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Area forecast discussion 
National Weather Service El Paso Texas/Santa Teresa nm
330 PM MST Monday Jan 26 2015

Synopsis...
a weak upper level disturbance will bring scattered showers to the
area overnight...with the main focus being over southwestern New
Mexico and the bootheel. Warm and fair weather will return Tuesday
and Wednesday with high temperatures approaching the 70-degree
mark in a few areas. A weak backdoor cold front will push into the
area on Thursday...cooling temperatures by about 5 to 10 degrees.
A significant and slow-moving storm system appears set to bring
widespread lowland rain and high-elevation snow to the area
Thursday night into Saturday.

&&

Discussion...
a weak upper level disturbance will bring a few showers to the
area overnight...with high probability of precipitation/low-qpf for SW New Mexico. Late-
week looks like a total mess as a significant high-amplitude
trough/upper low will bring several days of lowland rain and
mountain snow...with significant accumulations of both precipitation
types possible.

For the short-term...upper low is located well off the Southern
California coast with a Sharp Ridge centered over Colorado in a
Rex-block pattern. Middle and high-level subtropical moisture is
streaming north and northwest into northwest Mexico and Arizona.
Radar indicates initial light band of precipitation associated with middle-
level vorticity lobe stretching from beyond Las Vegas...through
Tucson...just barely into the nm bootheel...and down south of
ahumada. Precipitation amounts have been very light... generally just a
few hundredths across Arizona. Second area of precipitation is expanding
across southern Arizona into Sonora as isentropic lift steepens
and low and middle-level moisture increases.

Initial band of precipitation will be mostly virga in our County Warning Area. Better
precipitation coverage is expected after 10pm as isentropic lift and
moisture increases across the area. Precipitable water values are actually pretty
impressive overnight...peaking around 0.75 inches at 06z. Given
this... I couldn't really pull probability of precipitation back too much around lc/ep
despite the NAM/GFS producing scant quantitative precipitation forecast in the area. Various
mesoscale models (though not the hrrr) have a little better quantitative precipitation forecast.
Still...the main focus both for shower coverage and quantitative precipitation forecast will be in
far SW New Mexico into the Gila region...with storm totals ending
up in the 0.10 to 0.20 inch (liquid) range. Lifted indice's dropping to around
0c suggest some convective activity...but lightning is unlikely.
With deep subtropical southwest flow aloft...snow levels will be
start out safely above 10k feet...dropping to around 9k in the
Gila late tonight. High-elevation passes such as Emory Pass and
nm-15 over Tadpole Ridge could see a sloppy 0.5 to 1.0 inch of
snowfall by morning.

Drier air aloft will move in as the main upper low lifts into
Nevada tomorrow...ending the shower threat. Expect warm
temperatures the next few days as southwest flow continues. We
will be flirting with 70 at El Paso Wednesday assuming the
increasing high clouds remain thin enough...otherwise upper-60s.
Enjoy the fair weather while it lasts...it all comes apart
starting on Thursday.

High pressure building into the Central Plains will push a fairly
weak backdoor front into the area Thursday morning...with the
usual breezy conditions on west-facing slopes. Maximum temperatures will only
be held back into the lower and middle 60s for The Lowlands...with
mountains cooling back down to the 40s. However...a sharp upper
level trough currently west of -130 (longitude) will tap into
significant subtropical moisture as it slowly heads east.
Widespread showers will break out across much of Arizona/nm and northwest
Mexico Thursday night as upper level flow becomes increasingly
diffluent...moisture increases...and steep isentropic lift develops
behind the backdoor front.

With warm southwest flow aloft continuing...and the with the low-
level airmass behind the front not expected to be terribly
cold...snow levels will remain quite high as precipitation breaks out
Thursday night...around 7k feet in the sacramentos and 9k in the
Gila region. I have slightly lower confidence in snow levels for
the Gila as they may end up lower should precipitation break out a little
later in the evening.

Friday looks quite wet and the models and ensembles have been in
oddly very-good agreement on this fact for some time. GFS
ensembles indicate precipitable water values around 0.9 inches which is close to
the record for January climatology...and represents a +4 Standard
deviation event. Moderate rainfall amounts may lead to some
snow melt concerns in the Gila depending on where exactly snow
levels end up. Something to watch in the days ahead as the details
smooth out.

High probability of precipitation for Friday are moderate-high confidence given the above
parameters and model agreement. GFS and European model (ecmwf) suggest storm total
quantitative precipitation forecast of 1-2 inches for The Lowlands by Saturday morning...and up to
2.5 inches in the mountains...which would translate into very
heavy snowfall in the highest elevations (and likely a very wet
snow ratio given high snow levels).

