000
FXUS65 KABQ 181743 AAB
AFDABQ

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
1143 AM MDT Mon Sep 18 2017

.AVIATION...
18Z TAF CYCLE
Zonal flow aloft will strengthen during the next 24 hrs. Sct-bkn cu
possible east of the Pecos Valley and ovr the sw and south central
high terrain 19Z-02Z. Moderate sw wind gusts before 02Z to around
30kt.

&&

.PREV DISCUSSION...316 AM MDT Mon Sep 18 2017...
.SYNOPSIS...
Dry air will move over the area from the southwest during the first
half of the work week, but winds will strengthen with fire weather
concerns on Tuesday. An upper level low pressure system will deepen
over the northwest United States on Wednesday night drawing moisture
for showers and thunderstorms northward over central and western New
Mexico Thursday. Precipitation will become more widespread Thursday
night through Friday night as the upper low tracks slowly eastward
over the central and northern Rockies. Southwest winds will also
become breezy again Thursday and Friday. Drier air will shift
gradually eastward over western New Mexico again this weekend and
temperatures will trend downward, but a stream of moisture and
precipitation is forecast to persist across eastern areas through at
least Saturday night.

&&

.DISCUSSION...
A long wave trough will gradually deepen over the western US through
mid week with the first batch of shortwave energy ejecting over the
northern and central Rockies tonight and Tuesday. This shortwave
trough will steer 500-700 mb layer averaged winds in the 20-40 kt
range over the forecast area, while inducing a surface lee trough.
West and southwest winds will become breezy to windy Tuesday
afternoon until sunset with fire weather concerns over much of the
forecast area.

After a break from the winds in the wake of the first shortwave on
Wednesday, winds will shift more out of the south and become
breezy again Thursday and Friday as the longwave trough begins to
move slowly inland. However, humidities will also come up over New
Mexico as showers and thunderstorms become more widespread. Both
the GFS and ECMWF depict a fairly consistent stream of moisture
for showers and thunderstorms flowing north and northeastward over
eastern New Mexico Friday through Saturday night. These have the
potential to produce a half inch to locally over 1 inch of rain
across much of the plains. This could be a good setup for pulse-
severe thunderstorms with decent unidirectional shear developing.

Models show the stream of moisture across the east becoming less
focused and shifting eastward at some point on Sunday, before a gusty back
door cold front dives southwestward into the state Sunday night. The
longwave trough, however, is progged to stay just west of New Mexico
into early next week providing southwest flow aloft and good shear
for showers and storms.

44

&&

.FIRE WEATHER...

...CRITICAL FIRE WEATHER CONDITIONS TUESDAY...

Showers and thunderstorms exiting the eastern plains of NM early
this morning. A much drier day on tap for NM in the wake of a weak
short wave trough. Westerly, zonal flow aloft will mix down to the
surface today, producing breezy conditions on the western and
northern mountains and some of the northeast. Highs will be warmer
by up to 10 degrees in the northeast while minimum humidities drop
by 15 to 35 percent in the same area. But humidities will still be
too high for any critical fire weather concerns. Good to excellent
vent rates today. Fair to good RH recoveries tonight.

Zonal flow will strengthen Tuesday and humidities lower. Mixed
signals concerning critical fire weather conditions. Winds and
humidities will reach critical thresholds in parts of the west
and east, and temperatures will be near normal in the west and 5 to
10 degrees above normal in the east. But forecasted Haines values
are only as high as moderate in portions of the northwest and
northeast zones. Recent rain in the east has left the near surface
soil pretty moist, but a good day for drying of the fine fuels
today and again Tuesday. So, have decided to issue a Fire Weather
Watch for zones 101, 103, 104, 105, 107 and 108, covering a 6 hour
period from the afternoon to early evening. Excellent vent rates
Tuesday.

A weak back door cold front will probably make it into the northeast
Tuesday night before washing out on Wednesday. Just enough cooling
and low level moisture increase to preclude any more fire weather
concerns, plus winds will be lower on Wednesday. It will be another
dry day Wednesday, with generally good or better vent rates, except
for spotty fair to poor rates in the northeast, behind the back door
front.

The pattern shifts to unsettled in the extended with rain chances
from Thursday through next weekend. Another deep trough will form
over the Pacific Northwest this week, with a closed low forming by
Wednesday. The trough will extend to CA Thursday then shift to the
Great Plains Friday. Low level southerly flow will have a couple of
days to overspread NM, resulting in isolated to scattered showers
and storms over the western and central mountains Thursday, then
expanding rapidly Thursday night and Friday across nearly all of
the CWA. The trough will slowly advance east next weekend into the
early part of the following week. Rain will be in the forecast each
of these days, but with a gradual drying trend noted in the west.
High temperatures will generally cool and humidities mostly increase
during this time.

CHJ

&&

.ABQ WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Tuesday afternoon through Tuesday evening
for the following zones... NMZ101-103>105-107-108.

&&

$$