FXUS64 KHUN 230335

Area Forecast Discussion
National Weather Service Huntsville AL
1035 PM CDT Fri Jun 22 2018

.NEAR TERM...(Rest of tonight)
Issued at 1035 PM CDT Fri Jun 22 2018

Just some moderate rain showers lingering at this hour over Marshall
and Dekalb counties in northeastern Alabama. There may be an isolated
rumble of thunder, but most of this activity is just rain. Have cut
out pops after 1 AM given current radar trends. Kept high chance in
these counties mentioned above through then though to account for
departing showers. Despite some decent clearing north of the
Tennessee River, expect winds to remain around 5 mph all night. So
not including fog in the forecast overnight despite rainfall that has
occurred. Raised low temperatures a few degrees into the lower 70s
everywhere (even NE AL) based on current observations and guidance.

.SHORT TERM...(Saturday through Sunday)
Issued at 209 PM CDT Fri Jun 22 2018

With westerly or northwesterly flow synoptics, you know there isn't
much of a break in the action for very long. That is the case on
Saturday with a very fast-moving shortwave moving from the Rockies
through the Plains tonight and into the Ozark Plateau and mid south
Saturday morning. A large MCS will feed off the low level jet which
veers to the west over TN and north MS/AL on Saturday. This will
accelerate this system with some wind damage potential expected given
the unidirectional wind profile and strong instability and moisture
this system will feed off of on Saturday. Even if severe weather
doesn't materialize, locally heavy rain/training echoes are likely on
Saturday so will have to watch the flash flood threat.

As the LLJ wanes Saturday evening and backs to the south again, there
will be more of an anticyclonic curvature to the low level flow
locally with the low level convergence zone shifting to our north
into central and northern TN. One more more MCS clusters will
redevelop again along the boundary where a 25-35kt LLJ will reside.
Will draw the PoP field in this fashion with lower chances south and
slightly higher chances in our north counties Saturday night into
early Sunday morning. Sunday itself may be dry for most areas
altogether. Clouds, including anvil blowoff, may give us a small
break from the 90s for our northern counties, but still should reach
around 90 south.

.LONG TERM...(Monday through Thursday)
Issued at 209 PM CDT Fri Jun 22 2018

The building upper ridge will be the big weather story early to
middle of next week. This means the heat and muggy regime will return
for the last week of June. Will keep the low PoP the suggested blend
has for Monday into Tuesday in case some "ridge rider" thunderstorms
or small MCSs drop southeast and clip our region. The ECMWF/GFS both
suggest the ridge breaking down a bit for this to occur. However, if
the ridge remains in tact, the PoP may be dropped further in future
updates. Went above the blended guidance for high temperatures by a
few degrees in days 5-7 with lower to middle 90s quite possible.


.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 614 PM CDT Fri Jun 22 2018

Based on current radar trends, kept predominant -tsra in at KHSV
through 03Z, lowering vsbys into the mvfr realm. There could be
periods of lower vsbys into the IFR realm or lower due to heavier
thunderstorm activity some of that time. Not as sure it will be
as predominant or last that long at KMSL, so have a tempo of -tsra
between 23/00Z and 23/02Z lowering vsbys to MVFR realm at least.
Expect cloud cover to break up after 03Z at KMSL especially. KHSV
might hold onto a low stratus deck though. Thus, keep vsbys in the
mvfr realm through 23/09Z at KMSL, due to some expected fog
formation. VFR conditions should return by daybreak on Saturday.
Gusty northwest winds between 10 and 20 knots are expected in the





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