-- Discussion containing changed information from previous version are highlighted. --
516
FXUS64 KMAF 040550
AFDMAF

Area Forecast Discussion
National Weather Service Midland/Odessa TX
1250 AM CDT Sat May 4 2024

...New AVIATION...

.SHORT TERM...
(This afternoon through Saturday night)
Issued at 101 PM CDT Fri May 3 2024

WV imagery shows the upper trough persistently parked over
SoCal/Baja, leaving West Texas and Southeast New Mexico under
southwest flow aloft.  At the surface, a dryline extends from KTAT-
KINK-KFST-K6R6.  Td at KMAF @ 1430Z was 67F.  As such, the 12Z KMAF
RAOB came in w/4000 J/kg mucape, LI ~ -12, w/mesoanalysis suggesting
what little cap there is is either already gone or soon will be. mid-
lvl lapse rates are ~ 8.5 C/km, and environmental deep-layer shear
30kts.  Shear is forecast to increase through this afternoon, and
really ramp up tonight as the west coast trough begins moving east
and a 40+kt LLJ ramps up after sundown. Needless to say, a
continuing supercell threat is on tap for this afternoon/tonight
along the dryline and last night`s boundary that moved in from the
northeast. We`ll be throwing another balloon up at 18Z to further
monitor the situation.  S strong LLJ overnight and cloud cover will
keep lows 5-7F above normal.

Saturday, the west coast trough is forecast to be over southeast
Arizona at 12Z-18Z, and arrive in West Texas 21-00Z.  At the
surface, a boundary from tonight`s convection is expected to shove
the dryline to the western border of the CWA, while a front pushes
into the northeast by late morning, putting practically the whole of
West Texas and Southeast New Mexico in the warm sector.  Deep-layer
shear increases to 30-40 kts, stretching out the hodographs, and
lapse rates approach 10 C/km in the west near the dryline.
Convection looks to get going earlier and farther west than any
event yet this spring, and more widespread as well.  The only
promising detail is that forecast soundings saturate quite a bit by
00Z Sunday, w/PWATS at KMAF ramping up to over 1.5", which is about
2.5 std devs above the normal of 0.60".  So perhaps some areas west
of the Pecos, that really need it, may see a little relief.  The
other edge of that sword will be lightning-induced fire starts.  The
front will bring in cooler temperatures, and expected cloud
cover/convection should keep highs right around normal.

This activity could continue well into Saturday night.  As the front
settles in and instability decreases, there`s indications this may
transition to a heavy rain scenario, w/maybe even a little training
along the front as it moves south.  Lows will remain above normal.

&&

.LONG TERM...
(Sunday through Thursday)
Issued at 101 PM CDT Fri May 3 2024

Things begin to quiet down after an active day on Saturday for your
Sunday. Any thunderstorms that may be lingering across the eastern
and southeastern portions of the region should continue to weaken
and slide off to the southeast through the morning hours. The
combination of cloud cover and a convectively worked over airmass
may limit further thunderstorm activity through the late morning and
afternoon on top of resulting in slightly cooler temperatures.
Filtered sunshine should still allow for upper 70s and even 80s
across the bulk of the area but any 90s are confined to the Rio
Grande Valley. Though large scale support is expected to be waning
as we transition to the backside of a departing trough, daytime
heating may still result in enough destabilization along and east of
the dryline for scattered thunderstorms during the afternoon. The
best chance of any additional thunderstorms will be focused across
the eastern third of the region. Overnight temperatures remain mild
in the 50s and 60s as the dryline sloshes back west, ushering in
greater dewpoints.

A relatively benign pattern takes over by the start of the new week.
A large negatively-tilted trough is forecast to be lifting into the
central and northern Great Plains on Monday. This acts to mix the
dryline all the way east of the region, meaning we are warm and dry.
This allows temperatures to quickly climb back into the 90s for the
majority of locations. At night it remains warm but not as muggy
with the dryline staying east. It should be slightly cooler further
west behind the dryline. Tuesday and Wednesday see a similar
forecast as Monday, albeit with slowly warming temperatures each day
as quasi-zonal flow is maintained over the southern Great Plains.
The next potential change in the forecast may not arrive until late
in the week. A large positively-tilted trough axis appears to take
shape from the Great Lakes to central Rocky Mountains. This may be
enough to push a cold front south through portions of the area
beginning sometime Thursday bringing cooler weather for some,
especially on Friday. At this time, the dryline remains to the east
and little moisture is expected behind the cold front. This means
all of next week may be dry...

Enjoy any rain while it lasts!

-Chehak

&&

.AVIATION...
-- Changed Discussion --
(06Z TAFS)
Issued at 1240 AM CDT Sat May 4 2024

A very challenging aviation forecast this issuance, with MVFR
ceilings expected to develop and impact all terminals except PEQ
late tonight through Saturday morning. Ceilings will fall to
around 1500-2000ft, with improvement expected by mid to late
morning and VFR conditions returning areawide by 15Z-17Z. The main
focus thereafter will be scattered severe thunderstorms initiating
around 20Z-21Z, impacting area terminals through around 00Z-03Z
before exiting to the east. Have included VCTS mention for all but
CNM, and forecasts will be amended based on trends. Large hail,
erratic gusty winds, and lightning are all possible, as well as
IFR conditions in heavy rain. MVFR ceilings return areawide in the
wake of the storms near and just beyond the end of the forecast
period. Winds will generally be E/SE and intermittently gusty
through the period with gusts to 20-30kt, stronger and variable
near storms.
-- End Changed Discussion --

&&

.FIRE WEATHER...
Issued at 101 PM CDT Fri May 3 2024

A Fire Danger Statement remains in effect through this evening for
southeast New Mexico and the Guadalupe Mountains. A passing
disturbance this afternoon is causing relatively breezy conditions
over the critically dry airmass behind the dryline in an area of
ERCs exceeding the 90th percentile. Saturday should be very similar
to today, though moisture and rainfall potential is expected to be
pushed further west, limiting any fire weather concerns to the
westernmost areas where elevated conditions are maintained behind
the dryline. Sunday it continues to be dry behind the dryline from
the western foothills to the Big Bend where locally elevated to near-
critical fire weather may continue to be possible.

Fire weather concerns ramp up into next week. A stronger trough
passes to our north on Monday. This not only pushes the dryline east
of the entire area meaning critical relative humidity for almost
everyone, but winds are going to increase, especially across
southeast Mexico and the higher terrain. Given the lack of rain and
critically dry fuels out west, widespread critical fire weather is
anticipated. Further to the east, while it remains dry, recent
rainfall and better moisture return should limit fire potential.
This trend continues Tuesday and Wednesday, though winds will
slacken some, perhaps resulting in more localized critical
conditions. A cold front is set to arrive by late week and may
temporarily limit fire weather across much of the region.

-Chehak

&&

.PRELIMINARY POINT TEMPS/POPS...
-- Changed Discussion --
Big Spring               59  77  65  90 /  80  30  10   0
Carlsbad                 59  88  58  88 /  40   0   0   0
Dryden                   65  84  68  95 /  60  30  10   0
Fort Stockton            62  85  64  93 /  60  20   0   0
Guadalupe Pass           57  82  58  78 /  20   0   0   0
Hobbs                    56  81  60  87 /  60  10  10   0
Marfa                    51  87  50  87 /  20  10   0   0
Midland Intl Airport     60  79  65  90 /  80  20  10   0
Odessa                   61  79  66  90 /  70  20  10   0
Wink                     62  87  63  93 /  60  10   0   0
-- End Changed Discussion --

&&

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

$$

SHORT TERM...44
LONG TERM....91
AVIATION...84