more examples?. where do you expect what kind of fronts? slim wf?
TRANSCRIPT
Stronger kinkWeaker kink
0
0,2
0,4
0,6
0,8
1
1,2
0 20 40 60 80 100
phi (min (Azi-dir))
co
s p
hi
Stronger
weaker
Vrcos term related to sight azimuth
(1)
(1): line of same radar sight. Any change of Vr due to wind dir (or wind speed).(2): Front line at least line of wind dir change, so Vr change ( „Radial shear“).
(2)
Uniform wind veering at front (arrows)
Zero
line
Frontal signs more intense near zero line sector
Frontal change:
Phi (angle Dir, Azi)
phi1
phi2
~20°
const. sight
Radial shear
Azi
sh
ear
Prefrontal: blue line Vr intensifies radially red line Vr decreases radially
Radar
Radar
Often the frontal wind shift is only a narrow corridor
Postfrontal: blue line Vr ….……….. radially red line Vr ….………… radially
Radar
Remember: Vr closer to zero line: weaker!
Pull right line into diagramm position:
intensifies decreases
Warm con belt
Cold con belt
PU4UMD
MUC
MUC
When , compared to high warm air advection a very different low wind is indicated, it is then the cold prefrontal wind, nearly front parallel.
CAPPI 1-4, wind shift
UMD
Extreme CAPPI shear in H4
4
1
LIN, 18UTC
warmCCB warmwarmcold
slow
Wind backing!?
Discrepancy between height of assumed VAD frontal zone and surface position?
CAPPI1 PPI
H2
Stationary fronts, same case
CAPPI H1
1
2
Front position?
Band in H3km?
2
1
Here frontal wind shift identical with max. vertically veering?
…slow front
BB
band
06UTC