CLEX-9 October 12th, 2001 Operations

Synopsis

• The CLEX-9 forecast team has decided to stand by all operations for Friday, October 12th.
  
  
• Weather Forecast (made at 1530 MDT 10/11/01):

  
            Weather Discussion:
  
            An approaching upper-level short-wave trough and associated PVA and moisture 
            will produce wide-spread cloudiness over the North Platte and western Nebraska 
            region during early AM.  There may also be a few isolated showers in the western 
            NE/eastern WY region at 12z, with ample moisture and lifting at mid-to-low levels 
            behind the associated cold front.  Showers are forecasted to decrease in intensity 
            and coverage by 18Z in western NE and eastern WY.  
  
            Weather Outlook:
  
            Conditions for mid-level cloud look generally favorable through the weekend, 
            especially for Saturday.  For Saturday AM, the southern extent of a shortwave 
            brushes the western NE region.  This could be favorable for non-precipitating 
            mid-level cloud.  By Sunday, the target area is in NW flow aloft on the back 
            side of the 500-mb trough.  In this scenario, there is the potential for 
            unforecasted (not resolved well by models) mid-level clouds that dissipate 
            after sunrise.
     
            Larry/Adam
  
    
  Morning Update (made at 0330 MDT 10/12/01): 
  
            CLEX-9 operations are on go status for Friday morning (10/12/01).  
  
            Larry Carey and the King Air crew are going to be airborne by 0600 MDT.  The 
            target region is SW Wyoming (see IR satellite image below).  The plan is to 
            perform Lagrangian in-situ and cloud radar scanning observations on a target 
            cloud through the sunrise timeframe...
  
            The current synoptic situation has a large cirrus shield (with corresponding 
            precip) over the North Platte region.  The cirrus shield currently extends 
            westward to the WY/NE border.  West of the cirrus band are regions of mid-level 
            clouds (with cloud top temps of ~-15C on IR satellite).  An upper level dry slot 
            (centered over western WY) is slowly advecting into the region.  Most of the models 
            do not advect/dry out this region until well after the 1200 MDT TERRA overpass...
  
            Operations will continue until Larry decides to land and refuel and get an update.  
            At this time we will assess the synoptic and cloud situation for a possible 1200 
            MDT TERRA cloud sampling mission...
  
            Adam (from CLEX-9 central) 
  
  

Post Mission Update (made at 1030 MDT 10/12/01):

          The 12 Oct 2001 CLEX-9 mission over the southern WY/NE border region has been completed.  

          Larry reported that he was able to sample a wide variety of clouds during the mission.  
          Clouds sampled ranged from mostly liquid cloud (with tops near -4 C) to mixed phase 
          cloud (with tops near -15 C) to cirrus cloud (temps near -32 C).  The composition of 
          these clouds ranged from very thin liquid and mixed phase clouds to very thick cirrus 
          decks.  Multiple layers of clouds were also observed/sampled.  The overall cloud field 
          was very dynamic and even broken in places which necessitated the use of a wide variety 
          of sampling strategies.  A combination of spirals and long, straight-legged tracks were 
          incorporated to sample these clouds.  Both horizontal and vertical cloud radar profiles 
          were taken through the clouds.

          All aircraft probes, avionics and instruments worked well.  The cloud radar needed to 
          be re-booted a couple of times, but only a few minutes of data was lost.  There were 
          minimal airspace restrictions encountered throughout the entire flight.  

          Total time aloft was 2.5 hours (with 1.5 of those hours dedicated to sampling cloud).

          After landing at Laramie we decided to stand down any further operations for today.  
          All potential CLEX clouds had dissipated leaving only the large (and thick) cirrus shield 
          over western NE as the only available target.  There is also a wide region of light to 
          moderate precipitation associated with this cirrus deck.

Sunrise Information for North Platte, NE

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.                 

Weather Details

1200Z 500 mb Map



1246Z GOES IR Image and CLEX-9 12 Oct 2001 Target Region


 




1200Z North Platte, NE Sounding


 







 

Aircraft Operations

• UW King Air Operations: Total time aloft was 2.5 hours (with 1.5 of those hours dedicated to sampling cloud)

North Platte, NE Ground Operations

• Ground Instrument Status: Everything working well
  

Data Collection Highlights:

• Summary: Updated as soon as possible