Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Birmingham Alabama
944 am CDT Monday Mar 17 2014
Current surface observations shows the surface low near the
southeastern part of central Alabama. The cold front has moved to
the east of a line from Atlanta...to Alexander City...to
Montgomery...and southward. Along and to the east of the
front...light showers will continue to move to the east northeast
over through the day. Forecast models are still consistent in
bringing an upper level disturbance along the Gulf Coast...with
wrap around moisture surging northward across central Alabama this
afternoon and evening. Given the current observations and
guidance...have increased the probability of precipitation across the east...and left
slight chance for light showers across the remainder of the area.
Temperatures have dropped a few degrees lower than previous
forecast...due to the cold air advection behind the front. Cloud
cover will keep temperatures from rebounding too much this
afternoon...and therefore have lowered high temperatures across
central Alabama. Also updated hourlies to account for current
trends. Updates are out.
12z taf discussion.
Cold front is near mgm and will continue to push southeast across
the remainder of the area through the morning hours. Numerous light
rain showers have developed across much of central Alabama behind
the front in association with the upper low as it moves into the
region. Some reductions in visible are likely with these showers. Ceiling
forecast will be the most difficult this period. Most locations
are observing IFR ceilings at this time and believe there should be at
least some improvement through the day. Have lifted ceilings at all
terminals to MVFR...although some fluctuations to VFR may be
possible at a few locations. Winds will continue to shift to the
northwest behind the front with speeds generally 5-10 miles per hour...but can't
rule out a couple brief gusts this morning.
For tonight...most of the shower activity should move off to the
east. A wedge appears to develop across Georgia and tries to push into
the eastern counties this evening/overnight. Have kept at least
MVFR ceilings in for all terminals except tcl through the rest of the
period because of this. Some changes to the ceiling forecast are
likely with later issuances.
/issued 410 am CDT Monday Mar 17 2014/
Surface low is currently centered over northeast Alabama and
northwest Georgia. Cold front bisects the area from northeast to
southwest...with northerly winds at tcl...and eet. Dewpoints fall
quickly from the middle 50s at eet to middle 30s at Haleyville. Along
and ahead of the boundary...scattered light rain showers stream
northeastward. Heavier...more organized rainfall has pushed
southeast of the forecast area. Per water vapor...northeast to
southwest oriented trough stretches across the western Tennessee
Valley to the Texas Gulf Coast...and is slowly pushing eastward.
The trough and cold front will continue eastward through the day.
There remains a chance of showers across the area...with better
chances ahead of the front...across the east. Dry air at middle and
upper levels is quickly taking over the airmass...but weak forcing
with the upper trough could squeeze out scattered light showers.
Weak cool advection and cloud cover will keep afternoon temperatures
around 50 degrees across the northwest and lower 60s in the
southeast. Cloud cover should start to dissipate this
evening...and help temperatures cool tonight into the middle 30s to
Surface high pressure drops across the northern Gulf of Mexico
behind the front. This will keep return flow to a minimal ahead of
the next system crossing the eastern Continental U.S. By middle week. A trough
will cross the Midwest...dragging a front through the Tennessee
Valley on Wednesday. Only a slight increase in cloud cover is
expected. No noticeable change in temperatures with highs still hitting
the lower 70s for much of the area on Thursday.
Flow aloft becomes zonal for the end of the week...with
temperatures warming slightly each day. A trough crossing the
Midwest will push a front into the area Saturday...bringing rain
back to the area. Will keep low probability of precipitation in for several periods to
account for uncertainty on timing...but models are consistent with
pushing the boundary to the coast and the weekend not being a
complete washout. Many details to work out though between now and then.
Preliminary point temps/pops...
Gadsden 55 40 62 44 67 / 60 20 10 10 10
Anniston 57 40 62 46 69 / 80 20 10 10 10
Birmingham 53 39 66 47 70 / 20 10 10 10 10
Tuscaloosa 52 37 70 45 71 / 20 10 10 10 10
Calera 52 40 67 46 69 / 20 10 10 10 10
Auburn 58 42 61 45 70 / 80 30 10 10 10
Montgomery 57 43 70 45 75 / 60 20 10 10 10
Troy 58 42 67 44 73 / 80 30 10 10 10