Area Forecast Discussion
Issued by NWS Tucson, AZ
FXUS65 KTWC 291025
Area Forecast Discussion
National Weather Service Tucson AZ
325 AM MST Tue Nov 29 2016
.SYNOPSIS...A few light valley rain and mountain snow showers will
occur east of Tucson this morning. Clearing from the west with much
cooler temperatures and the coldest lows of the season so far
tonight and Wednesday night, with widespread freeze or hard
freeze conditions for Southeast Arizona. Temperatures will remain
below average through the week, and another storm system may bring
a chance of valley rain and mountain snow Friday into the weekend.
.DISCUSSION...An impressive trough dominates most of the country,
with a third impulse impacting our area this morning as it carves
down the back side of the trough before shifting eastward later
today. For us that means a few light showers with snow levels
falling as low as 4500 to 5000 feet, and another inch or so of
snow above 6000 feet. A dry and cool northwesterly flow behind
this impulse, with clearing from the west and northeast late
Clear with light winds by late evening, with the coldest overnight
lows of the season Wednesday morning. Temperatures will range from
the teens in some colder eastern valleys, to lower and middle 20s
south of Tucson, to upper 20s to lower 30s elsewhere (including
the greater Tucson area). Freeze and Hard Freeze warnings tonight
and again Wednesday night.
Another system will dig down from the north toward our area late
Thursday into Friday. This will keep temperatures well below
average and bring another chance of valley rain and mountain snow
Friday and Saturday.
The stacked pattern is hanging strong with a persistent eastern
Pacific ridge upstream and a high anchored near Bermuda and
southern Florida downstream. That keeps southern portions of the
intermountain west active, with early signs of yet another storm
system approaching our area by next Tuesday night.
.AVIATION...Valid through 30/12Z.
Expect isolated to scattered -SHRA and mountain -SHSN mainly east
of KTUS this morning. MVFR conditions will occur especially
across higher terrain. Clearing from the west later. Gusty
wly/nwly surface wind east of KTUS today, otherwise normal diurnal
wind trends with diminishing winds overnight.
Aviation discussion not updated for TAF amendments.
.FIRE WEATHER...A few valley rain and mountain snow showers will
occur from Tucson eastward into Tuesday morning, then a few showers
across southern Cochise County Tuesday afternoon. Dry conditions
will then occur Wednesday into Thursday. A low pressure system may
then bring more wintry weather and gusty east winds Friday into
Hard Freeze Warning from midnight tonight to 9 AM MST Wednesday
Hard Freeze Warning from midnight Wednesday night to 9 AM MST
Thursday for AZZ503.
Freeze Warning from midnight tonight to 9 AM MST Wednesday for
Freeze Warning from midnight Wednesday night to 9 AM MST
Thursday for AZZ502-504>506.
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