For MY (OUR) Coastal AO FCA.
**
The well-advertised storm system which will be crossing the
northern Gulf of Mexico on Friday will send plentiful
moisture
overhead in the form of dense mid-upper cloud cover. Isentropic
upglide most notably found along the 295K surface overlapping
with high
moisture content air will undoubtedly yield
precipitating clouds during Friday afternoon.
However, the
remains of the Arctic air mass will leave a considerable wedge
of dry air beneath these clouds, which will prevent this precip
from reaching the ground and instead use it to moisten the air.
This process will also result in evaporative cooling of the
low-level air, thereby leading to a chance for light snow or
sleet to reach the ground from late Friday afternoon into the
night across northern and western areas.
However, as a warm nose, (WAA), becomes increasingly established ahead of the approaching
surface low, precip type concerns switch to freezing rain where
air temps manage to evaporatively cool below freezing during the
early stages of this event; even so, preceding daytime air
temps in the low 40s and rising temps through the night preclude
much concern over ice
accretion, which may only be reserved to
elevated metal surfaces for a few hours where temps are cold
enough in our northern and western zones.
Otherwise, plain rain is still expected to become the dominant
precipitation type overnight as warm air both works its way down
and is advected inland at the surface ahead of the low.
Guidance continues to trend towards a faster
shortwave passage,
with rain chances peaking early Saturday morning and tapering
off from west to east during the morning into the early
afternoon.
QPF totals look to end up in the 0.25-0.75" range,
highest near the coast. Behind this storm system, there actually
may be some warming that occurs as clouds thin and precip
abates, leading to highs in the upper 40s inland and perhaps low
50s along/near the coast.**
