Analysis of synoptic data for selected hail days in northeastern Colorado, 1961

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ANALYSIS OF SYNOPTIC FOR DATA

SELECTED HAlL DAYS IN NORTHEASTERN COLORADO, 1961

by

Richard A. Schleusener

Civil Engineering Section Colorado State University Fort Collins, Colorado

Final Report, NSF Grant G-1 7964

Research supported by the Atmospheric Sciences Program National Science Foundation

August 1963 C'..v'.OR...,, ~OQL.u. CER63RAS34 ': 1 N1v J,SIT'.1, • ~ .. o IV

INTRODUCTION DATA AND METHODS

TABLE OF CONTENTS

Selection of days for study Synoptic Data . . . . . RES UL TS AND CONCLUSIONS . .

Mean values of synoptic parameters Severe hail days

Moderate hail days . . . . Days with no hail . . . .

Parameters with no apparent correlation with hail intensity Mean soundings SUMMARY OF PROJECT APPENDIX Page 2 2 2 2 2 3 5

ANALYSIS OF SYNOPTIC DATA FOR

SELECTED HAIL DAYS IN NORTHEASTERN COLORADO, 1961

INTRODUCTION

The successive objectives of the research on hail being conducted at Colorado State University are:

1. To obtain the climatology of hailfalls and rainfalls in the High Plains, a region of high frequency of hail

2. To determine the environmental factors

which favor the occurrence of hail

3. To design and conduct an experiment in hail modification by cloud seeding.

Work done under National Science Foundation

Grant NSF G 17964 was directed at the second of these objectives. This report presents an analysis of synoptic data for selected days with hail in North -eastern Colorado during 19 61. A summary of mean values of the various synoptic parameters examined and a discussion of their relative importance are given in the body of the report. The appendix includes data for case studies of six days of severe hail, six days on which hail of moderate intensity occurred, and six days on which no hail occurred during the period 1 May - 31 July 1961.

DATA AND METHODS

Selection of days for study - - Five criteria were used to classify hail intensity for each day during the 1961 hail season from 1 May to 31 July, using data from the Colorado State University network. These criteria were: 1) the number of reports of hail occ ur-rence received from cooperative observers; 2) maxi-mum stone size; 3) maximum energy number; 4) the

largest "most common" stone size; 5) the number of damaged hail indicators.

Using these criteria, the following dates were chosen as being a representative sample of hail days of the intensities indicated: Severe--May 13, May 16,

May 31, June 2, July 1, and July 14; Moderate- -May 21, May 24, June 8, June 13, June 28, and July 8; None--May 22, June 21, June 26, July 3, July 17, and July 23.

Synoptic data - - For each day, the following in -formation was obtained:

1. Surface synoptic patterns gathered from data collected a: 1100 and 2300 MST. The surface

weather maps for this report were taken fr om the Daily Weather Map prepared by the U. S. Weather

Bureau

2. 500 mb contour patterns at 1700 MST, also taken from the Daily Weather Map.

3, The jet stream configuration and isotach

analysis at 1700 MST, obtained from 300 mb facsi

-mile charts.

4. A mean wind profile over the area, obtained

by averaging upper wind reports from LND, DEN, BFF, LBF, GLD from the ground surface to the tro -popause.

5. Wind profiles along the mean wind direction for each respective upper-air station in the vicinity, including Lander (LND), Denver (DEN), Scottsbluff (BFF), North Platte (LBF), and Goodland (GLD).

6. Vertical air mass structures, obtained from plotted raob soundings (Skew-T, log P diagrams) at

0500 and 1 700 MST.

7. A precipitable water and stability index chart, taken from USWB facsimile charts.

8. A chart showing the forecast size of hail-stones at stations in and near northeastern Colorado

by the Fawbush-Miller method, using the 1700 MST raob soundings.

9. Diagrams showing the daily rainfall amounts and hail occurrences, compiled from reports by co

-operative observers and hail indicators in the hail

network.

These synoptic data are presented in the appen

-dix for each of the 18 days selected for study. RESULTS AND CONCLUSIONS

Mean values of synoptic parameters - - Table I

gives average values of selected synoptic parameters for days classified as having severe, moderate and no hail.

Table 1 shows little difference in the stability index and precipitable water for the three categories

of hail intensity. On the other hand, a faster mea!l

jet stream speed and high mean wind speed are asso -ciated with the severe hail days. A further

distinc-tion between severe and moderate hail lies in the orientation and location of frontal systems with re

Table I. Mean synoptic parameters for days with hail of three intensity classifications. Values given are means with six days per category.

-

-

-

-

---

-Hail Showalter Precipitable Jet Stream Mean Wind, Fronts

Intensity Stability Water, Category Index, Inches

Deg. C

- -

-

-

-

_

___,

!

Severe

_I

o.o .76 Moderate I 0.5 .76 None o. 6

_I

.64

These observations from Table 1, based on mean values, are substantiated by examination of data from individual days.

Severe hail days - - In examining the severe days, the existence of a jet maximum overhead of about

55-60 knots indicates a day of severe rather than

moder-ate or no hail. Values for moderate and "none" days

were approximately 35-40 knots. For severe days,

the value of the jet maximum ranged between 30 and

I 05 knots.

One of the best correlations was found to be the position and orientation of the surface front over the

region. In all six severe cases, the front was

posi-tioned to the southeast of the area. No distinction

was made in this analysis between mP and cP air

masses causing the fronts.

The presence of a low pressure system to the

south of the area favored the occurrence of severe hail. On 5 of the 6 days studied, low pressure systems

were noted to the south of the area, and three of these proved to be of substantial strength producing hall as

the low pressure area moved to the east. The average position of low pressure areas was in WSW Kansas

(120oz).

Moderate hail days - - Days with hail of

moder-ate intensity exhibited no strong preference for any of

the parameters studied. The mean frontal positions

for these days was with an orientation N-S, a distc..nce of about 205 miles to the WNW of the center of the forecast area. This might lead to the conclusion that the storms producing moderate hail were associated

with pre-frontal activity. Only one out of the six days

had a front which had already passed the area by 120oz.

The idea of the dew-point front might be suggested as a cause for hailstorms of moderate intensities,

since the most intense storms frequently occur after the frontal passage or as the dry denser air behind the

front and aloft over the mountains displaces the res

i-dual moist air remaining behind the front. Occassi on-ally, low pressure systems were noted SE of the

Speed Surface to Tro

-Knots popane, Direc-

IN

. Mi

. Distance

2

tion and Speed, Orien- and Direction Knots tation __

_{¥ ~.e.iw..m:.L}

NNE-57 260 /33 _.SSW

I

188 SE I 40 27 0 /25 N-S

_I

205 NW 38 I _{310 /26}

--

-I

--

-forecast area, but these were static and sluggish systems.

