Area Forecast Discussion
Issued by NWS Birmingham, AL

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FXUS64 KBMX 240905

Area Forecast Discussion
National Weather Service Birmingham AL
405 AM CDT Thu Jun 24 2021

/Updated at 404 AM CDT Thu Jun 24 2021/
Today through Friday.

This AM, we have a stationary boundary situated from W-E across S
AL. Some low stratus and patchy fog will be possible early this
morning as moisture rides N across this boundary. The boundary is
expected to meander some today. The W portion of the boundary is
expected to push N some tonight into Friday. This will be in
response to a low pressure moving NE out of KS that should push
the boundary back NWD some. At the same time, surface ridging
along the Atlantic Seaboard may cause the stationary boundary in
the SE part of AL to sag a little further S. What this means for
us is a N/S gradient for rain chances today will transitions to a
SW/NE gradient for tonight into Friday with the best chances being
in the S today and SW tonight into Friday closer to the better
available moisture. Highs will generally be in the 80s for today
and Friday. Overnight lows will be overall similar, but the
orientation of the temperature gradient will W-E instead of S-N as
the orientation of the boundary changes along with associated low
level moisture.


/Updated at 404 AM CDT Thu Jun 24 2021/
Friday night through Wednesday.

A ridge-trough-ridge upper-level troposphere will best describe
the synoptic setup beginning this weekend. Somewhat amplified
deep-layer ridging will deliver hot, dry conditions across the
West with a positively tilted trough extending from the Desert
Southwest to the Plains & Upper Mississippi River Valley. Areas
across the Southeast and East Coast will feel the affects of
subtle subtropical ridging while a weak upper-level cutoff low
continues to retrograde westward across the Gulf of Mexico. This
ridge will continue to build prominence across the western
Atlantic and have presence into the eastern CONUS next week.
Meanwhile, the ridge and trough across the rest of the CONUS
becomes less distinct as the overall Polar jet stream retreats
well into Canada.

All that being said, the expected weather across Central Alabama
for the long-term period will lack diversity. Steady state diurnal
temperatures are expected with sufficient moisture and
instability to foster convective rain chances, in some fashion,
every day. Temperatures shouldn`t stray too far from normally
expected values this time of year. With lack of a distinct
mechanism to enhance synoptic forcing near our area, I`ve tried to
continue favoring areas of greatest moisture content for the
highest PoPs. This obviously changes in day-to-day model guidance,
so the overall theme wasn`t made too complex. We may be a little
drier this weekend than thought in previous days as guidance has
suggested lower PWs with each run. Moisture values continue to
show a slight increasing trend into next week. Thus, a tempered
increase in diurnally-driven PoPs was utilized Monday through



06Z TAF Discussion.

There is a surface stalled boundary just to the south of TOI from
W-E across S AL. Moisture is expected to ride NWD past this
boundary into the SRN portions of C AL through the forecast. It
also meander some back into the SRN parts of the area later this
afternoon into this evening. MVFR and later IFR cigs along with
some patchy fog will likely be observed around TOI. I was not
confident enough on its progression to have a mention in for MGM.
Will be monitoring its progression for any needed amendments.
TSRA will be possible mainly during the afternoon/early even for
TOI/MGM/EET as moisture rides N of the front with daytime heating.
Have a prob30 mentioned for them. Low chances are possible
elsewhere but are too low to mention at this time as not confident
enough that sufficient moisture will make it that far N.

Note: AMD NOT SKED until further notice at KASN due to ongoing
equipment issues.




Slow and steady moisture advection will continue to favor increasing
afternoon rain chances for the next few days. For now the best rain
chances are forecast to extend along and south of I-20 through
Saturday. With a relatively warm and humid airmass each day, minimum
RH values in the 50-60% range are expected. This will likely be the
case for much of next week as the overall pattern will not change
significantly. Afternoon rain chances slowly increase by early next
week as moisture increases a bit more. Otherwise, expect surface and
transport winds to remain generally southeast at 5-10 mph for the
next several days.


Gadsden     87  64  87  66  87 /  20  10  10  10  30
Anniston    85  66  87  68  87 /  20  10  10  10  30
Birmingham  87  68  87  69  88 /  20  10  10  10  20
Tuscaloosa  89  70  87  70  90 /  20  20  20  10  20
Calera      87  69  86  69  87 /  30  20  10  10  30
Auburn      84  67  86  69  85 /  40  20  20  10  30
Montgomery  89  70  89  71  90 /  40  20  20  10  30
Troy        87  68  88  70  88 /  50  30  30  10  40





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