm front

S YNOPTIC - SCALE AND MESOSCALE ANALYSIS 1800 UTC 30 June 2011 Manual surface analysis: temperature (°C; red), mixing ratio (g kg −1 ; green), and SLP (hPa; black) Base reflectivity (dBZ; shaded) WE

S YNOPTIC - SCALE AND MESOSCALE ANALYSIS 1800 UTC 30 June 2011 Cross 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 ) WE LMWIMNMI g kg −1 source: RUC 20-km Pressure (hPa)

S YNOPTIC - SCALE AND MESOSCALE ANALYSIS 0000 UTC 1 July –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

S YNOPTIC - SCALE AND MESOSCALE ANALYSIS 0000 UTC 1 July 2011 Most-unstable CAPE (J kg −1 ; shade) and 0-to-6-km shear (knots; barbs) source: RUC 20-km

S YNOPTIC - SCALE AND MESOSCALE ANALYSIS 0000 UTC 1 July 2011 University of Wyoming Sounding

S YNOPTIC - SCALE AND MESOSCALE ANALYSIS 0000 UTC 1 July 2011 Manual surface analysis: temperature (°C; red), mixing ratio (g kg −1 ; green), and SLP (hPa; black) Base reflectivity (dBZ; shaded) warm front

S YNOPTIC - SCALE AND MESOSCALE ANALYSIS 0000 UTC 1 July 2011 Manual surface analysis: temperature (°C; red), mixing ratio (g kg −1 ; green), and SLP (hPa; black) Base reflectivity (dBZ; shaded) WE

S YNOPTIC - SCALE AND MESOSCALE ANALYSIS 0000 UTC 1 July 2011 Cross 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 ) WE LMWIMNMI g kg −1 source: RUC 20-km Pressure (hPa)

S YNOPTIC - SCALE AND MESOSCALE ANALYSIS Pressure (hPa) Temperature (°C) 1800 UTC 30 June UTC 1 July 2011 source: RUC 20-km RUC soundings

S YNOPTIC - SCALE AND MESOSCALE ANALYSIS Pressure (hPa) 1800 UTC 30 June UTC 1 July 2011 MAUL? Moist-Absolutely Unstable Layer (MAUL) criterion satisfied in RUC sounding at 0000 UTC 1 July 2011 (dewpoint depression <1°C and Δθ e /Δz<0) MAULs are maintained in regions of strong mesoscale dynamic ascent in the presence of weak convective instability (Bryan and Fritsch 2000)

O UTLINE 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 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 2011 Simulated 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 S UMMARY 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 S UMMARY 2

HRE S Annual frequency of warm season 24-h precipitation events >25 mm Data source: Unified Precipitation Dataset (UPD) May–October 1984–2003