Scientific Forecaster Discussion
fxus64 kbmx 201227
Area forecast discussion
National Weather Service Birmingham Alabama
627 am CST Sat Jan 20 2018
for 12z aviation.
today and tonight.
This am, we continue to have an elongated surface ridge stretched
across the southeast United States into the western Atlantic.
Across Alabama, this ridge continues to slowly weaken and crawl to
the east which will allow for increased moisture to feed into the
state today from the Gulf around the back side of the ridge. In
the upper levels, a shortwave will move across the southeast U.S.
For today, this will mean an increase in dew points, warmer high
temperatures and some cloud cover. We are not expecting any
precipitation today or tonight though as we start off with only
very shallow moisture and overall a very dry airmass which has a
lot of recovery to do first before we have sufficient moisture to
consider precip. In actuality, it should feel rather nice today
considering this is January and temperatures are trending more
toward near normal or even slightly above normal for mid January.
Sunday through Saturday.
A progressive pattern will take hold for the extended part of the
forecast. Our area will be between shortwave troughs on Sunday
with a deep-layer ridge overhead. This favors warmer temperatures,
and some locations across our south could touch 70f on Sunday
afternoon. Mid to upper 60s should be common elsewhere.
Height falls are expected on Monday as a strong plains trough
moves eastward. Moisture return should be sufficient for
widespread showers and possibly a bit of thunderstorm activity
along a cold front. Instability appears rather limited due to
dewpoints only reaching the upper 50s to around 60f, but lapse
rates are not too shabby. We will monitor for any upward trends in
dewpoints, which could lead to a marginal or low-end threat for
severe storms. This system should move through rather quickly with
dry and relatively mild weather returning for Tuesday through
Thursday. The next chance of rain could come with another system
late Friday into Saturday.
12z taf discussion.
VFR forecast is expected for today. Stratus cigs are present this
am, but mainly 4-5 kft and not expecting cigs to lower much this
morning, possibly less toward midday and more midlevel. Not much
in the way of winds today as still somewhat under ridge influence
but southwest/south up to 7kts or so will be possible during the
afternoon with mixing.
Relative humidity values will slowly increase through the weekend with values
remaining above critical levels. Light southerly winds are
forecast through the short term period and critical fire weather
conditions are not expected.
Preliminary point temps/pops...
Gadsden 55 36 64 44 63 / 0 0 10 10 80
Anniston 57 38 66 45 64 / 0 0 10 10 80
Birmingham 57 41 66 48 64 / 0 0 10 10 90
Tuscaloosa 59 41 67 50 65 / 0 0 10 10 80
Calera 58 40 66 49 64 / 0 0 10 10 80
Auburn 57 40 67 46 66 / 0 0 10 10 60
Montgomery 60 37 68 47 69 / 0 0 10 10 70
Troy 60 38 68 47 70 / 0 0 10 10 50