Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Birmingham Alabama
651 am CDT Sat Aug 29 2015
for 12z aviation.
Looking at water vapor imagery the cutoff upper low is currently
spinning over the north central Gulf with a ridge centered just
south of The Four Corners region. Two shortwaves are
discernible...one can be seen moving south and east into
Missouri/Illinois with the second diving southward across the
upper Midwest. Easterly flow continues at the surface across central
Alabama with ridging along the Appalachians. Moisture values will
continue to rise today with rain chances increasing from east to
west through the day. The highest probability of precipitation will remain east of Interstate
65 where precipitable water values will rise to near 2.0 inches. Temperatures will be
several degrees below normal thanks to cloud cover and rain.
Rain chances will slowly decrease on Sunday...generally from
southwest to northeast...as the upper low lifts northeast over the
Appalachians. With no real lifting mechanisms present on Monday
conditions should be dry across much of the forecast area with
only a slight chance of a shower/storm in the east.
Confidence in the forecast from middle week Onward drops off due
mainly to uncertainties in the evolution of what is currently ts
Erika. The latest forecast from NHC has Erika weakening as it
moves over Cuba with a small chance of it restrengthening over the
eastern Gulf. At this time no major impacts are expected here in
central Alabama but adjustments to probability of precipitation may be needed based on
future changes to the track/intensity forecast. For now will
continue with slight chance/chance probability of precipitation from Tuesday Onward.
12z taf discussion.
Moist overall pattern with mostly cloudy conditions expected for
entire forecast as upper low sits over northern Gulf allowing
moisture to stream into the state. Some MVFR ceilings/visibilities possible
this morning even before shower activity develops...but low level
moisture not as robust initially. Shower activity with a few
embedded thunderstorms this afternoon should get more widespread as we
progress during the day. Only mentioning thunderstorms in the vicinity for now as more rain showers
than ts expected.
Moisture values will continue to rise today with rain chances
increasing from west to east. Currently expecting scattered
convection across west central Alabama with more numerous
shower/storms in the east. Rain chances begin to decrease on
Sunday with isolated/scattered convection possible each day next week. No
fire weather concerns are expected at this time.
Preliminary point temps/pops...
Gadsden 82 69 83 68 87 / 60 40 50 20 20
Anniston 82 69 84 68 88 / 60 50 50 20 20
Birmingham 83 70 86 69 89 / 40 40 40 20 20
Tuscaloosa 87 70 89 70 92 / 30 20 20 10 10
Calera 84 70 86 69 89 / 60 30 30 10 20
Auburn 82 69 85 69 88 / 70 60 40 20 20
Montgomery 87 70 90 71 92 / 60 30 30 10 20
Troy 85 69 89 70 91 / 70 30 30 10 20