381
FXUS65 KABQ 182359 AAA
AFDABQ

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
559 PM MDT Fri Aug 18 2017

.AVIATION...
00Z TAF CYCLE
ISOLD showers and thunderstorms over E central and SE areas this
evening should end by midnight. The center of anticyclonic
circulation in the mid levels will shift SEWD over TX on Saturday
allowing better moisture northward over southern and eastern areas.
This will enable an uptick in thunderstorm coverage with SCT to
ISOLD aftn and evening activity favoring the central MT chain and
adjacent high plains, as well as S central and SW areas. A
disturbance will move northward over southern NM Saturday night
keeping convection going over southern parts of the forecast area.

44

&&

.PREV DISCUSSION...459 PM MDT Fri Aug 18 2017...
.SYNOPSIS...
Moisture pooling over northern Mexico will move slowly north toward
New Mexico Saturday then surge across the state Sunday and Monday.
The potential for locally heavy rainfall and flash flooding will
increase as this monsoon burst pattern takes shape over the region.
Temperatures will cool below normal as well for all areas. Tuesday
may be the transition day with a slight decrease in coverage of
showers and storms. A back door cold front will try to move into
eastern NM late Tuesday or Wednesday and focus another round of
potentially heavy rainfall through Thursday. There are still strong
indications that the overall weather pattern will remain active
through next weekend.

&&

.DISCUSSION...
Confidence is increasing that big changes are on the way after our
monsoon break the past several days. The latest water vapor loop
shows an upper ridge beginning to reorganize over NM as a large
scale upper trough translates east away from the southern Rockies.
Meanwhile, 700-500mb layer flow will become more to the south-
southwest thru Saturday as a weak upper low develops over southern
California. This will allow abundant moisture to surge north into
NM. The 12Z NAM, GFS, and EC still show remnant convective clusters
over northern Mexico moving north in this flow pattern and helping
to deliver more widespread showers and storms Sunday and Monday. One
of these waves may allow for a widespread stratiform rain event to
slide over central NM Sunday night. Model PW values rise to near
1" within central NM and near 1.5" over eastern NM. This will
elevate the potential for flash flooding, particularly in areas
that see training storms and high rainfall rates. WPC excessive
rainfall outlooks show a slight risk over all of NM Sunday. Temps
will cool below normal in this pattern as well.

It appears the pattern will remain very active for the remainder of
next week. A back door frontal boundary is shown to arrive either
late Tuesday or Wedesday while the upper high centers over eastern
NM. Upper troughing will remain in place along the west coast and
allow abundant mid and upper level moisture to stream northward into
NM. It`s hard to say what days will be the more significant threats
for flash flooding but overall chances for locally heavy rainfall
will continue just about everywhere thru late in the week. The 12Z
EC has a second back door frontal boundary entering eastern NM next
weekend while more moisture streams north from Mexico.

Guyer

&&

.FIRE WEATHER...
Dry air encompassing much of NM is currently limiting the number of
storms that can develop, but this trend will gradually change into
the weekend as subtropical moisture streams northward into the Land
of Enchantment. The current synoptic pattern is defined by a weak
upper level low off the CA coast while a dome of high pressure
stretches from the Gulf of Mexico coastline westward into NM. As
high pressure relaxes over NM through Sunday, another low over the
Gulf of CA, induced by previous storms, will sluggishly make its way
northward. This monsoonal burst will lead to increasing wetting
storms Sunday and subsequent days.

For the rest of today, storms will attempt to roll eastward off of
the interface of the central mountain chain and the high plains.
Thus far, storms have been paltry with minimal wetting footprints,
but as activity nears the NM-TX border, cells will likely strengthen
in the higher dewpoint environment. Similar to the past couple of
days, western and central NM are currently observing RH values in
the 15 to 25 percent range, coupled with higher Haines indices of 5
to 6. Breezes have remained tame though. Humidity recoveries tonight
will remain only fair to good in western and central zones, but the
east will once again benefit from excellent RH recovery near 80 to
90 percent.

The moisture return on Saturday will be a slow one, likely
benefiting areas along and just east of the central mountain chain
the most where scattered showers and storms will take shape.
Temperatures will be moderated by a few degrees and humidity will
observe gentle rises, primarily in central to southwestern zones.
This moisture increase will also erode away at the coverage of high
Haines (5 or higher), but some high values will still linger in the
northwestern third or so of the state. Higher dewpoints will
continue seeping northward Saturday night, boosting RH recoveries in
all zones, but the northwestern plateau will still only see fair
rebounds into Sunday morning.

The flux of moisture will increase further into NM on Sunday
afternoon as the Gulf of CA low works northward into NM. Substantial
coverage of wetting rain is expected with heavy rainfall in many
zones. This will quickly limit opportunities for planned burning in
many zones, especially central ones where storms will be most
concentrated.

While the Gulf of CA low should pass through and exit NM into
Monday, plenty of residual moisture should be left behind for daily
rounds of storms through the rest of next week. A back door front on
Wednesday will also recharge moisture from the northeast. Excellent
RH recoveries are expected each night while daytime temperatures
hover near to just slightly below average for mid to late August.

52

&&

.ABQ WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$