Area Forecast Discussion
Issued by NWS Huntsville, AL

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FXUS64 KHUN 280958

Area Forecast Discussion
National Weather Service Huntsville AL
458 AM CDT Tue Mar 28 2017

.NEAR TERM...(Today)
Issued at 458 AM CDT Tue Mar 28 2017

All of the active wx has diminished/moved s of the cntrl TN Valley
this early Tue morning, with some patchy dense fog now affecting
parts of the local area. With sfc winds pretty much decoupled now
along with dew pts in the mid/upper 50s, would not be surprised to
see more widespread dense fog develop over the next couple of hrs.
However, a persistent mid level cloud deck around 5-7K ft coupled
with some mixing just off the sfc may limit more widespread fog
development near daybreak, although this will be closely monitored
over the next few hrs in case a Dense Fog Advisory is warranted.

The stalled frontal boundary to the w should finally receive some
assistance in translating to the e later this morning, as the
departing upper shrtv to the ne and it`s parent sfc low move ewd into
the mid Atlantic Basin and help pull the front thru the local area.
Cannot rule out a few trailing showers along the front later this
morning into the early afternoon hrs, given some lingering moisture
in place below H85. However, the moisture column rapidly drys/weakens
heading into the late afternoon period in the wake of the frontal
passage, as drier air above H85 advects into the area from the w. It
should also be another unseasonably warm day, given the fact that any
cold air advection associated with the passing front is shunted well
to the n/w, with afternoon highs once again climbing into the mid 70s
for most locations.

.SHORT TERM...(Tonight through Wednesday night)
Issued at 458 AM CDT Tue Mar 28 2017

Relatively dry and quiet wx conditions are then xpcted tonight and
into Wed, with the cntrl TN Valley area pretty much in between the
departing upper trough axis/sfc low in the NE Atlantic and the next
amplifying trough pattern moving into the mid/srn Plains which is
xpcted to impact the region near the end of the work week. Global
models are showing an upper ridge pattern quickly building over the
SE region on Wed, and then translating ewd Wed night into Thu. The
ridge axis should help overall temps remain unseasonably warm, with
highs reaching the upper 70s/lower 80s Wed afternoon, while overnight
lows trend well into the 50s both tonight and again Wed night.

.LONG TERM...(Thursday through Monday)
Issued at 458 AM CDT Tue Mar 28 2017

It seems like showers and thunderstorms are on somewhat of a repeat
cycle in the TN Valley forecast. On the bright side, the weekend
looks nice!

On Thursday, a trough in the lower/mid MS Valley will lift past the
TN Valley and into the OH Valley by Friday. Models are still agreeing
on the overall pattern and that timing has slowed down a little bit,
but there are still some discrepancies to work out for this event.
For example, the GFS continues to have convective feedback,
especially along the Gulf Coast. As some models hint at a weak sfc
low developing in that area and additional QPF could occur, the GFS
continues to be the outlier. Thus, leaned more towards the ECMWF for
this forecast package.

On Thursday into Thursday night, highs will be in the upper 70s and
showers and thunderstorms will move into the forecast area and spread
west to east. Some storms could be strong to severe. There could be
CAPE towards 600 J/kg and Bulk Shear 40-50kts however, the best
instability and shear looks to remain to our west then to our south.
Not to mention, will have to see what the models do with the
previously mentioned convection near the Gulf to see how this may
affect the strength of these storms. Regardless, showers and
thunderstorms will linger into Friday until the cold front passes
through in the afternoon/evening.

The weekend will be dry and a few degrees cooler as a ridge builds
in. Highs will be in the low/mid 70s with lows in the low/mid 50s.
The ridge is short lived however as the next chance of rain is back
in the forecast by Sunday night into Monday as the next system is
already in the ArkLaTex and ready to swing up into the region early
next week.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1153 PM CDT Mon Mar 27 2017

An earlier line of convection has now moved to the southeast of the
KMSL and KHSV terminals, with little to no precip expected through
the next 24 hours. VFR conditions will give way to MVFR cigs around
08Z, as low level moisture remains elevated and low stratus moves in
from the north. Although there may be some light fog, surface winds
in the 5 to 10 kt range should keep most of the fog at bay. Cigs will
lift through the morning, with VFR conditions returning around 19Z.
A cold front will also drift southward, shifting surface winds to the
northwest between 15Z and 19Z.





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