Area Forecast Discussion
Issued by NWS Birmingham, AL
FXUS64 KBMX 240033
Area Forecast Discussion
National Weather Service Birmingham AL
733 PM CDT Sun Apr 23 2017
For 00Z Aviation.
The strong cold front has just exited into Georgia. A few
lingering showers were located from near Phenix City to near
Eufaula and these will soon exit into Georgia too. The latest
Water Vapor Imagery has the upper low spinning over western
Tennessee and far northern Mississippi and this low will continue
into Alabama overnight. As this low moves overhead, kept a small
mention of showers in overnight and into Monday. If you receive
any rainfall, it will barely be measurable. With the cloud cover
and cold air advection, overnight lows will be near 50 degrees.
Slightly warmer tomorrow with highs bouncing back to near 70.
00Z TAF Discussion.
We are VFR at most TAFs at this hour except TCL/BHM/ASN, which
are closer to the upper low pressure system currently spinning
over the Tennessee Valley. This low will dip some over to the
southeast across Central Alabama tonight as it spins across the
Southeast U.S. through tomorrow. MVFR cigs will spread across the
TAF sites as we progress through the night and the low dips
southeastward. At BHM/ASN/ANB we should also see IFR cigs as these
sites will be closer to the low center. Winds should stay up some
and so very low visibility is not anticipated. Some MVFR
visibilities are possible though. A few very light rain showers
are possible this evening, but widespread showers or heavy rain is
not expected with the low. Conditions improve to VFR across
MGM/TOI during Monday afternoon as the low pulls away.
Very small rain chances tonight into Monday as an upper low moves
overhead. Northerly flow persists Monday before shifting back
from the south on Tuesday. Critical fire weather conditions are
not expected at this time.
/Issued 341 AM CDT Sun Apr 23 2017/
Monday through Sunday.
The low pressure system moves eastward into the Carolinas on Monday.
Continued northerly flow will advect a cooler airmass over Central
AL with daytime highs on Monday could reach a few degrees below
normal for this time of year. The system shifts further east on
Tuesday as upper level ridging builds in ahead of a deepening trough
in the Plains. This will shift the winds back from the south leading
to a warming trend for the rest of the week.
A surface low develops in the Southern Plains on Wednesday and moves
northeastward into the Great Lakes through the day, stretching a
cold front down through the Mississippi River Valley. Previous model
runs have flattened this front out and kept it north of our area;
however, latest runs bring the cold front down through Central AL as
the trough becomes negatively-tilted on Thursday. Both the GFS and
ECMWF are in decent agreement on the 00z runs with the cold front
moving through on Thursday with >2000 J/kg environmental
instability. Models disagree on where the better shear lines up,
with the EC bringing the better shear further south into Central
AL while the GFS keeps it across our northern counties and not
overlapping with the better instability as much. Both models show
the best upper-level support remaining north and west. For now,
will hold off mentioning any severe threat in the HWO. I would
like to see how models trend over the next day or to see if
there`s any run to run consistency.
Upper level ridging builds back in Friday into Saturday as models
hint at a deepening trough over the Western US. A surface low
develops in the Southern Plains Saturday morning and tracks north-
northeastward through the Upper Midwest through the day on Saturday
and stretches another cold front down through the Mississippi River
Valley. Timing and details are still uncertain with this system as
it is just beyond the extended forecast period.
.PRELIMINARY POINT TEMPS/POPS...
Gadsden 51 69 51 82 54 / 30 20 0 0 0
Anniston 52 72 53 82 56 / 30 20 0 0 0
Birmingham 53 73 56 84 59 / 20 20 0 0 0
Tuscaloosa 52 74 53 84 58 / 20 0 0 0 0
Calera 52 73 56 83 58 / 20 10 0 0 0
Auburn 52 71 56 80 58 / 20 10 0 0 0
Montgomery 52 76 56 85 58 / 10 10 0 0 0
Troy 50 73 53 84 57 / 10 10 0 0 0