Area Forecast Discussion
Issued by NWS Birmingham, AL
FXUS64 KBMX 192357
Area Forecast Discussion
National Weather Service Birmingham AL
557 PM CST Sun Feb 19 2017
For 00Z Aviation.
We remain under an Eastern Conus surface ridge today with mostly
sunny skies being observed on satellite at this time. The area
has rebounded nicely today with warmer temperatures. The ample
sunshine today should help dry our boundary layer out some.
Although some patchy fog remains possible tonight across the south
and east, it should not be as dense as this morning. Also, we may
have some thin cirrus moving in late across the area tonight that
could help a little in that respect. With the elongated surface
ridge center pulling away from the Deep South toward Eastern
Canada, expect overall the same range of temperatures across
Central Alabama as last night but a shifting of the lowest values
from the northwest to the northeast counties in response to the
shift in the ridge and a resulting change in the boundary layer
Monday through Saturday.
Monday will remain dry and abnormally warm with a prominent 500mb
ridge over the Eastern U.S. ahead of an approaching trough. A few
places will probably top the 80 degree mark. The elongated upper
trough is expected to split with the southern part of the trough
closing off and moving southeastward toward the Florida Keys on
Tuesday into Wednesday. GFS/ECMWF are in less agreement than 24
hours ago, but the ECMWF run-to-run consistency is rather good and
paints a wet scenario for Alabama as the trough moves across the
Ark-La-Tex region and over the Gulf. This forecast favors the
ECMWF and maintains high POPs especially west of I-65 for Tuesday
into Tuesday night. After daybreak Wednesday, rain chances will
diminish as the trough moves away.
We should experience dry conditions with more abnormal warmth
between weather systems on Thursday into early Friday. Moisture
recovery looks somewhat limited ahead of the next upper trough and
frontal system which could bring our next chance of rain for late
Friday into early Saturday.
00Z TAF Discussion.
Chances of low clouds and fog appear lower overnight than what
occurred last night. Left most locations VFR throughout but did
keep some brief mention of Cat B restrictions at MGM/TOI. Far east
and south locations will be closest to the crossover temperatures
overnight, but with the surface high moving eastward, there will
be some dry air advection also occurring overnight. Not much in
the way of isentropic lift and the soundings indicate much less
moisture in the boundary layer. Additionally, plenty of sunshine
and mixing occurred today. Therefore, think any fog or low clouds
will generally stay south and west of the area. There is a
possibility of near surface ground fog, but will reassess through
the evening hours. Winds generally light and variable to calm
overnight. Winds start off light out of the east on Monday
swinging around to southeast at 5-6kts after 18z.
Some cirrus and possibly cumulus appear very late in the period
and did not mention at this time.
Some patchy fog will be possible across the south and east portions
of Central Alabama late tonight into early Monday morning.
Otherwise, dry weather is expected through Monday evening. Our
next chance of rain will come on Tuesday into Wednesday, but no
significant frontal passage is expected. There are no fire weather
.PRELIMINARY POINT TEMPS/POPS...
Gadsden 45 75 49 72 53 / 0 0 0 20 50
Anniston 48 76 51 73 55 / 0 0 0 20 50
Birmingham 50 76 54 73 56 / 0 0 10 20 40
Tuscaloosa 50 78 55 70 57 / 0 0 10 40 40
Calera 49 76 54 72 57 / 0 0 10 20 40
Auburn 49 76 54 73 57 / 0 0 0 20 40
Montgomery 51 79 55 76 58 / 0 0 10 20 50
Troy 50 79 54 75 57 / 0 0 0 20 50