MARCH, 1911. MONTHLY WEATHER REVIEW. 345
in amount were: 5th to Sth, 18th to 2Oth, and the last five or six days of the month. It was heavy over much of the district on the 6th, 7th, 8th, and 26th. The totals for the month ran to 6 inches over the upper watershed of the ancl Cheat Rivers, the southern ortion and over the upper
between 1 and 3 inches over the rest of the district. The smallest amount at any station in the district was 0.34 inch a t Loretto, Ky., and the largest 7.86 inches at Pickens, W. Va.
watershe K s of the Cuniberland and Tennessee Rivers, and
SNOWFALL.
Some snow fell during the month in all parts of the district, exce t in southwestern Tennessee and ilorthern
a trace to 28 inches. There were from 3 to 28 inches over western Pennsylvania, the latter amount being re- ortecl from Somerset on the Yougliogheny watershecl; from 20 to 23 inches in Garrett County, Mcl.; froni 4 to 9 inches in the higher elevations of West Virginia; ancl 3 to 17 inches over the wateisheds of the Mahoning, Mus- kingum, and up er portions of the Scioto Rivers in Ohio.
importance, only an occasional station re orthig as much
trict on the lst, 30th, and 31st. It was general over northern sections almost daily from the Stl to 7tli, in- clusive, and again on the 14th, 15th, and 16th. Snow did not remain on t,he ground long after any fall. The greatest amount on the ground at any one tinie was
trom 6 to 10 inches over the Allegheny and Biskeminitas watersheds from about the 6th to 10th. Sleet occurred in considerable quantit over various sections on the
sections on the 7th and 8th; in some portions of Hen- tucky on the 18th; and consiclerable in amount over Ohio on the 27th. On tlie 7th 4 inches of sleet fell a t Wytheville, Va., in a little over 12 hours.
Alabama. TR e total amounts for the month vaned from
Snowfall over t E e rest of the district was not of niuch
as 2 or 3 inches. Snow fell quite genera Y ly over the dis-
6th; it also was more or ry ess general in the more northerly
MISCELLANEOUS.
Thunderstorms occurred quite generally on the 5th, 6th, and 7th over Tennessee, Kentucky, Indiana, and Illinois and locally in Virginia and North Carolina and a
few other portions of the district. The were again gen- eral on the 9th and loth, escept in In c r iana and Illinois, and on the 12th and 26th; and were more or less general on the 27th, 2Sth, and 39th, while there were scattered local thunderstornis on the 13th. Hail attended the thunderstornis in localities on the 7th, 9th, loth, 12th, 13th, 27th, 2Sth, ancl 29th. The hail in some instanc.es was rather severe and did considerable damage. Strong winds prevailed on a number of days, and they were notably high on the 15th, 17th, and 37th. On the 27th
a severe windstorm passed across the State of Ohio doing considerable damage to wires, trees, roofs, and frail builcl- ings. A number of timber fires were reported in Illinois. Rivers.-In Pennsylvania rivers remained at good stages during the entire month, while they were low for the season in West Virginia. At Parkersbur , W. Va.,
on record for March. The Cumberlancl and Tennessee Rivers and most of the other tributaries of the Ohio were at moderate stages during the month. There was a bi tide, however, in the upper reaches of the Cumberlan River in Kentucky, due to heavy rains of the 6th-8th in the mountain section. The tide, estimated at 45 feet,
the highest sta e of tlie Ohio River cluring t 7 ie month,
12.8 feet on t 5 e 31st, is the lowest masinium stage
i
enabled the lumber mills in that region to secure a large supply of saw logs. The stages in the upper reaches of the Wabash and tributaries were coniparatively low throughout the month and fluctuated but little. Mod- erate stages were attained in the lower stretches of the White and Wabash Rivers near the middle of the month, but there was a general decline after that time and low water obtained at the close of the month.
A PALL OF DARKNESS, AT LOUISVILLE, KY., AND
SURROUNDING DISTRICTS, BY FERDINAND J. WALZ,
SECTION DIRECTOR.
