Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Albuquerque nm
1130 am MDT Wednesday Sep 2 2015
18z taf cycle
afternoon rain showers/thunderstorms and rain activity will be focused across the western and
northern high terrain...moving NE around 10kts. Thick cirrus will
delay initiation a bit...but a middle level disturbance located in
eastern Arizona will make sure storms develop. Regime setup points to
kgup and kfmn as best chances at least for thunderstorms in the vicinity with reduced
chances at other central nm sites. Thunderstorm outflow boundaries could
alter prevailing wind speeds/directions...and will determine
eastward extent of thunderstorm activity. Keeping thunderstorms in the vicinity at kabq and kaeg
with best chance window between 00z and 03z. Expect cloud bases to
lower across the west over the next 24 hours while broken cirrus
persists across eastern nm.
Previous discussion...321 am MDT Wednesday Sep 2 2015...
a much wetter pattern is on tap through Labor Day weekend as deep
moisture surges north ahead of a tropical storm developing in the
eastern Pacific. Temperatures will trend cooler with highs near to
slightly below average over much of the state. The most widespread
storms are expected Friday and Saturday with locally heavy rainfall
increasing the flash flood threat for western New Mexico. A back
door cold front will attempt to move into eastern New Mexico on
Labor Day...providing yet another focus for showers and storms
through next week.
the latest suite of surface observation...00z soundings...and satellite Observation
Point to highly favorable conditions for storms today and tonight. A
well defined upper wave over northwest Mexico is sliding north into western
nm/eastern Arizona. Surface dewpoints across southern nm indicate strong
moisture advection with many areas rising through the 50s into the
low to middle 60s. The latest Storm Prediction Center sseo/hrrr and local 5km WRF show a
robust area of convection firing up along the continue Divide today then
advancing east into the Rio Grande Valley and northwest nm tonight.
Raised probability of precipitation with higher confidence in these areas.
The NAM and GFS focus moisture transport and instability within a
700-500mb trough axis over western and central nm Thursday/Friday.
Naefs standardized v-wind and moisture transport anomalies average
between +1 and +2 over nm both days...increasing confidence that a deep
moisture tap will shift over the region. Wpc quantitative precipitation forecast for d1 to d3 have
trended up more with widespread 0.50 to 1.00 inch average expected.
Locally heavier rain will be likely. NASA-sport 0-10cm volumetric
soil moisture shows most favorable antecedent conditions for more
efficient runoff over the continue Divide and northern mts...elsewhere
it has been quite dry. Flash flood watches may be considered in
these areas...especially if today and Thursday provide impressive
An unseasonably strong 564dm 500 mb low taking shape within the Great
Basin through Saturday is shown to eject across the northern rockies by
Sunday. This will help force drier middle and low level air into at
least far western/northwestern nm Sunday. An even stronger 560dm
500 mb low then takes shape over socal while ridging strengthens over
Texas. This opens the door again with the GFS indicating a surge of
deep subtropical moisture into Arizona/nm Monday through Wednesday.
Meanwhile...a back door front moves south and west into eastern
nm. This could be another very good period for widespread storms.
The European model (ecmwf) is considerably drier through the entire forecast cycle so
confidence deteriorates for this secondary moisture tap.
satellite imagery early this morning depicts an upper level wave
over the Mogollon Rim. Models track this feature slowly
northeastward with scattered to numerous showers and thunderstorms
favoring west central areas this afternoon and tonight. An upper
level low pressure system will drop southward along the northwest
coast Thursday and Friday strengthening the monsoon moisture surge
over western nm. In general...Friday and Friday evening look like
a wetter period with broad coverage of 0.25 to 0.75 inch rain
amounts across the Continental Divide region. Far eastern areas
will be the least favored for precipitation through the end of the work
week with only spotty areas of rain accumulation.
The upper low on the West Coast is forecast to track slowly eastward
across the Great Basin Saturday...then to pickup speed as it ejects
northeastward across the northern rockies on Sunday. This should
shift the robust monsoon moisture plume eastward spreading better
precipitation chances to include the eastern plains Saturday
afternoon and evening. In the wake of the upper low models bring
drier air in from the west with the GFS and European model (ecmwf) favoring southern
areas for a chance/slight chance of showers and storms on Sunday.
The Canadian model is a little less progressive with the upper
low...slowing the drying across northern areas and focusing showers
and storms from SW to NE parts of the forecast area for another day.
This is cause for lower confidence in the drying forecast for
Sunday...especially since models were previously calling for some
drying across northern areas today and now that no longer looks to
Early next week GFS and European model (ecmwf) depict a return to the West Coast
trough and western Texas Ridge pattern with more monsoon moisture
streaming over nm. A couple of back door cold fronts are prognosticated to
enter eastern areas...though there isnt as much consistency between
models on their timing and strength. These fronts could help spread
better precipitation coverage to the plains.
Otherwise...high temperatures are expected to trend downward through
the end of the work week as precipitation and cloud cover become
more widespread. Some warming will then be possible through the
weekend...especially the latter half of the weekend if drier air
arrives. Cooling will then be possible with the cold fronts mainly
in the east next week. The better moisture and cooler air over
western areas should result in some pockets of poor ventilation
there Friday and Saturday...then the area of poor ventilation looks
to become more widespread across western and central areas early