AUGUST, 19 1 1. MONTHLY WEATHER REVIEW. 1287
WEATHER, FORECASTS, AND WARNINGS.
By H. C. FRANKENFIELD, Professor of Meteorology.
At tlie beginning of the month, and continuing for
several (lays, barometric pressure mas moderately low over the great central valleys and the lake region, and in
consequence frequent showers occurred over practic.ally all districts from the Hocky Mountains to the Atlantic
coast, with general aiid hetlvy rains over the Plaiuh States, the lower Mississippi Valley, aiid in the L4tlniitic
States from Pennsylvania to Florida. In the last-
named districts the rniiis aff orded perniaiieiit relief from the drought that had existed for a prolonged periocl,
especially in the Carolinas, Virginia, aiid snuthern R h y -
land. The temperature during the first, week of the month averqed near or below the normal ns it rule,
except in Texas, the Lake region, and the upper Oliio Valley, where there were several warm tlnys. However,
no estreinely high temperatures prevniled in any part
of the country. On August 6 the following weekly forecast \vn* issuetl :
The dktribution of atmospheric preswre, za shown lqr the weather chart of the Northern Hemisphere, is such a8 to indicate that there will
be no unseasonably warm weather in any part of the country during the coming week. and temperatures will average near or below the nor-
mal generally. The recipitation during the week mill be local, )Jut
fairly well dist+~teX over the greater part of the country- from the Rocky Mountains to the Atlantic co.wt. The principal barometric depreseion to crow the country during the week i R now forming over
the western Plateau refion: it mill crosa the Middle West about TTednea-
day, and the Eastern States Friday or Saturday.
During the first half of the second week of the month
a low area moved east-northeastward from the Rocky
Mountains to the lower St. Lawrence Valley, and it was
followed by a high area from the Northwest that reached the Atlantic coast on August 10. ,4t the same time coni-
parativelp low pressure continued over the Central West, and the result was a week of unsettled weather over the
northern half of the country east of the Rorky Moun-
tains with frequent thunderstorms. Dry weather con- tinued in the southwestern portion of the c-ountry except
along the mountain slopes, while in the East Gulf ant1
Soutli Atlantic States tliuiiclershowrrs were of tlaily
occurrence, except along the south Atlantic coftst. Dur-
ing the afternoon of August 11 a severe storm of very
limited area touched the Gulf const near Pensiicoli~ and
Mobile Bay, causing high winds in that iiiiriietlinte vicin-
ity, with some minor damage to shipping, etc., at Penstt-
cola. At, this place the wind reached n velocity of so miles from the southeast early in the evening of A4ugust
11, while nt Mobile the highest velocity was hut 34 miles
an hour, indicating the local character of the storm, which dissipated a short distance in the interior during
the morning of August 12.
There was a moderate cool wave over the northwestern
districts during the early clays of the week, reaching the
Lake region during Thursday and Friday, August 10 and
11, but with these except>ions high temperatures prevailed
east of the Rocky Mountains, with readings ahove 100 of frequent occurrence, except in the South Atlantic and
east Gulf States, where the showers prevented any
extreme heat. West of the Rocky Mountains the weather
was fair and cool, except in the interior of the estreme
Southwest, where temperatures were high.
Oii August 13 the following weekly Iorecast was issued:
The distrilJution of atmospheric pressure over the Northern Hemi-
sphere is such as to indicate that moderately high temperatureA wilI prevail the first half of the week in the Middle mest aud until the last
of the week in the Eastern States; in the Southern States and on the Pacific slope normal temperatures are probable. -4 change to lower
temperature will overspread the Northwestern States TueAday and Wednesday, the hiiddle West Wednesday or Thurday, and the EaRtern States by the last of the week. The principal barometric disturbance
to crnw the rountry duriny the week is now over the fm Northweet.
