NOVEMBER 1952 MONTHLY WEATHER REVIEW 227
COMPARISONS BETWEEN THE STORMS OF NOVEMBER 20-22/ 1952,
AND NOVEMBER 25-27, 1950
CLARENCE D. SMITH, JR. AND CHARLOTTE L. ROE
WBAN Analysis Center, U. S. Weather Bureau, Washington, D. C.
At 1830 GMT, November 19, 1952, a low-pressure
center was developing just south of Chattanooga, Tenn.,
on an eastward moving cold front. The center deepened
and apparently joined another center which formed
southwest of Hatteras, N. C. The development and
movement of the synoptic features during the following
several days were similar to those of the storm of Novem-
ber 25-27, 1950, [l, 21. Although other storms evolving
similarly are relatively rare, some have been described in
the literature, e. g. the storm of November 8-10, 1913
[3], and that of October 22-25, 1923 [4]. It is of interest
to compare the cyclones of November 1952, and 1950,
examining the similarities and differences, because attend-
ant weather conditions were sometimes extreme and
destructive and because the cyclones presented fore-
casters with challenging problems.
During the 1952 storm there were heavy rains and
high winds over the Atlantic Coastal States. Snow
accompanied by low temperatures occurred along the
Appalachian Mountains especially near the inception of
the storm. The total precipitation for the period Novem-
ber 19-22, 1952, for some selected stations is shown in
table 1. Knoxville, Tenn., received 18.2 inches of wet
snow within a 24-hour period establishing a new record
for any 24-hour period within the past 69 years. During
the 1950 storm heavy snow accompanied by record mini-
mum temperatures blanketed large areas of the eastern
United States, and very strong winds, some exceeding
hurricane force, occurred over certain Atlantic Coastal
States (see [l] and [2] for more detailed description).
TABLE l.-Total precipitation at selected stations for the period NovewLbw 19-26, 19.52
Station I Total (in.) 11 Station 1 Total (in.)
Conneciimt
Hartford _____ - __ _____________
Kentucky
Lexington .____.___..____..__.
Maryland
Baltimore ..___..____..__.....
New York
New York (City Office).-..-. Albany-. .. ._.........___.._.
Pennsylvania
2.7 Harrisburg .___..____._.......
Pittsburgh ..__...__..... _._..
Knoxville "" ..""..""".
~
Tennessee
2.5
// Roanoke ..__.._ _._..____._._.
1: 7 I District of Columbia
4.7 2.0
3.5
3 .6 4.5 2.0
North Carolina I 1 1 Washington (Airport) ._.____. I 4.6
In comparing any two storms it would be desirable to
use a quantitative measure of their strength rather than
rely upon the usual subjective opinions. One such meas-
ure would be the minimum central pressure attained
compared to the mean central pressure of a large group
of Lows in the same latitude zone. Statistics relating to
t,hat subject have been prepared by James [5] who has
proposed that the term "intensity" be used to describe
the central pressure of a Low or High. James has pub-
lished frequency tables of mean central pressure (4%
years data) and variance of North American Lows and
Highs. He suggested that f one standard deviation
(a) from the mean is normal; for Lows, between -a and
-2a is intense, and <-2a is very intense; for Highs,
between +u and f2a is intense, and >+2a is very
intense. Using James' data the Low of 1952, when at
its minimum (997 mb.), would be classed intense while
the High (1038 mb.) to the northeast would also be intense.
The Lowof 1950 (980 mb.) and the High (1049 mb.)
would both be classed very intense. These measures of
intensity confirm the subjective impression that the 1950
storm exceeded the 1952 storm in strength.
Figures 1 and 2 show the similarities of synoptic pattern
existing a t sea level in the early stages of the storms.
The north-south cold front, the Low over the Carolinas,
and the ridge over eastern Canada are significant features
common to both. Not only were the patterns analogous
but the geographical positions were also very similar.
In the 1952 case the transition from tropical to polar air
along the Atlantic Coast was very gradual, consequently
no warm front is shown.
The 500-mb. charts preceding the storm development
are shown in figures 3 and 4. The patterns are dis-
similar east of 85' W. longitude, but to the west the
presence of cold air southwest of the Low center and strong
north winds west of the center are important features in
common which are discussed further below.
The tracks of the two storms, a t sea-level and 500-mb.
are shown in figures 5 and 6. Retrogression and re-
formation west of the Appalachian Mountains are noted
in each case. After the 500-mb. Low in the 1952 storm
became fully developed, its track followed that of 1950
more closely than the track of the sea-level center fol-
lowed its 1950 counterpart.
The sea-level patterns of the storms when near ma-
turity are shown in figures 7 and 8. Except for details,
228 MONTHLY WEATHER REVIEW NOVEJIBhx 19.,2
FIGUBE 1.-Surface weather chart for 0630 QMT, November 20,1952. Bhading indicates
areas of active precipitation. Isobars are intervals of 3 mb.
