277
FXUS64 KHUN 300218
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
918 PM CDT Mon Apr 29 2024

...New NEAR TERM...

.NEAR TERM...
(Tonight)
Issued at 918 PM CDT Mon Apr 29 2024

Latest radar data indicates pockets of light rain spreading
eastward into northeastern AL at the current time, with an axis of
more widespread moderate-heavy rain and embedded thunderstorms
setting up across northeastern MS. Both regimes are occurring
within a region of deep/moist SSW flow, well ahead of a weak cold
front that should drift slowly southeastward across the Mid-MS
Valley and into southwestern KY/northwestern TN by 12Z as the
decaying cyclone that it is attached to lifts northeastward across
Lake Superior.

Recent versions of the HRRR model (as well as solutions from the
12Z CAMs) suggest that the axis of rain and embedded storms to our
west will continue to expand in coverage later this evening, as a
distinct mid-level shortwave trough (only partially phased with a
stronger northern stream disturbance ejecting into southwestern
Ontario) shifts east-northeastward from southern AR/northern LA.
The approach of this shortwave trough (and related SSW low-level
jet of 20-30 knots) should sustain the broader axis of precip as
it spreads eastward across our region, with rain/storms expected
to gradually diminish from SW-to-NE shortly before 12Z as the low-
level jet veers to WSW and weakens. Although deep-layer shear of
20-30 knots may result in some loosely organized storm structures
at times, CAPE will remain less than 500 J/kg and aside from a few
brief wind gusts up to 25-35 MPH, locally heavy rain and
lightning will be the primary storm impacts. Based on latest QPF
guidance from WPC, we are still anticipating widespread storm
totals between 0.5-1.5", with locally higher amounts.

Aside from minor updates to the POP/weather grids, other elements
of the forecast appear to be on track at this time, with lows in
the lower 60s.

&&

.SHORT TERM...
(Tuesday through Thursday)
Issued at 231 PM CDT Mon Apr 29 2024

Convection will gradually wane during the 12-18z window Tuesday
morning from west to east as the front shifts eastward through the
region. Cloud cover will dissipate by the afternoon as high
pressure builds into the area -- resulting in a sunny end to the
day Tuesday and a mostly clear night (some patchy fog may develop
early Wednesday morning). High pressure will continue to promote
tranquil conditions both Wednesday and Thursday -- with sunny/dry
weather forecast. A pronounced warming trend will again occur as
highs will reach the low to mid 80s on Wednesday and the mid to
upper 80s on Thursday.

&&

.LONG TERM...
(Thursday through Sunday)
Issued at 211 AM CDT Mon Apr 29 2024

An upper ridge pattern will continue to translate eastward into the
mid/southern Atlantic states heading into the end of the work week.
High pressure at the sfc will also remain layered from the NE states
into the Carolinas, resulting in afternoon highs climbing predom into
the mid 80s/near 80F both Thu/Fri. An upper trough axis will also be
rotating eastward thru the mid/northern Plains, with an attendant sfc
low lifting NE into the Great Lakes area. This sfc wave will help
drag a cold front eastward thru the Midwest/Mid South regions well
into the day Fri. Low-medium chances for showers/tstms (20-50%) will
develop along/ahead of the oncoming cold front late Thu into Fri. Sct
showers/tstms will then continue into the first half of the weekend,
as the frontal boundary moves SE thru the central TN Valley. Low
chances for showers/tstms (20-30%) will also linger thru the second
half of the weekend period, as the broad upper trough pattern moves
eastward across the region. Minimal low-level convergence/instability
coupled with better dynamic forcing displayed N/W of the area should
offset the prob for more organized/stronger tstms, with QPF totals
around 0.25-0.50 inches thru the upcoming weekend. Seasonably warm
temps will continue Sat/Sun, with highs mainly in the lower 80s/near
80F, while overnight trends predom in the upper 50s/mid 60s.

&&

.AVIATION...
(00Z TAFS)
Issued at 701 PM CDT Mon Apr 29 2024

Conditions will remain VFR at the terminals early in the forecast
period, but with bkn-ovc layers of high-based stratus and
altostratus as a band of lgt RA spreads eastward into the region.
Although this precipitation is occurring within a deep/moist SSW
flow regime well ahead of a weakening cold front (to our NW), both
coverage and intensity of rainfall will likely increase between
3-6Z as an upper air disturbance begins to approach the region
from the WSW. Prevailing MVFR cig and vsby conds are anticipated
for an extended period btwn 4-14Z, which is when moderate rain
will be most persistent and mixed with a few embedded TSRA. The
trailing/western edge of the precipitation band will shift
steadily eastward late tomorrow morning, with additional but more
scattered shower activity possible prior to the arrival of the
frontal wind shift to NW. A more pronounced clearing trend will
begin late in the TAF period.

&&

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

&&

$$

NEAR TERM...70/DD
SHORT TERM...AMP
LONG TERM...09
AVIATION...70/DD