Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albuquerque nm
1150 am MDT sun Aug 2 2015
18z taf cycle
abundant moisture associated from placement of the upper high
over southern portions of the state will continue to fuel afternoon
scattered to numerous rain showers and thunderstorms and rain across western and central New
Mexico. Convective coverage will peak from 18z to 00z. Storm
motion will be mainly west to east...but slow moving and erratic
at times. Look for brief periods of MVFR/IFR ceilings/occasional mountain
obscured for sites impacted by strong to possible severe
storms...following heavy rain and gusty winds near 40kt from
Previous discussion...326 am MDT sun Aug 2 2015...
today will be yet another day of very high atmospheric moisture
content across New Mexico...and as temperatures rise the
atmosphere will become unstable with periodic redevelopment of
scattered to numerous showers and thunderstorms. Many storms will
be capable of producing locally heavy rainfall again with a
continued threat for flash flooding in localized areas.
Finally...into Monday drier air will begin filtering into New
Mexico from the west...shunting the best probabilities for
precipitation to the east with much less overall storm activity.
This drier period is expected to last through the middle part of
next week with fewer storms and warmer temperatures.
While yesterday's abq balloon sounding revealed a slight reduction
in precipitable water at 1.03 inch...analyzing radar storm totals
indicates that the footprint of rainfall yesterday and last
evening was still fairly widespread over much of the forecast
area with hefty totals of one to two inches being common.
Forecast models show the precipitable waters remaining above average today...and
the NAM actually reveals some impressive values of 1.3 to 1.5 this
afternoon over many central zones...including the Albuquerque
metropolitan area. This coupled with the antecedent wet conditions and
saturated soils has prompted the issuance of yet another Flash
Flood Watch for a large chunk of the forecast area...roughly the
northwestern half or so. Other synoptic features of note will be
the consolidation of the upper high over southern nm and a speed
maxima working into western parts of the state where 300 mb winds
are projected to reach almost 40 knots. This speed maximum could vent
storm updrafts...making them a bit more efficient while also
introducing some divergence aloft that would enhance synoptic
scale upward motions. Storms should propagate from the SW to NE or
west to east for the most part...except in the north central to
northeastern zones where motions will be a bit more erratic and
slow. Otherwise temperatures will be fairly seasonable...running
just a few degrees below average in the western zones.
Into Monday the pronounced dry slot aloft that is currently
working inland off of the eastern Pacific will be spreading east
toward nm. This will quickly lower dewpoints and precipitable waters in the
western zones Monday...limiting storm potential substantially from
the trends of the past several days. Still some isolated to
scattered storms will be possible...but should be more focused
toward the Central Mountain chain and to a lesser extent the
eastern plains of nm.
The drying trend continues into Tuesday...and storm coverage will
continue to dwindle as the dry air filters into remaining eastern
zones of the forecast area. Probability of precipitation have been ratcheted down over the
past few shifts...and some minor tweaks down were also carried out
for this current forecast package. With the drier air filtering
in...temperatures will observe larger diurnal swings...first in
the west Monday and Monday night...then into remaining zones
By the middle of the week the drier air will still be in place
while the dome of high pressure centers up squarely over nm with
heights rising to the 594-595 decameter range. This will suppress
convection...but some isolated storms will still be able to fire
over high terrain areas. High temperatures will creep up a few
Into Friday an upper trough will move off of the Pacific into California.
This feature has been shown to be somewhat disconnected from the
polar jet the past few model runs...keeping a slower and farther
south track. This would be favorable for shoving the dome of high
pressure east of nm while drawing subtropical moisture northward
from the Sierra Madre Occidental and ultimately increasing
thunderstorm activity into the weekend.
Based on water vapor imagery...upper high center located over
south central New Mexico early this morning...with abundant
moisture lingering over the region. Cell motion today should be
mainly towards the east...although some slow and erratic motion
possible. Potential for locally heavy rainfall again
today...especially northern and western two thirds of the state.
Models continue to insist on a drier and warmer trend...and are even
more bullish with lower dew points spreading across the west and
north Monday and Tuesday. Did not totally buy into the degree of
drying projected on Monday...given the deep moisture currently over
the far west...but Tuesday seems more reasonable to trend more
toward the model forecast. Water vapor imagery does indicate drier
air to our southwest...but several disturbances and less dry air
queued up west of California. The disturbances are currently forecast to
ride over the ridge and to our north...but the size of the dry slot
appears to be shrinking a bit at this time so will continue to monitor. If
current model trends persist...only isolated convection anticipated for
the west Monday...and for most of the forecast area Tuesday through
Wednesday. With the drier air will come highs near to above average
and a forecast of high Haines. Winds should remain relatively light
though with min relative humidity values mostly above 15 percent and good overnight
Return of monsoon moisture still on tap for late this week and
through the weekend. Drier westerlies could resume early next
week...with the GFS suggesting a stronger trough passing through the
northern rockies than the European model (ecmwf).
Some areas of fair to poor vent rates north and east today and
Monday with improvement overall Tuesday and Wednesday forecast.
Flash Flood Watch through this evening for the following zones...