FIGURE 3.-5Wmh. chart for 1500 GMT, November 19,1952. Contours (solid lines) at
are drawn for intervals of 5 O C. Barbs on wind shafts are for wind speeds in knots; full
m f e e t intervals are labeled ill hundreds of geopotenthl feet. Isotherms (dashed linos)
barb for every 10 knots and half barb for 5 knots.
Flowrn Z.-Surface weather chart for 0030 QMT, November 25,1950. Small squares
connected by mow8 indicste past positions of main Low a t 1&hour intervals.
FIGURE 4.-5Wmb. chart for 0300 QMT, November 24,1954. Past positions of the Win
Low are at 12-hour intervals.
NOVEMBEB 1952 MONTHLY WEATHER REVIEW 229
the only apparent difference is in intensity. Figures 9
and 10 show the 500-mb. patterns after the full develop-
ment of the storms. Each was a mature "cold air drop"
with the 1950 case obviously exhibiting greater intensity.
Palmen [SI has discussed in detail the high-level cyclone
of which the subject storms are examples.
In the large-scale features of the circulation as de-
lineated by the 500-mb. charts, some similarities of
blocking action over the Atlantic are2 are apparent be-
tween the periods preceding the storms of 1952 and 1950.
Beginning about November 14, 1952, a branching of the
main current of the west'erlies appeared over Montana.
The small trough and ridge just east of the branching
current moved eastward, each developing, until on
November 19 a typical block with a closed High north of a
closed Low was established along 55O-6Oo W. longitude.
The blocking apparently contributed to the deceleration
of the northern portion of the large-scale trough over
western United Stat'es; this, in turn, allowed the southern
portion, which had been lagging behind, to advance to
about the same longitude as the northern portion setting
up the relatively narrow north-south t,rough shown in
figure 3. A large-scale trough and ridge arrangement
of that type indicates that cold air moving from the west
would be shunted far southward instead of proceeding
eastward. indicate fGr 1952. Labeled QMT/DATE/PRESSURE (in millibars).
FIGURE 5,"Tracks of thesurface Lo* centers. Dotted lhe indicates for 1950. Arrows
During November, 1950, initial symptoms of a blocking
situation indicated by the branching 01 the main current
of the westerlies appeared about the 19th near 40' N.,
55' W . and moved eastward while developing int'o a rna-
ture block near 40' W. by the 22d. The large-scale
trough west of the block was not as narrow as in the 1952
case. Furthermore the distance between trough and
block was 15'-20'of longitude greater in the 1950case
making any influences the block may have had on the
trough less apparent.
One of the relations used in the WBAN Bnalysis Cent'er
for prognosticating 500-mb. contours is the correlation
between height and temperature changes. I t has been
repeat'edly observed that stations experiencing sizeable
t'emperature changes often experience height changes of
the sa.me sign.' I t can beseen from figure 3 that the
coldest air was generally over Kansas and Nebraska and
that cold advection was indicated to the north. Using
the relation given above, sizeable temperature and height
falls would have been expected over the lower Mississippi
Valley and sizeable rises over the Dakotas, Minnesota,
and Nebraska. For the 24-hour period beginning 1500
GMT, November 19,1952, these indications were borne
out when the 500-mb. height at Nashville, Tenn., fell
490 feet, a t Atlanta, Ga., 520 feet, and at Lake Charles,
U. S. Weather Bureau, who obtained high correlation between interdiurnal height and
1 This observation is supported by some unpublished data compiled by Sidney Teweles.
temperature changes at 500 mb. for several stations in different geographical locations
in the United States.
F S ~U R E &-Tracks of the 500-mb. Low centers. Dotted line indicates track for
Arrows indicate for 1952. Labeled GMT/DATE/HEIQHT (in tens of feet).
1950.
230 M O N T H L Y W E A T H NOVEMBEB 1952
FTCUBE 7.-Surface weather chart for Om0 GMT, November 22,1952.
La., 730 feet while the temperature fell 5' C., 3' C. and
9' C., respectively. Concurrently, warming and height
rises occurred west of the Low. For the same period as
above, the 500-mb. temperature a t St. Cloud, Minn.,
rose 9' C., at North Platte, Nebr., 13O C. and at Bismarck,
N. Dak.,2" C.,while the heights rose 490 feet,510 feet,and
390 feet, respectively. In the 1950 situation cold air a t
500 mb. located southwest of the Low(fig. 4) was also
noted. During the 24-hour period beginning0300 GMT,
November24, 1950, the 500-mb. height a t Nashville
fell 1,140 feet and a t Atlanta 1,110 feet while the tem-
perature fell 10' C. and 9' C., respect,ively. During the
same period the height a t St. Cloud rose 1,050 feet while
the temperature rose 18O C.
Another feature common to the 500-mb. Lows of 1952
and 1950 was the presence of strong winds in the northerly
current west of the center (figs. 3 and 4). For the 1950
Low, that feature has been discussed by Smith [l]. For
the 1952 Low, figure 3 shows the 80-knotj wind a t Bismarck
directed toward a region of approximately 50 percent less
contour gradient. Using the arguments implied by the
term "delta region" [7], a marked fall in 500-mb. heights
in the southern part of the trough could be anticipated.
