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Area forecast discussion 
National Weather Service Albuquerque nm
1054 PM MST Tuesday Jan 27 2015

06z taf cycle
VFR conditions to remain the rule the next 24 hours. Moisture
trapped in the low levels will be significant enough across parts
of northwest and west central nm...mainly along and a little ways either
side of The Divide...that a few pockets of MVFR ceilings and even fog
may develop between about 10z and 16z Wednesday. These rather localized
conditions not expected to impact any taf sites. Moderate to
strong down slope flow off the central Montana chain tonight will dry
the atmosphere a little more across the eastern third to half of
nm keeping low ceilings out of the picture there. Some localized gusts
could reach 35 to 45 kts across and up to about 50 miles east of
central Montana chain between roughly 08z and 20z Thursday.



Previous discussion...256 PM MST Tuesday Jan 27 2015...
a couple more good warm days across New Mexico will keep to a
rapidly wet and snowy ending from Thursday night through much of
the a slow moving Southern California and Arizona
storm pushes much moisture over a much colder state. Snow will be
widespread and in large quantities for Friday and Saturday...with
snow coverage gradually shifting southward on Sunday as a round of
much colder air penetrates New Mexico from the Central Plains
states. Windy conditions in the wake of snow Monday will ease up
on snow over northern Mexico begins an eastward trip
back into the southern U.S.


currently...weak flow aloft gradually becoming widespread through
this dome of surface high pressure remains plastered
over The Four Corners region and much of northern Arizona. Trough
extending from the Canadian prairies in southern Saskatchewan
across the plains states to the Texas Panhandle provides one
border to the east of the surface high...while weak surface low
pressure sits over the eastern tropical Pacific Ocean near Baja California
California and the Southern California coast. reasonable agreement through the upcoming
weekend...with some differences in pattern evolution from late
Monday Onward of next week. Good start breaks down ridge over New
Mexico through tomorrow...leaving entire state in broad zonal flow
as upstream trough across the eastern Pacific draws ever closer to
the U.S. And Mexican west coasts. Trough will strengthen and drift
slowly eastward to lie from the bitteroot and Sawtooth Mountains
of Montana and Idaho southward across all of California to the
Pacific waters off the Baja California California coastline by Thursday
night. Set up this way...with broad and moist push of atmosphere
northward and splattered across all of New Mexico...the storm core
will remain over southwest Arizona through Saturday morning...and
then over Sonora and much of northwestern Mexico by Sunday
morning. Flow aloft over New Mexico will shift to northwest on upstream ridge extending from the Pacific Ocean to the
Great Basin area flops solidly southward across New Mexico by late
Sunday...and underlying trough starts to lengthen to the southwest
and lies from central Oklahoma across southeast New Mexico to the
southern tip of the Baja California peninsula by late Sunday. Models
differing by late European colleagues with European model (ecmwf) show
northern Mexico trough starting substantial eastward journey to
south Texas by midweek...while domestic GFS simulation locks
progress up to near zero with closed low over the West Texas Big
Bend country and neighboring Chihuahua in Mexico. Can still keep
these differences split for now...with key issue the strength of
northwest flow over New Mexico to the north heading into the
middle of the week. Will keep an eye on this one for better
agreement in future runs.

Overnight...another warm overnight period the wake
of an otherwise warm day. Off chance for some very isolated shower
coverage over the western high country from the Arizona line to
the Continental Divide...and over northwestern border of the state
with southwest Colorado. Warm temperatures will keep all but the
highest spots in rain...with very little accumulation in very high
country snow.

For Wednesday...last of the good solid warm days across New
Mexico...with the east 8 to 15 degrees above normal...and the west
5 to 12 degrees above in a day with some hazy cloud cover
developing west and north...but quite clear to the east and south.
Flow aloft will veer from southwest to zonal by Wednesday surface pressure gradient tightens slightly between
Great Basin high pressure and Central Plains Missouri River valley
low. Surface winds will run northwest in general...with breezes
along summits and slopes of the sangre Delaware cristo and Central
Mountain chains...and along eastern half of Interstate 40 and
points south through late Wednesday afternoon. Cloudiness
continuing gradual increase...especially in the west...through
Wednesday night into Thursday morning.

