Area Forecast Discussion
Issued by NWS Birmingham, AL

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FXUS64 KBMX 281603

Area Forecast Discussion
National Weather Service Birmingham AL
1103 AM CDT Sun May 28 2017

Morning Update.



The outflow boundary that was generated by the storms overnight
has made into the southern counties this morning and is now
generally south of the I-85 corridor. Behind it we have a meso
high that has developed and will keep most of the area
precipitation free for the good portion of the afternoon. Can`t
rule out an isolated shower/storm anywhere as we will do remain
moist areawide.

Will continue to mention the some threat of strong to severe
thunderstorms for the northern two thirds of the Central Alabama.
The timing will generally be after 7pm but more likely even later
than that. This threat would last into the overnight hours
especially with any impulse or mesoscale boundary from upstream.
The main threats will be damaging wind gusts and some hail.


Numerous showers and thunderstorms are expected for Memorial Day
in the southwest to northeast oriented moisture axis along and
south of the front which will have stalled. These will be aided by
weak shortwaves in the southwest flow aloft to the south of the
strong upper low over the Great Lakes. Strong storms will continue
to be possible, and an isolated severe storm cannot be ruled out.
0-6 km bulk shear values will be marginal at 25-35 kts, mid-
level lapse rates will be weakening, and profiles will be
fairly saturated. Ongoing precipitation may also hamper
destabilization. Therefore, chances of an organized threat are too
low to mention in the HWO at this time.

The forecast area will remain in the moisture axis south of the
old front Tuesday and Wednesday with continued cyclonic upper-
level flow south of the upper low lifting into Ontario. Scattered
showers and storms will continue across the area, with the best
chances around peak heating. For the rest of the week, the upper
low will continue to lift northeastward while ridging develops
over the Plains. A few southern stream waves will try to under-cut
the ridge. A warm and humid air mass will remain in place over
Central Alabama, with continued summertime afternoon scattered
showers and thunderstorms.



12Z TAF Discussion.

Chaotic skies across Central Alabama this morning. A few
complications with the forecast in the first few hours. Isentropic
lift in a  saturated layer around the 300k surface should produce
some IFR/MVFR ceilings at the terminals. Just before writing, not
much low clouds were present thanks to the thunderstorm complex
that moved across north central Alabama earlier. So expect a non-
uniform layer of lower ceilings developing in several spots in the
next hour or so. We should begin heating and a slow rise in the
restrictive ceilings.

Showers and a few storms along an outflow boundary between
northern and southern terminals at this writing. Expect the
outflow to slow down and did not mention and rain at TOI/MGM this
morning. Will monitor this activity closely for any adjustments.
The area of generally showers north will gradually decrease in
coverage with time and therefore did not mention at this time.

Showers and thunderstorms are possible for all the terminals, best
chance north, will be after 21z and most likely after 00z. The
development or lack of development will affect the development of
any restrictive ceilings especially near MGM/TOI. So for after
00z, generally kept ceilings around 040 and mention of thunder at
this time.




The morning coverage will decrease by afternoon, then increase
again late this afternoon and this evening. Scattered showers and
storms will be possible each day Critical fire weather conditions
are not expected due to abundant low level moisture.


Gadsden     84  67  82  65  80 /  30  60  60  40  50
Anniston    86  69  83  66  79 /  30  60  60  40  60
Birmingham  85  70  84  68  80 /  30  60  70  50  60
Tuscaloosa  88  71  84  67  82 /  30  60  70  50  60
Calera      85  71  84  67  80 /  20  60  70  50  60
Auburn      85  70  84  68  81 /  40  40  60  30  40
Montgomery  90  71  85  68  83 /  60  40  60  40  50
Troy        89  72  85  67  84 /  30  30  60  20  40




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