Area Forecast Discussion
Issued by NWS Birmingham, AL
FXUS64 KBMX 221146
Area Forecast Discussion
National Weather Service Birmingham AL
546 AM CST Wed Feb 22 2017
For 12Z Aviation.
Today and Tonight.
Upper level low is centered along the northern Gulf coast this
morning, just to our southwest. Wind flow on the east side of the
low has maintained a moisture axis across east Central Alabama
overnight, resulting in widespread light rainfall. Activity
becomes more scattered west of I-65. The upper low will rotate to
the southeast today, into the Gulf of Mexico, pushing the
moisture axis to the east. Upper level winds become northerly and
high pressure builds in at the surface across the north. This will
lead to a gradual end of rain showers through the day, with dry
conditions by this evening.
With moist ground conditions and low level moisture lingering
across the area tonight, have mentioned fog after midnight.
Boundary layer winds will be elevated, but near saturated surface
conditions should result in at least localized development.
Thursday through Tuesday.
For Thursday into Friday the forecast area will be situated
between troughs, one moving toward the Plains and the other near
the Bahamas. In between, a 500mb ridge with strong anticyclonic
curvature will lead to subsidence and very warm temperatures.
Highs should range from the mid 70s to lower 80s.
A fairly strong surface low near 990mb should track from Kansas
toward the Great Lakes, but the upper trough near the Bahamas will
prevent strong moisture recovery. Just enough moisture should
arrive as the front moves into Alabama for showers to develop
Friday night into early Saturday, but rainfall amounts are
expected to be generally under 1/4 inch. Rain should end around
daybreak Saturday with cooler and drier conditions through Sunday.
Warm advection with a zonal upper-level pattern could lead to
another chance of showers on Monday and Tuesday as a moist
southwesterly low-level flow regime sets up. Abnormally warm
temperatures are expected once again with a strong low-amplitude
500mb ridge over the Gulf of Mexico and Bahamas.
12Z TAF Discussion.
Strengthening easterly low-level flow to the north of low pressure
over the Gulf will result in moist low-levels through the period.
Discontinuous/variable cigs ranging from LIFR to MVFR are
currently present. Confidence in exact details is low, but daytime
mixing should allow cigs to improve to MVFR by late morning and
VFR by mid afternoon. Light rain will decrease in coverage
through the morning with additional scattered shower development
by midday, but should not have much of an impact on visibilities.
Tonight a low stratus deck will move in from the east but models
vary on timing. Patchy fog will also be possible ahead of it.
Light to moderate rain will continue this morning across East
Alabama with a decrease in activity this afternoon. Dry and warm
conditions return for Thursday and Friday. The next chance of
light rain should come Friday night with a front. There are no
fire weather concerns.
.PRELIMINARY POINT TEMPS/POPS...
Gadsden 71 54 75 54 78 / 50 10 0 0 10
Anniston 71 56 76 55 78 / 60 10 0 0 10
Birmingham 71 58 77 57 79 / 40 10 0 0 10
Tuscaloosa 73 56 78 56 80 / 30 10 0 0 10
Calera 72 57 77 56 79 / 40 10 0 0 10
Auburn 70 58 77 56 78 / 80 10 0 0 10
Montgomery 73 59 79 57 81 / 50 10 0 0 10
Troy 72 58 79 56 81 / 70 10 0 0 10