Days with no hail - - A primary difficulty in this study was an inability to find parameters which dis

-tinguished days of moderate hail from days of no hail

occurrence. As mentioned earlier, there was little

difference in the jet speeds, the value for both being 35-40 knots. Frontal and low pressure activity and

centers were indefinite for the no-hail days. One positive correlation did appear, however, on the

no-hail days. For days of no hail, the direction of the

mean wind speed from the surface to the tropopause was from the NW (310°), while the direction for the moderate and severe days was 270° and 260°, respec -tively.

Parameters with no apparent correlation with hail intensity - - Some of the parameters showed no correlation with hail intensity. The.Showalter

Sta-bility Index and the Precipitable Water Amounts were such parameters. The respective values were as

follows: Severe--SSI = 0, with range of -3 to +4; precipitable water = • 67; Moderate--SSI = 0, with range of Oto +2; precipitable water = • 76; None--SSI

= 0, with range of Oto +4; precipitable water = • 64. Mean soundings - - Finally, computations were

made to determine mean soundings for the days in

question. By grouping all the days of severe, moder -ate, and no hail, respectively, three average sound -ings for the area were constructed to demonstrate a severe hail day sounding, a moder ate hail day so und-ing, and a "no-hail" day sounding. These soundings are given in Figures 1, 2 and 3. These average sound -ings were determined by taking the soundings for the

individual stations of LND, BFF, LBF1

, DEN, and GLD, for both 120oz (morning) and 0000Z (evening). After averaging for each station, a weighted average was determined for the six days of the study.

Figures 1 and 2 show remarkable similarity which suggests that they represent typical hail so und-ings without regard for intensity.

Examination of the soundings indicates no obvious

features such as, for example, the typical hail and tornado soundings of the middle West, studied by Faw-l::ush and Miller. It may be noted that the surface temperature tends to increase at OOOOZ when the hail intensity decreases. This could be attributed to the fact that on the severe.and moderate days a lower sur-face temperature may be caused by the presence of thunderstorms in and over the area, with the result-ing downdrafts coolresult-ing the region.

A lo° C dew-point spread was common for all levels of the severe hail sounding, increasing to I 0-15° C spread for moderate soundings, and finally to as much as 20° C spread for days of no hail. These

soundings indicate that the occurrence of no hail is related to the dry soundings, but to determine whether severe or moderate hail would occur cannot be deter-mined from the sounding. Analysis of the soundings also indicates that the mean severe sounding is some

4-5° C cooler from the surface to 400 mb than the

lapse rate for the mean no-hail sounding. This can not be attribi.:ted to the presence of thunderstorms, since both the morning and evening soundings for the severe day exhibit this temperature reduction. One important conclusion is that when analyzing the sound-ings for the CCL (using the 120oz for predicting pur-poses) and the convective temperature, Tc , which would initiate cumulus development by heating alone, the Tc lies below the reported surface temperature for the OOOOZ observation. Granting that this observation may take place after the afternoon maximum tempe ra-ture is realized, the meteorological events resulting in this conve tive activity are not caused by just reaching the Tc and then retreating. This observation leads to the conclusion that other effects must be active in causing rapid convective development.

Synoptic data are presented in the appendix to permit case studies of each day.

SUMMARY OF PROJECT Period: Personnel: May 1961 - December 1962 Richard A. Schleusener John D. Marwitz August H. Auer

Publications (prepared in whole, or in part with

sponsorship from Grant NSF G 1 7964).

l. Schleusener, R. A. On the relation of the latitude and strength of the 500-milli-bar west wind along 110 degrees west longitude and the occurrence of hail in the lee of the Rocky Mountains. Prepared for Amer. Meteor. Soc. Conference on Severe Storms, Norman, Oklahoma, Feb. 1962. Colo. State Univ., Civ. Engg. Rpt. CER61RAS46.

3

2. Sch_eusener, R. A., and T. J. Henderson Hail genesis areas in and near north-eastern Colorado. Colo. State Univ. Civ. Engg. Rpt. CER61RAS58, Oct. 1961.

3. Schleusener, R. A., and L. 0. Grant Characteristics of hailstorms in the Colorado State University Network,·

1960-61. Proc. Ninth Weather Radar Conf. , Oct. 19 61.

4. Schleusen.er, R. A., and T. J. Henderson Observational data on the position of hailfalls with respect to precipitation cells. Presented at Amer. Meteor. Soc. Conference on Severe Local Storms, Norman, Oklahoma, Feb. 1962. Colo. State Un-iv. Civ. Engg. Rpt. CER62RAS1.

5. Schleusener, R. A. "Hailstorm c haracteri-zation and the crystal structure of hail. Pending publication in Amer. Meteor. Soc. Monograph on Severe Local Storms

Colo. State Univ. Civ. Engg. Rpt. CER62RAS9, Feb. 1962.

All times

4

Fig.I Mean sounding for severe hail days

.

Fig. 2 Mean sounding for moderate hail days

.

APPENDIX

Data for Case Studies of Selected Hail Days in Northeastern Colorado, 1961

Hail Intensity Category

Severe Moderate None 5 Dates May 13, 16, 31 June 2 July 1, 14 May 21, 24 June 8, 13, 28 July 8 May 22 June 21, 26 July 3, 1 7, 23

Ha

i

l reports

,

0

ESI0

()

I

0<E~

I

00

•

E> 100

Cose

of

•

Hail c loss if icot

ion

Number of rep

ort

s from

CSU network

1

Mox

stone

siz

e

1

Mox

E,

ft

-

lb

s

per sq ft

.

1

Largest

"

most

co

mmon•

stone size

•

13 Moy 1961

Severe

72

I •

14

1552

Number of dam

ag

ed

i

ndicators, CSU network

1

90

oSIDNEY

Mox size of stone

,

i

~

el 0

6

HOLYOKE 0 OTIS

Reports of Ho i I

E • impa

ct

energy,

tt- lbs

per sq

ft.

S= max

st

one

size,

·

inches.

M• missi

ng

data

.

Rain

fall

Depth

(Inches)

C WRAY

0

O<s::;f

6

_4<S:52

I"

.1.'.'

0-

f'

<S$.

111

9

l"<S:5 2

11

-0

S>2"

Surface Synoptic Pattern

II AM

a

II PM MST

05CXJf1ST

Precipitable Water ( inches)

a

Stability Index

Cose

of

Hail Classification•

13 May 1961

Severe

500

MB

Flow

1700 MST

Jet Stream 50

a

100 kt.

