Scientific Forecaster Discussion
fxus65 kfgz 191631
Area forecast discussion
National Weather Service Flagstaff Arizona
931 am MST sun Feb 19 2017
Synopsis...a Pacific storm system will bring periods of rain and
high elevation snow along with colder temperatures to northern
Arizona today. Expect areas of winter driving conditions in the
mountains above 6000 feet today. Dry weather and warming
temperatures are forecast for Monday and Tuesday. Another round of
showers is possible Wednesday and Thursday when a cold front is
forecast to move through Arizona.
no significant changes to the forecast this morning as a low
pressure system is currently centered just northeast of Flagstaff.
Have updated probability of precipitation and weather categories
to better account for satellite and radar trends. Will continue to
let the Winter Weather Advisory run its course through at least
the afternoon forecast package.
Previous discussion /400 am MST/...the upper level low pressure
center is rotating into northern Arizona this morning. A frontal
band of precipitation has moved into far northern Arizona across
the Navajo/hopi reservations with showers continuing behind the
front across central Arizona. The greatest rainfall amounts have
fallen across southeastern Yavapai County where 1 to 2 inches fell
and northwestern Gila County where up to an inch has fallen.
Precipitation intensity has decreased over the past few hours and
we expect this trend to generally continue through the day as the
low center continues to lift northeast and out of Arizona. With
the downward trend in precipitation intensity, we have canceled
the Flash Flood Watch as flash flooding is no longer expected to
pose a threat. However, southeastern Yavapai/northwestern Gila
County will continue to see gradual creek/stream rises through the
day before subsiding later tonight or Monday.
Light snow has fallen overnight across the Mogollon Rim generally
above 6000 feet and continues to fall early this morning from the
South Rim of Grand Canyon southward along the Mogollon Rim and
east toward Show Low. Will keep the winter weather advisories
intact for this morning to account for period of winter driving
conditions, but later shifts may be able to end these earlier
Showers will come to an end tonight with condtions gradually
clearing out through Monday morning. Areas of low clouds and
perhaps some fog will linger into Monday morning. A period of
mostly dry and warmer weather will return Monday through Tuesday
as high pressure builds over the southwestern U.S.
Southwest winds increase by Wednesday afternoon ahead of another
trough entering the western U.S. Coast. As this trough progresses
east, it will push a quick moving cold front through Arizona
bringing the chance for showers Wednesday and Thursday followed by
colder temperatures Thursday. Yet another weather system looks
possible sometime next weekend. Stay tuned.
Fgz watches/warnings/advisories...Winter Weather Advisory until 5 PM MST this afternoon for