Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Memphis Tennessee
1147 PM CST Sat Nov 28 2015
06z aviation discussion.
Previous discussion... /issued 933 PM CST Sat Nov 28 2015/
updated for flash Flood Advisory cancellation and to adjust overnight probability of precipitation.
Heavier rain and the threat for flash flooding has ended across
northeast Mississippi...the bootheel of Missouri and Lake County
Tennessee. Any additional overnight rainfall/drizzle will be
light. In addition...rainfall in the region will slowly recede
tonight and tomorrow before rain returns tomorrow night and Monday.
This second round is expected to remain light enough to not pose
any flash flooding.
Have also lowered overnight probability of precipitation across the north and added the
threat for drizzle to points north of the front.
Previous discussion... /issued 319 PM CST Sat Nov 28 2015/
rain continues. The frontal system is slowly moving across the
area...estimate it is moving at about 4 miles per hour. The front
will continue it slow movement to the east and continue to give
the middle-south a steady dose of rain. In the next 48 hours the
maximum axis of rainfall will be along a line from Memphis to
Jackson...Tennessee...forecast maximum will be about 2 inches in
the next 48 hours. Have left the Flash Flood Watch up even though
some of the area is only seeing light rain now as another wave
will move through tonight and with the estimate rainfall in some
places getting over 4 inches of rain. Jonesboro has had 3.24
inches since the rain started yesterday.
The overall forecast is just as it has been for the last couple of
days with high precipitable water content in the atmosphere and a
slow moving front that is not being pushed by the upper level
low that is just about stationary over the Great Basin. The upper
low will move to the east beginning on Sunday and this will allow
for a more zonal flow over the middle-south and thus will push the
front to the east...sparing west Tennessee and north Mississippi
from getting the excessive rainfall that northeast Arkansas and
the bootheel of Missouri received over the last day or so.
With the upper level zonal flow the current front will be out of
the area on Sunday...however...another surface low and frontal
system will develop in the plains and then move across the middle-
south later on Sunday. This will not exit the region until middle-
week...so parts of the middle-south has a chance for through
Temperatures will be just about normal for the period.
06z taf cycle
In an area just to the north of a slow moving cold front...to
include kmem and kmkl...should keep LIFR ceilings in place overnight.
Further north at kjbr...slightly drier air should keep ceilings at IFR
through the night with only temporary reductions to LIFR. Ktup
should remain south of the front overnight with VFR ceilings lowering
to MVFR late tonight as the front nears. Light rain or drizzle
will continue through the night at all sites.
Ceilings will not move much on Sunday as another wave of low pressure
spreads steadier rain back over much of the region. LIFR ceilings
early may rise to low end IFR for a few hours before lowering back
to LIFR at all sites again Sunday evening.
Winds should remain below 6 kts from the north at all sites except
ktup tonight. Ktup will keep southwesterly winds around 5 kts through
sunrise Sunday. Light north winds will develop at all sites later
Sunday and continue through the period at 5 kts or less as the
front pushes further southeast.