Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Aberdeen South Dakota
1246 PM CDT Wednesday Sep 17 2014
18z aviation discussion updated below.
The current forecast looks good. No significant changes were made.
short term...today through Friday
temperatures across the region are a bit warmer this morning
compared to 24 hours ago. Within the past hour...fog satellite
showing some subtle hints of fog along the James Valley. Abr visibility
dropped below 1sm for a short time in shallow ground fog. Oakes ND
down to 3/4sm as well. Have added patchy fog in the forecast
through the morning hours.
Otherwise...looking at a tranquil day across the area with very
similar highs to Tuesday. On Thursday...pressure gradient tightens
ahead of an approaching frontal boundary. South to southeast winds
will become breezy/windy by afternoon with these winds bringing an
increase in low level moisture as well. Dewpoints are forecast to
approach 60 degrees by Thursday afternoon.
Will then be watching frontal boundary moving through the area on
Friday. With a lack of any appreciable shortwave energy or strong
surface convergence...not looking at any well organized convection or
overly impressive chances for rainfall. Will maintain low probability of precipitation in
Long term...Friday night through Tuesday
weak energy will track across the northern plains in zonal flow
Friday night...with the flow then becoming northwesterly on the
east side of a ridge building over The Rockies. The ridge looks to
finally push over the plains states on Tuesday.
The combination of a surface front tracking across the County Warning Area...a
weakening cap and weak instability may result in a few showers or
thunderstorms over mainly the eastern County Warning Area Friday night. High
pressure then moves over the plains and will be the dominant
weather feature through the day Monday. As the high slides east on
Tuesday...a low pressure trough digs down the Lee of The
Rockies allowing for an increasing pressure gradient...but with
conditions remaining dry.
Near normal temperatures will be the rule...with daytime highs in
the 70s and overnight lows mainly in the 50s.
18z tafs for the kabr...Katy...kpir and kmbg terminals
Mainly VFR conditions are expected at all terminals through tonight
and Thursday. Although...do expect some light fog to form later
tonight/early Thursday at abr and aty with light winds and mostly
clear skies. Also...expect south to southeast winds to pick up at
all locations through Thursday morning as the surface pressure
gradient tightens up and the mixing layer deepens.