I t will; fi~yj;eRi#bo&rd over the Middle West about Kedneaday, and reactti. the Emtern StareR about Friday. I t will be preceded and
attended hy coneidPral~le cloudinesR and local Rhowera aud thunder-
ut (nriiih
There were no pronounced barometric henomena
moderate depression from extreme northern Tl!lnois, after reaching the New E land coast, developed mto a pro-
but, fortunately without hlgh winds, so far as reports
indicated. There was also a marked redevelopment of a disturbance in the same locality during the night of August 13-19, again without high wincls. Both of the
disturbances moved off to the northeastward, and the
moderate high area following the second one brought
wit8h it a shnrp teiiiperature fall over the eastern portion of the coiintq,, the cool weather continuing for several
Only scattered showers occurred west of the Mississippi
River, although over ortions of the lower Mississippi
Valley aiid the west bulf States they were heavy at
times, and the precipitation for the week was in excess of the normal amount. There were heavy thunderstorms
on the 15th over the northeastern districts and g9od show- ers again on the lSth, so that the total precipltation for
the week was somewhat in excess of the average. There
were also frequent showers in the South Atlantic and east
Gulf States. At the beginniiig of the week temperatures were quite
high east of the Rochc Mountains, but about the middle
of the week n moderately high pressure area from the
Northwest moved eastward, and by Saturday, August 19,
comparatively cool weather irevailed over the northern
In tlie central Plains States and the Southwest high tem- peratures continued. West of the Rock Mountains the
week was cooler, with generally fair weat t er, except over
the estrenie southern districts, where the temperatures
were high. On Sunday, August 20, the following bulletin was
issued :
Fair weather with moderate temperature will continue Monday and Tuesday in the lower Lake region, the Middle Atlantic States, and
New England. A disturbance now over the Northwest will move east- ward, preceded and attended by showers and rifling temperature that will cover the Northwest and the central Plains States Monday and
Tuepday, with showers continuing Tuesday in tho latter district; the hfissouri and upper Mississippi Valleys and the upper Lake re ion by Tuesday, reaching the Middle Atlantic States and New Eng&nd
Wednetday and Thursday. The disturbance will be followed by a high area now on the north Pacific coat, bringing with i t falling tempera-
tures that will reach the Northwestern States Monday and Monday night, the great central valleys and the up er Lake region Tuesday or Wednesday, and the eastern portion of &e country Thureday and Friday. Generally fair weather will prevail after Wednesday m the
during the week, except over New Englanc: I
nouiicecl diqturbance 9 c tiring the night of August 15-16,
A very
days.
districts from the Rocky R. ? ountains to New England.
1288 MONTHLY WEATHER REVIEW. AUGUBT, 1911
central West, and after Tuesday in the extreme West, except in the central and eouthern Rocky Mountain region, where local 6hOwerS are
probable. In the South Atlantic and east Gulf Statea local chowers will continue, while in the west Gulf States the weather will br gen-
erally fair. Another low area will probably appear in the Rritibh Northwest toward the end of the week, attended by rising temperature in the Northwestern States.
Subsequent conditions were in accordance with the
forecast, except that showers continued local1 in the
week and were of frequent occurrence in eastern Texas during the second half of the week. The northwestern
high-pressure area was accompanied by a decided drop in
temperature, and frosts occurred quite generally in the Northwestern States and Wyoming from August 23 to
28, inclusive. Heavy to killing frosts occurred on August
27 and 28, and on August 39 livht frosts occurred in northern Wisconsin and the Lake Buperior region.