·

isotochs

I

I

I

I

I

I 0 LNO 0

~r

BFF LBF 2

r

OEN

G1o

Mean Wind - Surface to Tropopause

(knots) 1700 MST

I

l

LNO 0

t

BFF 0 LBF I 8 0 OEN

G1o

Forecast Size of Stones (inches)

·

Cose of, 13 Moy 1961 Hail Classification, Severe

Lander _{North Platte}

Denver

SKEW-T

Diagrams

0S00MST

=

l200Z

l 700MST=0000Z

Cose of, 13 Moy 1961 H oil Cl a ssificotion, Severe

ro.-~---

- -

~ - -

-

- - - ~

r o ~ - ~ - - - -

-

- -

- -

-0 ..._

)

/

.-(

.-,<..

\

J

,(,_ IQ 20 :30 40 50 60 7 Wind Speed ( knots)

Lander 80

ro~.---

- - - -

---l

0

·~--...

--·:::---..

·-

-~

.

.Y'-.

IQ 20 :30 40 50 60 70 a, Wind Speed (knots) Denver Legend Doy before•

-·-·-Doy of severe hail= -Doy ofter•

Hail Intensity Classification Doy before• Doy of, Doy ofter= Severe Severe Moderate

Wind Profiles Along Mean Wind Direction For 1700 MST

0 IQ 20 :30 40 50 60 7 80 Wind Speed (knots)

Surface Synoptic Pattern

II

AM

a

11 PM MST

Precipitable Water

( inches)

a

Stability Index

Cose

of

•

Hai I

Classification•

16 Moy 1961 Severe

500

MB

Flow

1700 MST

Jet Stream 50 a 100 kt

.

isotachs

I

!14

LND I 0 BFF H B F ~ N

dfo

Mean Wind - Surface to Tropopause

(knots) 1700 MST

I 8 0 LND 0 I BFF 8 0 LBF I

~

DEN

G1o

Forecast Size of Stones (inches)

Hail reports

,

0

ES.10

0

I0<E~I00

•

E> 100

Cose

of

,

Hail classif

i

cat

i

on

•

Number of reports

from

CSU network

•

Mox

stone

size •

Mox E,

ft

-

lbs per sq ft

.

,

Largest

•most common•

stone

size

•

Number of damaged indicators, CSU network

I

cSIONEY

NEBRASKA

COLORADO

6

el

6

D RAYMER D FT.MORGAN D STERLING

6

66

~

6

0 . . el C OTIS ~

Reports

of Hail

HOLYOKE

o

c

00

D WRAY

E• impac

t

energy,

ft-lbs

per sq

ft.

S= max

s

tone

size,

·

inches

.

M•

miss

in

g

data.

u

NEBRA

S

KA

COLORADO D RAYMER D FT.MORGAN

Ra

infall

.25 C OTIS Depth

ff

(Inches)

D WRAY

~;,1

~

16 Moy 1961

Severe

20

3"

4

301

3"

4

8

Max

size

of stone ,

0

O<s~f

6

I"

J.'.'

4<S~

.

2

0-

f'

<S$.

111

Q

1"<S$.

2

11

-0

S>2

11

Case of, 16 May 1961 Hail Classification= · Severe

ro

ro.---,c---+-0 ~40 C: 5! :,

i

30 C: ~20 > .!! LLI 0 / /

I

/

/ IO 20 30 4 0 5 0 6 0 7

Wind Speed (knots)

Lander

80

o,'---;I0~-::;2~0-,30/;.;---,4t:.o:---•50~----;;6l;,;O-¾-.dd

Wind Speed (knots)

Denver

Legend

Day before=

-·-·-Day of severe hail= -Day after,

Hail Intensity Classification Doy before , None

Day of= Severe Day after= None

Wind Profiles Along Mean Wind Direction For 1700 MST 0 ~40 C: 5! :,

i30

20 30 4 0 5 0 6 0 7 80

Wind Speed (knots)

North Platte

Case of, 16 Moy 1961 Hail Classification , Severe

Lander _{North Platte}

Denver

SKEW-T

Diagrams

0S00MST

=1200Z

Hail reports

•

0

E~IO

()

IO<E~IOO

•

E>IOO

Cose

of •

Hail classification

1

Number

of re

ports

from

CSU network

1

Max stone

s

ize •

Max E,

ft-

lbs

per

sq ft

.

,

Laroest

•

mos

t common•

stone size

•

Number

of da

maged in

dicators, CSU network

,

NEBR

ASKA

COLO

RADO

0 RAYMER 0 FT.MORGAN ® cSIDNEY - A

\J-~o

""

-()

<te-()

•

0 STERLING

.

ens

Reports

of Ho

i

I

6

C HOLYOKE 0 WRAY

E • impact

energy,

ft- lbs

per sq ft.

S=

max

stone

size,

inches.

M• miss

ing

data.

- 2 ~

- ~

NEBR

ASKA

( t j ]

COLOR

AOO

0 RAYMER 0 FT.MORGAN

Rainfall

0 STERLING

.

ens Depth C HOLYOKE

(Inches)

0 WRAY 31 Moy 1961

Severe

17 1" 260 ~II

4

7

Max size of stone

,

0

O<s~f

6

I"

.1.'.'

4<S~

.

2

0-

f<s~1"

Q

l"<S~ 2

11

-0

S>2"

I/NI

llll

Surface Synoptic Pattern

II

AM

a

II PM MST

Precipitable Water { inches)

a

Stability Index

Cose

of

•

Hai I Classification,

31 Moy 1961 Severe

500

MB

Flow

1700 MST

!7COMST

Jet Stream 50

a

100 kt. isotochs

~NO

'l

~FF 0 LBF ~ N

Gio

Mean Wind - Surface to Tropopause

{knots) 1700 MST

0 0 LNO 0 _I B1-F ₈ 0 LBF I 8 0 OEN

Gio

Forecast Size of Stones {inches)

{Fawbush

a

Miller)

1700MST

60~-

- - - f

C

120

_> .!! LLI 0

--

~

K) 20 30 4 0 5 0 6 0 7 80

Wind Speed (knots)

Lander G Q , ~ - - - -- - - 1

.,

.! 50 0 ~40 5! :>

!30

C

~

20 > .!! LLI 0 K> 20 30 4 0 5 0 6 0 7 80

Wind Speed (knots)

Denver

Case of• 31 May 1961 Hail Classification• Severe

Legend

Day before• • • -Day of severe hail• -Day after•

Hail Intensity Classification Day before, Severe

Day of• Severe Day after• None

Wind Profiles Along Mean Wind Direction For 1700 MST 0 C ~20 > .!! LLI 10 0 K> 20 30 4 0 5 0 6 0 7 80

Wind Speed ( knots)

Case of•

Hail Classification,

31 Moy 1961 Severe

Hail

reports ,

0

ES.10

() I0<ES.100

•

E>

1

00

Case

of

,

Ha

i

l

cl

as

s

if

i

cati

on

Number of repo

rts

from

CSU

network ,

Max

stone

siz

e

•

Max

E,

ft- lbs

p

er sq ft

. ,

Largest

•

most

com

mon•

stone size

•

Number of dam

aged

indicators,

CSU

network

•

' NEBRASKA COLORADO ct-() <al ()

~

• . ~~ME~

J

••

STEiLING

i

....

