Area Forecast Discussion
Issued by NWS Huntsville, AL

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FXUS64 KHUN 010135

Area Forecast Discussion
National Weather Service Huntsville AL
835 PM CDT Sun Apr 30 2017

.NEAR TERM...(Tonight)
Issued at 835 PM CDT Sun Apr 30 2017

Convection is redeveloping just ahead of the cold front in eastern
MS, mainly along the AL/MS border. 00Z soundings from both JAN and
BMX and from VORTEXSE show strong cold pools in the wake of the
afternoon convection. However, latest mesoanalysis shows MUCAPE of
between 250-500 J/kg across east-central MS and this is where we are
seeing a few better updrafts developing. As storms have crossed into
the more stable air (northern MS) storms do exhibit some weakening.
With stronger shear and better convergence along the front, we should
be able to see storms continue to develop this evening immediately
ahead of the front.

Given the strong cold pools though, a majority of the storms that
move into the TN Valley will be elevated and capable of wind gusts of
up to 40-50 mph. Adjusted grids for the remainder of the evening and
into the overnight to handle the movement of the storms and cold
front across the area. All activity should be out of the area by
sunrise Monday morning.

We`ll continue to watch trends and may make another update to the
forecast package before midnight.

.SHORT TERM...(Monday through Tuesday)
Issued at 417 PM CDT Sun Apr 30 2017

Much drier and cooler air is forecast to move in behind the front on
Monday. Some lingering showers or thunderstorms are possible through
around 10 AM on Monday. CLoud cover could linger a bit longer, until
around noon. However, expect clear skies by the early afternoon
hours. Despite this sunshine, cold air advection will keep highs in
the 70 to 75 degree range. It will be windy on Monday with sustained
southwesterly winds around 20 mph with gusts up to 30 mph. A weak
area of high pressure will remain over the Tennessee Valley through
Tuesday night, as a slow warming trend occurs.

.LONG TERM...(Tuesday night through Saturday)
Issued at 417 PM CDT Sun Apr 30 2017

By Wednesday a strong longwave trough axis moves southeast into
Oklahoma and Kansas. Forcing ahead of this feature moves into
northwestern Alabama on Wednesday. With some limited surface based
instability and decent shear over the area isolated to scattered
showers and thunderstorms area expected in northern Alabama and
Southern Middle Tennessee. Coverage of this activity will continue
to increase through Thursday as this upper level energy and
associated surface low push northeast into northern Tennessee. Much
better instability will be present near the Gulf Coastal states south
of this surface low.

A drying trend is expected Friday into Friday night, as the forcing
rotating around the surface low moves well northeast of the area.
Warmer temperatures are expected by Saturday, as high pressure
remains over the area.


.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 638 PM CDT Sun Apr 30 2017

A line of showers and thunderstorms, some that were strong to severe
in intensity have weakened and are now east of the area. The main
cold front with this system was moving across the Mississippi River
in the Mid South region. Model timing on when the front will reach
the region remains inconsistent. Leaning towards some of the higher
resolution output, the boundary should reach KMSL before local
midnight and pass across KHSV between 06-09Z. The passage of this
boundary will end rain chances from west to east during the overnight.
A heavier shower and/or brief t-storm cannot be ruled out with the
front. A drying trend, with S-SW winds increasing into the 15-25 kt
range with higher gusts by the late morning, should continue into
the afternoon.


AL...Wind Advisory until 10 PM CDT this evening for ALZ001>010-016.

TN...Wind Advisory until 10 PM CDT this evening for TNZ076-096-097.



NEAR TERM...Stumpf

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