Area Forecast Discussion
Issued by NWS Birmingham, AL
FXUS64 KBMX 241933
Area Forecast Discussion
National Weather Service Birmingham AL
233 PM CDT SUN JUL 24 2016
Today through Monday Night...The area is experiencing slowly
weakening deep layer ridging as the center of mid level ridging
was analyzed across New Mexico. The remnants of yesterday`s MCV
across the Mid South region is being reflected as a weak upper
level low over the Arklatex region. Water vapor imagery indicates
an upper level speed max moving west across the eastern portion of
the area, aided by the height gradient from an upper low across
the eastern Florida peninsula with the expansive ridging aloft
across the Mid Mississippi River Valley.
Shower and thunderstorm activity is expected to be less widespread
today with less instability depicted on modified soundings.
Relatively drier air is over our southern counties and is largely
inhibiting convective development while a more favorable upper level
environment exists across the northern third of the state. The
aforementioned upper level speed max will move west across the
area for the remainder of the afternoon and evening. This feature
is associated with drier air higher aloft so that may help to
further limit convective development as well.
Overnight expect convection to wane with decreasing coverage after
dark. Lows will fall into the 70`s across the area. A northeasterly
flow aloft will persist across the area tomorrow as deep layer
ridging remains to our west while an upper low will continue to
retrograde across the central Florida peninsula into the eastern
Gulf of Mexico. Monday will feature highs again in the low to mid
90`s with isolated shower and thunderstorm activity, largely in the
late morning through afternoon and into the early evening hours.
Again, the higher chances look to be across the northern half of the
Tuesday through Sunday...Central Alabama starts off the period in
a weakness between two ridge centers. One will be located over the
Four Corners region while the other drifts just off the eastern
seaboard. We will be much closer to the western periphery of
eastern ridge center Tuesday and Wednesday. The southerly wind
component through the layer will bring variable mean relative
humidity to the area, as a few weak short waves migrate westward.
Thermodynamic conditions will generally be close to what we are
experiencing today. Therefore, rain chances near normal of 35
percent and temperatures near normal 90 to 95 and 70 to 75.
For Thursday and beyond, the deep moisture pool associated with
the upper low starts to move eastward as an upper trough swings
eastward in the westerlies. The model suite still has some timing
and amplitude issues with trough and the ridge with the ECMWF a
bit slower. So at this time, will keep Thursday very close to
Tuesday and Wednesday conditions with an increase in rain chances
north. It appears the highest rain chances will come Saturday and
Sunday. The ridge to our southeast should limit this rain increase
to north and west. High temperatures a few degrees lower due to
clouds and rain around. Lows still in the 70s.
Beyond Thursday, winds aloft increase at least for summer.
Precipitable water values are advertised near 2 inches, SBCapes
2000-3000, 500mb temps around -6 to -7, and DCape maybe 1000. Bulk
Shear values are limited at best while mid level lapse rates are
poor. This should put the wet microburst potential into the
moderate range. This would not completely rule out a random
strong storm or two this period, with winds 35 to 45 mph and heavy
18Z TAF Discussion.
Expect VFR conditions through the forecast period. A few TSRA will
be possible around TCL/BHM/ASN/ANB this afternoon and evening.
Will mention at VCTS ANB/ASN but confidence too low to mention
elsewhere. Some low clouds and patchy fog possible mainly in the
river valleys but confidence on affecting any terminals too low
just yet. Winds remain rather light.
A few showers and thunderstorms are expected over the next
several days with highs in the 90s. Surface winds will be rather
light and variable. Since surface dew points are so high,
critical fire weather thresholds are not expected to be met with
no watches or warnings anticipated.
.PRELIMINARY POINT TEMPS/POPS...
Gadsden 73 94 73 93 72 / 40 40 20 40 20
Anniston 73 94 73 93 73 / 30 40 20 30 20
Birmingham 77 94 76 93 76 / 30 40 20 30 20
Tuscaloosa 75 93 74 93 73 / 30 40 20 30 20
Calera 75 93 74 92 73 / 20 40 20 30 20
Auburn 75 93 74 92 73 / 20 40 20 30 20
Montgomery 76 95 74 94 75 / 20 30 20 30 20
Troy 72 91 71 91 72 / 20 30 20 30 20