It rolls in when it
wants to, covers everything in its path and makes visibility so
poor you can barely see your hand in front of your face. It is what
some in Karshi-Khanabad Air Base, Uzbekistan, call “the fog
of war.”
This fog, however, is the real thing. It is a fog so thick it
makes missions for Operation Enduring Freedom here sometimes
difficult. But there is a weapon against it -- up-to-the-minute
weather forecasts and predictions by 416th Expeditionary Operations
Support Squadron weather flight Airmen.
“Uzbekistan is a semi-arid, plains-type desert,”
said Capt. Kristopher Long, operational meteorologist in charge of
the flight here. “As a result, it gets very little rainfall
in a typical year. However, from last December to right now, we are
approximately 500 percent above normal in rainfall. And the trend
looks like it will continue through January and February.
“One consequence of more rain, besides mud and standing
water, is that is brings more low clouds and fog with it,”
Captain Long said. “This makes life a little more difficult
for the aircrews flying in and out of here.”
Fog, by definition, is simply a cloud that forms at the surface,
Captain Long said. “Fog can appear at an airfield in two ways
-- it can form directly on the airfield where forecasters call it
‘radiational fog,’ or it can form somewhere else and
move on to the airfield, which is called ‘advection
fog,’” he said.
The level of the dense advection fog is a particularly
troublesome weather problem at this base, Captain Long said,
because it significantly impedes airfield operations. The
forecasters built a unique theory on the K-2 fog based on many
factors. The theory was built by Captain Long and his team of
weather technicians who include Tech. Sgt. Troy Walker, who
recently returned to the United States, and Staff Sgts. John
Radford and Bobby Baum.
Captain Long said the theory states that about one to two days
after a cold front passes through K-2, the winds at and near the
surface shift.
“If this (shift) occurs at late afternoon or later in the
night, and our (sky is) clearing or losing clouds, then the
environment becomes favorable for fog formation, especially if it
rained significantly as the front came through,” Captain Long
said. “At the same time, up in the snow-covered mountains, a
dense fog will begin to form because the air is being cooled at the
higher altitude and snow covered ground.
“When that cooled air gets cold enough, it becomes
saturated and fog forms,” the captain said. The winds flowing
out of the mountains then grab the fog and pull the fog toward the
base, he said.
“Usually this happens well after sunset, but sometimes it
occurs just as the sun is setting, and we are able to see it form
in the mountains with our weather satellite imagery,” he
said. Captain Long said the dense fog he described can drop
airfield visibility to less than one-quarter of a mile in less than
15 minutes.
“Obviously the fog creates many problems for aircraft
trying to land or takeoff, so forecasting the fog accurately is
extremely important,” he said.
To combat the fog, Captain Long said the forecasters refine
their forecasts based on the knowledge and experience they have
built in their time here in Uzbekistan along with their recorded
climatology. So far, the base has had eight major advection
fog events since October and had several dozen advection fog events
recorded from 2002 to 2004, Captain Long said.
“Each event has given us more information and clues as to
the behavior and characteristics of the fog,” he said.
Captain Long said the team also uses computer-model forecasts and
satellite imagery.
“Mostly our computer models don't foresee these dense
advection fog events perfectly,” he said. “But one
computer model in particular has been able to somewhat accurately
predict the fog. More importantly, our aircrews have been really
terrific (letting) us know when the weather starts
changing.”
Through forward observations, prior experience and the computer
models and satellite imagery, the forecasters have been able to
refine their advection fog theory, he said. With the weather team's
effort, Captain Long said OEF missions are less hindered, and, he
hopes, mission success is that much higher. [ANN Salutes Tech. Sgt.
Scott T. Sturkol, 416th Air Expeditionary Group Public Affairs]