Area Forecast Discussion
Issued by NWS Huntsville, AL

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FXUS64 KHUN 291657

Area Forecast Discussion
National Weather Service Huntsville AL
1157 AM CDT Mon May 29 2023

...New AVIATION...

(Rest of Today)
Issued at 1107 AM CDT Mon May 29 2023

An upper-level cyclone (currently centered across northern SC)
will shift slowly east-northeastward into eastern NC over the
course of the day. As this occurs, NNE flow aloft on the order of
10-20 knots across the TN Valley will back to NNW and subside by
late afternoon, with broad scale subsidence in the wake of the low
maintaining dry conditions and partly cloudy skies this
afternoon. Based on a persistence forecast, we have increased
blended guidance max temps to reflect values similar to yesterday,
with highs ranging from the mid 70s in elevated terrain to the
u70s-l80s in the valley.


(Tonight through Wednesday night)
Issued at 308 AM CDT Mon May 29 2023

Higher heights and moisture returning as the low departs further
to the east, should make for a somewhat milder night with lows in
the upper 50s to around 60. Under partly cloudy skies, highs on
Tuesday should warm into the low/mid 80s. This warmth with the
moisture return will bring isolated (~20% chance) of afternoon
showers and thunderstorms. The better rain chances should occur
near/east of the I-65 corridor, but have included our western
areas as well. A loss of daytime heating and a more stable
atmosphere should result in showers ending Tue evening. Even
milder with lows by daybreak Wednesday in the low/mid 60s.

Additional moisture and stronger lift should bring more chances
of showers/thunderstorms on Wed, especially in the afternoon. Have
raised PoPs into the scattered range (~30-40%) for most of the
area. Shower activity should end in the evening with lows Wed
night in the mid 60s.


(Thursday through Sunday)
Issued at 308 AM CDT Mon May 29 2023

Thursday brings a Gulf low pressure system to the southeastern US as
high pressure resides in the Appalachians region. This high pressure
may allow moisture to fuel the TN Valley due to southeasterly flow
and bring a low chance of showers with embedded thunderstorms
(25-30%) Thursday morning which will increase to medium chances (45%)
in the afternoon/evening hours due to assistance from diurnal
heating as highs are forecast to be in the low to mid 80s. Model
guidance continues to show the aforementioned high pressure
sticking around through the weekend, with highs reaching the mid
to upper 80s Friday onward and overnight lows dipping into the
60s. Therefore, kept NBM guidance in for PoPs, allowing low-
medium chances (less than 40%) of showers with low chances of
thunder in the afternoon due to diurnal heating and increased


(18Z TAFS)
Issued at 1157 AM CDT Mon May 29 2023

Current satellite data indicates that the western edge of wrap-
around stratus clouds (associated with an upper low to our east)
will continue to erode across northeast AL this aftn. Modest
warming of the boundary layer will support the development of sct
Cu/Ac at the terminals, which should dissipate shortly before
sunset, leaving only sct Ci for much of the evening. Stratocu will
begin to return to the region around or shortly after Midnight as
winds in lower-levels begin the process of veering from NE to
ESE, with development of cigs arnd 5 kft possible by the end of
the TAF period. Some patchy BR/FG may also develop invof the
terminals from late this evening-sunrise tomorrow, but with
uncertainty regarding the evolution of early morning clouds, we
will not include vsby reductions in the forecast attm.





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