Spring/ Summer Banter

[Holston_River_Rambler]

Hope everyone is doing well in these dry conditions.

I'm about to head out for the annual camping trip to the southwest and was reading the ABQ forecast discussion. It was informative (mostly  in the short term), but also kind of funny (mostly in the long term), so I thought I'd share

.SHORT TERM...
(Today through Sunday)
Issued at 107 AM MDT Sat May 9 2026

Day 1 Saturday: It is May so that means virga "bomb" season in
New Mexico. Virga being rain that evaporates from a thunderstorm
before reaching the ground. The rain cooled air still does reach
the ground causing a dry microburst hence the "bomb" term. Today
looks to be a decent set up for that to occur over the northern
mountains into the northeast Highlands. Isolated activity should
develop over the central RGV and then back over the Gila Forest as
well. Instability (CAPE) looks rather limited with weak
"moisture" over the state within increasing NW flow aloft. Storms
will be moving pretty quickly as well so any convection could
produce a quick microburst with winds most likely not reaching
severe levels due to lack of CAPE and downdraft CAPE (DCAPE).

Impacts from the gusty winds will be pretty minor and limited to
the typical blowing dust and displaced trampoline or bouncy house.

Day 2 Sunday: The downburst potential increases more on Sunday
with a much more supportive upper level pattern. A fast moving
short wave trough passes through northern NM on Sunday increasing
the NW flow aloft and cooling aloft. Lapse rates steepen quite a
bit more by early afternoon and supportive of CAPE around 400-800
J/kg and DCAPE around 600 J/kg. Deep layer shear increases to
30-40 kts especially from the Highlands south towards SE NM and in
phase with the instability. HREF hints at a least small chance
(<10%) of CAPE reaching 1000 J/kg in a few spots in E NM. Should
the models be under forecasting CAPE then maybe there is support
for a marginal severe weather risk for damaging winds. More than
likely storms produce wind gusts closer to 50 mph than 60 mph. The
main impacts from these kinds of winds will again be blowing dust
but could damage weak structures and toss trampolines.

Hi-res CAMs and synoptic models all have a pretty clear signal for
convection developing in the Las Vegas (not Nevada) area of the
Highlands in the early afternoon and then work off to the SE.
Isolated activity then develops down the mountain chains towards
the Sacramento Mountains. It looks like storms will be in the
vicinity of Ruidoso but likely moving too fast and with not a lot
of rain to cause any issues on the burn scars.

The wildcard in all of this is the back door surface cold front
that surges down the eastern Plains bring a surge of moisture to
the region. Models need to have a good handle on it`s evolution
and magnitude of moisture. The boundary layer moisture will be key
to the whole convective scenario and where the forecast goes
sideways for the intensity of storms. Will dewpoints in the 40s be
the key to this all? Lastly we will throw in the mention of east
canyon winds for the ABQ metro area late Sunday due to the back
door front but just not a lot of confidence on the intensity of
winds with it.

39

&&

.LONG TERM...
(Sunday night through Friday)
Issued at 107 AM MDT Sat May 9 2026

Day 3 Monday: The upper level ridge strikes back. Star Wars
reference intended. Yes that synoptic feature that reared its ugly
head back at the end of March comes back to life like Darth Maul.
Synoptic ensemble model suites are all in pretty good agreement
with an anomalously high (+12 DAM) 500 mb ridge building over
AZ/NM on Monday. As such temperatures rebound quite a bit in E NM
with temperatures back into the mid/upper 80s after 70s on Sunday.

Day 4-7: Tuesday the ridge builds over NM with 590 DAM heights at
500mb or again about +12 DAM above normal. It will be quite
possible that kind of 500mb height would be close to a record on
the 18Z ABQ sounding. And that would make sense given this height
would be right around the 99th percentile of climo. Heat risk
builds into the moderate category for much of NM as high temps
reach the 90s which will be only about 2 weeks ahead of schedule
instead of 2 months (at least for ABQ metro). Roswell will
probably be in reach of 100F.

Wednesday through the end of the week the upper level ridge moves
over Texas and southwest flow aloft develops over NM. A weak
shortwave passes by on Thursday which could bring some elevated
convection to the area. Again not much moisture with this system
so virga will be the most likely outcome from any convection.
After that ensemble model suites become quite divergent in their
solutions. Cluster analysis shows exactly that...a cluster. GFS,
ECMWF and Canadian ensembles all favor different outcomes from
each other. All this means is that there is very low confidence in
the forecast day 7 and beyond.

39/Discussion courtesy the WCM working night ops. Take it for what
it is worth.