Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Glasgow Montana
521 am MST Wednesday Jan 28 2015
Short term...for northeast Montana...today through Friday...
A split trough temporarily knocked down the ridge last night. The
southern short-wave feature will send moisture through southeast
Montana and Wyoming today...while the northern wave sends moisture
east across central Saskatchewan. Associated with this northern
trough will be a cold front sent south over northeast Montana
today. The NAM and GFS frontal timing are different indicating
some uncertainty. The rap has picked The Middle Ground...so expect
the cold front to cross the international border around late
morning. Temperatures aloft will be cooler than we have
experienced for a while...so highs will trend lower than Tuesday.
A surface trough sets up to our east which will develop brisk
northwest winds over the area today...in the 20kt range. With
increased mixing of strong winds aloft toward the surface...also
expect gusts to 30kt. By afternoon the front should be well into
northeast Montana. Limited overrunning moisture could produce some
light precipitation. BUFKIT suggests precipitation type to be
freezing rain or rain in the morning and rain in the afternoon.
Slight chance probability of precipitation will be limited to the eastern zones.
Tonight...the cold boundary once again sets up northwest to southeast across the
County Warning Area. The overrunning moisture will create low stratus over the
eastern zones...and possibly a little more light intermittent
precipitation in the evening. Increasing high surface pressure
from the north will diminish northwest wind significantly.
Thursday through Friday...flow aloft continues from the northwest
as the stationary boundary wanders around just northeast of our
area. 850mb temperatures will remain near 0c which will be much
cooler than the last several days. Models continue to differ with
expected surface temperatures. But until the stationary front
drops south again temperatures will continue above normal by
around 15f-20f. Scattered
Long term...Friday night through Wednesday...
persistent long wave upper level ridge hangs over Pacific northeast
region throughout extended forecast period. Ridge axis slowly
retrogrades westward as upper level Hudson Bay low deepens later
in the weekend. Temperatures will slowly cool to below seasonal
normals Sunday and Monday. By Wednesday ridge reestablishes its
influence over the area for a return to near normal temperatures.
Several shortwaves sweep through the northwest flow aloft for a
slight chance of showers...with best chances Saturday afternoon and
evening. Weak surface pressure gradients will result in relatively
light winds through period. Britton
flight category: VFR.
Synopsis: an upper-level ridge of high pressure persists over the
region today and will allow for some high cloudiness.
Ceilings and vsby: VFR ceilings and visibility will continue through period.
Wind: winds will increase through the day on Wednesday.
due to the recent warm temperatures some of the creeks and small
streams have begun to run. Minor flooding was reported at 7 mile
creek near Glendive which prompted the issuance of a small stream
Flood Advisory through early morning.
Temperatures are expected to trend lower towards normal by the
weekend which will will begin to limit any further flooding.