The feature of the week was a hurricane that, as closely
as could be conjectured from later reports, originated in the Atlantic Ocean about Au ust 23 at about latitude 34O
approach toward the coast were noted on Sunday morning August 27, a t Charleston, S. C., when the barometer read
29.82 inches, a fall of 0.14 inch in 13 hours, with a wind velocity of 32 i d e s an hour from the North. At the
same time the barometer at Savannah, Ga., read 29.90
inches, a fall of 0.04 inch in 12 hours, with a wind velocity
of 20 miles an hour from the Northwest. Advisory warnings were sent a t once to these places, and special
observations called for. At 11 a. m. storm warnings were ordered from Fort Monroe to Savannah, and all coast
stations from Boston to New Orleans and the meteoro-
logical offices a t Habana, Cuba, notified accordingly. Later special observations indicated that the storm would
be a severe one, and hurricane warnings were ordered at
3.45 p. m. for Charleston and Savannah, and northwest storm warnings ordered at Jacksonville, Fla. The storm
center apparently moved very slowly in a west-northwest
direction, and it was not until 8 a. in., Monday, August
28, that it reached the coast a t a point a short distance
north of Savannah. The lowest barometer readings were as follows: Charles-
ton, 29.30 inches, nt 11.50 p. ni., August 27, and Savan- nah, 29.02 inches, a t 8 :t. in., August 28. The highest
wind velocity at Charleston was about 106 i d e s an hour
from the northeast a t 11.50 p. m., August 27, and at
Savannah, 88 miles froni the northwest n t 3.10 a. m., August 28, with an extreme velocity of 06 miles an hour
at 3.08 a. rn The storm path was of limited width, and
no high winds were reported north of Wilmington, N. C., or south of Jacksonville, Fla. At Wilmington the wind
attained a velocity of 30 miles an hour from the east early
in the afternoon of Sunday, August 27, and at Jackson-
d e 48 miles an hour from the northwest early in the afternoon of Monday, August 28. Great clamage was
caused by the winds and high tides between Charleston and Savannah, and the loss of seven lives was re orted.
report of the district editor in another portion of this
Review and also in the special bulletin immediately fol-
lowing. The storm began to diminish in intensity after reaching
the coast, and in the interior of the State of Georgia
Plains States and the Northwest during the mid J le of the
and longitude 67 30. The a rst definite indications of its
More detailed accounts of the storm will be founc Y in the
recurved to the northeastward and passed to sea off the
New Jersey coast. The storm was followed by a cold
high area from the northwest and strong northeast to east winds and general rains set in along the Atlantic
coast from Nantucket to Hatterns, with cool weather
prevailing over the eastern half of the country.
On Sunday, August 28, the following special bulletin was issued:
4 haronietric depression that is central ovpr the hfissiRRippi Valley and another that is off the south Atlantic co& will niove toward New Enzl~nd and he attended hy general rains within the next 4s hours
ox er the greater I m t of the country from the hhsimippi Valley to the
Atlnutir const nurl in the Southwest. I t is probable that strong winds
will prevail off the Atlantic coast. Following the passaze of these dis- turbances the preswre mill rise rapidly and a chanqe to considerably
cooler weather will overspread the Great Central Valleys and the Lake region Monday and hionday niqht and the eaRtern and Houthern States
Tuesday and tVednesday. Thia change to cooler weather will prob- ably cause frosts in exposed places the first part of the week in the
northern Rocky hIountain reyion, the northern plains States, the ex-
treme iipper hliusiwippi Valley, and the upper lake region Another disturbance is due to appear in the northwed about Redneeday, whence it will move eaatward and cross the ?diddle Rest Thursday or Frichy and the Eastern Stater near the clore of the week; this disturb-
ance will tie preceded by a reaction to warmer weather and be attended
by conriderable c1oudine.w and local areas of precipitation in the region east of the Rocky Mountains.
INTERNATIONAL PRESSURE.
Except on one or two days pressure was high over
Alaska until August 24, when a eriod of moderately low
pressure set in, continuing u n t f the end of the month. Over the Atlantic Ocean pressure was variable within
narrow limits, and nearly normal except from August 19
to 22, inclusive, when it was low over the Azores, and after August 21 when high pressure prevailed over the
islands of Bermuda.
Over
storm conditions prevailed from August 4 to 8, inclusive,
followed by a reaction to abnormally lugh pressure (30.40
inches), and a gradual decrease after August 15. From August 21 to 29, inclusive, pressure was again low over
the British Isles, but nearly normal over Iceland until the
Last day of the month, when there was a very rapid fall of
0.9 inch to 38.84 inches, the fall extending over the
extreme northeast Atlantic Ocean and the northern por-
tion of the British Isles.
