Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Birmingham Alabama
1129 PM CST Sat Nov 28 2015
for 06z aviation.
The surface high pressure centered just to our east has kept the
wind flow light and with an easterly component. Winds just above
the surface do swing around to a southerly direction overnight and
become a bit stronger. A low level maximum wind zips across the
Tennessee Valley overnight but the models are not picking up on
any huge low level convergence. Some synoptic lift was noted on
the models but shower development to our west has been limited. It
appears the surface to 850mb moisture increase may be slightly
delayed. Therefore...decreased rain chances slightly northwest
overnight with the highest probability of precipitation confined to the few far northwest
counties. The rain chance gradient should be rather high with
nothing expected for much of the south and east.
The front slowly moves southeast on Sunday and will a rather large
moisture and rain chance gradient from north to south...best
chances north. Went ahead and slowed the increase of higher
chances spreading...blending the overnight into middle day probability of precipitation. Made
some minor adjustments to temperatures as far southeast locations
have cooled down with mostly clear skies. Overnight lows near 50
southeast and in the 60s northwest.
06z taf discussion.
No significant changes to previous taf reasoning. Upper level and
surface ridge components will make significant eastward
progressionof system difficult for the next 24 hours. Very light
precipitation perhaps falling north of taf sites and do not expect to see
precipitation affect north and western sites until middle-late morning
tomorrow. Lower clouds expected to work in overnight...but again
any significant lowering/MVFR occurs 12-18z for tcl/bhm/asn and
after 18z for eet/anb. Not going to bite on IFR sigs for tcl/bhm
at this point based on current reasoning. System will not make it
to mgm/toi this taf period where high/middle clouds will prevail.
Rain chances will increase tonight in the far northwest part of
central Alabama...expanding slowly to near the I-20 corridor on
Sunday and Monday. This wet pattern will continue through middle week
with greatest rain chances across the north. There are no fire