Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albuquerque nm
1132 am MDT Thursday Jul 31 2014
18z taf cycle
upper ridge axis stretched from central Arizona to south central nm
with generally northwest flow aloft over northern and central nm.
Low level easterly gradient to persist over the region. Areas MVFR
ceilings with isolated embedded IFR ceilings/visibilities in br obscuring terrain
from the east slopes of the central Montana chain to the Texas border to
gradually improve through 22z. Best instability before 00z to exist
over western nm...where scattered thunderstorms and rain surface wind gusts to 40kts expected to
develop and occasionally obscure mts. Steering flow would take
this activity into the Rio Grande Valley after 21z. Thunderstorms and rain/rain showers may
possibly advect/develop over portions of the east after 00z...and
expect redevelopment of MVFR ceilings/visibilities in br after 03z east slopes
central Montana chain.
Previous discussion...747 am MDT Thursday Jul 31 2014...
with precipitable waters ranging from 1 to 1.5 inches...and a slow moving
disturbance sinking south and southeastward across Colorado...we
reconsidered the flash flood potential. Antecedent moisture is
present in places like western San Miguel County and along the
east slopes of the central mountains...where locally heavy rain fell
yesterday. Further...the Southwest Mountains had some rain
overnight...so places like the White Water Baldy burn scar should
produce rapid runoff with any precipitation that falls today.
Decided to issue a Flash Flood Watch for the western mountains
east of the Continental Divide and south of the Rio Chama...and
also for the southern sangres...central mountains and adjacent
Highlands. Since convection is expected to drift slowly toward the
south and southeast...added the west Central Highlands and Santa
Fe area...too. Storms should become most widespread during the
afternoon across the western mountains...since they are starting
off with less cloud cover. Western storms should also benefit from
some residual easterly upslope flow lingering from yesterdays
back door cold front. In contrast...the upslope flow...associated
low clouds and temperatures several degrees below normal will slow
the start of convection across the north central and central
mountains. Models do agree on some quantitative precipitation forecast bulls eyes here during the
evening and overnight...apparently keying on some late day heating
and gradually improving forcing aloft with the approaching
disturbance over Colorado.
The Flash Flood Watch may need to be expanded to the northern
sangre Delaware cristos...south central mountains and their adjacent
Highlands/High Plains. This will depend on the dissipation of low
clouds and convective debris clouds lingering from last nights
Previous discussion...348 am MDT Thursday Jul 31 2014...
daily rounds of scattered to numerous showers and thunderstorms
are expected each afternoon and into the night time hours through
the weekend. A robust monsoon moisture plume is expected to stream
northward over central and western parts of New Mexico as a
subtropical low drifts slowly northward west of New Mexico...then
eastward north of New Mexico. Thunderstorms will be capable of
producing locally heavy rain with a risk of flash flooding. Except
for some near normal readings west of the Continental Divide
today...high temperatures will generally vary from a few to 14
degrees below normal each day.
considered issuing a Flash Flood Watch for today...but couldnt
muster enough confidence due to concerns about how cool it will be
along and east of the Central Mountain chain and about the amount
of convective debris clouds likely to linger over central and
southeast areas well into the day. Post frontal high temperatures
should only reach the 60s to middle 70s today across the sangre Delaware
cristos and northeast Highlands...where models are generally
agreeing on some of the better quantitative precipitation forecast. Chatted with National Weather Service Pueblo and we
decided to let the day shift re-assess the situation based on the erosion
of debris clouds and updated model runs. At this time it looks
like the Southwest Mountains may have the best chance of flash
flooding during the afternoon due to more sun...warmer
temperatures and slower storm motions there. The risk for flash
flooding may then shift to the east slopes of the northern and
central mountains as a slow moving disturbance aloft shifts closer
to NE New Mexico from north Colorado in northwest flow aloft.
The upper high is prognosticated to shift from SW of nm today to northern
nm and Colorado by Saturday night as the subtropical wave shifts
northward out of the Gulf of California. After the subtropical moisture
plume crosses this weekend...some drier air is forecast to shift
over nm from the southwest around the base of the wave as the
system crosses the central rockies. This should result in a
noticeable downtick in convection Monday and Tuesday...though
there should still be scattered to isolated cells around. Models
then depict the subtropical wave dropping southeastward over NE
nm as an upper level trough and back door cold front Wednesday and
Wednesday night. This could be another period of heavy rain along
and east of the Central Mountain chain.
upper level high pressure...currently positioned over southern
Arizona...will drift about over the next several days. Moist
southeast to south low level flow and an active monsoon plume over
eastern Arizona and western New Mexico to persist through at least
the weekend. Thus...wetting rain is a good bet for most areas...with
the extreme northwest plateau least favored. Early next...wetting
rain looks to favor the higher terrain with drier conditions across
the east but an upper level disturbance and possibly a back door
front into the east could shift the focus to the eastern plains by
Temperatures to remain below seasonal normals through the period.
Ventilation will be poor to fair most areas today except for the
extreme west with little improvement on Friday. For the weekend...
ventilation rates improve across the east on Saturday and across all
zones by Sunday.
Flash Flood Watch through late tonight for the following zones...