Precipitation looks to be more showery on Saturday as main vortmax lifts
out but trough axis remains to our west. Low level easterly flow
briefly breaks down in the wake of the departing vortmax...but
then another push of very cold air comes in Saturday night.
Meanwhile our upper low will begin pushing south of the area.
There is some potential for lowland snow Saturday night into
Sunday but it looks like the cold air will be chasing the moisture
out with not much overlap between the two.

GFS and European model (ecmwf) diverge early-middle next week with the GFS trying to
bring the low and significant subtropical moisture back to the
north...while the European model (ecmwf) pushes the low more to the east and keeps
most of the moisture east of Big Bend. The latter solution is more
typical and favored for now. There is plenty of potential for high
impact weather in the medium range anyways!

&&

Aviation...
valid 27/00z-28/00z...
a band of showers will rotate northward around an upper low pressure
system off the Baja California peninsula and graze the Borderland with a chance
of rain showers tonight. 00z-06z: sct060 scattered-bkn120-140 bkn220-250
vcsh mainly west of Continental Divide. Winds northwest-NE 07kts.
06z-15z: scattered-bkn040-060 scattered-bkn100 broken-ovc200-250 with isolated 6sm
-shra bkn040 ovc080 mainly west of dmn-tcs line. NE wind 7kts. After 21z:
west-northwest winds 07kts sct050 sct100 sct250.

&&

Fire weather...
an upper low off the Baja California peninsula will spread more cloudiness over
the area today through Tuesday morning. It will bring a few showers
later this afternoon into Tuesday morning mainly west of the
Continental Divide. Any snow should be confined to the very highest
elevations. Another upper trough will move off the Pacific to the
Baja California Thursday afternoon...spreading more clouds and another chance
of showers. Showers will begin Thursday afternoon and continue
through the weekend. This system will start out with out with high
snow levels. A cold front will move in Saturday afternoon...bringing
snow levels down by Saturday night and Sunday. Some light snow could
fall as low as 4500 feet. Heavy snow is expected in the mountains
for this period...especially the Sacramento Mountains.

&&

Preliminary point temps/pops...
El Paso 44 68 41 70 41 / 30 0 0 0 0
Sierra Blanca 44 67 42 70 40 / 20 0 0 0 0
Las Cruces 41 64 37 68 39 / 30 0 0 0 0
Alamogordo 40 64 36 67 37 / 20 0 0 0 0
Cloudcroft 33 49 28 50 29 / 20 10 0 0 0
Truth or Consequences 41 64 39 65 38 / 20 0 0 0 0
Silver City 41 65 36 66 37 / 60 20 0 0 0
Deming 41 65 35 69 37 / 50 0 0 0 0
Lordsburg 40 66 36 68 38 / 60 0 0 0 0
west El Paso metropolitan 45 69 44 70 43 / 30 0 0 0 0
Dell City 41 68 35 70 35 / 10 0 0 0 0
Fort Hancock 44 70 43 73 41 / 20 0 0 0 0
Loma Linda 44 64 42 65 42 / 20 0 0 0 0
Fabens 43 67 40 71 39 / 30 0 0 0 0
Santa Teresa 42 66 39 69 39 / 30 0 0 0 0
White Sands hq 43 65 40 69 40 / 30 0 0 0 0
Jornada range 39 63 30 66 35 / 30 0 0 0 0
Hatch 40 67 34 70 37 / 30 0 0 0 0
Columbus 42 64 38 69 40 / 50 0 0 0 0
Orogrande 42 65 38 68 40 / 20 0 0 0 0
Mayhill 39 62 37 63 36 / 10 10 0 0 0
Mescalero 35 55 31 56 31 / 20 10 0 0 0
Timberon 40 58 37 59 36 / 20 10 0 0 0
Winston 38 60 38 61 35 / 30 10 0 0 0
Hillsboro 43 62 40 64 39 / 30 10 0 0 0
spaceport 39 65 36 67 37 / 30 0 0 0 0
Lake Roberts 37 61 34 63 33 / 50 20 0 0 0
Hurley 39 63 36 65 36 / 60 10 0 0 0
cliff 39 67 33 68 34 / 60 20 0 0 0
Mule Creek 35 63 29 64 31 / 60 20 0 0 0
Faywood 42 63 39 65 39 / 60 10 0 0 0
Animas 39 69 34 70 37 / 60 0 0 0 0
Hachita 39 68 33 70 36 / 50 0 0 0 0
Antelope Wells 38 68 33 70 37 / 60 0 0 0 0
Cloverdale 41 67 36 69 40 / 70 0 0 0 0

&&

Epz watches/warnings/advisories...
nm...none.
Texas...none.

&&

$$

25-hardiman / 20-novlan

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