®-6

·

®

()

6

~f

C>-oQ FT.MORGAN~ _® C OTIS cSIDNEY C HOLYOKE D WRAY

Reports of Hai

I

E • impac

t

energy,

ft-

lbs

per sq

ft

.

S= max

ston

e size,

inches

.

M

•

missi

ng

data

.

Rainfa

ll

Depth

(inches)

2 June

1961

Severe

49

1¼"

776

3"

4

65

Max

size

of

stone •

0

O<s~f

6

I"

.l.'.'

4<S~2

0-

f'

<SS I"

Q

l

11

<SS 2

11

-0

S>2"

Surface Synoptic Pattern

II AM

a

11PM

MST

Precipitable Water ( inches)

a

Stability Index

Case

of

·,

Hai I Classification,

2 June 1961

Severe

500

MB

Flow

1700

MST

700!'1ST

Jet Stream

50

a

100

kt. isotachs

L ~3 0 BFF

3

\\\_.-fBF

jN

,

lfo

8

Mean Wind - Surface to Tropopause

(knots)

1700 MST

I

a

0 LND 0 I BFF 8 0 LBF I 8 0 DEN I 8

dto

Forecast Size of Stones ( inches)

(Fawbush

a

Miller)

1700

MST

Lander

Denver

Cose of• H oil Clossifi cation •

~ June 1961 Severe

SKEW-T

Diagrams Goodland

0500MST

=

120oz

1700MST

=

0000Z

6(),--

- - - ;

.

o

0

l 0 2 0 2 0 4 0 5 0 6 0 7 80

Wind Speed (knots)

Lander

IO 20 20 40 50 60 7

Wind Speed (knots)

Denver 80 Case of• Hail Classification, Legend Day before• • • -Day of severe hail• -Day after,

Hail Intensity Classification Day before, None

Day of= Severe Day after• Moderate

2 June 1961

· Severe

Wind Profiles Along Mean Wind Direction For 1700 MST 60 .; .. 50 0 ~40 C 5! :,

i30

C 0 ·~ 20 > .!! w 10 0

.,

.! 50 0 ~40 C 5! :,

i30

C ·~ 20 > .!! w 0 IO 20 20 40 50 60 7 80

Wind Speed (knots)

North Platte

10 20 20 4 0 5 0 6 0 7 80

Wind Speed (knots)

Hail

reports,

0

E~I0

() I0<E~I00

•

E>

100

Case

of •

Hail classification •

Number

of repor

ts

from

CSU network

,

Mox stone

size •

Mox

E,

ft-

lbs

per sq ft.

,

Loroest •most

common•

stone size

•

Number of domooed indicators,

CSU network

NEBRASKA

COLORADO

C RAYMER C FT.MORGAN oSIONEY el ~ d.lNG

_e>@

e>

•

() 0 OTIS

••

..

Reports

of Ho

i

I

() 0 HOLYOKE C WRAY

E

• impact

energy,

ft-

lbs per sq

ft.

S• max

stone

size,

inches.

M•

missing

data. oSIDNEY NEBRASKA COLORADO

~

_(:) C RAYMER 0 HOLYOKE

6

C FT.MORGAN C WRAY Rainfall Depth (inches)

July 1961

Severe

13

I •

14

2660

1" 6

Mox

0

6

Cr

Q

-0

size

of stone

,

O<s~f

I"

.L'

4<S~2

f<s~ In

l

11

<S~ 2

11

S>2"

Surface Synoptic Pattern

II AM

a

II PM

MST

Precipitable Water { inches)

a

Stability Index

Case

of

•

I July 1961

Hail Classification

•

Severe

500

MB

Flow

1700 MST

/700MST

Jet Stream 50

a

100 kt. isotochs

. !J..1.-0 7 _LND

~

_.El BFF

, ~

LBF l½iN

t

Mean Wind - Surface to

.

Tropopause

{knots) 1700 MST

0 LND I T 0 I BFF T 0 LBF I

~

DEN I

e

G<tD

Forecast Size of Stones { inches)

{Fawbush

a

Miller) 1700MST

Case of• 1July1961 Hail Classification• Severe

60,~---.~ - - - 1

~~

0 C ~20 > .!! w ~ 0 60 ~ 50 0 {!l 40 C 5! ::,

i30

C ~20 > .!! w 10 0

~=---

_--...::-

_.

...

-._

IO 20 Zl:l 40 50 60 7

Wind Speed (knots)

Lander

BO

IO 20 Z() 40 50 60 7 80

Wind Speed (knots)

Denver 0 C

~

20 > .!! w 0 IO 20 Zl:l 40 50 60 70 80

Wind Speed 'knots)

Scottsbluff

Legend

Day before•

-·-•-Day of severe hail• -Day after•

Hail Intensity Classification Doy before, Moderate

Day of• Severe

Day after• None

Wind Profiles Along Mean Wind Direction

For 1700 MST 6 0 ~ - - -- -- - - ;

.,

~ 50 0 0 60 C

~

20 > .!! w 0 IO 20 Zl:l 40 50 60 7

Wind Speed ( knots)

North Platte

80

Zl:l 40 50 60 7 80

Wind Speed (knots)

Lander

Denver

Cose of•

H oil Clossifi cation 1

s

Cott

s bluff I July 1961

Severe

SKEW-T

Diagrams

0S00MST 120oz

l 700MS T

=

0000Z

Goodland

Hail reports

,

0

ES.IQ

() I0<ES.100

•

E> 100

Case

of •

Hail

cl

as

si

f

ica

tion ,

Number of reports

f

rom

CSU network •

Max stone

size ,

Mox E,

ft

-

lbs pe

r

sq ft.

•

Laroest •most com

m

on•

stone size •

14

July 1961

Severe

18

3"

4

233

Number of damaged

i

ndicators, CSU network •

20

NEBRASKA

COLORADO

0 ®

ct®

•

D (t FT,MORGAt,I ® 0

()-6

0 STERLING oSIDNEY D OTIS

R

eports of Hail

0 HOLYOKE D WRAY

E • Impact e

ne

rgy,

ft-

lbs per sq ft.

S

=

max s

t

on

e

size,

inches

.

M•

missing

data.

oSIDNEY

Rainfall

Depth

(Inches)

Mox

0

6

0-Q

-0

size

of stone

•

O<s~f

I•

J..'.'

4<S~2

f<~I"

l"<S~ 2

11

5>2"

Surface Synoptic Pattern

II AM 811PM

MST

Precipitable Water ( inches)

a

Stability

Index

Case

of

,

Hai I Classification•

14 July 1961 Severe

500

MB

Flow

1700

MSl

,,,,,.-25

170011ST

, ,

Jet Stream 50

a

100 kt.

