Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Memphis Tennessee
846 PM CDT Tuesday Jul 29 2014
Updated to raise low temperatures for a few degrees.
A large upper level trough over the eastern U.S. Will keep the middle
south under northwest flow aloft and also allow for unseasonably
cool temperatures. Cloud cover will continue to skirt western
portions of the area overnight with mainly clear skies to the
east. Although low temperatures will be several degrees below
average tonight...have raised low temperatures a few degrees to
account for current and anticipated trends. Otherwise...the
forecast looks good and no other changes were needed. Forecast
updates will be sent shortly.
Previous discussion... /issued 237 PM CDT Tuesday Jul 29 2014/
below normal temperatures to continue through the end of the
week...courtesy of a persistent longwave trough over the eastern
Continental U.S.. this longwave trough will gradually weaken and lift out with
the breakdown of an Omega block over the western North Atlantic
An upper level shortwave will dig into the lower MS River Valley
from the Central Plains Wednesday night...lowering midlevel
heights and aiding in the development of scattered showers. NAM
925mb temperatures are prognosticated 1c to 2c cooler than today. Cloud cover
and coverage of rain will have a big impact on temperatures. At this
time...it appears that coverage of both will be sufficient to keep
daytime highs in the middle 70s to lower 80s. This pattern is not too
unlike July 18...when temperatures struggled to reach 70. There is some
bust potential for Thursday...any amount of afternoon sun will
boost temperatures by several degrees. Friday will likely also be a bit
cooler than previously forecast...particularly if clouds persist
into the afternoon. As has been the case much of the Summer...GFS
MOS daytime highs appear to show a warm bias.
As mentioned above...upper level heights will begin to increase
late in the weekend...the upper trough lifts out to the northeast
and an upper level ridge encroaches from the west. Temperatures across
the midsouth should recover to near normal early August values by
around this time next week.
00z taf cycle
MVFR visibility possible at mkl towards sunrise. Otherwise...VFR
weather this period. Light or calm winds overnight increasing to
5-8 kts from either the northeast or southwest depending on site.