Scientific Forecaster Discussion
fxus64 kmeg 221545
Area forecast discussion
National Weather Service Memphis Tennessee
1045 am CDT Tue Oct 22 2019
Forecast is on largely on track, though I bumped temperatures
slightly, mainly across north Mississippi. Afternoon highs will
be in the middle to upper 60s under clear skies.
Previous discussion... /issued 627 am CDT Tue Oct 22 2019/
Discussion...surface analysis this morning places an occluded
surface low near Duluth, Minnesota with an occluded front
extending from the low into the Ohio Valley, east Tennessee, and
Georgia. Meanwhile, GOES-16 satellite trends indicate an upper
level trough axis located over the middle and lower Mississippi
valleys. As of 4 am CDT, temperatures across the mid-south are in
the lower to middle 50s.
Short term (today through thursday)...high pressure is expected
to result in rain free weather across the mid-south today through
Thursday. High temperatures today will be somewhat cooler in the
60s with the upper level trough axis in place across the region.
Lows tonight will fall back into the 40s at most locations and
perhaps a potential for temperatures to fall back into the upper
30s near the Tennessee River. Southwest upper level flow aloft
will begin to return for Wednesday and Thursday with temperatures
rising into the upper 60s to lower 70s.
Long term (friday through monday)...long term models continue to
struggle with the upper level synoptic flow across the United
States as an upper level trough digs across the southwest United
States at the start of the period. European model (ecmwf)/European model (ecmwf) ensembles/Canadian
solutions suggest an upper level low will develop across the
southwest United States and Southern Plains and move into portions
of the middle/lower Mississippi valleys over the upcoming weekend.
Meanwhile, the operational GFS continues to show a fast,
progressive bias as the past few days and it's ensemble members
show little if any consensus on the overall pattern. Thus, i've
blended the forecast towards a European model (ecmwf)/Canadian blend and kept rain
chances on the low end for the time being until better model
consensus appears in subsequent model runs.
IFR visibilities south of tup should lift through 15z, if not
sooner, as northwest winds increase with the onset of surface heating.
Those surface winds will decouple following sunset later today.
For the majority of the overnight, NAM model depicts fl020 winds
from the northwest at 15 to 25 knots, which should limit fog potential
following a day of sunshine and occasionally gusty surface winds.