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![Page 1: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/1.jpg)
An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area
Stephen JessupM.S. Student
Dept. of Atmospheric ScienceCornell Univ.
![Page 2: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/2.jpg)
Project Objectives
● Develop a long-term climatology of flash flood events for the BGM CWA.
● Identify any spatial differences in flash flood frequency and flood producing meteorological conditions across the CWA.
● Analyze a set of meteorological variables to quantitatively identify combinations of variables that are associated with flash flooding.
● Compare the conditions associated with flash floods to the conditions associated with non-events
![Page 3: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/3.jpg)
Flash Flood Climatology
● Spatially: FF's most common in NY/PA border counties and in eastern NY counties
● Diurnally: – Peak in late afternoon/early evening
– Secondary max. in morning
● Seasonally:– Peak in summer (June max.)
– Min. in late fall/winter
![Page 4: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/4.jpg)
18
66 8
7
7 6
8
5
16
16
16
13
4
92513
24
28 5 7
82
11
![Page 5: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/5.jpg)
24.3
17.4
12.37.3
6.19.6
5.0
35.4
11.5
58.8
10.116.0
11.1
7.6
13.29.0
16.021.3
18.5
12.9
13.4
25.0
12.6
17.8
Flash floods per county area
![Page 6: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/6.jpg)
0 EST
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EST
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EST
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EST
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EST
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EST
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EST
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EST
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EST
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EST
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EST
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EST
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EST
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EST
0
2
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12
Flash Flood Start Time, 1986-2003
Time
Perc
ent
of
Fla
sh F
loods
Mostly Fall/Winter/Spring
Mostly Spring/Summer
![Page 7: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/7.jpg)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec0
5
10
15
20
25
Number of Flash Floods per MonthP
erc
en
t of
Fla
sh
Flo
od
s
![Page 8: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/8.jpg)
Antecedent Precipitation● Determined for one week (7 days) and one month
(30 days) prior to flash floods● Climatology for comparison
– Consists of all non-flood years (from 1986-2003) for each flash flood date
– To test hypothesis that floods tend to occur during periods of above-normal precipitation
● Flash floods tend to occur in anomalously wet periods
![Page 9: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/9.jpg)
0-0.
25
0.26
-0.5
0
0.51
-0.7
5
0.76
-1.0
0
1.01
-1.2
5
1.26
-1.5
0
1.51
-1.7
5
1.76
-2.0
0
2.01
-2.2
5
2.26
-2.5
0
2.51
-2.7
5
2.76
-3.0
0
3.01
-3.2
5
3.26
-3.5
0
3.51
-3.7
5
3.76
-4.0
0
4.01
-4.2
5
4.26
-4.5
0
4.51
-4.7
5
4.76
-5.0
0
5.01
-5.2
5
5.26
-5.5
0
5.51
-5.7
5
5.76
-6.0
00
1
2
3
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5
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9
10
Precipitation Amounts for Flash Flood Events for a Full Year
Precipitation (inches)
Nu
mb
er
of
Eve
nts
![Page 10: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/10.jpg)
Climatology vs. Flash Flood Antecedent Precip. (7-day)
0 1 2 3 4 5 6 70
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
7-day Antecedent Precip Cum. Dist.
ClimoFloods
Inches of Precip
Cu
m. F
req
.
![Page 11: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/11.jpg)
Climatology vs. Flash Flood Antecedent Precip. (30-day)
0 2 4 6 8 10 12 14 160
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
30-day Antecedent Precip Cum. Dist.
ClimatologyFlood Events
Inches of Precip.
Cu
m. F
req
.
