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Area forecast discussion 
National Weather Service Huntsville Alabama
622 PM CDT Tuesday Sep 30 2014

Update...
for 00z tafs

&&

Discussion...
/issued 335 PM CDT Tuesday Sep 30 2014/
once the early morning low clouds finally diminished/lifted...it has
turned out to be a fairly nice and quiet day across the central Tennessee
Valley...albeit a little warm for this time of the year. A broad
dome of high pressure is pretty much in control of the overall weather
pattern across much of the eastern Continental U.S....with a secondary high layered
west to east across the lower MS/Tennessee Valley regions. Upper ridging out of
the plains states was also translating eastward into the southeast/Gulf region
this Tuesday afternoon...thereby helping with the unseasonably warm
temperatures in place...or more in the middle 80s across several locations. A
gradual warming trend by a few degrees looks to evolve over the next
couple of days...as the broad surface high shifts far to the E/NE...with
return flow developing after middle week. Moisture return initially
looks to be fairly slow...before a deepening upper trough axis out of
the northwestern states begins to approach the area on Thursday. A surface wave
developing in response to the upper trough pattern over the northern/middle
plains states is also xpcted to drag a cold front eastward through the
region Thursday night...as the surface low lifts into the Great Lakes area.

As mentioned...a fairly strong cold front should begin to approach
the area late Thursday...as the upper trough axis crosses the middle/Southern
Plains and pushes into the Midwest/Ohio Valley regions and points S.
Latter half of the model suites are hinting at some impressive
middle/upper forcing developing along the trough pattern. With a southerly
flow pattern in place...surface based instability looks to overspread
the region from the short wave ahead of the front...although total shear
does not look that impressive. In any case...showers/tstms should
begin to develop along/well ahead of the approaching cold front on
Thursday...with the coverage/intensity increasing sig Thursday night. Modest
convergence/speed shear along the surface boundary may yield a few
strong/marginally severe thunderstorms...with the main threat being damaging
wind gusts. Model consensus has the timing of the surface front moving
across the area late Thursday into Friday morning...with rainfall/convection
then tapering off from the west Friday afternoon. Another large/strong
dome of high pressure out of the Pacific northwest then looks to usher moderate
polar air into the southeast region this weekend...with temperatures/dew points
falling anywhere from 10-20f pending the model of choice.

09

&&

Aviation...
for 00z tafs...a weak upper disturbance over Arkansas will spread scattered ac/cirrus
across the County Warning Area tonight. No precipitation is expected due to a fairly dry air
mass over the Tennessee Valley. However NAM does hint at the chance of MVFR
fog between 10z and 14z along with some scattered low clouds (arnd 2000
ft). At this time will not include MVFR ceilings...but will monitor.
Otherwise expect VFR conditions for the remainder of the forecast period.

07

&&

Hun watches/warnings/advisories...
Alabama...none.
Tennessee...none.
&&

$$

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