Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Memphis Tennessee
710 am CDT Tuesday Sep 1 2015
Updated for the 12z aviation discussion.
Previous discussion... /issued 358 am CDT Tuesday Sep 1 2015/
Hot weather will return to the middle-south through next week with
only limited chances for precipitation...
Currently...patchy dense fog has developed in favored areas of
the Tennessee River valley with visibilities ranging anywhere from
1/4sm to 3sm at mkl. The fog will persist until solar heating
begins to erode the surface inversion.
On Tuesday...the upper level low pressure/trough axis continues to
shear out. Water vapor imagery still shows several smaller-scale
circulations within the larger area of low pressure...but this
feature will continue to weaken today. At the surface...the
frontal boundary is almost impossible to detect through surface
observation...but a diffuse boundary does still exist. For this
reason...added a slight chance of a few showers or thunderstorms
into the forecast for eastern Arkansas. These will be more
nuisance than anything else. High temperatures today will warmer
as well...with areas along the Mississippi River valley reaching
the low 90s. Points northeast will be cooler with highs in the
upper 80s to near 90.
The forecast completely dries out through the middle and even late
portions of this week. Aloft...the upper level flow pattern
significantly amplifies in response to strong troughing digging
into the Pacific northwest. An anomalously strong ridge develops
well north into the Hudson Bay region of Canada with the middle-
south squarely under its influence. This is a strong signal for
above normal temperatures through at least early next week. Models
begin to diverge on when to break down the ridge by Monday and
Tuesday of next week. At present...am leaning toward the solution
which breaks down the ridge more slowly. Models have been delaying
this process further with consecutive model runs which makes sense
given how strong the forecast ridging will be. Limited chances for
precipitation will exist through much of this period.
12z taf cycle
VFR conditions will prevail through much of the period with the
exception of visibility reductions in fog at kmkl and ktup both early
this morning and early Wednesday morning. Diurnal cumulus along
with high level cirrus should be present through the day but not
expecting much if any convection this afternoon. Winds should
remain light southeasterly through the period.