Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Memphis Tennessee
1233 am CDT Friday Aug 22 2014
Updated for 06z aviation discussion.
Previous discussion... /issued 958 PM CDT Thursday Aug 21 2014/
Large upper ridge in place across the southern U.S. This evening
with mainly clear skies across the midsouth. It is another warm
and muggy night across the region as well with temperatures still above
80 in many locations. Forecast on track with lows in the 70s.
Previous discussion... /issued 324 PM CDT Thursday Aug 21 2014/
The main story through at least this weekend will be the heat.
Guidance does now indicate a better chance of cooler...at least
near normal temperatures...and a return to at least spotty rain
chances next week.
An isolated shower/thunderstorm cannot be totally ruled out
between now and Sunday...but a strong ridge and surface high
pressure will keep conditions mostly dry.
Current temperatures are generally within a degree or so of where
we were 24 hours ago with another degree or so of warming
expected. Afternoon highs should maximum out in the middle 90s. Dew
points have not mixed out quite as much today as yesterday...so
heat indices are slightly higher...but still below our heat
advisory criteria of 105 degrees for most of the area.
Expect more of the same tomorrow...and over the weekend as a
strong ridge and surface high pressure dominates the weather
across the midsouth. Models tend to break down and or move these
strong ridges east faster than what usually occurs...so will rely
heavily on persistence in the forecast. The European model (ecmwf) is the slower
model...so will favor its solution for now. Lows will be in the
middle to upper 70s each day with highs in the middle to upper 90s.
For now it looks like Saturday and or Sunday will be the warmest
days with the warmest areas possibly hitting 99 degrees. Resulting
heat indices will be largely determined by dew points and the
amount of atmospheric mixing we see each day. Heat advisories may be
needed...but will be issued on a day by day basis.
As mentioned in the opening paragraph...guidance indicates a
better chance of relief from the heat next week...and better rain
chances. By next Thursday high temperatures should trend 4-5
degrees cooler approaching normal readings.
06z taf cycle
VFR conditions will continue for much of the forecast period. Some
fog is expected develop overnight in the kmkl and ktup areas which
would bring visibilities down to MVFR levels. Winds will be mainly
from the south around 5 overnight then they will become southwest at
around 10 knots late Friday morning before diminishing Friday