Over continental Euro e high pressure prevailed during
ern portion, followed then by a fall that was most marked over Russia from August 15 to 21, inclusive. There was
a gradual recovery to more normal conditions after Aug-
ust 21. Over Siberia pressure was variable within a
moderately wide range, with a well-defined low period
from August 11 to 16, inclusive, and a lesser one about the
middle of the first decade of the month. During the sec-
ond half of the month the tendency was toward conditions
somewhat above the normal. . On the Asiatic coast pressure was also variable, but within narrow limits, except for a pronounced de ression
pressure was above normal as a rule, but well marked
depressions were noted on August 1, 10, and 25. Over
the Sandwich Islands moderately low pressure prevailed.
Nothing unusual develo ed in the West Indies.
Iceland and the British f sles marked low pressure and
the first half of the inont R except over the extreme south-
on August 11 in the Yellow Sea. Over the P h 8 ppines
AUGUST, 19 1 1. MONTHLY WEATRER REVIEW. 1289
I
Average temperature and departure from the nonnal.
New England. ........ Middle Atlantic. ...... South Atlantic. ....... Florida Peninsula.. ... East Gulf ............. West Gulf ............ Ohio Valley and Ten- nessee.. ............. Lower Lakes.. ........ Upper Lakes.. ........ North Dakota.. ....... U per &Usissippi Val-
dverage relative humidity and departures from the normal.
81 77 IIl
79 82 73
74
73 75 74
___
Average Since Jan. 1.
-____-
New Eyland :. :. ................. Middle tlantic .................. South Atlantic.. .................. Florida Peninsula I... ............. East G#l ......................... West .$ ......................... Ohio Valley and Temess e&.. ..... Lower Lakes.. .................... Upper Lakes.. .................... North Dakot8.L.. ................. p p e r Mississippi Valley.. ........ lssouri Valley.. ................. Northern Slope .................... Middle s l o r .. .................. Southern ope ................... Southern Plateau I -.. ............. Middle'Phteau 1.. ................ Northern Plateau 1.. .............. North PaciEc ...................... Middle Paciflc ..................... South Pacific I ...................
-
iccumu. lated SlUce Jan. 1 .
__
+ 4.i
+ 7.9
+IO., +l9. I)
+22..;
t l 6 .7 +13.1 +21.4
+ 0.4 +22.1 +26.8
+ 3.8 +23.0
+%. 1
- 0.3
+ 3.6
- 2.9
- 9.2 -10.7
- 0. t i
+E.!
~-
I
Aver-
1 %e. Pistricts.
East Gulf.. ........... West Gulf.. .......... Ohio Valley and Ten- nessee ............... Lower Lakes .......... Upper Lakes .......... North Dakota ......... U per Mississippi Val- fey ..................
Deuar- // I
ti.0 +0.8 1 Southern Plateau.. .... 2.5 4.1 +O. 1 , Middle Plateau.. .... .I 3.2
Northern Plateau.. .. .I 2.5
5.8 +1.3 North PaciEc ......... 5.2 5.4 +0.8 Middle Pacific __._____! 3.8 5.1 +0.4 South Pacific ......... i 1.8 5.2 +1.2
5.0 +0.8 I
--
Average ;emper& tures for the cur- rent month.
--
67.3 73.7 79.0 80.7 79.6 81. 8
75.5 70.1 65.7 66. 2
71.9 73.0 63.6 75.2
81.3 7s. 2
tis. 5 06.2
W. 6
64.0
69. 6
Depar- :me from the nor- mal.
Aver- tw-from the nor- 11 ' Districts.
mal.
Depar- tures, current m0nt.h.
Districts. Number
Of
stations.
