Area Forecast Discussion
Issued by NWS Tucson, AZ
FXUS65 KTWC 062230
Area Forecast Discussion
National Weather Service Tucson AZ
330 PM MST Tue Dec 6 2016
.SYNOPSIS...A few rain and snow showers may occur across the White
Mountains into Wednesday. Otherwise, dry conditions will prevail
into early next week. Expect some minor cooling Wednesday, then
above normal daytime temperatures will return by Friday and continue
into next week.
.DISCUSSION...A shortwave trough over the Great Basin this afternoon
will move eastward toward the Four Corners region tonight, then
continue to move eastward into the central CONUS plains Wednesday.
06/12Z GFS/ECMWF were similar with depicting a few hundredths of an
inch of liquid amounts to occur tonight into Wednesday across
portions of the Mogollon Rim northeastward to near the Four Corners
However, have noted that the 06/12Z NAM remained fairly consistent
with respect to several previous NAM solutions in depicting a few
hundredths of an inch of liquid amounts to occur by daybreak
Wednesday much further southwest across western Pima County and
south central Pinal County. The NAM scenario of maintaining light
rainfall west of Tucson then continues into Wednesday afternoon.
For this forecast issuance, the NAM scenario has once again been
discounted. Thus, given the synoptic scale ascent associated with
this shortwave trough, there may be sufficient moisture to generate
a few rain/snow showers across the White Mountains tonight into
Thereafter, dry conditions will prevail into at least next Tuesday
as the upper level pattern will generally be characterized with a
trough over Canada extending south into the central/eastern CONUS.
Meanwhile, a ridge will prevail near the West Coast. Although precip-
free conditions are forecast to occur, there will be variable
amounts of mainly high-level clouds moving across southeast
Cooler temps will occur Wednesday as the shortwave trough passes
northeast of the area. A warming trend will then prevail Thur-Sat,
then only very minor daily temp changes should occur Sun-Tue. Thus,
high temps Fri-Tue will average about 5-10 degs or so above normal
depending upon location.
.AVIATION...Valid through 08/00Z.
Isolated -SHRA/-SHSN may occur across the White Mountains into
Wednesday. Otherwise, expect SCT clouds around 12k-15k ft AGL and
BKN-OVC clouds above 20k ft AGL through the period. Surface wind
will diminish to less than 12 kts for most locales this evening and
then continue into Wednesday afternoon. Aviation discussion not
updated for TAF amendments.
.FIRE WEATHER...There is a slight chance of rain and snow showers
across the White Mountains into Wednesday. Otherwise, dry conditions
will continue into next Tuesday. 20-ft winds will diminish to less
than 10 mph this evening and continue into Wednesday, then winds
becoming easterly or southeasterly on Thursday and Friday. 20-foot
winds will mainly follow terrain at less than 15 mph this weekend
and early next week.
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