Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Memphis Tennessee
333 PM CDT Monday Mar 10 2014
a progressive early Spring pattern will prevail over the lower 48
states through the week...with a midweek cold front briefly
interrupting normal to above normal temperatures across the
Midafternoon GOES water vapor imagery showed an upper low over
northern Mexico...with associated cloudiness across south Texas.
Midsouth skies were clear in downstream shortwave ridging over the
midsouth. An increase in high clouds will occur Tuesday morning...
as the upper low lifts east across the Gulf Coast. NAM soundings
show the boundary layer weekly capped to deep convection Tuesday
afternoon over the midsouth...but little to no height falls and
aforementioned high clouds will likely limit or preclude
thunderstorm formation. Have included a 20 percent chance of
afternoon thunderstorms...mainly south of i40 Tuesday afternoon.
A northern branch upper trough will dive from the northern High
Plains into the middle MS River Valley by late Tuesday evening. An
associated Pacific surface cold front will enter northeast Arkansas
shortly after midnight Tuesday night... and move through the
remainder of the midsouth through midmorning Wednesday. Scattered
areas of postfrontal light rain will occur Wednesday...mainly
north and east of the Memphis metropolitan. Wind will be the main story
for Wednesday...particularly through midday.
Thursday and Friday should see temperatures quickly recovering to near or
slightly above normal values...under low amplitude ridging aloft.
Weekend and early next weekend periods are complicated by lack of
GFS and European model (ecmwf) model agreement. The 12z European model (ecmwf) showed large differences
from the 00z run...while the GFS showed good interrun consistency.
As such...the GFS received a heavier weighting for the weekend and
early next week periods. The late periods forecast calls for weak
northeast surface flow behind a back door front...under a slowly
encroaching upper level ridge to the west.
18z taf cycle
VFR conditions are expected to prevail this afternoon and into
late evening. Winds will be SW 8 to 12 kts this afternoon...relaxing
to 5 knots or less after Sundown. Medium confidence exists that a
strong temperature inversion will develop overnight and lead to
patchy fog across all taf sites including mem after 09z. Have
introduced tempo groups with MVFR visibilities to address this. All sites
should return to VFR by late morning as SW winds pick up to around
Preliminary point temps/pops...
mem 51 76 51 54 / 0 10 30 10
mkl 46 75 49 52 / 0 10 60 30
jbr 46 74 45 50 / 0 10 40 10
tup 49 74 56 58 / 0 20 40 10