Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albuquerque nm
1042 PM MST sun Dec 28 2014
06z taf cycle
strengthening west to northwest flow aloft through 29/18z. Surface low over
NE nm at 29/06z will sag southward through 29/18z. VFR with variable
amounts of high clouds...but could not rule out isolated MVFR/IFR
ceilings/visibilities in br where snow covers the ground mainly in a few northern
valleys before 29/12z. Arctic front with widespread MVFR/IFR ceilings
in it/S wake will be in vicinity of NE nm/southeast Colorado border by 29/21z.
Previous discussion...326 PM MST sun Dec 28 2014...
a back door cold front will usher Arctic air into New Mexico
Monday through middle week. The plains will experience subfreezing
temperatures for much of the week. The coldest day for eastern
areas will be Tuesday when claytons temperature may not rise out
of the single digits. The front will push through gaps in the
Central Mountain chain with a brisk East Canyon wind in the
Central Valley Monday night through Tuesday night. Easterly
upslope flow will also bring light snow accumulation from the east
slopes of the Central Mountain chain eastward mainly Monday night
through Wednesday. With the cold air in place...an upper level low
pressure system is then expected to cross from the west with the
potential for a broad area of significant snow accumulation
Wednesday night through Friday or Friday night.
with the early week back door cold front...models have slowed the
arrival of the coldest air into central areas until
Wednesday...when easterly upslope flow could even yield some
light snow accumulation along the east slopes of the western
mountains. Though the snow coming early through middle week will be
light...the very cold temperatures should allow it to stick to
surfaces and produce some potentially significant travel impacts.
Though they have also slowed the latter week system down
some...models seem to be agreeing better on the depth and track of
the upper low pressure system. There are still some differences on
timing and quantitative precipitation forecast amounts/positioning. Will issue an Special Weather Statement this
afternoon to explain potential impacts...which could be
significant due to widespread snow on new years evening and New Years
Day. Based on forecast soundings...there could even be some
freezing precipitation along and east of a line from Duncan to
Tucumcari Wednesday into Thursday morning making new years evening
significant middle level dry slot has brought relative humidity values into the teens
to upper single digits across the the southern Highlands and southeast
plains today. Much lower than expected although localized. This dry
slot will weaken and shift south/westward during the next 36 hours
but some impacts will remain over southern portions of the area Monday.
Tried to capture this in the gridded dewpoint forecast.
Nevertheless...cooler than normal temperatures will continue
although modify some on Monday. The gustier winds observed over the
higher terrain and areas to the east of the central mountains will lower
tonight although remain steady over the higher terrain. Mixing
heights will generally rise on Monday thus resulting in higher
transport winds and ventilation rates. Northeast and east central
areas will see lower rates due to the initial Arctic intrusion.
The Arctic blast...although becoming modified...will push westward
Monday night through Tuesday night. High temperatures on Tuesday
will be as low as nearly 40 degrees below normal across the NE
plains. Light to moderate snow is expected with the Arctic intrusion
and impact the east slopes of the central mountains and adjacent High
Plains...especially focused across the NE Highlands. Ventilation on
Tuesday will be varied but looking at lower readings overall
compared to Monday.
Weather models have slowed the upper level Pacific system. They are
placing the upper level low over Southern California Wednesday
afternoon versus the Las Vegas Nevada area the past two days. The system
still looks to be anomalously deep or cold. The initial heavier
precipitation associated with this wave should occur either late
Wednesday night or Thursday morning across the west. The heavier
precipitation...in the form of mainly snow...should transition
eastward Thursday night into Friday with the potential of some wrap
around snow Friday night into Saturday across portions of the area. The
European model (ecmwf) continues to show a weaker signature of liquid water from the
system than the GFS but wetting possibilities are very likely with
either solution. This appears to be a slow moving...high impact type
of system so stay tuned.
The Arctic airmass will have modified quite a bit between Wednesday
to Thursday as warmer/moist Pacific airmass moves northward ahead
of the upper low. Either way...afternoon temperatures should remain
below normal through the week. Ventilation appears to be the lowest
on Wednesday although improves across the far west due to the
proximity to the upper low. Rates will gradually increase
Thursday/Friday as the low moves over the area.