·

isotochs

-~ LND 0

~

_BFF 9~ LBF

9

,

' DEN 0 G D

Mean Wind - Surface

to

Tropopause (knots)

1700

MST

I

B

LNO I I) 0 ..L BFF 8· 0 LBF I

8

DEN _I T G~D

Forecast Size

of

Stones (

inches) (Fawbush

a

Miller)

1700

MST

•

,! 50 0 0 0

f

40 Iii _:,

!30

C ~20 > .!! LI.I IO 0 10 20 ~ 40 50 60 7 80

Wind Speed ( knots)

Lander

IO 20 ~ 4 0 5 0 6 7 80 Wind Speed (knots)

Denver Cose of• Hail Classification• 14 July 1961 Severe 6 Q . . . - - ' . . - ~ - - - j C ~20 > .!! LI.I 0 IO 20 ~ 4050 80

Wind Speed (knots)

Scottsbluff

Legend Doy before, • • -Doy of severe hail• -Doy ofter,

Hail Intensity Classification Doy before, Moderate

Doy of, Severe Doy ofter• None

Wind Profiles Along Mean Wind Direction For 1700 MST

60~---+

•

.. 50 0 .. 40

i

:,

~30

C ~20 > .!! 10 0 ~ 4 0 5 0 6 80

Wind Speed {knots)

North Platte

6Q1.---..,...---f

0 IO 20 ~ 4 0 5 0 6 Wind Speed (knots)

Lander

Denver

Case of, 14 July 1961 Hail Classification • Severe

Scottsbluff

SKEW-T

Diagrams

0S00MST 120oz

1700MST

=

0OO0Z

North Platte Goodland

Case

of

•

Hail

classification

,

Number of reports from

CSU

network ,

Mox stone

size

,

Max

E,

ft-

lbs

per sq

fT

.

,

Laroest •most

common•

stone size •

21 May 1961

Moderate

I"

4

r,,lumber of damaoed

indicators,

CSU

network

,

None

Hail occurred at Fort Collins

Reports of Ha

II

Surface

Synoptic

Pattern

II

AM 8

11

PM MST

Precipitable Water ( inches)

a

Stability Index

Case

of

•

21

May

1961

Hai I Classification,

Moderate

500

MB

Flow

1700 MST

!700M5T

Jet Stream 50

a

100 kt.

·

isotochs

~ND 0 BFF ~ B F M N G<r_D

Mean Wind - Surface to Tropopause

( knots) 1700 MST

I

'!

LND 0 BFF <.!. 8 0 LBF I

!

DEN G1D

Forecast Size of Stones (inches)

Case of• 21 May 1961 Hail Classification• Moderate

r o - - - 1

r o , - - - ~

0 IO 20 30 40 50 60 7 80

Wind Speed (knots)

Lander

r o , - - - -

---1

0 IO 20 30 4 0 5 0 6 0 7 80

Wind Speed (knots)

Denver

Wind Profiles Along Mean Wind Direction For 1700 MST

0 IO 20 30 4 0 5 0 7 80

Wind Speed (knots)

Case of, 21 May 1961 Hail Classification, Moderate

Lander North Platte

Denver

_SKEW-T

_Diagrams

0S00MS T

=

1200Z

Hail reports,

0

E~I0

0

I0<E~I00

•

E> 100

Case

of •

Hail

classification

1

Number of reports from

CSU

network

1

Max stone

size

,

Max

E,

ft- lbs per sq

ft

.

•

Largest

•most common

•

stone

size

•

Number of damaged indicators

,

CSU

network

•

NEBRASKA

COLORAl

C RAYMER C FT.MORGAN C STERLING cSIDNEY 6

.

OTIS 0 HOLYOKE 0 WRAY

Reports of Hai

I

E • impact energy.

tt- lbs

per sq ft.

S11

max

ston

e

size,

inches.

M•

missing

data.

cSIDNEY

0

OTIS

Rain

fall

Depth

6

0 HOLYOKE

(Inches)

C WRAY

24 May 1961

Moderate

5

3"

4

248

Max size of stone

0

O<s~f

6

I"

.1'.'

4<S~2

0-

-f<s~ 1"

Q

l

11

<S~ 2

11

-0

5>2

11

Surface Synoptic Pattern

11 AM

a

11 PM MST

Precipitable Water ( inches)

a

Stability Index

/

I

'

Cose

of

•

Hail Classification•

24 Moy 1961

Moderate

500

MB

Flow

1700 MST

,

__

170011ST

Jet Stream 50

a

100 kt

.

isotochs

I l I i I

~

_LND 0 BFF

II---,

LBF P-~N

Gio

Mean Wind - Surface to Tropopause

(knots) 1700 MST

<.L 8 0 LND 0 BFF I 4 0 LBF <..!._ 8 0 DEN

Gio

Forecast Size of Stones (inches)

Cose of• 24 Moy 1961 Hail Classification• Moderate

6 ( ) 1 , - - - j 6 ( ) 1 , - - - +

0

0 ! 0 2 0 3 0 4 0 5 0 6 0 7 BO

Wind Speed (knots)

0 _{! 0 2 0 3 0 4 0 5 0 6 0 7 80} Wind' Speed (knots)

Lander North Platte

6()1,-- - - +

0 _{!0 2 0 3 0 4 0 5 0 6 0 7 80}

Wind Speed (knots)

Denver

Wind Profiles Along Mean Wind Direction For 1700 MST

Case of, 24 May 1961 Hail Classification, Moderate

Land er North Platte

Denver

SKEW-T Diagrams

0500MST= 120oz

Hail reports,

0

ES.10

()

I0<ES.100

•

E> 100

Case

of

•

Hail

classificati

on

Number

of

repor

t

s

from

CSU

network

Max

stone

size

,

Max E,

ft- lbs

per

sq

ft

.

•

Laroest

•most

common•

stone

size

•

Number of damaged indicator

s, CSU network

•

NEBRASKA COLORADO D RAYMER D FT.MORGAN C STERLING cSIONEY

6

D OTIS C HOLYOKE C WRAY

Reports

of

Hai

I

E• impact

energ

y, ft-lbs

per sq ft.

Si:: max

stone

size,

inches

.

M• missing

data.

NEBRASKA COLORADO D RAYMER

0

D STERLING

6

D OTIS

Rainfall

Depth

C HOLYOKE

(inches)

C WRAY

8 June 1961

Moderate

2

6

Max size

of stone

•

0

O<ss.f

6

I"

..1'.'

