Wa. Gallus et M. Segal, Diabatic effects on late-winter cold front evolution: Conceptual and numerical model evaluations, M WEATH REV, 127(7), 1999, pp. 1518-1537
The impact of diabatic heating on late winter frontogenesis is evaluated bo
th through conceptual scaling and the use of high-resolution Era Model simu
lations of a strong but relatively dry cold surface front that occurred dur
ing the Storm-scale Operational Research Meteorology Fronts Experiment Syst
ems Test (STORMFEST) project. Although skies were clear ahead of the front,
it was trailed by an extensive area of cloud cover that influenced frontal
strength during the daylight hours by reducing solar insolation and sensib
le heat flux.
An Era control simulation of the event agreed reasonably well with observat
ions and indicated intensification of the frontal temperature gradient duri
ng the daytime with a weakening at night. Additional simulations have been
done to investigate sensitivity to several diabatic processes. These tests
include the role of cloud shading on surface sensible heat flux, the role o
f soil moisture in the warm sector, and the role of evaporative cooling of
precipitation in the light precipitation area behind the cold front. All of
these diabetic processes have a measurable impact on the front. although s
oil moisture and cloud shading appear to play the most important roles. The
moisture and static stability of the frontal environment were unfavorable
for precipitation along the front, and the increase in frontal strength due
to reduced surface sensible heat flux from extensive cloud shading behind
the front did not significantly influence near-front precipitation for this
event.