"YIPPEEEEEE!" Wind in EXCESS of 50 MPH...temps in the 10's to 20's "Ahhhhh, PERFECT snowman weather
Dennis
Area forecast discussion
National Weather Service Flagstaff
925 am MST Monday Dec 20 2004
Synopsis...for today...expect clear skies and light winds.
Temperatures will be well above normal over most areas. On
Tuesday...a strong cold front will bring much cooler conditions
along with a slight chance of rain and snow showers. Another surge
of even colder air will arrive Wednesday and Thursday with windy
conditions also developing. Moderating temperatures and dry
conditions are expected over the Christmas Holiday weekend.
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Discussion...the high amplitude ridge that has given US fair and
warm weather for the past few days is now retrograding into the
Pacific. Today will be the last warm and relatively calm day this
week as disturbances begin to plunge southward on the eastern
periphery of the ridge. The first of these disturbances can be seen
on water vapor satellite just now moving into the Pacific northwest.
Model forecasts agree that this shortwave will move across southwest
Arizona Tuesday. Best dymamics will be to our south...but the
deepest saturation should be over northeast Arizona along the cold front.
The airmass over northern Arizona this morning is very dry...but the GFS
brings moisture in with the system on the northwest flow. Will
probably not be increasing probability of precipitation for Tuesday too much from where they
are now...around 20 percent. The big story for Wednesday and
Thursday will be the much colder temperatures and locally strong
northeast winds. The exact timing of the coldest air and the
strongest winds has been changing each model run. The current runs
indicate that the coldest day will be Thursday as another strong
shortwave drives southward into eastern Arizona...pulling some of the
Arctic airmass with it. It will be windy along and just downstream
from the higher terrain Wednesday. However...the windiest period now
appears to be Thursday into Friday as 7h wind in the GFS is 40-50kt
with a strong surface pressure gradient. If the GFS pans out...we will
need wind advisories for higher terrain and downslope areas for that
time period. Only update to the forecast this morning will be to
decrease cloud cover for today...looks like a mostly sunny
afternoon.