Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Albuquerque nm
1041 am MST Wednesday Jan 28 2015
18z taf cycle
VFR conditions to continue through taf period...though some lower
of cloud decks is expected across SW to western portions of area. Lee
side troughing today will weaken through this afternoon east of the
central mts...though gusts up to 40kts will be possible near kcqc.
A backdoor cold front will slide down the plains this evening and
push through the gaps of the central mts by Thursday morning. Gap
winds will be strongest near kabq...with gusts up to 30kts. Cloud
coverage will increase south to north through the day Thursday.
Previous discussion...347 am MST Wednesday Jan 28 2015...
an upper level disturbance will pass eastward across the central
rockies today. This feature may induce a few stray showers over
the northern mountains of New Mexico while also bringing some
breezy to windy conditions along and east of the Central Mountain
chain of the state. Otherwise...today will be the last day of
temperatures exceeding seasonal averages...as a cold front
will plunge into New Mexico on Thursday. Temperatures will fall
short of normal over most of New Mexico Thursday while a
significant upper level trough moves over the eastern Pacific
waters toward the Gulf of California. This trough will become
better organized into a low pressure system that will draw copious
amounts of subtropical moisture into New Mexico Thursday night
through Saturday. Widespread precipitation will ensue during this
time frame with snow accumulations becoming significant at
elevations higher than 9000 feet.
very interesting forecast shaping up for Thursday night through
Saturday...one that tickles the fancy of any true weather geek.
But prior to the onset of this upcoming storm system...Wednesday
will be defined by a final round of above normal temperatures. The
remnants of yesterday's low worked into Nevada...and has now
shifted east as an open short wave trough that will track across
the central rockies. A stray shower over the northern nm mountains
could be possible today and tonight...but unlikely. Some stronger
momentum aloft will hit the sangre Delaware cristos and central
mountains of nm as a Lee side surface low migrates into the
Central Plains of the nation.
Tonight the cold front will spill southward into nm...giving a
bookend on the recent stint of above normal temperatures.
Initially the surface high will Orient itself north of nm...giving
many locations a north northeast wind component tonight.
However...as Thursday unfolds the surface high will shift into the
Central Plains of the nation...setting up a widespread synoptic
easterly upslope flow into the eastern half of New Mexico while
driving a gap/canyon wind through many central areas prone to this
scenario of gusty winds. At this point...wind forecast has been
kept below advisory criteria for abq/saf metropolitan areas and other
favored gap/canyon wind locales...but this will be monitored
closely and revised as needed. Precipitation will just begin
taking development late Thursday...driven by upslope and
frontogenetical forcing along the east faces of the Central
Mountain chain...and also to a lesser extent on the east faces of
the Continental Divide. By late Thursday the Pacific trough will
still have its axis located just east of the Baja California peninsula...and
diffluent flow will just be starting to arrive into nm.
As Thursday night progresses the trough will deepen into a low
over the San Diego/tijuana vicinity with a healthy tap into deep
subtropical moisture taking place in the warm sector on the
eastern periphery of the low. Already the total precipitable water
product from NASA sport satellite imagery reveals juicy precipitable waters of
1.8 inches in this sector.. while this will certainly be modified
as it treks over the Mexican Mainland...am very optimistic that
moisture will be copious and easily transported into nm. In fact
the NAM model indicates that precipitable water values will rise to 0.65 inch
over central nm by Friday...which would be 3 Standard deviations
above normal and near record values. Precipitation probabilities
are thus very high...beginning in the southwestern zones of the
forecast area Thursday evening and spreading northeastward toward
daybreak Friday. The Fly in the ointment will be temperatures and
boundary layer moisture/dewpoints. Currently the 700 mb temperatures
are prognosticated to be at only 0 to -1c over much of the Gila...likely
relegating snow accumulations to elevations above 9000-10000 feet
or so Thursday night. Temperatures aloft will be cooler farther
northeast near the sangres/northeast Highlands...but the onset of
heftier precipitation will be delayed by 12-18 hours there. Many
lower elevation areas below 7000 feet Thursday night will likely
only see brief mixing of snow with rain...and accumulations may be
hard to come by...especially if dewpoints rise above
freezing...impeding the wet bulb effect. Precipitation shadow may
be in effect for abq metropolitan area Thursday night...but should fade
into Friday as the dynamics aloft and copious moisture overcome
the east wind.
