Analyses of the 10 June and Analyses of the 10 June and 19 June 2002 IHOP 19 June 2002 IHOP

Convection Initiation CasesConvection Initiation Cases(with a minor plug for BLE!)(with a minor plug for BLE!)

Yvette P. RichardsonYvette P. Richardson

Nettie R. ArnottNettie R. Arnott

James N. MarquisJames N. Marquis

Brian MonahanBrian Monahan

June 14, 2004June 14, 2004

IHOP Scientific WorkshopIHOP Scientific Workshop

Surface Analysis Surface Analysis 1900 UTC1900 UTC

Overall EvolutionOverall Evolution

Data Collection: 1918 UTC – 2118 UTCCI: 2103 UTC

10 June 2002 IOR10 June 2002 IOR

Sounding in IOR 2044 UTCSounding in IOR 2044 UTC

3 km AGL

LCL

Top of domain

Dry air above boundary layer

Weak capping inversion

Sounding near CI 1935 UTCSounding near CI 1935 UTC

3 km AGL

LCL

High Temporal Resolution LHigh Temporal Resolution Loopoop

King Air W vs. Radar WKing Air W vs. Radar W

-3

-2

-1

0

1

2

3

King Air Radar

740 m AGL Correlation = 0.78

A A’

-3

-2

-1

0

1

2

3

King Air Radar

1230 m AGL Correlation = 0.83

A A’

King Air track = black line

Warm colors = +w

Cold colors = -w

100 m AGL

Warm colors = convergence

Cold colors =

Divergence

Contoured every

2 x 10 –3 s-1

(0 contour not shown)

23.

5

km

23.0 km

23.

5

km23.0 km

100 m AGL

Warm colors = convergence

Cold colors =

Divergence

Contoured every

2 x 10 –3 s-1

(0 contour not shown)

23.

5

km23.0 km

100 m AGL

Warm colors = convergence

Cold colors =

Divergence

Contoured every

2 x 10 –3 s-1

(0 contour not shown)

23.

5

km23.0 km

100 m AGL

Warm colors = convergence

Cold colors =

Divergence

Contoured every

2 x 10 –3 s-1

(0 contour not shown)

Parcel trajectory moviesParcel trajectory movies

Box =IOR

Height = 1.4 km

View Point: Ahead of the cold front looking towards the North West

Parcels reach 100 m AGL at 1953 UTC

Parcels reach 100 m AGL at 2017 UTC

1955 UTC 1946 UTC

2007 UTC 2010 UTC

2020 UTC

IOR convergence beings weakening

2025 UTC

IOR convergence beings weakening

2034 UTC

IOR convergence beings weakening

2039 UTC

IOR convergence beings weakening

2045 UTC

IOR convergence beings weakening

2037 UTC

2055 UTC

IOR convergence beings weakening

2056 UTC

2143 UTC

Why was there no initiation of Why was there no initiation of deep convection within the deep convection within the

IOR?IOR?

Behind cold front Ahead of cold front

Potential Temperature at 600 m Potential Temperature at 600 m AGLAGL

P3 Track

1939 UTC

1956 UTC

2035 UTC2018 UTC

Mobile Mesonet WarmingMobile Mesonet Warming

Convection did not initiate in Convection did not initiate in IOR because…IOR because…

Weakening temperature gradient Weakening temperature gradient across cold front led to weaker across cold front led to weaker frontal circulationfrontal circulation

Dry air aloft made growth difficult Dry air aloft made growth difficult to sustainto sustain2007 UTC 2056 UTCWeakening

convergence

Why did convection initiate Why did convection initiate so close by?so close by?

Enhanced Enhanced convergence?convergence?

Cold front did not Cold front did not dissipate?dissipate?

Boundary – cold front Boundary – cold front intersection? Hints of intersection? Hints of this in satellite and this in satellite and radar dataradar data

Did wave pattern along Did wave pattern along front have any front have any influence?influence?

Future WorkFuture Work

ELDORA data near CI (with Kingsmill)ELDORA data near CI (with Kingsmill) Photogrammetry to map cloudsPhotogrammetry to map clouds Submit paper for Special IssueSubmit paper for Special Issue Data assimilation / Numerical modelingData assimilation / Numerical modeling

Fill in data gapsFill in data gaps Influence of nearby developing convectionInfluence of nearby developing convection Influence of warming and convective Influence of warming and convective

instabilityinstability

June 19 CI CaseJune 19 CI Case

Dryline near Colby, KSDryline near Colby, KS

DOW3

XPOL

DOW2 DOW2

XPOL

IOR #1

IOR #2

DOW3

DOW2

XPOLDOW2

Deployment #2 – 21:20+ Deployment #2 – 21:20+ UTCUTC

2514

13.5

Deployment B Loop 1Deployment B Loop 1 Deployment B Loop 2Deployment B Loop 2

Z=400m

Vorticity in Color

White contours of w

Strong misocyclones – separated from w by approximately ¼ wavelength

wmax

Misocyclones similar intensity to previous time

Updraft filling in along line

Z=400m

Vorticity in Color

White contours of w

DOW3 21:23

Initiation of Deep Convection

Cells apparent at 21:23 in DOW3 scans

Initiation captured by XPOL but occurs ‘behind’ DOW3 while DOW2 is in motion

Unclear if origin can be traced to features within the IOR

Aircraft may be needed to fill in the gaps

DZ

Later InitiationLater Initiation

Deployment 2 Loop 3Deployment 2 Loop 3

MisocycloneMisocyclone Loop w/raw radar data Loop w/raw radar data

4pm CDT Dustdevil 6 pm CDT Landspout

Future WorkFuture Work

Combine wind analyses with water vapor Combine wind analyses with water vapor measurements (lidar, mobile mesonets, measurements (lidar, mobile mesonets, dropsondes, satellite, MIPS, mobile dropsondes, satellite, MIPS, mobile radiometer, etc.)radiometer, etc.)

Perform trajectory calculations to look at Perform trajectory calculations to look at initiation and misocyclone formation/evolutioninitiation and misocyclone formation/evolution

Cloud Photogrammetry Analysis (with Erik Cloud Photogrammetry Analysis (with Erik Rasmussen)Rasmussen)

Submit Paper for Special IssueSubmit Paper for Special Issue

Boundary Layer EvolutionBoundary Layer Evolution(14 June 2002)(14 June 2002)

Fine Resolution Radar Loop from 130Fine Resolution Radar Loop from 1300-1900 UTC0-1900 UTC