A CASE STUDY OF THE GREAT PLAINS BLIZZARD OF 27-28 NOVEMBER 2005

P. S. Market, C. J. Melick, B. P. Pettegrew,A. E. Becker, and L. L. Smith

Department of Soil, Environmental and Atmospheric SciencesUniversity of Missouri-Columbia

Presented at the Winter Weather Workshop National Weather Service Office, Pleasant Hill, MO

29 October 2007

With the aid of…

• John Stoppkotte, SOO

North Platte, Nebraska, NWS

• UMC students enrolled in

ATMS-4720, Synoptic Meteorology II

• The National Science Foundation

Introduction

• Analysis of occluded cyclone– Well-developed trowal structure

• Multiple bands of precipitation

• Blizzard conditions for an extended period in LBF CWA

• Lightning activity present but limited

gusts(mph)

snow(in.)

Courtesy, NOAA/NWS LBF

Purpose

• Assess the nature of the unique trowal structure– Influence on banded precip?

• Assess lightning observations– Are they valid?

• Assess the production of extreme winds

gusts(mph)

snow(in.)

Courtesy, NOAA/NWS LBF

- Synopsis -

12Z 2005 Nov 28

12Z 2005 Nov 28

12Z 2005 Nov 28 – 925 mb

12Z 2005 Nov 28 – 850 mb

12Z 2005 Nov 28 – 700 mb

12Z 2005 Nov 28 – 500 mb

12Z 2005 Nov 28 – 300 mb

12Z 2005 Nov 28 – RADAR

Storm total snow (in.) , 27-30 Nov 2005

- Event Specifics -

2005 Nov 28 – Surface Obs

• KAUH 1310Z +SN LTG DSNT SW– With NLDN flash near this time

• KVTN 1622Z, 1652Z, 2008Z, 2032Z, 2052Z, 2109Z TSSN

– KAUH – Aurora, NE– KVTN – Valentine, NE

2005 Nov 28 – NE Sfc Stations

2005 Nov 28 – 1300Z

• Initial development of lightning and thunder

• Reported in Aurora, NE, METAR

• Corroborated by NLDN

2005 Nov 28 – 13Z RUC20 – AUH Sounding

2005 Nov 28 – 2100Z

• Redevelopment of lightning and thunder

• Emergence of trowal feature– And a unique double trowal signature

• Evolution of meso- circulations

• Significant banded precipitation underway

2005 Nov 28 – 19Z RUC20 –VTN Sounding

2005 Nov 28 – 21Z VIS Sat

2005 Nov 28 – 21Z IR Sat

2005 Nov 28 – 21Z WV Sat

2005 Nov 28 – 21Z Sounder CTP

2005 Nov 28 – 21Z RADAR

2005 Nov 28 – IR Loop 13Z-23Z

2005 Nov 28 – RADAR Loop 18Z-23Z

- Trowal Structure -

Various Model Solutions for trowal21Z Nov 28 2005 – 308 K e

Cross Section through Double trowal2100V009 Nov 28 2005 – NAM 212 Trowal Surface

Cross Section through Double trowal21Z Nov 28 2005 – NAM 212 Grid Cross Section

WRF 12-km SolutionsValid 21Z Nov 28 2005 – 21 hr Solutions Reflectivity (Shaded & contoured)

WRF 12-km SolutionsValid 21Z Nov 28 2005 – 21 hr Solutions Reflectivity (shaded) with θe

WRF 12-km SolutionsValid 21Z Nov 28 2005 – 21 hr Solutions θe - Full Physics (green) / No microphysics (brown)

WRF 12-km SolutionsValid 21Z Nov 28 2005 – 21 hr Solutions θe (white contours)

WRF 12-km SolutionsValid 21Z Nov 28 2005 – 21 hr Solutions Reflectivity with ω

Conclusions

• AUH - 13Z - One NLDN CG flash establishes a history of electrical activity

• VTN - 16Z, 20Z, 21Z – METARS report TSSN based upon surface sensor– Valid, to the best of our knowledge

• Also, soundings support existence of lightning

Conclusions

• Existence of double trowal appears valid– Reason(s) for creation of the structure are

unclear– Structure seems to have some bearing on

banded precipitation development and/or evolution

• The trowal aspect of this cyclone warrants further study

Thank you!

Questions?Comments?

marketp@missouri.edu

ROCS Homepage : http://weather.missouri.edu/ROCS/