CLEX-9 October 31st, 2001 Operations

Synopsis

• The CLEX-9 forecast team has decided to stand by all operations for Wednesday, October 31st.
  
  
• Weather Forecast (made at 1500 MST 10/30/01):

  
             We are going to be on stand by for possible WYKA and SPEC CLEX operations on 
             Wednesday, 31 October 2001.  The earliest GO/NO GO decision will be at 0500 MST 
             (1200Z).  Expect earliest possible takeoff for the King Air at 0700 MST (1400Z) 
             and for the SPEC Learjet at 0730 MST (1430Z).  The target for dual-aircraft 
             operations will be over North Platte, NE. 
  
             WEATHER DISCUSSION:
  
             Much like today, there will be cloud cover around tomorrow.  How much of that 
             cloud will be mid-level remains to be seen.  The ETA does move a nice fetch of 
             500 mb moisture through the CLEX region between 12Z and 18Z tomorrow (but this 
             could just translate to another big bloom of orographically-induced cloud).  
             Weak NVA is forecasted Colorado southward with more favorable PVA to the north 
             (all rather weak).  Any mid-level clouds that do form will most likely be 
             accompanied by patchy to solid cirrus.
  
             The earliest GO/NO-GO decision will be made at 0500 MST (1200Z) after determining 
             the availability of suitable types of clouds over LBF.
  
             OUTLOOK:
  
             By Thursday, the main axis of the upper-level trof should be east of our region.  
             The models hint at potential mid-level cloud cover over eastern NE (under a 
             corresponding 1730Z TERRA overpass).  Will have to see how this model solution 
             evolves.  For Friday and beyond, we will be in NW'erly flow with what looks like 
             relatively dry mid-level flow.  Could be an ideal CLEX situation if there is enough 
             moisture around to squeeze out a few clouds.  Will wait and see...
  
             Adam/Curtis/Don
  
    
  Morning Update (made at 0600 MST 10/31/01): 
  
             CLEX-9 is a GO for a dual aircraft mission over LBF.  The WYKA is expecting to take 
             off at 7:30 AM MST with Adam Kankiewicz on board.  The SPEC Learjet is expected to be 
             on station over LBF between 9 - 10 AM.  The Learjet is now operating out of Centennial 
             Airport due to recently imposed FAA restrictions on flights near Rocky Flats.
  
             A large plume of cirrus cloud covers the CLEX area and extends back over most of Colorado.  
             Infrared imagery indicates some breaks in the cirrus with a mid level cloud deck below.  
             John Davis at LBF at 5 AM MST reports good lidar returns between 4 - 5 km, with more 
             returns in the 8 - 9 km range.  Temperatures at this level are about -5 C.  Radar indicates 
             some virga over the NE panhandle.
  
             Another update will be issued late morning / early afternoon after the completion of the mission.
  
             John Forsythe 
  
  
  

Post Mission Update (made at 1230 MST 10/31/01):

           The King Air and Spec Lear jet completed a unique coordinated sampling mission of mid-level 
           and cirrus clouds today from 9:30 - 12:00 MST.  WYKA departed LAR at 07:30 MST and ferried 
           from LAR to LBF.  They sampled some good mid-level clouds enroute with high liquid water 
           content at -17 C.  WYKA landed and refueled at LBF.

           The SPEC Lear jet departed Centennial Airport at about 9 AM MST, having ferried from Jeffco 
           the previous night due to new flight restrictions at Jeffco and causing about a two hour 
           delay in earliest morning takeoff.  Initially a 30 mile leg was set up over the instrument 
           site at LBF.  WYKA and the Lear completed coordinated sampling, on a 30 mile leg oriented 
           over LBF.  WYKA reported only ice falling out from above but could see better mid-level 
           clouds to the NW of LBF.  WYKA flew at FL 290 - 310, while WYKA flew near FL 200.  A decision 
           was made to start a new racetrack about 50 miles WNW of LBF.

           There was an overlying cirrus layer at FL 290, with mid level cloud between 15 - 20000 feet.  
           The Lear descended to FL 220 to skim the top of the mixed-phase cloud while WYKA flew 
           underneath and in the cloud with the radar.  The Lear had to land in LBF for fuel by 11:30 MST.  
           The entire cloud mass was observed by aircraft and satellite to be in a dissipating state by 
           this time, something we have often observed during CLEX.  

           The WYKA then flew to the west and and sampled another set of layered mid- and high-level 
           clouds for another 30 minutes.  Upto three distinct layers of clouds were observed on the cloud
           radar.  The clouds started to dissipate and we decided to head back to Laramie (landing at 1349 MST).

           GOES-8 Rapidscan was called from 15 - 19 Z.  John Davis successfully launched a sonde that made 
           it to 50K feet.

           Air to ground and air to air communications worked well and the LBF and CIRA ground sites were 
           able to frequently communicate with the WYKA mission scientist, Adam Kankiewicz.

           The next CLEX-9 Forecast update will be at 3 PM MST today.

           John Forsythe/Adam Kankiewicz - CLEX Operations - CIRA

Sunrise Information for North Platte, NE

Sunrise   
                     Central Standard Time          

        Begin civil twilight       6:45 a.m.                 
        Sunrise                    7:14 a.m.                 
        Sun transit               12:27 p.m.                 
        Sunset                     5:40 p.m.                 
        End civil twilight         6:08 p.m.                 

Weather Details

1200Z 500 mb Map



1545Z GOES IR Image and CLEX-9 31 Oct 2001 Target Region


 




1200Z North Platte, NE Sounding


 







 

Aircraft Operations

• UW King Air Operations: Total time aloft was 6.7 hours (with 4 hrs of that devoted to sampling cloud).

North Platte, NE Ground Operations

        The UW King Air and the SPEC Lear Jet flew coordinated missions over North Platte 
        and Scott's Bluff today.  Clouds over North Platte were mainly cirrus, but mixed 
        phase clouds were reported to the North and West.
 
        The NOAA microwave radiometer was not operating for today's missions but has been 
        repaired and is currently operational.
 
        The Micro Pulse Lidar collected approximately 7 hours of data and gave the initial 
        indication of mid level clouds beneath the cirrus shield.
 
        Interferograms were collected before, during and after the aircraft operations over 
        North Platte today.
 
        A sonde was launched shortly after the arrival of the SPEC aircraft at North Platte.
 
        Solar and infrared downwelling hemispheric irradiances were collected throughout the 
        day.
 
        As of 21:00 GMT on 10/31 all instruments at the surface site are operational.

Data Collection Highlights:

• Summary: Updated as soon as possible