![Page 12: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/12.jpg)
0 1 2 3 4 5 6 7 80
1
2
3
4
5
6
Storm total vs. Antecedent Rainfall
Weekly Antecedent Precipitation
Flood t
ota
l rain
fall
![Page 13: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/13.jpg)
0 2 4 6 8 10 12 140
1
2
3
4
5
6
Storm total vs. Antecedent Rainfall
Monthly Antecedent Precipation
Flo
od
tota
l ra
infa
ll
![Page 14: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/14.jpg)
Improving FF Forecasting Procedures for NWS BGM: Methodology
● Construct independent databases of flash flood and null event cases
● Determine meteorologically significant parameters and their values during events
● Find combinations of variables that improve predictability
● Plot composites to determine whether the synoptic situations of FF's and null events differ
● Merge these into a forecasting methodology
![Page 15: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/15.jpg)
Datasets● Warm-season flash flood cases (~May-Oct), n=51
– Separated by at least one week (7 days)
– Drawn from 1986-2003
● Warm-season heavy precipitation events, n=36
– At least 1” in one hour, at least 1.5” in six hours
– Separated from each other & FF's by at least one week
– Drawn from 1986-2003
● Random days representing same seasonality as FF's, n=51
– Random year (1986-2003) assigned to the date of each FF case
– Separated from each other & FF's by at least one week
● Watches/warnings that did not verify, n=17
– Separated from each other by at least one week
– Drawn from 1995-2003
![Page 16: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/16.jpg)
Dataset Methodology
● NCEP Regional Reanalysis used as primary data source: 32 km, 3-hour resolution
● Three time periods used: time closest to the flood, two time steps of three hours prior
● Most variables averaged over quadrilateral area containing FF counties
– Area for prior time periods determined by backtracking four corners of this area using 850 mb wind
– 850 wind, storm motion vectors backtracked an extra timestep to reflect inflow
● Backtracking not used for several variables classified as synoptic; parameter representing large-scale field used instead
![Page 17: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/17.jpg)
Highlights: Current BGM FF Checklist
● Winds/storm motion– Slow storm movement (MBE/Corfidi vector)
– Low level jet >= 20 kts
– 700 – 500 mb winds < 30 kts
– Weak mid-level (700-500 mb) shear
– Upper level divergence
● Atmospheric Moisture– Mean 1000-500 relative humidity >= 70%
– Precipitable water >=150% normal or >= 1.4 inches
![Page 18: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/18.jpg)
BGM FF Checklist, continued
● Synoptic-scale features– Nearby surface boundary
– Low-level theta-e axis
– Upper level ridge axis
– 1000-500 mb thickness diffluence
● Other parameters– “Tall and skinny” CAPE
– Warm cloud depth exceeding 3-4 km
![Page 19: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/19.jpg)
Summary: Results● Thresholds in checklist generally agree with FF results, but are
often exceeded in non-events
● Exception: Low-level jet apparently not as important for flash flooding, but more common for heavy rainfall non-events
● Measures of antecedent soil moisture a good first-guess criterion between both flood/heavy and flood/watch
● Properties of the 850-mb theta-e field differ in both flood/heavy and flood/watch comparisons
● Measures of 850-mb and 700-mb moisture (dewpoints and RH) differ for flood/heavy and flood/watch
● Notable differences in large-scale mid and low level wind patterns
● Notable differences in 850-500 relative humidity patterns
![Page 20: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/20.jpg)
Flood
Watch
Heavy
Sea LevelPressure
![Page 21: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/21.jpg)
850-mb wind speed
Expect strong LLJ
![Page 22: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/22.jpg)
850-mb wind directionSome SE Mostly SW to W
![Page 23: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/23.jpg)
850-mb wind speed vs. 850-mb wind direction
F = floodH = heavyW = watchR = random
SE mostly floods
NW often non-events Fast winds either
![Page 24: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/24.jpg)
850 mbwind vector
Weak LLJ, convergence Stronger LLJ
Strong LLJ, convergence
![Page 25: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/25.jpg)
Storm Motion Speed
Not necessarily slow storm motion
![Page 26: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/26.jpg)
Storm motion direction
Primarily SSW to W
![Page 27: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/27.jpg)
Mid-level (500 mb – 700 mb) Shear SpeedWeak shear
![Page 28: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/28.jpg)
Mid-level (500mb-700mb) shear directionWeak directional shear
![Page 29: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/29.jpg)
Mid level shear: direction vs. speed
Larger shearcan flood!
![Page 30: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/30.jpg)
700 mbwind vector
Weak, convergence Strong
Strong, convergence
![Page 31: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/31.jpg)
500 mbwind vector
Weaker Stronger
Stronger
![Page 32: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/32.jpg)
250 mbwind vector
![Page 33: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/33.jpg)
Precipitable water (% normal)
![Page 34: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/34.jpg)
Weekly Ant. ppt. vs. Precipitable Water (% normal)
![Page 35: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/35.jpg)
PrecipitableWater(anomaly)
Localized moisture Frontal signature?
Perhaps some of both?
![Page 36: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/36.jpg)
850 mb Theta-e vs. weekly antecedent precipitation
Floods lower theta-e and wetter antecedent
![Page 37: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/37.jpg)
CAPE
Long, skinny CAPE?
![Page 38: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/38.jpg)
850 Wind Direction vs. 850 Dewpoint
Floods: lower 850 Td
![Page 39: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/39.jpg)
850 mb RH
Floods have higherRH than heavy
![Page 40: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/40.jpg)
700 mb RH
![Page 41: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/41.jpg)
500 mb RH
![Page 42: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/42.jpg)
Summary
● LLJ not as significant in FF's as in null events● Composites suggest theta-e ridging is less
significant in FF's than in null events● Atmospheric moisture greater and more localized
in FF's than in null events● Possible connection between antecedent soil
moisture and local maximum in moisture content during FF's?
● Caveat: small sample size, small spatial domain!
![Page 43: An Examination of the Climatology and Environmental Characteristics of Flash Flooding in the Binghamton, New York County Warning Area Stephen Jessup M.S.](https://reader035.fdocuments.in/reader035/viewer/2022070400/56649f135503460f94c280a8/html5/thumbnails/43.jpg)
Acknowledgements
● COMET Outreach Project S05-52254 ● Art DeGaetano, Cornell University● Mike Evans, NWS Binghamton