WMOD00176

• Project Name: Annual Report
• Title: Seeding Operations & Atmospheric Research, 2005 Annual Report
• Prepared By: Duncan Axisia
• Date: 12/31/2005
• Weather Modification - Doc Type: Report

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With tropical storm Candy in the Gulf of
Mexico and a moderate lU out of the
southeast advecting moist tropical air out in
front of the cold front. the Southern Ogallala
program conducte<l operations on the 6"". An
active pattern began to establish itself. A
suffident amount of moisture advected into
the area along the southeast surface flow.
With a northern component to the upper level
flow due to a stubborn upper level ridge over
the southwest portion of the country, coupled
with the southeast surface flow, there was
enough convergence to destabilize the
atmosphere. With temperatures above norma!
(in the mid-upper 90's) throughout the region
and vorticity advection wrapped in the upper
level flow SOAR was able to operate on the
8th, 91~ and 10th.

By the 11t11 a surface boundary extending
through the Texas panhandle had eroded and
hurricane Dennis was making landfall over the
Gulf shore. Despite ample moisture from
hurricane Dennis the southern plains lacked
any surface features to trigger thunderstorms.
By the 14th the remnants of Hurricane Dennis
had moved into the tower Ohio vaHey and a
low pressure ejecting out of the Rockies into
the central plains was responsible for a cold
front extending into the northern Texas
panhandle. A second boundary extending
from the remnants of Dennis was also
affecting our region. With temperatures in
the 90's convection initiated along these
surface fronts on both the 14lh and 15th.

A Quiet weather pattern began on the 16th
when the polar jet became zonal. With zonal
flow aloft giving way to an upper tevel ridge,
high pressure was again the story until the
ridge translated east and an upper level
trough began to eject a series of shortwaves
into west Texas, On the 25th, a surface low
formed east of the Rockies in the centrat
plains and the cold front associated with this
low extended through northeast New foAexico.
Thunderstorms developed at the foot of the
mountains in New Mexico and slowly moved
east toward the Southem Ogallala target
area, carried by a shortwave moving through
northeast New Mexico into the Texas
panhandte, The 26lh proved to be very similar
to the 25th but with stronger storms and much
mOfe rainfall. With precipatabte water values
between ',5" and 2" and another shortwave

moving through the region, thunderstorms
again developed at the foot of the mountains
in an area of strong surface convergence. The
storms moved slowly toward west Texas
providing us another day of operations.
Almost the entire target area saw at least a
trace of rain with many locations getting well
over an inch, High pressure again became the
primary influence on west Texas weather.
With a weak elongated surface boundary
extending through the southern perimeter of
the target area and an upper level shear axis
through central Texas providing upper level
instability on the 29th, convection was
triggered along the front and SOAR flew the
last mission of the month.

August 2005

August began with a high pressure across the
region and seasonal temperatures in the
low/mid 90's. The upper level ridge responsible
for the fair weather began to translate east by
August 41~. A cold front associated with a low in
southeast Canada moved through the
Southern Ogallala target area from northeast
New Mexico during the day. Behind the cold
front was an amplifying high pressure, A low in
northern Mexico advected warmer
temperatures into west Texas out in front of the
surface boundary. With southeast flow at
850mb drawing in moist Gulf air and surface
winds out of the northeast behind the front
there was moderate surface convergence
along the boundary, Thunderstorms developed
by late morning in the central Texas panhandle
and slowly moved south-southeast along the
boundary headed for the Southern Ogallala
target area. This was the first seeding mission
for August. On Aug. 5th, a lingering frontal
boundary to the south along with surface
temps in the mid 90's continued to fuel
convection in west Texas. Vorticity advection
in northeast upper level flow coupled with moist
LLJ al 850mb produced scattered
thunderstorms in the southem portions of west
Texas. The unstable weather pattem continued
on August 6~. An upper level shear axisvthrough west Texas coupled with an
abundance of surface moisture and a weak
frontal boundary to the south all contributed to
scattered thunderstorms developing in the
Southem Ogallala target area. On August 7m,
an upper level shortwave approaching from
northeast New Mexico and a surface low in

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