The confirmation of that event was striking in the following
24 hours as indicated by the height falls given above.
Vederman [8] has published statistics showing the
average changes in thickness of the standard layers over
the centers of deepening Lows in eastern United States.
His results indicated that the lower two-thirds by weight
FIGURE 8.- Surface weather chart for 0030 GMT, November 26, 1950.
of the central column becomes thinner (denser) while the
upper one-third becomes thicker (less dense). It is of
interest to compare this feature of the Lows under discus-
sion. During the 24-hour period ending 1500GMT,
November 21, 1952, when the maximum deepening (6 mb.)
occurred, the thickness changes were in agreement with
the average changes. Smith [l] has pointed out that
during the 24-hour period ending 1500 GMT, November
25, 1950, when the maximum deepening (24 mb.) occurred
in that more intense storm, the entire central column
became thicker, however, during the 24-hour period ending
0300 GMT, November 26, 1950, when the Low deepened
22 mb., the thickness changes were compatible with the
average. It may be said, then, that the cases under
discussion generally confirm the average changes.
I n discussing the storms of 1952 and 1950 the question
arises whether a trend for intensification could have been
seen near its inception. One interesting technique which
would have shown this to a rather significant degree is the
comparison of %hour sea-level pressure tendencies with
24-hour tendencies according to the rule of Scherhag [7].
The rule states that 3-hour tendencies increased 5 times
are comparable to 24-hour tendencies and can be used as
trend indicators. In an unpublished study, C. L. Bristor
of the U. S. Weather Bureau, Washington, has applied
this technique with the following results. The zero 24-
hour isallobar a t 0630 GMT, November 21, 1952,lay
approximately along a line from Hartford, Conn., to
Binghamton, N. Y., to Atlanta, separating an extensive
NOVEMBER 1952 MONTHLY WEATHER REVIEW 231
FIGURE 9.-500-mb. chart for 15M) GMT, November 21,1952. FIGURE 10.--500-mb. chart for 0300 OMT. November 26.1950.
fall center (value - - 7 mb.) near Hatteras, from a rise
area through the Mississippi Valley. The 3-hour pressure
changes (normal diurnal removed) for the period ending
at the same time converted to 24-hour changes according
to the rule above showed that the zero isallobar moved
southward to the Virginia border, and westward to a line
from Dayton, Ohio, to Birmingham, Ala. This indicated
a trend for concentration of the center of the fall area
over North Carolina and the spreading of a portion of it
northwestward over West Virginia and Ohio. The central
value of the fall area wasshown to have decreased to
-13 mb. over southeastern North Carolina confirming a
clear trend toward intensification.
Concerning the 1950 storm, the following indications
were obtained. The 24-hour pressure change for 0330
GMT, November 24, 1950, showed a +5-mb. isallobar
along a line from near Columbus, Ohio, to Chattanooga,
Tenn., with a -5-mb. center over Lake Huron. The
%hour changes expressed in fifths of millibars for the
period ending at the same time showed that the +5-mb.
isallobar had not moved eastward appreciably even though
other prognostic techniques would have suggested such
movement, and that a -5-mb. center had formed near
Knoxville, Tenn. The trend was evident, then, for inten-
sification in that case also.
This report has compared the storms of November 1952
and 1950 and has pointed out several features which may
beof use in anticipating the development and movement
of future retrograde storms over the eastern United States.
As shown by these storms, however, the detailed differ-
ences between analogous situations can make very signif-
icant differences in the accompanying weather events.
REFERENCES
1. C. D. Smith, Jr., The Destructive Storm of November
25-27, 1950, Monthly Weather Review, vol. 78,
No. 11, November 1950, pp. 204-209.
2. C. L. Bristor, The Great Storm of November, 1950,
Weatherwise, vol. 4, No. 1, February 1951, pp. 10-16.
3. C. P. Mook, The Famous Storm of November, 1913,
Weatherwise, vol. 2, No. 6, December 1949, pp. 126-
128.
4. J. Bjerknes and M. A. Giblett, An Analysis of a
Retrograde Depression in the Eastern United States
of America, Monthly Weather Review, vol.52,
No. 11, November 1924, pp. 521-527.
5 . R. W. James, The Latitude Dependence of Intensity
in Cyclones and Anticyclones, Journal of Meteor-
6. E. PalmBn, The Aerology of Extratropical Disturb-
ances, Compendium of Meteorology, American Mete-
orological Society, Boston, 1951, pp. 599-620.
7. R. Scherhag, Neue Methoden der Wetteranalyse und
Wetterprognose, Springer, Berlin, 1948.
8. J. Vederman, Changes in Vertical Mass Distribution
over Rapidly Deepening Lows, Bulletin of the
American Meteorological Society, vol.30, No. 9,
November 1949, pp. 303-309.
ology, V O ~. 9, NO. 4, August 1952, pp. 243-251.
U. 1. COVERNMLNT PRINTING OFFICE8 I 9 I J
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