4<S~2

Cr

f<ss. 1"

Q

l"<SS. 2

11

-0

S>2

11

Surface

Synoptic

Pattern

IIAMS 11PM MST

Precipitable Water ( inches)

a

Stability Index

Cose

of

=

Hai I Classification•

8 June 1961

Moderate

500

MB

Flow

I /

so

I I

!700MST

1700 MST

Jet Stream 50

a

100 kt. isotochs

~

; LND 0

,,

BFF LBF

'\

I DEN 2~0 I

Mean Wind - Surface to Tropopouse

( knots) 1700 MST

'

<!

LND 0 <_!_ BFF 8 0 LBF <.!. 8 0 DEN <_!_ 8

G1o

Forecast Size of Stones (inches)

6 0 1 . . - - - 4

0 10 20 30 40 50 60 7 80

Wind Speed (knots)

Lander

f,()1,--- - - - ,

0 IO 20 30 4 0 5 0 6 0 7 80

Wind Speed (knots)

Denver Wind Case of• Hail Classification• 8 June 1961 Moderate

Profiles Along Mean Wind Direction

For 1700 MST 6 0 , , - - - + 0 <:: ~20 > .!! LLJ 10 North Platte 6 0 . . - - - ; 0 IO 20 30 40 50 80

Wind Speed ( knots)

Lander Denver Case of• Hail Classification • 8 June 1961 Moderate SKEW-T Diagrams 0500MST= 12002 1700 MST=0000Z Goodland North Platte

Hail reports,

0

E~I0

()

I0<E~I00

•

E>

100

Case of •

Hail classification

Number of reports from CSU network , Mox stone size ,

Max

E,

ft- lbs per sq

ft

.

,

Largest "most common• stone size ,

Number of damaged indicators, CSU network •

NEBRASKA COLORADO C RAYMER C FT, MORGAN C STERLING cSIDNEY

or,S

6

Reports of Hai

I

0 HOLYOKE C WRAY

E •

impact energy,

ft-

tbs

per

sq

ft. S = max stone size , inches .

M• missing data. cSIDNEY NEBRASKA COLORADO C RAYMER

6

&

C STERLING

(!JJ

HOLYOKE C FT.MORGAN Rainfall

~

2.5" 0

,£ffj

OTIS ~ Depth (Inches) C WRAY

13

June

1961

Moderate

2

-r

13

1."

4

Max

0

6

0-9

-0

size of stone ,

O<s~f

I"

.L'

4<S~2

f<s~ 1"

l"<S~ 2

11

S>2"

Surface Synoptic Pattern

11

AM

a

11 PM MST

/700MST

Precipitable

Water (

inches)

a

Stability Index

Cose

of

,

Hai I Classification•

13 June 1961

Moderate

500

MB

Flow

1700 MST

Jet Stream 50

a

100 kt. isotochs

LNO 4 BFF i fBF 2 ~ N 4 0

Mean Wind - Surface to Tropopause

(knots) 1700

MST

(.L 8 0 LNO I

g

J_ BFF 2 0 LBF I 8 0 OEN

¾

G

1

o

Forecast Size of Stones (inches)

6 0 - - - 1

0 l 0 2 0 3 0 4 0 5 0 6 0 7 80 Wind Speed (knots)

Lander

60,.----

- - - -

- - - l

.,

~ 50 0 C ~20 > ~

...,

0 l 0 2 0 3 0 4 0 5 0 6 0 7 80

Wind Speed (knots)

Denver

Case of• 13 June 1961 Hail Classification• Moderate

60---

-

- - - - -

---1

.,

., 50 0 ~40 C 5! ::,

!30

C 0

'E

20 > ~

...,

10 0 l 0 2 0 3 0 4 0 5 0 6 0 7 80 Wind Speed (knots)

Scottsbluff

Wind Profiles Along Mean Wind Direction

For

1700

MST

60

0 l 0 2 0 3 0 4 0 5 0 6 0 7 80

Wind Speed (knots)

North Platte

60....---

- - - -

-4-0 C

~

20 > ~

...,

0 10 20 30 40 50 60 7 80

Wind Speed (knots)

Lander

Denver

Case of, 13 June 1961

Hail Classification I Moderate

Scottsbluff SKEW-T Diagrams 0500MST= 120oz 1700 MSTs00OOZ Goodland North Platte

Hail reports

1

0

E~I0

0

I0<E~I00

•

E> 100

Cose

of

1

Hail

classification

Number of

reports

from

CSU network

1

Mox stone

size

,

Mox E,

ft- lbs per sq

ft.

1

Largest

•most

common•

stone size

1

Number of damaged

indicators,

CSU network

•

NEBRASKA COLORADO C FT.MORGAN 0 STERLING oSIDNEY

.

OTIS 0 HOLYOKE 0 WRAY

Reports of Ho

i

I

E• impact

energy,

tt-lbs

per sq ft.

S• max stone

size,

inches.

M• missing

data

.

NEBRASKA COLORADO

(:)

FT.MORGAN 0 STERLING

Rainfa

ll

oSIDNEY

.

OTIS Depth C HOLYOKE

(Inches)

0 WRAY

28 June 1961

Moderate

2

16

. .L'

4

None

Mox

0

6

0-Q

-0

size of stone

•

O<s~f

I"

.1'.'

4<S~2

f'

<S~ 1

11

l"<S~ 2

11

S>2"

Surface Synoptic Pattern

II AM

a

11PM MST

Precipitable Water ( inches)

a

Stability Index

Case

of

•

Hai I Classification,

28 June 1961

Moderate

/9200 ,t"~..::.l' ,/ j [}{} ,: ,' -•--J, \J'!_'lt}9-- .,'

500

MB

Flow

1700 MST

/7WMST

Jet Stream 50

a

100 kt

.

isotachs

l ND BFF 6

ll-t

eF

I 0 N 3 8 G D

Mean Wind - Surface to Tropopause

(knots) 1700

MST

<.' ""8" 0 LND <....L. 8 0 <.l. BFF 8 0 LBF I 8 0 DEN I 8 G<?_o

Forecast Size of Stones (inches)

6 0 - - - 1 0 ~40 C 51 :,

!30

C

l20

_> .!! w 10 0 IQ 20 30 4 0 5 0 6 0 7

Wind Speed (knots)

Lander

G O r 1

-0 IQ 20 30 4 0 5 0 6 0 7

· Wind Speed (knots)

Denver

-

....

Cose of• 28 June 1961 Hail Classification= Moderate

6 0 - - - ! C ~20 > .!! w 0 IQ 20 30 40 50 60 7 BO

Wind Speed (knots)

Scottsbluff

Wind ,..Profiles Along Mean Wind Direction For 1700 MST 6 ( ) , ~ - - - f 0 ~40 _C 51 :,

!30

C 0 '; 20 > .!! w 0 IQ 20 30 4 0 5 0 6 0 7 BO

Wind Speed (knots)

North Platte

6 ( ) , ~ - - - +

0 IQ 20 30 40 50 BO

Wind Speed (knots)

Lander

Denver

Cose of, 28 June 1961 H oil Clossifi cation , Moderate

Scottsbluff SKEW-T Diagrams 0500MST= 12002 1700 MST,.00002 Goodland North Platte

Hail reports,

0

E~I0

() I0<E~I00

•

E> 100

Cose

of

1

Hail

classification

,

Number of reports

from

CSU network

1

Max stone

size

1

Mox

E,

ft- lbs per sq ft

.