7, shortly aft.er 8 o'clock, a
rolled over Louisville, Ky., surrouncling count in darkness a few feet away cou 7 d not be dis-
tin iishect and birds and chickens went back to roost. It r jegan growing Clark about 7.55 a. m., but about 8.05 a. ni. an unusually black and low-liangino cloud waa observed coming rapidly out of the west. ?his cloud in
a few minutes conipletely enveloped tlie city, and dark- ness incxeasecl until a t 8.15 a. m., when it was densest, it was as black as night. A41>out 8.20 a. ni. it began to clear in the northwest and in a few minutes the dark cloud had disappeared in the east. Rain had been falling in varyin amounts, never more
passage of the dark cloud it increased to a considerable downpour and was attencled by hail, a few flashes of lidibning, but very little thuncler, and a wind squall. TYie latter lasted only about three minutes, 8.15 to 8.18
a. ni.? and reached a masimuni velocity of about 60 miles per hour. Tlie barometer had been falling steadily since 1 a. m., the clecline being about 0.36 inch from 1 a. m. to 8. a. m., but when the black cloud struck there was a sudden rise of nearly 0.25 inch ancl an almost e ually sudden
7 a. m. read 29.41 inches, at 8.16 a. m. 29.64 inches, and at 8.30 a. m. 29.42 inches, marking a change in pressure of nearly 0.50 inch in one-half hour. There was a fall in temperature of about 4 degrees. The winds were from the ea.st up to S.10 a. m., when they backed quickly to the northwest with the squall, but at 8.25 a. m. they veered to northeast and continued from that direction during the rest of the day. The intense blackness ancl generally oniinous appear- ance of the storm spread terror throu hout the city,
having been visited by a clevastating tornado in March, 1890, when 76 people lost their lives. Also, hap ening at the tinie of clay it did, hundreds of school cgldren were on their way to school and &rents were wild with
streets men and women ran wildly to escape the im ending
to pelt them, many ran away, residents generally were terrorizecl, ancl for a short half hour confusion reigned.
An investigation of the general weather conditions obtaining March 7 shows that at 7 a. m., central standard time, a barometric disturbance of moderate gradient cov- ered the central Mississi pi Valley. Tlie area of disturb
the minor axis about 450 miles in nearly a north and south direction. The circumference of the ellipse was formed by the closed isobar of 30.1 inches. There were two distinct centers of low pressure, one about SpringGeld,
than moclerately heavy, since mi f night, but during the
fall with its passing away. The station 1 arometer at
augmented no doubt by the fact of t %I 's commumty
apprehension for tlie safety of t P ieir children. On the
storm, horses were frightened, and, when tlie ha1 f began
ance was elli tical in siape, 7 about 650 mi Y es in nearly an east and west direction and the major axis extending
348 MONTHLY WEATHER REVIEW. MARCH, 1911
Mo., barometer 29.98 inc.hes, the other a t Evansville, Ind., barometer 29.95 inches, these two coinciding in position with the foci o During the day the disturbance southeastward and at 7 p. ni., central standard t h e , was centered about northwestern Georgia. (See figs. 1 and 2,
daily weather maps 7 a. m. and 7 p. m., central standard time.) The temperature gradient at 7 a. m., as shown by tlie readings, was considerable: Memphis, 66'; Nmliv' follOY e, 62'; Cairo, 52'; St. Louis, 42'; Evansville,
44O; Louisville, 42'; Lexington, 40'; Inclianapolis, 34'; Cincinnati, 36'; and Parkersburg, 34".
to tlie Ohio River. Reachin that river at a point new
where turning near1 due eastward it passed on over the
the t,iiiie this storm was advancing through Kentucky a
violent sleet storni was raging over southwestern Vir- ginia, 4 inches of sleet falling a t Wytlieville, Va., between
7.40 a. ni. and 9.27 p. m. There was very little disturbance noted at Nashville, Temi., on the south, and Indianapolis and Cincinnati on the north, and at Parkersbur , W. Va., on the east. Par-
its mouth, it advanced up t E e river to Louisville, Ky.,
blue rass re on of H entucky, finally disappearing among the I T ppalac lian foothills in eastern Kentucky. During
ticularly noticeable are the s a arp peaks in the barometric
U. S. Department of Agriculture. WEATHER BUREAU
WlLLlS L.MOORE. Chief.
fieSda]r, March 7, 1911.
