Conventional and Isentropic Analyses of a Cold-Season Heavy Rainfall Episode Associated with

Elevated Convection

Dr. Scott M. RochetteDepartment of the Earth

SciencesSUNY Brockport

24-h Rainfall ending at 1200 UTC 14 November 1993 (in.)

0000 UTC 14 November 1993 Surface Chart

(standard notation/symbology)

0000 UTC 14 November 1993 850-hPa z/V

0000 UTC 14 November 1993 850-hPa e

(note strong gradient over MO)

0000 UTC 14 November 1993 850-hPa e Advection

(red positive)

0000 UTC 14 November 1993 250-hPa z/V

0000 UTC 14 November 1993 Precipitable Water

(MO: 230-270% of normal)

0000 UTC 14 November 1993 KLZK e Cross-Section

(note deep CI layer above shallow stable layer near surface)

0000 UTC 14 November 1993 304 K Moisture

Transport Vectors(note MO downstream from MT maximum)

0000 UTC 14 November 1993 304 K Wind

Vectors/Isobars/Omega(solid isentropic UVM)

0000 UTC 14 November 1993 Ageostrophic/Omega

Cross-Section(Point C northwest MO; Point D south-central

MO)

Summary

• Cool-sector MCS – cool side of sfc boundary– cool side of 850-hPa e

• Strong LLJ– coupled to ULJ?

• MCS in region of positive LL e advection

• Stable boundary layer– elevated CI– MCS not rooted to

boundary layer

• High moisture content– PW 230-270% of normal

• Diagnosis of UVM– Cross-sections surfaces

• Isentropic MT vectors very illustrative– MCS forms downstream

of max MT vectors