1

Largest

"most

common•

stone size

1

8 July 1961

Moderate

Number of damaged

indicators,

CSU network

I

None

NEBRASKA COLORADO C RAYMER C FT.MORGAN

6

oSIONEY C STERLING

.

OTIS HOLYOKE C WRAY

Reports

of Ho i

I

E• impact

energy,

ft-lbs

per sq

ft.

S= max stone size,

inches.

M• missing

data.

Rainfall

Depth

(Inches)

Max size of stone,

0

O<s~f

6

I"

.1'.'

4<S~2

Cr

f<S~I"

Q

l"<S~ 2"

-0

S>2"

Surface Synoptic

Pattern

II AM

a

11PM MST

/700MST

Precipitable

Water ( inches)

a

Stability

Index

Case

of

•

·

Hai I Classification•

8 July 1961

Moderate

L

,iooo

~9{XX)

18800 \ ' \ I / ' \ I

____

.... \ /8800 ...

----J,,:--=:::::,....:::::__----.jL,' '

_'

\

'----mar'

500

MB Flow

1700 MST

25--OSOOMST

I I I I

Jet Stream 50

a

100 kt.

·

isotochs

e LND BFF 9 ~ LBF I ~ DEN

Mean Wind - Surface to Tropopause

(knots)

1700

MST

i

₀ LND I 8 0 3 BFF ₄ 0 LBF I 8 0 DEN I 8 G<r_D

Forecast Size of Stones (inches)

( Faw bus

_

h

a

Miller) 1700 MST

0

-..,

C i ::,

!30

C ~20 > .!! w C 0 ~20 > .!! w 0 () 20 ~ 4 0 5 0 6 0 7 80 Wllld Speed (knots) Lander () 20 ~ 4 0 5 0 6 0 7 80

·wind Speed (knots)

Denver

Cose of• 8 July 1961

H oil Cl a ssificotion • Moderate

601...---i

5 0 , , - - - +

~40 C 5l ::,

!30

C 0 i; 20 > ..!! w 0 () 20 ~ 4 0 5 0 6 0 7 80

Wind Speed (knots)

Scottsbluff

Wind Profiles Along Mean Wind Direction

For

1700

MST

0 _{0 20} ~ 4 0 5 0 6 80

Wini! Speed (knots) North Platte

601...--- -- - - +

0 _{0 20} ~ 4 0 5 0 6 0 80

Wind Speed (knots)

Lander Denver Cose of• H oil Classification • Scottsbluff 8 July 1961 Moderate SKEW-T Diagrams OOOOMST= 120oz 1700 MST•00OOZ North Platte Goodland

Cose

of

•

Hail classification

,

Number of reports

from

CSU network •

Mox stone

size ,

Mo• E,

ft- lbs per sq ft

.

•

Largest •most

co

mmon•

stone size

•

22

Moy 1961

None

None

None

None

None

Number of domaoed

i

ndicators, CSU network

None

oSIDNEY

NEBRASKA

COLORADO

₀

_d

6

D D

6

RAYMER STERLING 0

0

HOLYOKE

d

6

c:39

D FT.MORGAN

.

OTIS D WRAY

Surface Synoptic Pattern

II AM

a

11PM MST

050011ST

Precipitable Water ( inches)

a

Stability Index

Cose

of

,

22 May 1961

Hai I Classification

I None

500

MB

Flow

1700

MST

!700MST

Jet Stream

50

a

100

kt. isotachs

~

_LNO 0 I BFF

[

LBF I~ DEN G<r_o

Mean Wind - Surface to Tropopause

( knots)

1700 MST

0 LNO 0 BFF , 1-8 0 LBF ,...L

s

DEN G<r_o

Forecast Size of Stones (

inches)

s o , ~ - - - ;

'S {; 40 C g :,

!

30

C ~20 > .!! LI.I 0 IO 20 30 40 50 60

Wind Speed (knots)

Lander

6 ( ) 1 , - - - +

0 IO 20 30 40 50 60

Wind Speed (knots)

Denver

Case of• Hail Classification•

22 May 1961 ·None

Wind Profiles Along Mean Wind Direction For 1700 MST

s o ~ - - - 1

0 l 0 2 0 3 0 4 0 5 0 7

Wind Speed (knots)

Case of, 22 May 1961

Hail Classification • None

La n d er North Platte

Denver

SKEW-T Diagrams

OOOOMST= 12002

Case

of

•

Hail

classification ,

Number of reports

from

CSU network

•

Max

stone

size •

Max

E.

ft- lbs per sq ft

.

•

Laroest

•most

common•

stone size

•

Number of damaoed

indicators,

CSU network

•

21 June 1961

None

None

None

None

None

None

Surface Synoptic Pattern

II

AM

a

11

PM MST

!700MST

Precipitable Water (

inches)

a

Stability Index

Cose

of

,

.

21 June 1961

Hai I Classification•

500

MB

Flow

1700

MST

\.

170011ST '- - -

-None

Jet Stream

50

a

100

kt.

·

isotachs

I I

I

I

I

I

'

~

LNO z,~

z\

I BFF LBF _I I ~ I OEN

z

\o

Mean Wind

-

Surface to Tropopause

(knots)

1700

MST

<g

LNO l. ~ BFF .l 8 0 LBF

½

₀ DEN .1. G~D

Forecast Size of Stones (inches)

(Fawbush

a

Miller)

1700

MST

•

.! 50 0

-g

40 Iii ::t

!30

C ~20 > Jl! Ill IQ 0

•

.! 50 C ~20 ~ Jl! Ill IQ 0 I() ₃₀ 4 0 5 0 6 0 7

Wind Speed (knots)

Lander

10 20 30 4 0 5 0 6 0 7 BO

Wind Speed (knots)

Denver Case of• Hail Classification• 21 June 1961 None 6 ( ) , ~ - - - -- - - - ---, 0 IO 20 30 40 50 60 7

Wind Speed (knots)

Scottsbluff

Wind Profiles Along Mean Wind Direction

For

1700

MST

60•~---0 .;g 40 C 5! ::t

i30

C 0

i5

20 > .!! Ill 10 0 IO 20 30 4 0 5 0 6

Wind Speed (knots)

North Platte

r o ~ - - - -

-..

