We are on standby for WYKA CLEX operations on Friday 2 November. Earliest
GO/NO-GO call will be made at 0300 MST (1000z) for an earliest WYKA takeoff at
0500 MST (1200z).
DISCUSSION:
The ETA/AVN bring in weak PVA and associated 500 mb moisture along the flat
ridge by 12z at the WY/NE panhandle border. The moisture hangs in until 18z
according to ETA. However, there may be significant diurnal die-off of mid-
level cloud. Hence, the early morning decision. There is a near full moon
for easy cloud viewing prior to civil twilight.
There is also a MODIS/TERRA overpass at 1812z just west of the operations
area in Central-Western Wyoming. So, if the cloud hangs in there, we may have
the opportunity to two missions, with the 2nd mission being a TERRA overpass.
Because of the timing of the moisture, LBF will likely not be favorable for
early AM operations but we'll make a decision on target early tomorrow AM.
OUTLOOK:
Saturday looks like mid-level cloud will be a bit north of operations area
along Wyoming/South Dakota border as ridge lifts east-northeastward. By
Sunday, CLEX area is fully under ridge influence and mid-level clouds are not
likely.
We are now at 31.7 hours of flight time. If we have 2 missions tomorrow,
we'll likely hit our budgeted target of 38!
Larry/John/Curtis/Adam
The WYKA with Larry Carey onboard has completed a successful mission on a mature-through-
dissipating mid-level cloud over the North Platte, NE region. Larry reports significant
liquid water at cloud top (along with a strong cloud top inversion) with larger ice
observed in the lower part of the cloud. cloud top liquid water contents were around 0.2
g/m3. FSSP measurements showed most of the liquid drops were centered around 10 um size.
Cloud top temps were around -12 C, with a cloud thickness of around 0.5-1.0 km.
John Davis reports all ground instruments worked during this mission, and that he was able
to launch two supplementary rawinsonde in addition to the 1200 UTC North Platte NWS rawinsonde.
The cloud can be characterized as having the previously observed liquid water "cells" on top,
with mixed phased regions within a few hundred meters of cloud top. When the cloud started
to dissipate, Larry noted that these "cells" just seemed to weaken, and the cloud base began
to increase in altitude. Even when the cloud was less than 100 m thick it still had
significant liquid water present (0.1 g/m3) (i.e. did not completely glaciate out).
The total in-cloud sampling time just over three hours. After landing and heading back to
Laramie - just about all of the budgeted flight hours (38) will have been used up.
Adam (from CLEX central)
Sunrise
Central Standard Time
Begin civil twilight 6:47 a.m.
Sunrise 7:16 a.m.
Sun transit 12:27 p.m.
Sunset 5:37 p.m.
End civil twilight 6:06 p.m.
UW King Air flew for over three hours in thin alto cu, landed and then ferried
back to Laramie.
NOAA microwave radiometer was operating reporting water vapor path of around
1.4 cm and a small amount of liquid ... around 0.05 mm.
The Micro Pulse Lidar operated for the duration of the aircraft operation
period.
Interferograms were collected before, during and after the aircraft operations.
Two sondes were launched; one during the overcast period and one after the
clouds had dissipated.
Solar and IR data were collected.