By Friday and Friday night the precipitation event will be fully
underway as the low moves sluggishly eastward along the Arizona/Sonora
border. This will keep a healthy slug of divergent flow aloft over
nm with the subtropical hose continuing to saturate nm. Confidence
in steady moderate to occasionally heavy precipitation is very
high in this scenario. The challenges will by precipitation type
outside of the mountains. Colder air will be found in northeast
Highlands and to an extent the far northeastern plains...where
some snow have more likelihood of falling through cooler and more
supportive boundary layer temperature/dewpoint profiles. Inability
for profiles to wet bulb below freezing could hamper many east
central to southeastern plains...as well as many of the central to
western valleys. Thus...some accumulations may occur in the late
overnight periods to early mornings...but will likely melt/settle
as rain becomes predominant precipitation type during the daytime.
It will be a different story entirely in the
mountains...especially above 9000-10000 feet where one to two feet
of snow could be possible on the higher peaks.
Into Saturday the low jogs a bit farther southeast than was
advertised the past few days...courtesy of an earlier arrival of a
Canadian clipper. Precipitation would still be quite widespread
through the day Saturday across nm...however the steadiness and
heaviness might decline a bit. Into Saturday night the clipper
looks to win out...shoving the low back southward into old
Mexico...and essentially drying nm out considerably in
cooler/drier northwest flow. This will end the event a bit sooner
than was believed to be the case 24 hours ago...but nonetheless a
significant and long duration wet and snowy period for the state.
The drier northwest flow looks to prevail through the first half
of next week...before buckling to a longer wave trough. Northern
zones might be skimmed with some precipitation from this trough
passage...but the bulk of it looks to bypass nm.
high temperatures peak today then fall to below average Thursday
and Friday...then remain below average through early next week.
Dry weather today and tonight...with the exception of a few High
Mountain showers far north...then a widespread precipitation event
unfolds Thursday night through Saturday.
Much of the moisture will originate from the subtropics...so cold
air...or lack of...will be a factor in precipitation type. A cold
front remains on schedule to impact the eastern plains
Thursday...and models associate some drier dew points with this
feature...although evidence for this isn/T observed in upstream observation
just yet. However...all models pretty much on board with this
idea...so make some changes to inherited dew point grids. The drier
air in the boundary layer may affect snow levels before dew points are
forecast to increase again Friday. Still...it appears cold enough
for significant High Mountain snow accumulations late this week.
Gusty east winds into the rgv may be sustained Thursday through
Friday before tapering off Saturday. Model timing consistent with
the wind starting sometime Thursday morning but not so much when it
would slack off...the European model (ecmwf) terminating it faster...and the GFS
holding onto it longer into Saturday.
Another cold front Saturday night/Sunday will push much colder air
into the east and central...but by then the upper dynamics and
moisture will have exited to the south. GFS continues to attempt to
lift the upper system to the north/northeast...but the stronger northwest
flow aloft associated with the building ridge to our west shunts it
southward. A few last gasp showers will linger Sunday then dry
weather expected for early next week.
Vent rates remain fair to poor much of the north and west
today...and improve some Thursday. Poor rates will be widespread
Friday. A mixed bag of mostly fair to poor rates anticipated Monday
with improvement to good for most areas Tuesday in a west to northwest flow
aloft and Lee surface trough regime.
Winter Storm Watch from late Thursday night through Saturday
afternoon for the following zones...nmz502-506-508-521-526.
Winter Storm Watch from Friday morning through Saturday afternoon
for the following zones...nmz510>515-527.