Jennifer Q. BelgeEric G. Hoffman

Plymouth State University

11/06/08Northeast Regional

Operational Workshop

Preferred Regions of Convective Development over

Northern New England as a Function of Flow Regime: Southwesterly Flow Case

Studies

http://www.eoearth.org/upload/thumb/6/61/Mature_thunderstorm_cloud.jpg/250px-Mature_thunderstorm_cloud.jpg

Previous Work- Evan Lowery (2008) 5 year climatology of northern New

England thunderstormsKGYX radar domainApril – September2003-2007SCIT

Spatial distribution of cells as a function of large-scale flow at 700 hPa

Results- Lowery (2008)

SW FLOW5 clusters

○ Central Oxford, Franklin and Somerset counties in ME

○ Just south of Belknap, Merrimack border in NH

○ Southern Oxford county in ME

○ Northern Grafton county in NH

○ Southern Somerset county in ME

Grafton

Oxford

FranklinSomerset

Coos

CarrollBelknap

Merrimack

York

Strafford

Rockingham

Hillsborough

Sullivan

Cheshire

Piscataquis

Aroostook

Cumberland

Androscoggin

Kennebec

Penobscot

WaldoKnox

LincolnSagadahoc

NW FLOW 3 clusters

Border of Strafford (NH) and York (ME) counties

Tri-county border of Oxford (ME), Carroll (NH) and York(ME)

Border of Grafton (NH) and Coos (NH) county

Motivation

Lowery’s study did not address:Why are there preferred regions of

development with respect to flow regime?

Differences between flow regimes? Forecasting potential

KGYX

Scientific Questions

Why do thunderstorm cells initiate where they do as a function of large-scale flow?SW and NW @ 700 hPa only

Are there certain meteorological patterns present in the mesoscale environment that is conducive to convection in these regions found by Lowery (2008)?

Data and Methodology

Case StudiesRadar reflectivity examined for each

case from May-September 2007 only Case study selection

1.Cells were to initiate in the significant areas identified by Lowery (2008)

2.Cells were to not be associated with a frontal zone○ Eliminate influence of frontal boundary

in mesoscale analysis

Results

Radar Sounding 12 UTC

KGYX Surface analysis RUC

Synoptic overview

12 UTC LAPS

KGYXMesoscale

analysis17 UTC

July 13, 2007

Synoptic Analysis12 UTC

Surface Analysis 12 UTC

500 hPa Height 12 UTC

250 hPa Height and Wind 12 UTC

Sounding 12 UTC

Mesoscale Analysis17 UTC

Surface Analysis 18 UTC

Surface Dew Point 17 UTC

Surface CAPE 17 UTC

Surface Flow Vectors and Topo 17 UTC

Surface Flow Vectors and Topo 17 UTC

Surface Convergence 17 UTC

Mean Sea Level Pressure 17 UTC

Conclusions

Preliminary Results July 13, 2007 SW

Flow CaseMoisture &

instability sufficient over entire area○ Genesis region

was not uniqueSurface

convergence and corresponding surface trough could provide the necessary lift

Results from the August 2, 2007 case show the same results and conclusions

WORKS CITED

Lowery, E.M, 2008: Using the WSR-88D Storm Structure Product to Develop a Climatology of Northern New England Thunderstorms as a Function of Large-Scale Flow, Plymouth State University, Master of Science Thesis

WORKS CITED

Lowery, E.M, 2008: Using the WSR-88D Storm Structure Product to Develop a Climatology of Northern New England Thunderstorms as a Function of Large-Scale Flow, Plymouth State University, Master of Science Thesis

Questions?

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