493
FXUS64 KMAF 181120
AFDMAF

Area Forecast Discussion
National Weather Service Midland/Odessa TX
620 AM CDT Wed Sep 18 2024

...New AVIATION...

.SHORT TERM...
(Today through Thursday afternoon)
Issued at 340 AM CDT Wed Sep 18 2024

A few showers persist over SE NM Mexico and the Permian Basin this
morning, but will gradually rain themselves out over the next couple
hours. Enough rain to wet the ground and most likely dry off before
sunrise is all that is expected this morning. SImilar to yesterday,
a diffuse dryline will sharpen up over the Caprock southward towards
the Davis Mountains and mix slightly to the east through the day.
With upper level ridging still in place over Central Texas, it will
be tough for storms to develop once again. Isolated storms will
develop during the mid to late afternoon, but location remains
uncertain and the current suite of CAMs reflect that with highest
chances staying over the Davis Mountains and the foothills to the
east in Pecos and Reeves counties thanks to the topography of the
area. Storms look less likely across the Permian Basin, but the
chance is non-zero. Any storms that do form will be able to access
~1000 J/kg MUCAPE, ~30kts effective shear, and a decently tall dry
layer near the surface. All that to say damaging winds will be
possible in the few strong to severe storms that develop.

Into tonight, storms will gradually decay with the loss of daytime
heating and the dryline retreats back to the west as the LLJ kicks
in and brings in low level moisture from the SE. Temperatures today
tick up about a degree or two over yesterday, yielding highs in the
mid 90s nearly areawide with the exception of the cooler mountains.
Lows remain about 10 degrees above average as return flow delivers
more warm, moist air during the night. The trend up in temperatures
continues on Thursday as the upper level ridge amplifies over Texas
and another degree or two can be added on to what today will see.
With a stronger ridge, drier conditions can be expected for the
region.

-Stickney

&&

.LONG TERM...
(Thursday night through Tuesday)
Issued at 340 AM CDT Wed Sep 18 2024

For those who like cooler weather, it`s on the way.  Friday, an
upper trough is forecast to be over the junction of AZ/CA/NV by 00Z
Saturday, nudging the ridge over Texas farther east and starting a
precipitous decline in thicknesses into next week under southwest
flow aloft.  Friday should be the warmest day of the extended as
highs top out ~ 10 F above normal.  Large-scale ascent will combine
w/impulses moving through southwest flow aloft for a slight chance
of convection over Southeast New Mexico Friday afternoon/night.

Saturday, the trough ejects northeast, arriving just east of the
Four Corners by 00Z Sunday.  A Pac front will enter the higher
terrain from the west, but models stall this feature late afternoon
along the Texas/New Mexico border, which will also serve as a focus
for convection mainly during the afternoon.  Like yesterday`s setup,
deep-layer shear ahead of the approaching trough will increase to 35-
45 kts.  Mid-level lapse rates supportive of large hail will once
again be confined north and west of the CWA, but dcapes in excess of
1000 J/kg and dry subcloud layers/inverted-v soundings suggest a
damaging wind threat.  Highs should be a couple of degrees cooler
than Friday.

Sunday, the upper trough pushes into the Central Plains, flattening
the ridge along the Texas/Louisiana coasts.  This will push the Pac
front a little farther into the CWA, and orient it more SW-NE across
the CWA, resulting in a slight chance of convection over the lower
Trans Pecos.  Thicknesses continue to diminish, with highs remaining
in the 80s for much of the CWA.

Sunday night, long-range models bring a cold front into the area,
but confidence in this is somewhat low attm.  Yesterday`s GFS had it
arriving at KMAF 12Z Sunday, and the latest run puts it more like
18Z Monday.  This uncertainty is illustrated quite nicely in LREF
75th-25th temp spreads Monday afternoon.  To be fair, late-summer
cold fronts are most always capricious, so this is just the nature
of the game at this point.  That said, NBM is hard to argue with,
although it too will most certainly change as the front comes into
hi-res territory.  Confidence will remain low on timing until the
NAM gets ahold of it.  That said, Monday now looks to be the coolest
day this forecast, with highs within a couple of degrees of normal,
which puts all but the Rio Grande Valley under 90 F Monday
afternoon.  Isolated convection is possible invof the Davis
Mountains.

Tuesday, temperatures attempt to recover under zonal flow aloft, but
not by much.  Long-range models are all over the place by that time.
Stay tuned.

&&

.AVIATION...
(12Z TAFS)
Issued at 620 AM CDT Wed Sep 18 2024

VFR continues through the period. Winds remain southerly to
southeasterly through the day. Gusts becoming more consistent during
the afternoon. Iso TS possible mid to late afternoon particularly
near PEW/INK/HOB, but timing and location are uncertain. Mention
will be made in later issuances or with amendments.

&&

.PRELIMINARY POINT TEMPS/POPS...
Big Spring               95  73  97  71 /   0   0   0   0
Carlsbad                 96  69  97  70 /   0   0   0   0
Dryden                   96  73  96  72 /   0   0   0   0
Fort Stockton            98  71  98  70 /  10  10   0   0
Guadalupe Pass           88  68  89  69 /   0   0   0   0
Hobbs                    94  68  94  68 /  10  10   0   0
Marfa                    92  64  92  63 /  10  10   0   0
Midland Intl Airport     95  72  95  71 /  10   0   0   0
Odessa                   95  73  95  72 /  10   0   0   0
Wink                     99  74  99  73 /  10  10   0   0

&&

.MAF WATCHES/WARNINGS/ADVISORIES...
TX...None.
NM...None.
&&

$$

SHORT TERM...93
LONG TERM....44
AVIATION...93