000
FXUS64 KMAF 230901
AFDMAF

Area Forecast Discussion
National Weather Service Midland/Odessa TX
401 AM CDT Tue Oct 23 2018

.DISCUSSION...

..Showers and isolated thunderstorms return to the forecast today,
with widespread rainfall and possible localized flooding tonight
through Wednesday...

Early this morning, surface flow has started backing to the E/SE,
with upslope flow aiding in saturation of the lower boundary
layer, yielding fog development across portions of the Lower
Trans Pecos, Permian Basin, and Southeast New Mexico. Observations
and reports indicate visibility of 1/4 mile or less in some
locations, with the expectation of the dense fog to become more
widespread by daybreak. Thus, a Dense Fog Advisory has been issued
for much of the Southeast New Mexico Plains, Guadalupe Mountains,
Upper Trans Pecos, Permian Basin, Stockton Plateau, Lower Trans
Pecos, and the eastern slopes of the Davis Mountains until
16Z/11AM CDT. Cloud cover and increased moisture will keep
temperatures in check today, with highs only expected to reach the
middle 50s and 60s across the area.

The main focus continues to be on the upper trough to the west,
which has slowly begun to translate eastward as indicated by this
morning`s satellite imagery. A plume of tropical moisture is also
apparent on water vapor imagery, currently streaming across
Central Texas. As the trough draws nearer to the region, the fetch
of tropical moisture will be routed more northerly across the
area, yielding increased moisture (up to 2-3 standard deviations
above normal!) and potential record precipitable water values near
1.25". Lift ahead of the approaching trough will first increase
across western zones today, where rain chances ramp up this
afternoon. While instability will be lacking, there may still be
just enough elevated instability to yield isolated thunderstorms
this afternoon, mainly across the higher terrain from the
Guadalupe Mountains south to the Big Bend Area/Presidio Valley.
Rainfall may be heavy at times, especially if thunderstorms
develop, though any flash flooding is expected to be localized and
mainly affect urban areas, areas with poor drainage, or otherwise
vulnerable locations such as arroyos or small streams.

Tonight, the trough will develop a slight negative tilt as it
nears West Texas, and the models are in very good agreement in
handling the open wave and associated rainfall potential. Have
gone with widespread rain areawide tonight and Wednesday, and
currently do not expect thunderstorms beyond this afternoon. Due
to the tropical nature of the airmass, efficient rainfall rates
are expected, which could lead to locally higher amounts for some
locations than those forecast. Currently through Wednesday, around
1.00-1.50" of rainfall is possible across the Permian Basin and
Lower Trans Pecos/Stockton Plateau, with amounts around 0.50-1.00"
for locations further west. Have foregone any flood headlines at
this time, as any flooding is expected to be localized, though
conditions will still bear watching as the event unfolds.

Temperatures Wednesday will be well below normal due to the rain
and clouds, only topping out in the lower 50s to lower 60s for
most. Wednesday evening, as the trough axis swings through the
region, precipitation will quickly end from west to east, with a
chilly night in the 40s on tap across much of the area.
Thereafter, the weather pattern will quiet down as the trough
deepens across the eastern half of the country, and ridging
develops west. Dry northwesterly flow aloft will mitigate rainfall
Thursday onward, with dry conditions areawide through next
weekend. A warming trend will also begin Thursday, with near
normal temperatures in the middle 70s expected by Friday/Saturday.
Temperatures will also rebound into the lower to middle 70s for
most of the area by the start of the weekend. Models indicate the
potential for a cold front to move through the area late Sunday,
though impacts look to be fairly minimal.

&&

.PRELIMINARY POINT TEMPS/POPS...
Big Spring                     64  49  52  45 /  40  90 100  20
Carlsbad                       61  51  55  47 /  80 100  70  10
Dryden                         60  53  59  50 /  60 100  70  10
Fort Stockton                  62  50  55  48 /  50 100  70  10
Guadalupe Pass                 58  47  55  46 /  70 100  60  10
Hobbs                          61  47  51  43 /  60 100  90  10
Marfa                          61  49  60  43 /  70 100  50  10
Midland Intl Airport           63  49  52  46 /  50 100 100  10
Odessa                         62  49  52  45 /  50 100 100  10
Wink                           63  52  54  47 /  60 100  80  10

&&

.MAF WATCHES/WARNINGS/ADVISORIES...
NM...Dense Fog Advisory until 10 AM MDT this morning for Central Lea
     County-Eddy County Plains-Guadalupe Mountains of Eddy
     County-Northern Lea County-Southern Lea County.

TX...Dense Fog Advisory until 11 AM CDT /10 AM MDT/ this morning for
     Andrews-Big Bend Area-Borden-Crane-Davis/Apache Mountains
     Area-Dawson-Ector-Gaines-Glasscock-Guadalupe Mountains-
     Howard-Loving-Martin-Midland-Pecos-Reagan-Reeves County and
     Upper Trans Pecos-Terrell-Upton-Van Horn and Highway 54
     Corridor-Ward-Winkler.

&&

$$

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NWS MAF Office Area Forecast Discussion