The Norm Phillips Symposium


Thanksgiving Weekend Storm of 1950

Robert E. Kistler, NOAA/NWS/NCEP/EMC, Camp Springs, MD; and L. Uccellini and P. J. Kocin

In recognition of the pioneering work of Norm Phillips in numerical weather prediction, we revisit a case that served as a catalyst in the creation of what is now know as the National Centers for Environmental Prediction. The east coast storm of Thanksgiving weekend, 1950, was ranked as one of the top ten storms of the 20th Century by the Weather Channel. We first revisited this storm in the course of the 50 year NCEP/NCAR Reanalysis, where it was noted in Kistler, et al (2001):

Near the top of the list of candidates for "Storm of the Century" over the United States would be the storm of November 25-27, 1950 (Smith, 1950, Bristor, 1951). The storm caused East Coast flooding, widespread wind damage, and record snowfalls and minimum temperatures during its rampage over the northeastern United States. In the years following the storm, it served as a case study by the pioneers in numerical weather prediction (e.g. Phillips, 1958)…

The initial conditions depict a weak cyclonic wave over Minnesota, along the leading edge of a very cold air mass over southwestern Canada. Over the course of the next 5 days, the record breaking cold air moved southeastward, eventually spawning a coastal "bomb" that retrograded back to the lower Great Lakes underneath a deep closed vortex.

At the time of the storm, the manually derived forecasts of the day were unable to anticipate this extreme event. The storm severity and lack of warning served as motivational focal points during the infancy of NWP. As Norm recounted in his address to the 50th Anniversary of Numerical Weather Prediction in Potsdam, Germany, (Phillips, 2000) the 1950 storm was chosen the first test case for Charney’s 2 Level model. Even though the results of the test were not as successful as hoped, they did set in motion the meetings and plans that would ultimately evolve into the formation of the multi-agency Joint Numerical Weather Prediction Unit (JNWPU) in 1954. The JNWPU then became the National Meteorological Center, and, subsequently, the present day NCEP.

In his address Norm revisited the 1950 storm using an expanded set of NCEP Reanalysis T62L28 re-forecasts (Kistler, 2001) we provided to note the progress in NWP from the early 50’s to the late 90’s. (See the T62L28 analyses and forecasts at URL

In the process of creating a synoptic climatology of east coast storms, we are updating and expanding the list of storms described in Kocin and Uccellini (1990). The 2003 Global Data Assimilation System (GDAS) of resolution T254L64 has been rerun for each of the selected storms in hindcast mode, driven by the observations collected for the Reanalysis. Prominent in that expanded set of storms is the Nov 1950 event.

In tribute to Norm we repeat the November 1950 reforecasts with the NCEP 2003 Global Forecast System. We will examine the results from the reforecast of the 1950 Thanksgiving storm using the higher resolution reanalysis and current operational forecast model to determine if 1) these model and analysis attributes extend the lead time predictability beyond the 3.5 days established with the first attempt to simulate this storm and 2) if the higher resolution models and related analysis scheme provide a deeper cyclone and indications of the severity with greater lead time.

References Bristor, C.L., 1951: The Great Storm of November 1950. Weatherwise, 4,10-16.

Kistler, R.; Kalnay, E.; Collins, W.; Saha, S.; White, G.; Woolen, J.; Chelliah, M.; Ebiszusaki, W.; Kanamitsu, M.; Kousky, V.; van den Dool, H.; Jenne, R.; Fiorino, M.; The NCEP-NCAR 50 Year Reanalysis, BAMS, 82, 2001, 247-267.

Kocin, P. J., and L. W. Uccellini, 1990: Snowstorms Along the Northeastern Coast of the United States: 1955 to 1985. Meteor. Monogr., 22, No. 44, 280 pp.

Phillips, N. A. 1958: Geostrophic Errors in Predicting the Appalachian Storm of November 1950. Geophysica, 6, 389-405.

Phillips, N. A. 2000: A review of theoretical questions in the early days of NWP, 50th Anniversary of Numerical Weather Prediction Commemorative Symposium, Wissenschatspark Albert Einstein Telegrafenberg, Potsdam, Germany, 9-10 March 2000

Smith, C.D. 1950: The Destructive Storm of November 25-27, 1950. Mon. Wea. Rev., 78, 204-209.

wrf recording  Recorded presentation

Session 1, A Review and Update of Norm Phillips Many Contributions (Room 615/616)
Thursday, 15 January 2004, 8:30 AM-5:30 PM, Room 615/616

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