Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Birmingham Alabama
611 am CDT Thursday may 28 2015
for 12z aviation.
The pattern continues in a status quo with an elongated Atlantic
ridge and Alabama on the onshore flow side of the weak ridge over
the southeast U.S. In the lower levels. In the upper levels...a
shortwave will move through the southwest flow today with the best
chance for rain in the east half of central Alabama for today and
tonight. This wave will weaken and move off for Friday and probability of precipitation
should be lower with less focus for convective development but
still scattered and diurnally based as a large scale trough digs
into The Rockies on Friday.
For Friday night through Saturday night...rain chances will
decrease but we should see a pop gradient with better chances in
the northwest as a surface front sinks southeast across the
central U.S. And the upper main trough shifts eastward and digs a
little further south.
For Sunday into Monday...a surface front will have developed
across the central U.S. But only make a little progress south and
eastward to the Appalachians and middle Mississippi River valley then
into Texas. However...although the front may reach Alabama
briefly...it will likely stall and push northward and only scape
the area. The upper flow will give little help as the longwave
trough builds over the central U.S. On Sunday into Monday
eventually becoming a closed low over Arkansas and Louisiana with
Alabama staying on the wet onshore flow side of the low. This will
keep scattered convection possible for each day with the help of
diurnal heating through at the very least the middle of next week
until this trough attempts to open up and weaken. However...that
is 8 days out...so the wet pattern continues for now.
12z taf discussion.
Low clouds have been patchy across area so far this morning but
still expect patchy IFR conditions in low stratus/fog to develop
during next couple of hours and to then lift to MVFR by middle to late
morning. Conditions expected to improve to VFR by 18z with more
scattered to numerous rain showers and thunderstorms and rain during the afternoon as weak
upper troughing continues across the area with abundant moisture.
Precipitation should mostly end before 03z...but look for patchy
development of MVFR conditions in fog/stratus again late tonight.
Hard to Pin-Point where this will occur (areas receiving more rain
today would be most likely to see this) so indicated chance at all
Preliminary point temps/pops...
Gadsden 82 66 84 65 85 / 60 30 40 20 30
Anniston 82 67 84 65 85 / 70 30 40 20 20
Birmingham 82 68 84 67 86 / 60 30 40 20 30
Tuscaloosa 84 68 87 68 86 / 50 20 40 20 40
Calera 82 67 85 66 86 / 60 30 40 20 30
Auburn 82 66 84 66 86 / 60 30 30 10 10
Montgomery 86 68 88 67 89 / 60 30 30 20 20
Troy 85 66 87 65 89 / 60 30 30 10 10