Area Forecast Discussion Issued by NWS Huntsville, AL
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000
FXUS64 KHUN 270922
AFDHUN
Area Forecast Discussion
National Weather Service Huntsville AL
322 AM CST Sat Feb 27 2021
.NEAR TERM...(Today)
Issued at 322 AM CST Sat Feb 27 2021
Shower activity for the most part has ended across the Tennessee
Valley for now, given a warm front had moved north of the area. The
showers were displaced to our north, heading NE from SW Arkansas to
across Nashville and eastern Kentucky. This has brought a noticeably
warmer and more moisture laden atmosphere across the forecast area.
Temperatures since the midnight hour have risen from the mid/upper
50s, now into the low/mid 60s. Normal highs for today are around 60
for reference. The warm air came with a little fan fair, as light ESE
winds veered to the SW and increased into the 10-20 mph range with
gusts above 25 mph.
SW winds should subside somewhat later today into the 5-15 mph range.
Despite more clouds than sun, warm air advection will boost high
temperatures later today into the lower 70s most spots, obviously
much warmer than a usually cooler late February. The warmer air has
lessened an inversion previously above the surface, allowing for more
instability to realized with the warmth. With plenty of moisture in
the column (precipitable water in the 1.3" range), have to keep in a
chance of showers and maybe an embedded thunderstorm or two in the
afternoon. With shower activity staying on a scattered basis, did not
hoist Flash Flood nor Flood Watches this issuance, given that only
1/4 to 1/2 inch of rainfall is expected.
.SHORT TERM...(Tonight through Monday night)
Issued at 322 AM CST Sat Feb 27 2021
Shower activity should wind down Sat night with a loss of daytime
heating and more stable atmosphere. Unseasonably mild conditions for
late Feb will continue, with lows only in the lower 60s. For the
start of a new week, even warmer conditions despite more clouds than
sun are again expected. High temperatures on Sunday should warm into
the low/mid 70s most spots. The higher end of this should it occur
will challenge standing record high temperatures of 80-1918 in
Huntsville and 77-1904 in Muscle Shoals (KMSL will be a close one).
The warmth and resultant instability will also bring more chances of
showers and thunderstorms.
The frontal boundary to our north will also begin returning southward
as a cold front Sun afternoon and evening. Precipitable water amounts
in the 1.5 to 1.6 inch range will bring another dose of locally heavy
rainfall. Another 3/4 to 1.5 inches of rainfall falling on an
already wet ground will increase chances for flooding. A Flash Flood
or Flood Watch may be needed for Sun afternoon to early Monday if
this wet trend continues. That said, rainfall amounts have backed off
somewhat from previous runs, but there is enough to push more
rivers/streams into Action or Flood Stage, as well as produce areal
or flash flooding. This is something we`ll monitor closely over the
next couple of days.
Colder air following the front passing before daybreak Mon will be a
reality check, as temperatures tumble into the upper 40s late Sun
night. Highs on Mon under cloudy skies and a chance of showers will
only warm into the mid/upper 50s, and lows Mon night cooling into the
mid 30s.
.LONG TERM...(Tuesday through Friday)
Issued at 322 AM CST Sat Feb 27 2021
The latter half of the global model suites continue to diverge with
the evolution of the overall wx pattern over much of the SE states
heading into Tue, with the OOZ ECMWF far more aggressive than the
latest GFS solution. The ECMWF continues to hint at a sfc wave
developing across the NW Gulf, as an upper low/trough axis rotates
ewd into the ARKLATEX region Tue morning. THE 00Z GFS on the other
hand has more of an open wave over the far wrn Gulf, as a very weak
upper shrtwv traverses ewd across the lower SE. The blended guidance
continues to favor the more aggressive ECMWF, with sct/perhaps num
showers/tstms spreading into the area later in the day Tue, as the
sfc low lifts into the srn Atlantic states, while the upper low
translates more ENE across the Mid South/mid TN Valley regions.
This could result in some locally heavy rainfall late Tue thru Tue
night, before rainfall tapers off to the east Wed morning, as the
sfc wave passes SE of the area. A few showers may linger on Thu,
given some residual moisture in the area. Rainfall amounts Tue/Tue
night are lower now given a faster/more progressive blended solution,
with QPF totals near 0.5-1.0 inch with maybe locally higher amounts.
Given perhaps some type of a clearing trend developing Wed, afternoon
highs look to climb into the lower/mid 60s thru the end of the work
week, while overnight lows trend in the lower 40s. Weak upper ridging
over much of the Gulf region will also help keep temps near seasonal
trends for the second half of the week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1049 PM CST Fri Feb 26 2021
VFR conditions will gradually give way to MVFR to IFR conditions due
to reduced visibilities and ceilings from light fog/mist and low
ceilings between 700 to 1500 feet. Gradual improvements will occur
during the day on Saturday, but expect generally MVFR ceilings to
continue through most of the daytime hours even as visibilities
improve. Some scattered -SHRA will likely develop in the afternoon,
but given the limited coverage and the lack of appreciable impacts,
have kept a mention out of this TAF issuance.
&&
.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&
$$
NEAR TERM...RSB
SHORT TERM...RSB
LONG TERM...09
AVIATION...AMP.24
For more information please visit our website
at weather.gov/huntsville.