0
+9
+2 -3
+1
+.1 -5
+a -4 -2
Missoilri Valley. -. - ._. 67
Northern slope. ....... 61
.......... 61
-
12 15 10
: 10
13 10
12
9 14 12 9 6
10 11 7
5
4
10 8
+0.2
+l. 1
+1.2 -0.4
+O. 4 +l. 0
+O. 7
+o. 6
-0.3 -4.0 -0.9
-3.2 0.0 +1.5 +0.3 -1.0 -1.2 -0.5 -2.7 -1.0
-n. 7
+n. fi
+1.0 +1 .R
+1.3
+2.4
+2. t i
+z. 1
+2. I
0.0 +2.8 t 3 .4 +O. 5 +a. 9 +3.1 0.0
t 0 .4
-0.4
- 1.2 -1.3 -0.1
+l. 5
...... 58
... 43
Northern Plateau ..... 38 ...... 75
........ 63
......... M
+
1 1
daerage cloudiiieaa and departures from the normal.
Depar- ure from the nor- mal.
0.0 +O. 6
+o. 1
+O. 4 -1.2 -1.1
+O. 2
+O. R +o. 2
+l. 0
1 Regular Weather Bureau and selected cooperative stations.
Average precipitation and departure from the normal.
Districts.
Average. Departure
~~ ~~
Percent- age of normal.
~~
Accumu- lated sin- Jan. 1.
N U l h
Of
stations. Zurrent month. CuITent month.
--
5.05
7.63 7.06
8.09 4.70 4.19
4.43
3.93 2. 18 3.38 3.84 3.32 1.40 2.45 1.44 0.72 0.60
0.4s
0.23
0.01
0.00
~
4faximu.m wind iielocities. 11 15 11 8 11 10 13 10 13 9 15 12 9 6
8 10 11 11 7 8 4
-~
+l.2 +3.3
+o. 9 +l. 0 -0.2 +l. 2
+1.0
+o. 9 -0. s +l. 2 +O. 6 +O. 1
+o. 1
0.0
-0. , -0.4 0.0 -0.6
0.0 0.0
-0.9
~~ ~
- 3.8
- 4.1 -14.6
- 9.2
- 5.2
- 4.2
- 3.2
- 1.1 - 1.5
+ 0.2
- 3.9 - 6.6
- 2.1
- 3.7 - 3.7
+ 2.0
+ 0.4 - 2.3
+ 6.7
+ 3.5
+ 7.4
~
~-
New Enlland :. .................. Middle tlantx .................. South Atlantic ................... Florida Peninsula 1 ............... East Gulf ........................ West Gulf ........................ Ohio Valley and Te nnessee... .... Lower Lakes. .................... Upper Lakes.. ................ .:. North Dakota 1 ................... Upper Mississippi Valley.. ....... Mlssouri Valley.. ................ Northern Slope ...................
Southern s ope 1.. ............... Southern Plateau I... ............ Middle Plateau 1.. ............... Northern Plateau 1 ............... North Paciec ..................... Middle Paciflc .................... South Paciflc .....................
Middle slo $.... ................
__
.- !i Y
$
~
se.
nw.
S.
nw. nw. nw. nw. nw.
UW.
nw.
sw. nw.
nw.
-~
Stations.
Cape Henry Va ........ Charleston, 8. c ........
Marquehe Mich.. .....
Db.. ............... Columbus, Ohio.. ...... Devils Lake, t3. Dak.. .. F.1 Paso Tex ...........
Mount Tahalpais, Cal.. Do ................. Do ................. New York. N. Y.. ..... Do ................. Oklahoma, Okla.. ...... Pensacoln, Fla.. ........
.. 18 .. 27
.. 28 .. 17
__ 13
.. 22 .. 21 .. 7 . 16 .. 17
__ 15
.. 18 .. 4 .. 10
~
............ 11 Do ................... 12
. 1
W. ................... 9
w .1 Do ................... 8 sw. Do ................... 16
Do ................... 17 Do ................... 18 nw. Po ................... 19 ............ 27
nw. Do ................... 28 nw. Walla Walln Wash ....... 14 w. Williston. NI ~a l i . ....... 13
1 Regular Weather Bureau and selectod cooperative stations.