Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Albuquerque nm
445 am MST sun Dec 21 2014
12z taf cycle
northwest flow and thick high cloud cover will increase over the
region today ahead of a potent upper level jet stream. An area of
middle level clouds near 070 stretching from kfmn to kgup...kabq...
and ksaf will shift southeast and slowly dissipate by early
afternoon. Northwest wind gusts up to 40 kts will impact the area east of
the Sandia/Manzano mts...then focus along the east slopes of the
sangre Delaware cristo mts tonight. Flurries or light snow showers will
develop along west slopes of the northern high terrain this
afternoon and overnight...creating Montana obscurations. Monday will be
a much more active day across the state.
Previous discussion...341 am MST sun Dec 21 2014...
northwest winds will strengthen today and especially Monday as the
jet stream moves overhead. In east central areas gusts should peak
around 50 miles per hour today...then potentially around 6o miles per hour on Monday.
Locations west and northwest of the central mountains will also be
breezy to windy Monday. A strong cold front will plunge southward
into the state Monday with falling temperatures during the
afternoon north of Interstate 40. An upper level trough will also
deepen as it crosses Monday and Monday night...producing easterly
upslope flow that will favor the northern mountains...northeast
areas and east central areas for a few inches of snow
accumulation. Several inches will be possible along the higher
peaks and east slopes of the sangre Delaware cristo mountains. Tuesday
will be a cold day with highs only in the 30s and 40s at lower
elevations and some lingering light snow along and east of the
Central Mountain chain.
models are bringing in the front faster and stronger Monday. Went
below consensus guidance on the plains for temperatures...though
this was risky since highs will come early in the day in many
places. Rain should change to snow across much of the northeast
Highlands and plains by late Monday afternoon. The earlier arrival
of the front resulted in more of an easterly upslope flow
component to the surface winds as the upper trough crosses Monday
night. Models are also in good agreement on decent quantitative precipitation forecast from the
sangres southeastward to around Clovis...where many areas should
receive a few inches of snow. We will have to watch that the
sangres dont come in with warning amounts...which they could if
the systems dwell time lengthens at all. Further...the depth of
the system now looks deep enough for the San Juans and Jemez
Mountains to squeeze out a few inches of snow.
Around the base of mondays upper trough a speed maximum in the polar
jet stream will cross from our northwest corner to our southeast corner. It
should arrive as early as Sunday with speeds around 45 knots at 700
mb. The 700 mb flow is expected to peak Monday afternoon with
speeds in the 50-70 knots range. Buoyant mixing ahead of the front
and mechanical mixing with the cold front could enable some
potentially damaging wind gusts to reach the surface
Monday...especially along and just east of the central mountains.
Also...strong north winds will be possible behind a back door cold
front Monday night and into Tuesday across the far eastern plains.
Winds should weaken late Tuesday and Wednesday...only to
strengthen again on Christmas day as west winds aloft strengthen
and a sharp Lee trough develops ahead of another upper level
trough that will cross the central rockies Thursday night and
Friday. The latest GFS and European model (ecmwf) runs weakened this trough
some...so its main impact may only be scattered to isolated
showers favoring northern areas. Behind it on Friday night and
Saturday...a secondary upper trough is now slated by both models
to track southeastward over the area. This one looks to be
preceded by a somewhat dry back door cold front that will provide
easterly low level upslope flow as it crosses. However...moisture
may be too limited for significant snow accumulation.
Much colder temperatures will be likely at the end of the week
and into next weekend.
surface winds will increase today over many areas as a potent
upper level jet axis approaches from the Great Basin. Ridge top
and east slopes are gusting to near 35 miles per hour...and this will
increase over the High Plains late this morning. Temperatures will be
above normal again for today but min relative humidity values plenty high...so no
issues expected for fire weather. Vent rates are also improving
over the past several days with most areas in the good category.
Enough middle and upper level moisture streaming out ahead of the
Pacific jet will force a few snow showers along west slopes of the
northern mts...with little to no snow accumulation expected.
The nose of the upper jet will spread closer to northern nm tonight.
Windy conditions will continue along the immediate east slopes of
the sangres through sunrise. Temperatures will remain well above normal all
areas. Widespread breezy to windy conditions will then impact just
about everyone Monday and Monday night. High winds are possible for
areas from the southern sangres to the Sandia/manzanos into the High
Plains. Min relative humidity values will remain above 30 percent all areas. Temperatures will
begin to fall during the day as strong cold advection approaches
from the northwest. Again...enough moisture and forcing will be
present for a few snow showers along west slopes of the northern mts.
Ventilation through this period will improve to excellent for most.
Changes continue to trend toward a stronger and more moist storm
system Monday night and Tuesday across northern and eastern nm. A
back door front will slide down the plains and force a band of snow
over the plains...most likely from the sangres southeast to near
Las Vegas and Clines Corners then the east Central Plains. Light
snowfall accumulations are likely...with blowing snow and much much
Tuesday will be very chilly with below normal temperatures and breezy winds
continuing. Wednesday will transition back to deteriorating vent
rates with lighter winds. Upper flow will begin to back from northwest to
west through Thursday ahead of the next storm system. Overall little
change was made for Thursday through the weekend with low forecast
confidence on models. It does appear cold temperatures will continue over
the area...with at least increasing winds all areas and some light
snow over the northern high terrain.
Wind Advisory from 10 am this morning to 8 PM MST this evening for
the following zones...nmz523-533-539.