Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Birmingham Alabama
352 am CST Wednesday Jan 28 2015
Short term...today through Friday.
A blanket of low clouds over northeast Alabama has been slowly
eroding overnight and the remaining clouds should be mostly gone
by mid-morning. A surface ridge will move across the area today
and the winds will switch from northerly in the morning to east
and southeast this afternoon. Warmer tonight as southerly flow
increases in advance of an approaching cold front. A few showers
will develop in the late afternoon Thursday across north Alabama.
Moisture will be limited ahead of the cold front and rainfall
amounts will be generally less than one-tenth of an inch as the
band of showers tracks southeast Thursday night. A relatively warm
day on Thursday due to southwest flow ahead of front...with most
areas climbing into the 60s. Clearing and turning colder Thursday
night and Friday.
Long term...Saturday through Tuesday.
Saturday will be a day of transition as clouds increase ahead of
next low pressure system. A cut-off upper low over the southwest
states will shift southeast into northern Mexico over the
weekend. This system will feed Pacific moisture into the southern
states. Precipitable water values will increase to near 1.5 inches
along the Gulf Coast. A northern stream short wave trough will
interact with deeper moisture and trigger widespread showers and
possibly a few thunderstorms across central Alabama Sunday and
Sunday night. The GFS and Canadian models show a rapidly deepening
surface low as the short wave trough amplifies. This cyclogenesis
will help pull better low level moisture northward into South
Alabama Sunday night. There should be enough forcing and
instability for some isolated thunderstorms generally along and
south of I-85 Sunday night and early Monday morning. Strong cold
air advection on the back side of the surface low could bring a
brief mixture of light rain and snow to the northwest counties
late Sunday night. The moisture should pull out of the area
Monday morning with clearing and colder conditions Monday night
06z taf discussion.
VFR conditions currently across the terminals. Infrared satellite
imagery and current observation indicate an area of MVFR stratus moving
southward out of middle Tennessee and northeast Alabama. Expect
MVFR ceilings will move into kanb and kasn over the next hour with
kbhm on the western periphery of the MVFR ceilings. Due to
this...just went with a tempo for MVFR conditions for kbhm at this
time and expect VFR conditions by 12z. Elsewhere...VFR conditions are
expected throughout the taf cycle.
Preliminary point temps/pops...
Gadsden 51 32 59 35 49 / 0 0 20 30 0
Anniston 53 33 60 37 50 / 0 0 20 30 0
Birmingham 54 37 62 37 50 / 0 0 20 20 0
Tuscaloosa 56 37 66 39 53 / 0 0 20 20 0
Calera 55 36 62 38 52 / 0 0 20 20 0
Auburn 55 34 59 39 54 / 0 0 10 30 0
Montgomery 56 34 66 40 56 / 0 0 10 20 0
Troy 57 32 64 42 57 / 0 0 0 20 0