Area Forecast Discussion
Issued by NWS Birmingham, AL
FXUS64 KBMX 191148
Area Forecast Discussion
National Weather Service Birmingham AL
548 AM CST Sun Feb 19 2017
For 12Z Aviation.
Today and Tonight.
Plenty of moisture out there this morning as high pressure builds
in. With calm winds and eroding high level clouds, areas of fog
and low clouds have developed across the north and have advected
into the south. Issued a dense fog advisory for the south and east
through 8 am and will monitor to see if this needs to be extended
for the entire forecast area as we approach sunrise. Once the low
clouds and fog burns off this morning, sunshine will be abundant
and temperatures will climb in to the 70s area wide. Temperatures
will drop off into the 40s and 50s again tonight and will need to
monitor for patchy fog once again. Uncertainties for the fog
development will be how low do the dewpoints reach this afternoon
and can any of the low level moisture work out. Best chances will
be in the south and may once again be due to advection fog from
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.
12Z TAF Discussion.
Areas of dense fog south with patchy fog north. This will remain
the rule through 14Z then some improvement. The fog is not lasting
long at spots in the north so only used as tempo here and
persistent in the south. Generally light northerly winds during
the day, with calm winds again tonight. Will need to monitor the
advection fog again tonight and how far north it can go. Right now
pretty confident in it reach TOI so included here.
Fog will persist through the early morning hours. Otherwise, dry
weather is expected today and Monday. Our next chance of rain will
come on Tuesday into early Wednesday, but no significant frontal
passaged is expected. There are no fire weather concerns.
.PRELIMINARY POINT TEMPS/POPS...
Gadsden 72 47 75 49 72 / 0 0 0 0 30
Anniston 72 48 76 51 73 / 0 0 0 0 30
Birmingham 73 51 76 54 73 / 0 0 0 10 40
Tuscaloosa 76 52 78 55 70 / 0 0 0 20 60
Calera 74 50 76 54 72 / 0 0 0 10 40
Auburn 73 50 76 54 73 / 0 0 0 0 20
Montgomery 76 51 79 55 76 / 0 0 0 10 40
Troy 75 51 79 54 75 / 0 0 0 0 30
Dense Fog Advisory until 8 AM CST this morning for the following