Mission Forecast:
As today, the western NE area will be in NW flow aloft tomorrow with embedded
weak short waves and associated mid-tropospheric moisture. The ETA and AVN bring
a moisture tongue through the LBF area tomorrow. As is typical with this scenario,
the NWP models are not entirely consistent on timing and details. ETA brings the
moisture in around 18z while AVN brings a weak disturbance through early AM (12z).
We will make a Nowcast at 0330 MDT to determine our exact mission time. Earliest
mission would be 0530 to 0600 MDT takeoff.
Weather Outlook:
On Monday, the NW'ly mid-tropospheric flow regime continues. Details are even more
murky on timing and location of mid-level clouds but conditions are generally
favorable for CLEX operations in western NE. Tuesday-Wednesday look less favorable
for NE/WY/CO region as a ridge builds at 500mb.
Larry/Adam
Larry has landed in North Platte, NE after a successful morning CLEX-9 mission. The
mission started out with a under cloud transit of the continuous mid-level cloud field
from just east of Laramie, WY to North Platte, NE. The onboard cloud radar was able to
vertically profile the cloud deck during this entire transit.
Once in North Platte, Larry then proceeded with Eularian cloud sampling over the CLEX-9
ground site. Several east-west oriented flight legs were run over North Platte at
different altitudes (7, 10, 13, 17 and 20 Kft). They then completed this part of the
mission with an Eularian spiral downward. During this time the cloud field above North
Platte was observed to be dissipating and no liquid water (though there was ice present)
noted.
Larry then proceeded to head NW to a thicker deck of mid-level cloud. They sampled this
cloud deck with Lagrangian spirals and ascending profiles. The cloud radar was used to
document the vertical profile of the cloud deck throughout the time they were present
within the cloud.
John Davis reported that he launched a rawindsonde to support this CLEX-9 mission around
0800 MDT. He also reported that all ground instruments were working well during this
timeframe. In addition, John reported that ground radio communication with the King Air
worked well. Airspace restrictions today were again minimal.
Larry has decided to go up for another mission to sample the cloud deck under the 1140 MDT
TERRA overpass and then head back to Laramie.
Adam (from CLEX-9 central)
Larry reported 1112 MDT takeoff, scanning the clouds overhead vertically. They then made
a straight run ascent to NW from LBF to 17-18 Kft (where cloud tops were observed). Noted
lots of water at cloud tops - began sampling with probes and side look cloud radar. Very
bumpy at 17.2 Kft. At 1138 MDT they turned around and headed SE back toward LBF in a
straight descent, still scanning with the side view cloud radar. At 1154 MDT (at 8.5 Kft -
which put them under cloud base) they turned around and headed NW with the cloud radar in
vertical mode. By 1200 MDT they were level at 8.5 Kft under cloud base (pointing cloud radar
vertically) heading back NW. At 1233 MDT they terminated the run under cloud and head back
to Laramie. Larry reported a cloud-sampling time of 1.5 hrs.
Sunrise
Central Daylight Time
Begin civil twilight 7:24 a.m.
Sunrise 7:52 a.m.
Sun transit 1:29 p.m.
Sunset 7:07 p.m.
End civil twilight 7:35 p.m.
CLEX-9 Morning Mission #1 Target Region (10/14/01)
(0615 MDT IR Satellite Image)

CLEX-9 Morning Mission #2 Target Region (10/14/01)
(1002 MDT IR Satellite Image)

10/14/01 Terra Orbit Track

Some of the highlights from this day of flying include observations of what appear to be
generating cells at cloud top with all liquid water at very top turning to mixed phase
within a few hundred meters or less. The ice then sediments out of generating cells in
fall streaks to SE associated with NW'ly shear. Ice from multiple generating cells/fall
streaks merge into one 1.5 km layer of mostly ice. There is a hint of aggregation around
-12 C to -9 C in the middle of the ice layer in the 2D-C and also in enhanced reflectivities
there (-10 dBZ). These generating cells (and corresponding fall streaks) can be seen in
the cloud radar cross section below. Cells of this nature were also observed on yesterday's
CLEX-9 mission.