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000
FXUS64 KHUN 121948
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
248 PM CDT Fri Apr 12 2024

...New NEAR TERM, SHORT TERM...

.NEAR TERM...
(Remainder of today and tonight)
Issued at 248 PM CDT Fri Apr 12 2024

General thoughts from the near term forecast update earlier today
remain valid this afternoon, as current radar data now suggests
that convective shower activity (related to a passing mid-level
vort max and plume of steep low-level lapse rates) will remain
displaced to the immediate N/E of the local area. Although a few
of our ASOS/AWOS sites have briefly exceeded the gust threshold
for a Wind Advisory, present indications are that winds will begin
to subside late this afternoon as the center of a surface high
migrates into the central Gulf Coast, relaxing the pressure
gradient across the TN Valley.

Seasonably strong/dry NW flow aloft will persist across the TN
Valley overnight in the wake of a deepening mid/upper-level low
lifting northeastward through western New England and into
southern Quebec. This will result in clear skies and provide
nearly optimal conditions for radiational cooling with a surface
high centered to our south. We have lowered blended guidance to
reflect temps ranging from the u30s (NE AL) to l-m 40s elsewhere,
and although not explicitly indicated in the grids, conditions
will be favorable for the development of patchy fog near large
water sources (particularly between 8-13Z).

&&

.SHORT TERM...
(Saturday through Monday night)
Issued at 248 PM CDT Fri Apr 12 2024

Very little change in the synoptic pattern is anticipated on
Saturday, as northwest flow will continue in the mid/upper
troposphere, while a low-level ridge remains centered to our
south. Abundant sunshine and light winds will provide a pleasant
day across the region, with highs rebounding into the 75-80F range
for most valley locations.

Short term model data still indicates that the center of the
surface high will migrate eastward into the northern FL peninsula
Saturday night and into the western North Atlantic on
Sunday/Sunday night, while a surface low (related to a subtle
northern stream trough) spreads eastward across the Upper MS
Valley/western Great Lakes Saturday night and off the coast of New
England by 12Z Monday. The contracting pressure gradient between
the high to our SE and low to our N will support increasing SW
flow in the low-levels, with most guidance now indicating a 35-40
knot WSW low-level jet across the region on Sunday
afternoon/evening. In the mid/upper-levels, flow will
progressively back to WNW and diminish with time as we go through
the weekend, with a weak lower-latitude wave predicted to shift
east-southeastward into the region from the western Ozarks on
Sunday afternoon/evening. A modest increase in mid/high-level
clouds will accompany this feature, with a few low-topped
convective showers also possible beneath a developing inversion
aloft. However, with low-level moisture return impeded by the
western extension of the Bermuda ridge into the eastern Gulf, the
greatest risk for showers will likely occur within a zone of
stronger moisture advection to our north. Regardless of clouds,
highs should reach the u70s-l80s for most locations on Sunday,
with lows more gradually warming into the u40s-l50s Sunday morning
and m-u 50s Monday morning.

During the period from Monday-Monday night, low-level flow will
back to SSE in response to another compact shortwave trough
tracking across the central Rockies and deepening area of surface
low pressure in the lee of the central Rockies. This will allow
dewpoints to gradually rise back into the u50s-l60 (especially for
the western half of the CWFA), but present indications are that
we will remain capped, with the greatest coverage of
showers/thunderstorms occurring in the vicinity of a developing
warm front to our north. Highs will remain in the u70s-l80s on
Monday, with lows in the u50s-l60s Tuesday morning.

&&

.LONG TERM...
(Tuesday through Friday)
Issued at 303 AM CDT Fri Apr 12 2024

Afternoon Update: There have been no significant changes to the
extended forecast this afternoon, with global models still in
agreement that our next decent chance for showers/thunderstorms
will come late Tuesday night/early Wednesday morning as a surface
trough and weakening cold front shift southeastward into our
region from a dynamic storm system well to our north/west.
Although both deep-layer and low-level shear will be rather
impressive (and highly favorable for organized/severe convection
during this timeframe), instability appears to be rather meager,
but this is certainly an event that we will need to monitor over
the coming days. The cold front will likely not make much progress
southeastward into our region before stalling ahead of another
(potentially stronger) cold front that could bring another round
of thunderstorms Thursday evening.

Surface high pressure situated over the SE Lower-48 will be the
main feature controlling this area`s sensible weather. A southerly
flow rounding the ridge will return Gulf moisture to the region.
Ridging will also be developing aloft, east of a developing upper
low over the southern Great Basin. This next low should continue
moving to the east across the Four Corners, then heading to the NE
and reaching the upper Mississippi Valley on Wednesday. More
clouds will be realized as the moisture deepens over this region.
Despite an increase in clouds, even warmer conditions are forecast
to start the new work week. Under mostly cloudy skies, highs on
Tuesday should again rise into the lower 80s. Normal high/low
temperatures on the 15th are around 75/51.

The previously mentioned upper low will result in the development
of another synoptic scale storm system. As this next rather
strong system heads to the NE from the Front Range to western
Great Lakes, lift ahead of it will return lower end shower and
thunderstorm chances Tuesday night into Wednesday. Showers should
begin over NW AL and progress eastward over the rest of the area.
Despite more clouds and the showers, high temps Wed should warm to
around 80. Have gone with a drier trend for Wed night into early
Thursday, as the main area of low pressure moves further away. But
another system forming over the Southern Plains will head to the
east and bring more chances of convection Thu afternoon and night.
Highs on Thu should warm into the low to mid 80s despite clouds
and rain chances.

&&

.AVIATION...
(18Z TAFS)
Issued at 1149 AM CDT Fri Apr 12 2024

Aside from a few high-based Cu, skies will remain mostly sunny at
the terminals this aftn. However, with a sharp pressure gradient
and deep/well-mixed boundary in place across the region,
conditions will remain rather windy, with WNW flow 20G30 kts
expected to persist thru 22Z. Gradient winds will diminish
considerably btwn 22-2Z as a sfc ridge builds into the region from
the SW, with SKC conds anticipated for the remainder of the TAF
period. Although some patchy/light mist and fog may form early
Saturday morning in local valleys and near large bodies of water,
confidence in any vsby impacts at the terminals is too low to
include attm.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...None.
TN...None.

&&

$$

NEAR TERM...70/DD
SHORT TERM...70/DD
LONG TERM...RSB
AVIATION...70/DD