90th Meridian Tiam
Fro. 1.-Daily weather map.
The course of the smaller center of action, or the one tracings at stations visited bv the storm, and tlie depres- located near Evansville, Ind., at 7 a. m., can be fairly well followed from the barograph trace Sheets at tlie several regular stations of the Weather Bureau. These curves show sharp barometric disturbances occurring at St. Louis about 4.50 a. m.; at Cairo, Ill., about 6.52 a. m.; at Evansville, Ind., about 7.02 a. ni.; a t Louisville, Ky., about 8.15 a. m., and a t Lesin ton,
storm, wind squall, and remarkable darkness a t each of these stations coincides with the time of the barometric disturbance as shown on the tracings. The course of the storm appears to have been about as follows: Commenc- ing at St. Louis, it continued in a southeastward direction
(See fig. 3.)
Ky., about 8.55 a. m. The time of appearance of the 5 iail-
sions h the tracings at stations lying north of its path. especially at Indianapolis. Also the marked rise in tern- era.ture occurring during the day at Nashville, Tern., and gairo, Ill., contrasts strongly with the very small change hi temperature occurring at other stations in the Oluo Valley. (See fig. 4.)
The following estracts are taken from the reports of officials in charge of the several Weather Bureau stations:
S t . Loick-The storm of March 7 ended in the early morning and no unusual phenomena could be ohwrved directly. The extreme velocity of the wind was 45 miles per hour, and hail, estimated at 0.05 inch, occurred shortly before 5 o'clock. The storm waa severe in parts of the city.
347 MAKCH, 1911. MONTHLY WEATHER REVIEW.
Cairo, Ill.-Relative to the storm of March 7, the wind waa south until 6.58 a. m., when it shifted suddenly to northwest., and a heav dark cloud was observed approaching from that direction. We OE: served that it became quite dark a t 7 a. m., when it seemed as if a rainstorm might be in progress on the Kentucky side of the Ohio River northeast of the etation. The wind reached a velocity of 2G miles er hour from the northwest a t 7.10 a. m., but by 7.15 a. m. it had Xecreased to 12 miles per hour Ei~ansaille, 1nd.-On March '7 the day opened cloudy, with a cloudy sunrise and a light fog prevailing over the city and ita vicinit.y. A t
of northwest wind, reaching 26 miles per hour, did some minor dam e to chinine e, cornices, copings, overhead wires shade trees, shrusery, etc., tiroughout t,he cit,y. The hi h wind lasted only about 5 minutes, from 7.03 to 7.08 a. m. T t e spell of darkness lasted for about 6 minutes. Lexington, Ky.-A thundemtorm began during the night and ended a t 10 a. m. The rain was heavy the last two hours of t.he storm, but there was very little wind. Lightning was very eharp during the few minutes in which hail fell. The hailstones were about the size of peas, and were not enough to do any damage. About 9 a. m. it became so
about 7.02 a. ni. the wind suddenly backed from southeast, through east and northeast. to northwest, mth a sudden increase in velocity from fresh to high; li ht rain began; the barometer began to rise rapidly; the light fog%ecame dense, and a mass of dark, threaten- ing clouds, having the ap earance of an approaching thunderst,orm, began movin in from t f e southwest. The dense fog conibining with the d a g clouds resulted in a pall of darkness, almost ae
dark aa night, settling over the city and vicinity. A high gust
dark that it waa necessary t,o turn on the lights. The period of dark- ness lasted about 20 minutes. Cineitinnti, Ohio.-On the morning of March 7 there wan no unusual darkness beyond what, might ordinarily at,tend cloudy weat,her at, this &ation. There was no thunderstorm on that day and no hail. The wind direction varied from nor& to east between 8 and 10 a. m., being generallv from the northeast. There waa no decided variation in wind velocity during that time.
MONTHLY WEATHER REVIEW. .MARCH, 1911
M 2 4 6 8 10x112 4 6 810’M ’ L I .!!!,
..
u’ 2 1 6 8 10 XI1 2 1 8 8 t0.M
FIG. 4.-Thermogrcrme.