Post-Landfall Option
   Motivation:

    Previous observational studies have shown that the primary mechanism 
responsible for the decay of TCs after landfall is the large reduction 
in latent and sensible heat fluxes after landfall. These 
post-landfall reductions in surface fluxes have been shown to be the 
result of decreases in land temperature beneath the storm that result 
from the limited heat capacity of the the soil subsurface. Several 
studies have also shown that the rate of TC decay after landfall is 
proportional to the landfall intensity and that the wind associated 
with landfalling TCs decrease rapidly within the first few kms of the 
coastline. However, the above findings have typically relied upon a 
relatively sparse observational network and/or compositing techniques 
that assume stationarity over a considerable length of time. Clearly, 
collecting high resolution landfall data sets against which these 
findings can be verified is a worthwhile task, particularly in 
light of  the substantial damage and loss of life incurred in 
inland regions during Hurricanes Hugo (1989), Andrew (1992), 
Opal(1995), and Fran(1996).  

   Post-Landfall Option:

The WP-3D will fly a figure 4 pattern over land with leg lengths of (~150 km)   after the hurricane has made landfall at the 
at an altitude of ~10,000-15,000 ft (3-5 km). The DC8/ER2 will fly the 
coordinated pattern shown in Fig. 9 with leg lengths of ~150 km at an 
altitude of ~37,000 ft (11 km) and ~67,000 ft (20 km) respectively.  
If feasible, the DC-8 and WP-3D should fly legs along WSR-88D 
radials with the ARMAR and tail Doppler data in FAST mode. These 
data will aid in rainfall estimation and will help document the 
changes in vortex and rainband structure over land that are crucial 
to understanding the environment that supports tornado and mesovortex 
development. 
 
   Over land, 12 mesonet stations, 3 profilers and 2 DOW Doppler radars  
should be deployed along the path of the landfalling hurricane to 
identify the changes in storm structure as the hurricane moves inland. The 
mesonet stations should be deployed in 3 lines of 4 stations each. The 
mesonet stations will be employed to obtain high resolution surface wind, 
temperature, pressure, relative humidity, and perhaps rainfall 
measurements.  A profiler will be placed at the center of each of 
the lines of mesonet stations. The profilers and collocated RASS sounder
will provide wind and temperature measurements within the lowest 3 and 1 
km, respectively. If possible, rain gauges should be collocated at each
profiler and DOW radar site to obtain high resolution rainfall 
measurements useful both for calibrating the radar rainfall algorithms 
and for documentation of storm rainfall. 
     
  The first of the three lines of the mesonet stations should be placed as 
close as possible to the coastline to enable accurate documentation of the 
surface wind field just after landfall. The other two lines should be placed 
~65 and 135 km inland respectively; however, these distances will vary 
depending upon the intensity and speed of motion of the landfalling 
storm as well as safety considerations.  Fig. X provides estimates of 
the amount of time after landfall that is required for the TC winds
to decay to various wind threshold levels as determined using the HRD 
empirical inland wind decay model.  The inland profilers should be 
highly mobile so that it will be possible to follow severe weather 
producing rainbands provided that safety and logistical considerations 
allow. The DOW doppler radars should be placed roughly halfway between 
the two rear lines of mesonet and profiler stations.  The DOW radars in 
combination with the 3 profilers with RASS will aid in documenting the 
changes in kinematic and thermodynamic structure of the hurricane 
after landfall. An accurate analysis of such changes is crucial to 
learning more about the development of  mesovortices and/or tornadoes 
spawned by the landfalling hurricane. They will also  help document the 
changes in winds within the PBL of a landfalling hurricane. Finally, the 
radars will aid in the measurement of the rainfall associated with the 
landfalling hurricane.