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Downloaded 09/26/21 02:02 AM UTC 454 Vol locus on forecasting A Synoptic Analysis of the 25-26 January 1978 Blizzard Cyclone in the Central United States Ellen M. Salmon 1 and Phillip J. Smith Department of Geosciences, Purdue University, W. Lafayette, Ind. 47907 Abstract the blizzard except for analyses of snowfall and damage impact in Illinois included in a paper by Changnon Based on detailed surface analyses and National Meteorolog- and Changnon (1978). ical Center (NMC) facsimile products, the evolution of the The three primary objectives of the present study January 1978 midwestern blizzard-producing cyclone is described. The behavior of the storm is contrasted with the were to: 1) present a detailed analysis of the evolution actions of typical winter cyclones. Forecasts by the Limited- of the surface cyclone, 2) compare the behavior of the Area Fine Mesh (LFM) numerical model are compared with blizzard with that of typical winter cyclones, and 3) observed conditions. briefly compare predictions made by the Limited-Area An injection of polar air, resulting in the revitalization of Fine Mesh (LFM) numerical model with actual the baroclinic zone, and concurrent strong upper-air flow are found to be important factors in the dramatic intensification observed conditions. of the low. The movement and deepening of the low, although not unprecedented, were found to deviate substantially from normal winter cyclone behavior. Although LFM forecasts underestimated the deepening of the low, the amount of predicted intensification was substantial. 2. Data analysis and procedure This study was based primarily on detailed analyses of airways surface data for the central and eastern 1. Introduction United States, spanning the period 1800 GMT 26 January-1200 GMT 26 January 1978. Particular The blizzard of 25-26 January 1978 has variously attention was given to sea level pressure, surface been categorized as the "worst blizzard in a century" temperature, 3 h pressure tendency, and 6 h liquid (Wagner, 1979) or the worst blizzard since 1918 water equivalent precipitation amounts. (Ludlum, 1978), and with good reason. The cyclone In addition, extensive use was made of the National deepened over 40 mb in 24 h, yielding numerous record Meteorological Center (NMC) facsimile map products, low sea level pressures, and was accompanied by up to including surface, 700, and 300 mb analyses and LFM 12 in of snow blown by hurricane-force winds into numerical forecasts. These maps were available from drifts as high as 25 ft (Wagner, 1979). Weather condi- 1200 GMT 24 January to 0000 GMT 27 January. tions paralyzed the midwest for several days and caused numerous accidents, injuries, and fatalities. It is evident that such a vigorous storm deserves closer scrutiny. However, the authors know of no previous studies of 3. General synoptic discussion a. Cyclone evolution 1 Present affiliation: Department of Meteorology, The Pennsylvania State University, University Park, Pa. 16802. Positions of the cyclone center, with corresponding central pressures, are shown in Fig. 1. The cyclone 0003-0007/80/050453-08$06.00 developed from a weak Gulf low that moved inland © 1980 American Meteorological Society along the southeast Texas coast at 1800 GMT 24 Bulletin American Meteorological Society 453 Unauthenticated | Downloaded 09/26/21 02:02 AM UTC 454 Vol. 61, No. 5, May 1980 January. The cyclone deepened slightly and moved slowly to the northeast through 1800 GMT 25 January, when both the rate of intensification and the speed of propagation of the cyclone increased. A central pressure drop of 9.9 mb between 0000 GMT and 0300 GMT 26 January marked the maximum rate of intensification, which occurred as the storm moved on a more northerly track from eastern Tennessee to northeastern Kentucky. Occlusion also began during this period. The minimum central pressure of 955.5 mb was reached after 1200 GMT 26 January north of Detroit, Mich. A gradual filling of the cyclone followed, and the storm returned to its slower northeastward trajectory after 1200 GMT 26 January. Precipitation was widespread in the system, with maximum amounts occurring just ahead of the low, to its east, and following the low to the west and southwest. Early in the period a northeast-southwest line north of the low (shown for 1800 GMT 25 January in Fig. 1) separated precipitation types, with snow to the west and rain to the east. By 0600 GMT 26 January, the FIG. 1. Cyclone center positions and corresponding central rain-snow line became more S-shaped (see Fig. 1), pressures (mb) for 3 h intervals from 1200 GMT 25 January corresponding to the injection of cold air south of the to 0000 GMT 26 January 1978; rain-snow dividing line low and the penetration of warm air to its north. As (dashed) for 1800 GMT 25 January and 0600 GMT 26 January. the cold air became dominant, the proportion of liquid FIG. 2. 