For Thursday...Leading Ridge core from West Texas across New
Mexico to Yellowstone National Park in northwestern Wyoming will
allow broad penetration of colder air out of the northern plains
states to eastern and central New Mexico early on Thursday. Double
digit drops in temperatures over the east will bring daytime highs
to a few degrees below late January normals...with somewhat
reduced drops on tap for the west keeping temperatures single
digits above normal. Flow aloft starting to shift southwesterly
and loaded with moisture through Thursday afternoon...with
isolated shower coverage getting a late afternoon start over the
western and southwestern mountains...and over the sangre Delaware cristo
and Central Mountain chains heading into early Thursday evening.
As central action of the trough moves solidly inward Thursday
night...rain and snow will become widespread and heavy at times
statewide...with heaviest snow amounts mainly over the western and
central mountains south of Interstate 40. Will be expecting broad
round of winter weather watches for Thursday night in future
forecasts...and will introduce this idea with another round of
special weather statements to make sure folks get the word.

For Friday...storm core sprawled over Southern California and
western Arizona...with northbound circulation blasting across New
Mexico as eastern cold front slams westward through the day.
Widespread snow and rain will run across the state through the day
and Friday evening with wet sloppy snow accumulations remaining
part of the forecast for all but the northern low country...and
the Rio Grande Valley to the south. Weather hazard statements will
undoubtedly continue through Friday evening and on toward
Saturday morning.

Outlook...weekend through Monday...weakening cold front Saturday
as storm core moves to southern Arizona and northern Sonora...and
moisture remains a major player through the day. Next southbound
cold push will slam southward on storm core shifts
southward to southern Sonora and out of Arizona and New Mexico.
Cold front invading from the north will shape up over southern New
Mexico Sunday night...with precipitation coverage forced to the
southern third of the state as the weekend winds up...and points
to the north running colder but clearer heading into Sunday night.
Ridge core from the eastern Pacific will expand rapidly eastward
across New Mexico on storm core drifts even further
south across the Gulf of California to the southern tip of the
Baja California peninsula. Surface low will deepen very rapidly from eastern
Colorado to northeast New Mexico and the northern Texas
Panhandle...returning breezy westerly winds Monday over the
eastern plains along and south of Interstate 40.



Fire weather...
ventilation will improve the next couple of days and lead into a
fairly robust and moist/long duration wetting event Thursday night
through Saturday. Confidence is pretty high for this wetting event
although confidence is much lower in terms of snow accumulation
levels and type of precipitation during various stages of the event.
It becomes the battle of moist/subtropical air from the south and a
back door cold front from the north.

Drier conditions will return on Wednesday. A broad ridge will be
over the area but the wind flow aloft will increase. Mixing heights
will also increase thus leading to an increased ventilation rate
regime. Poor values still show up for maximums but not nearly as
much compared to the past few days. Surface temperatures will remain well
above normal. Interesting drying phenomena could impact the sangre
Delaware cristo range and areas to the east of the range due to a
combination of dry slotting aloft and mechanical mixing at the
surface. The surface wind flow will most certainly increase over the
higher ridges of the central mountains tonight and could drag drier air
down to the surface across the lower elevations on Wednesday. Only
one model shows this surface drying to the Lee of the sangres.
Decided to go with this model despite the lack of consensus. Thus relative humidity
forecasting will be tricky across the northeast Highlands and
plains. Otherwise...relative humidity values look to be near seasonable if not a
little above seasonable values.

Thursday still appears to be the transition day. The initial back
door cold front will push into the area Wednesday night into
Thursday. Much cooler air and lower dew points will following the
cold front at the surface. At the same time...the air aloft will
gradually warm as ridging develops out ahead of the next Pacific
low. A long duration wetting event is setting up for the Thursday
night through Saturday night period. Ventilation will improve some
on Thursday due to an increase in transport winds. The flow will be
more east/southeast though. Ventilation on Friday should be reduced
with the higher values favoring the western tier. Quite a messy and
tricky precipitation type forecast remains for this period.
Different levels of the atmosphere will see moistening/drying and
thermal changes at different time frames during the event. Plan

Drier weather is depicted by the Middle Range models for the Sunday
period as the upper low digs further south over Mexico and the Baja California
area. Models have varied somewhat the past few days on this
particular solution although there has been some consensus the past
1.5 days. This cut off low will be watched closely for any sort of
impacts to the area early next week but at this time the long range
models show this particular low as being a non factor. The European model (ecmwf)
model shows a Pacific wave from the northern branch of the jet clipping
the area by the middle of next week. Lots of uncertainty exists for
the early next week time period...especially in terms of
ventilation/temperature and precipitation trends. The European model (ecmwf) model would
indicate better ventilation rates than the GFS. The GFS is used to
populate our gridded vent rate forecast between days 5 to 7.



Abq watches/warnings/advisories...



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