24 May 2002 WCR & KA data
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24 May 2002 WCR & KA data • VPDD: – 19:10 Z @ 2000 m AGL: dryline below – 19:14 Z descending from 2000 m to 1500 m AGL: intercept the cold front in a 180 degree turn. Cold front is 16 km to the WNW of dryline – 19:18 Z @ 1500 m AGL: dryline below – 19:29 Z @ 900 m AGL: dryline below – 19:32 Z @ 900 m AGL: cold front, 14 km to the WNW of dryline • Low SSP up: – 19:35 Z @ 360 m AGL: cold front and dryline, separated some 11 km (10 km at corrspndg angle) – 19:49 Z @ 170 m AGL: cold front and dryline, separated by 3-4 km • VPDD: – 20:00 Z @ 2300 m AGL: cold front and dryline, separated by 1-2 km – 20:09 Z @ 2300 m AGL: cold front and dryline collapsed (wind synthesized) – 20:25 Z @ 1200 m AGL • Low SSP up: – 20:28 Z @ 170 m AGL: cold front has surged under the dryline – 20:46 Z @ 170 m AGL; cold front has surged under the dryline • VPDD: – 20:54 Z @ 1200 m AGL – 21:11 Z @ 2400 m AGL: cold front, about 9 km behind deep-convective initiation (estimated frontal speed relative to dryline : 6-7 m/s)
description
24 May 2002 WCR & KA data. VPDD: 19:10 Z @ 2000 m AGL: dryline below 19:14 Z descending from 2000 m to 1500 m AGL: intercept the cold front in a 180 degree turn. Cold front is 16 km to the WNW of dryline 19:18 Z @ 1500 m AGL: dryline below 19:29 Z @ 900 m AGL: dryline below - PowerPoint PPT Presentation
Transcript of 24 May 2002 WCR & KA data
24 May 2002 WCR & KA data
• VPDD:– 19:10 Z @ 2000 m AGL: dryline below– 19:14 Z descending from 2000 m to 1500 m AGL: intercept the cold front in a 180 degree turn. Cold front is 16
km to the WNW of dryline– 19:18 Z @ 1500 m AGL: dryline below– 19:29 Z @ 900 m AGL: dryline below– 19:32 Z @ 900 m AGL: cold front, 14 km to the WNW of dryline
• Low SSP up:– 19:35 Z @ 360 m AGL: cold front and dryline, separated some 11 km (10 km at corrspndg angle)– 19:49 Z @ 170 m AGL: cold front and dryline, separated by 3-4 km
• VPDD:– 20:00 Z @ 2300 m AGL: cold front and dryline, separated by 1-2 km – 20:09 Z @ 2300 m AGL: cold front and dryline collapsed (wind synthesized)– 20:25 Z @ 1200 m AGL
• Low SSP up:– 20:28 Z @ 170 m AGL: cold front has surged under the dryline– 20:46 Z @ 170 m AGL; cold front has surged under the dryline
• VPDD:– 20:54 Z @ 1200 m AGL– 21:11 Z @ 2400 m AGL: cold front, about 9 km behind deep-convective initiation
(estimated frontal speed relative to dryline : 6-7 m/s)
19:10 Z
dryline
cold front
16 km
Ground ~650 m highClouds between 1200-2100 m AGL
Moist side sounding:
nadir beam
Time match correct
ESE110
WSW290
19:10:09-19:11:20dryline
19:13:48 19:15:22
Cold front
nadir beam
SE NW SENW
Cold front
19:14 Z
cold front
19:18 Z
Wind shift
Flight level: ~1500 m AGL
Time match correct ESE110
WSW290
Dryline?
coldfront?
Ahead of cold front, in the dry sector?? Dryline? Moist airnadir beam
19:29-19:32 Z
cold front
dryline
ESE110
WSW290
cold frontal surface @900 m dryline
Moist airCold air
foreward beam!!!
dry sector thermal ??
14 km
170 m
360 m 170 m
360 m
cold front @ 360m@ 19:35
cold front @ 170m@ 19:49 dryline
@ 170m@ 19:48
cold front
dryline
cold front
dryline
Low SSP up
19:33
19:43
19:52
UWKA
SE135
NW315
cold front
Height aboveflight level(m)
total length: 11.2 kmaspect ratio: 1:1
frontal motion
flight level: 360 m AGL
Relative humidity
Mixing ratio
e
SE135
NW315cold
front
NW SE
convergence!
ascent
kft km
Height above flt level
total length: 5.9 km
flight level: 360 m AGL
frontal motion
SE135
NW315
frontal motion
cold frontal surface @360 m
vm/s
um/s
cold frontal surface@360 m
dryline
westerly
northerly
southerlyvm/s
um/s
11 km
Time matched OK
Attenuated??
20:00 ZVPDD
Flight level: ~2300 m AGL
19:59:08-20:02:38
ESE110
WNW290
frontal motion
front Dryline? Moist air
Flight level: ~2300 m AGL
20:10 ZVPDD
cold front below
@ 20:09 Z
SSE164
NNW344
frontal motion
front & drylinemoist air
Time match OKcold air
Aspect ratio : 2:1
WCR nadirantenna reflectivity
Time (UTC)
Flight level: 2300 m AGL
Height below flight level(m)
dBZ
20:25 ZVPDD
descending to 170 m
Flight level: ~1200 m AGL
cold front below@ 20:25 Z
20:21:50-20:25:40
ESE164
WNW344
frontal motion
front
km possibly stratus clouds
cold front @ 170m@ 20:46
cold front @ 170m@ 20:28
km
-5
-45
dBZ
Total length: 11.7 km, flight level: 170 m
mixing ratio
wind direction
potential temperature
dewpoint
temperature
wind speed
SSE164
NNW344
6 8
frontal motion
SE120
NW300
frontal motion
vertical velocity
mixing ratio
wind direction
potential temperature
dewpoint
temperature
wind speed
Total length: 11.7 km, flight level: 170 m
km
20:54 ZVPDD
ascending from 170 m
Flight level: ~1200 m AGL
cold front belowaround 20:54 Z
20:51:58-20:56:28ESE110
WNW290
frontal motion
Not sure about time match
Moist air ahead of dryline
Dry air above the cold front
If the air ahead of the sharp gradient is drier and warmer, why does it seem to have a cloud at flight level?
Embryo of a Cb cell that develops here in the next 15 min?
Flight level: ~2400 m AGLLast leg
21:11 ZVPDD
(ascending after this time)cold front belowaround 21:11 Z
First cumulonimbus formation (~21:12:30)
21:06:36-21:13:20
ESE110
WNW290
frontal motionGravity waves in the cold-frontal stratus?Questionable (dixit Sam)
This is a cloud whose towering tops had grown well above 4 km AGL, part of a line of storm cells aligned with the cold front
Deep convection develops 9 km ahead of sfc cold front
9 km
AMA21:05
21:15
UWKA