700 mb height contours in 30 dm intervals. Dots indicate surface cyclone positions. Unauthenticated | Downloaded 09/26/21 02:02 AM UTC Bulletin American Meteorological Society 455 precipitation diminished until, by 1800 GMT 26 tilt of the closed center to the north and of the trough January, the precipitation was essentially all snow. to the west was apparent at this time. This tilt and the strong horizontal temperature gradient at 700 mb (not shown) are indicative of the baroclinic zone present b. Upper-air conditions from the Great Lakes to the Gulf States. The super- The upper-air flow for the period of this study is position of the two upper-air systems coincided with represented by the 700 and 300 mb patterns presented the period of greatest pressure fall within the surface in Figs. 2 and 3. Prior to cyclogenesis, a ridge over the cyclone (0000-0300 GMT 26 January). Pacific and Atlantic Oceans and a cutoff low over At 1200 GMT 26 January the dominant feature at Arizona characterized the upper-air pattern at 300 mb both 700 and 300 mb was the intensifying upper-air (not shown). A trough extended westward into northern system over the midwest, which supported the surface Manitoba from a nearly stationary closed low off the cyclone development. The closed centers at the two coasts of Labrador and Greenland. Twelve hours before levels exhibited a northeast to southwest tilt in response the beginning of the present data period, the Labrador to the southward penetration of the cold air. Finally, trough moved to the south over central Manitoba, by the last map time both upper-air lows moved north- where a closed low formed above a surface cyclone eastward to the eastern Great Lakes region with only a moving out of Canada. During the same period, the weak southward tilt remaining. Arizona low began to open and move eastward. The surface low was under areas of maximum 300 mb By 1200 GMT 25 January the trough associated flow until the last two map times, when the low moved with the Arizona low, no longer closed at 300 mb, northward away from the major baroclinic zone. began to catch up with an essentially stationary trough Recall that the cyclone began to fill during this latter extending from the low over Manitoba. At 0000 GMT period. For the first two periods the surface low was 26 January the two troughs were aligned, extending located downstream from the 300 mb trough in a southward from a closed low at 700 mb in the upper region where strong vorticity advection and correspond- midwest down to the Gulf of Mexico. A pronounced ing upper-level divergence would be expected. However, FIG. 3. 300 mb height contours in 120 dm intervals (solid) and isotachs for wind speeds greater than 90 kt in 20 kt intervals (dashed). Dots indicate surface cyclone positions. Unauthenticated | Downloaded 09/26/21 02:02 AM UTC 456 Vol. 61, No. 5, May 1980 FIG. 4. Surface analyses with fronts, sea level pressures in 4 mb increments (solid), and surface temperatures in 10°F intervals (dashed). by 0000 GMT 27 January the occluding surface low precipitation amounts are presented in Fig. 5. Fronts was nearly aligned with both the 700 and 300 mb were located by examining NMC frontal positions and centers. making adjustments where indicated by the more detailed surface analyses. a. Fronts and air masses 4. Detailed surface analyses The cyclone of primary interest was centered in The blizzard-producing cyclone intensified as it merged northeastern Mississippi at 1800 GMT 25 January. with a Canadian low. This sequence of events was A stationary front extended northeast from the low accompanied by strong temperature advections and through central Kentucky and Tennessee, southeastern significant precipitation amounts, both of which are Ohio, and northwestern Pennsylvania. Cool air was dramatically revealed in detailed analyses of surface located north and west of this front, while moist air data. Sea level isobars, surface temperatures, and with intermediate temperature was positioned along fronts are depicted in Fig. 4, while isallobars and the Appalachian Mountains south of the stationary Unauthenticated | Downloaded 09/26/21 02:02 AM UTC Bulletin American Meteorological Society 457 FIG. 5. Three hour pressure tendencies in 2 mb increments (solid) and 6 h liquid water equivalents in 0.2 in increments (dashed). Middle dots correspond to cyclone positions at map times; others represent positions 3 and 6 h before and after map times. front and north of a warm front through the southern Alabama border moved across western Georgia. The Atlantic states. A third air mass of warm tropical air low over Wisconsin remained stationary as the asso- lay south of the warm front. The cyclone was located ciated cold front advanced south and east, spreading at the northern extent of the baroclinic zone between polar air over Illinois, Missouri, northwestern Arkansas, the cool air mass and the tropical air.
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