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Area forecast discussion...updated 
National Weather Service Albuquerque nm
538 PM MDT Wednesday Aug 27 2014

Aviation...
00z taf cycle
closed upper low center over northwest Colorado with mainly dry westerly flow
aloft over northern and central nm. Isolated -shra/-tsra expected
through around sunset. Best chances for afternoon and early evening
convection Thursday will be from the Tusas Mountains east to the sangre
Delaware cristo mountains east to NE Highlands and NE plains...possibly
impacting klvs around mid-afternoon. Elsewhere Thursday...scattered cumulus
clouds along with breezy northwest and west winds anticipated by late
morning/early afternoon.

33

&&

Previous discussion...331 PM MDT Wednesday Aug 27 2014...
synopsis...
a deep low pressure system is slowly moving out of Utah and into
Colorado...steering the best plume of subtropical moisture to
farther east. As drier air steadily arrives from the west...the
best chances for precipitation will linger over south central and
eastern sections of New Mexico with only isolated storms
elsewhere through the evening. Temperatures have been slightly
below average in much of central to western New Mexico with
eastern parts of the state hovering close to normal for late
August. As the low pressure system continues on its track eastward
Thursday...a front will push into northeastern New Mexico where
only slightly cooler temperatures will be found with lingering
showers and thunderstorms. Any showers and storms will favor areas
along and east of the Central Mountain chain of the state on
Friday with only isolated storms expected Saturday.

&&

Discussion...
a dry slot can be seen on water vapor imagery...rounding the base
of the upper low trekking eastward into Colorado. This has already
translated into a drying trend in the precipitable water values
while partly impeding the ability for storms to go up over New
Mexico. Thus...cells have stayed very few in number thus far...but
there still is some potential for the south central mountains and
The Lowlands/plains eastward to see some healthier storms with
better rainfall efficiency as precipitable waters are still hanging on to 1-1.3
inch values in this quadrant of the state. This is where highest
probability of precipitation will be through the evening...falling off to just isolated
coverage after midnight.

Forecast models sill indicate that the upper low will begin fill
in with higher pressure heights...and open into a wave over
eastern parts of Colorado/nm by Thursday. Wrap-around northwest flow along with
a surface wind shift will usher in slightly cooler air with some
deeper moisture confined close to the trough axis. Thus...the best
rain chances will shift along and east of the sangre Delaware cristos
Thursday.

Probability of precipitation were increased slightly in the eastern zones on Friday...to
account for a return flow off of the Gulf of Mexico...keeping
sufficient dewpoints and boundary layer moisture intact along with
an upslope wind component. Otherwise...westerly winds aloft will
generally turn much lighter into Friday...especially in the
western half of the state...as a new dome of high pressure
establishes itself near the Gulf of California. Also...the drier
airmass in the western half of the state will inhibit storm
development west of the Rio Grande. Friday night the NAM model
actually gets quite bullish with a nocturnal moisture push amidst
the southeasterly surface flow in eastern nm. It even advertises
cape values soaring to 2000 j/kg overnight. Have kept probability of precipitation
isolated for now...but these may need to be boosted if this trend
continues.

We have also raised the probability of precipitation some on Saturday...staying in the 10
to 20 percent range...but covering a fairly large majority of the
forecast area. Through this time the aforementioned dome of high
pressure then will be trying to take up residence near nm...but it
appears the westerlies will make a stand...basically the result of
a more active storm track and subtle Equator-Ward shift in the
polar jet. This will pose difficulties for forecast models. All it
will take is just a slight relaxation in westerlies over the
central rockies allowing subtropical moisture to creep back into
nm. For now forecast has sided on the mostly dry side...but it
will be difficult to keep up with Sunday through Tuesday.
Thereafter the high is shown to become better rooted over the MS
valley with a deepening low pressure area potentially forming near
the Pacific northwest states.

52

&&

Fire weather...

Isolated to scattered showers with wetting rain will continue this
evening from the Central Mountain chain eastward...ahead of an
approaching upper level trough. Look for breezy conditions across
the northeast plains through the rest of the afternoon before
transitioning to the higher terrain of the sangre Delaware cristos
tonight. Lower humidity will filter into the area tonight and reduce
maximum recoveries.

The drier conditions will continue favoring western and central New
Mexico on Thursday. The upper level low will continue to slowly move
eastward over central Colorado toward the Central Plains. Expect
wetting rain chances and cooler temperatures for areas east of the
sangre Delaware cristos because of a back door front...otherwise
temperatures will gradually warm elsewhere. Expect breezy winds
across the northwest as well...especially favoring areas along a
line from Farmington to Clines Corners.

Friday going into the weekend...temperatures will continue to warm.
High temperatures will be near normal on Friday but trend upward and
generally be above normal during the weekend. On Friday the best
chance at some showers...most likely lighter precipitation amounts
would be found over the northern sangre Delaware cristos. Some lighter
shower/thunderstorm chances remain Saturday across the far east on
Saturday. Another Pacific trough will impact The Rockies region on
Sunday and drag drier air aloft over most of the area. Perhaps some
residual low level Gulf moisture across the southeast/east Central
Plains. This trough will bring breezier conditions pretty much
areawide. Pretty noticeable. Higher confidence for this scenario
based on past and current model trends.

Models tend to agree on a ridge pattern building over the region early
next week following the trough passage. Temperatures would warm and
humidity values would initially be seasonable if not below normal or
dry for this time of year. A middle level dry intrusion will need to be
watched during this scenario in terms of how low to go with surface
dewpoints and humidity. The models begin to diverge midweek and
mainly differ how quickly they bring monsoonal moisture back over
the area. The European model (ecmwf) is more bullish or quicker than the GFS. Either
way...the European model (ecmwf)/GFS depict a similar overall pattern. Too early to
say when the wetting rain potential would become significant but
expect by late next week. The wind pattern should be fairly light
during the earlier half of the week but as thunderstorm potential
grows...so will the downdraft/outflow wind potential.

32/50

&&

Abq watches/warnings/advisories...
none.

&&

$$

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