.! 50 0 .;g 40

i

::t

i30

C ~20 > Jl! Ill IO 0 10 20 30 40 50 BO -Wind Speed ( knots)

Lander

Denver

Cose of,

H oil Closs ifi cation •

21 June 1961 None Scottsbluff SKEW-T Diagrams 0500MST= 120oz 1700 MST=0000Z Goodland

Case

of

I

Hail classification

,

Number of

reports

from

CSU network

Max

stone

size ,

Max E,

ft- lbs per

sq

ft

.

,

Largest •most common•

stone

size •

Number of damaged indicators,

CSU

network ,

-NEBRASKA COLORADO D RAYMER D FT.MORGAN D STERLING Rainfall oSIONEY

.

OTIS Depth C HOLYOKE D WRAY (inches)

26

June

1961

None None None None None None

Surface

Synoptic

Pattern

II AM

a

II PM MST

Precipitable Water (

inches)

a

Stability Index

Case

of

•

26

June

1961

Hail Classification•

None

I ' I ' , , 191()()..,,✓,'

500

MB

Flow

1700 MST

/700MST

Jet Stream

50

a

100 kt.

isotochs

0 LND

1

4

'---'El

\

BFF LBF

\

DEN 2 ~D

Mean Wind

-

Surface to Tropopause

( knots)

1700 MST

0 0 LND 0 0 _{(J__} BFF 8 0 LBF 0 0 DEN 0 G1D

Forecast Size of Stones ( inches)

(Fawbush a

Miller)

1700 MST

0

60,.---

-

---4

0 IO 20 30 40 50 60 ·wind ed ( knots Denver Case of• Hail Classification• 26 June 1961 Noni,

60.---__)

0 l 0 2 0 3 0 4 0 5 0 6 0 7 80

Wind Speed (knots)

Scottsbluff

Wind Profiles Along Mean Wind Dire.cti on For

1700

MST 60...---➔

..

.! 50 0

i

'I() Iii :,

!30

C ~20 > .!! LI.I 0 IO 20 30 40 50

Wind Speed (knotW

North Platte

60...---+

0 IO 20 30 4 0 5 0 6 7

Wind Speed (knots)

Lander

Denver

Case of, 26 June 1961

Hail Classification, None

Scotts bluff SKEW-T Diagrams 0500MST= 120oz 1700 MST=0000Z Goodland North Platte

Case

of

•

Hail classification ,

Number of reports

from

CSU

network

•

Max stone

size •

Max

E,

ft- lbs

per

sq ft. •

Laroest

•most

common•

stone

size

•

Number of

domooed

indicators,

CSU

network

•

cSIDNEY

NEBRASKA

COLORADO

D C RAYMER STERLING C

eJJ

.

HOLYOKE C FT.MORGAN 0 OTIS C WRAY

Rainfall

Depth

(Inches)

3

July 1961

None

None

None

None

None

None

Surface Synoptic Pattern

II AM

a

11PM MST

170011ST

Precipitable Water

( inches)

a

Stability

Index

Cose

of

•

3

July

1961

Hail

Classification•

None

500

MB

Flow

1700 MST

..50

1700 MST

Jet

Stream 50

a

100 kt.

isotochs

8 ~

DEN

BFF _{I ~}

LBF

Mean Wind - Surface to Tropopouse

(knots) 1700 MST

0 0 LND

(!

BFF (J_ 8 0 LBF <J_ 8 0 DEN

<i

G1D

Forecast Size of Stones (

inches)

Case

of

I

3 July 1961

Hail

classification

,

None

Number of reports

from

CSU netwo

rk

I

None

Mox stone

size ,

None

Max

E,

ft- lbs per sq ft

.

I

None

Largest

•most

common•

stone s

ize

I

None

Number of damaged

indicators,

CSU

network

,

None

oSIDNEY

NEBRASKA

COLORADO

0 C RAYMER STERLING 0 5

(3)

HOLYOKE 0 FT.MORGAN

.

OTIS 0 WRAY

Surface Synoptic Pattern

II AM

a

11PM

MST

!700t15T

Precipitable Water

( inches)

a

Stability Index

Cose

of

1

3

July

1961

Hai

I Classification,

None

500

MB

Flow

1700 MST

.50

1700 MST

Jet

Stream 50

a

100 kt. isotochs

4LND

BFF _{I ~}

LBF

8 ~ DEN

Mean Wind - Surface to Tropopouse

( knots) 1700

MST

0 0 LND

'i

_{BFF ,.L} 8 0 LBF ,.L 8 0 DEN

,t

GiD

Forecast Size of Stones {inches)

60 .; ~ 50 0 ~ 40 C 5l :, i30 w 0 IO 20 30 40 50 60 70 80

Wind Speed (knots)

Lander 60 .; ~ 50 0 ~40 C 5l :,

i30

C 0 f; 20 > .!! w 0 IO 20 30 40 50 60 70 80

Wind Speed (knots)

Denver Wind 60 .; ~ 50 0 ~40 C 5l :, i3o C 0

g

20 .!! w 0 IO Cose of• H oil Cl a ssificotion • 20 30 40 50 60 3 July 1961 None 70 80

Wind Speed (knots)

Scottsbluff

Profiles Along Mean Wind Direction For 1700MST 60 .; ~ 50 0

-g

40 0 "' :, 0 :!: 30 C 0 f; 20 > .!! w 10 0 IO 20 30 40 50 60 7 80

Wind Speed (knots)

North Platte 60 .; ~ 50 0 ~ 40 C 5l :, 0 :!: 30 0 IO 20 30 40 50 60 7 80

Wind Speed ( knots)

Lander

Denver

Case of, 3 July 1961 Hail Classification, None

Scottsbluff SKEW-T Diagrams 0500MST= 120oz 1700 MST=0000Z Goodland North Platte

Cose

of

•

Hail

c loss if icotio

n

,

Numbe

r

of reports

from

CSU

network

,

Mox stone

size ,

Mox

E,

ft- lbs

pe

r

sq

ft

.

,

Loroest

•mo

st

common•

stone size

,

Number of

domaoed

indi

cators,

CSU

network

,

NEBRASKA

COLORADO

0 RAYME 0

@

I FT.MORGAN D STERLING

Rainfall

cSIONEY

6

.

OTIS Depth C HOLYOKE 0 WRAY .

(Inches)

17 July 1961

None

None

None

None

None

None

Surface Synoptic Pattern

II AM

a

11PM MST

Precipitable Water

(

inches)

a

Stability Index

Cose

of

•

17 July 1961

Hai

I

Classification•

None

, __ ---19KJO _______ _

500

MB

Flow

1700 MST

ZS

!700MST

Jet Stream 50

a

100 kt. isotochs

0 LND 0 0 BFF

~

_LBF 0 ~ DEN ~D

Mean Wind - Surface to Tropopouse

( knots) 1700 MST

0 0 LND 0 0 BFF

_<½

0 LBF <.!..

B

DEN 0 GiD

Forecast Size of Stones (

inches)