Area Forecast Discussion
Issued by NWS Boise, ID
FXUS65 KBOI 010903
Area Forecast Discussion
National Weather Service Boise ID
303 AM MDT SAT OCT 1 2016
.SHORT TERM...At 09Z north/south oriented surface cold front was
about 20 miles west of the western Idaho border. Front should move
into western Idaho by 12Z and central Idaho 18Z. Only a few
sprinkles or light rain showers along front. Winds will shift to
west or northwest as the front passes but only 10 to 20 mph. The
air is noticeably cooler behind the front but not as cool as in
yesterday`s forecast. Ahead of the front there is still enough
instability for isolated thunderstorms today in Idaho on the eastern
edge of our CWA. Clearing and colder tonight, especially in eastern
Oregon where the air will become very dry and winds will be light.
On Sunday the main upper low currently along the coast will come
inland into Oregon and generate light rain showers in Harney County.
Southerly flow aloft will also generate light rain showers in
central Idaho. Between those two areas southwest Idaho should stay
dry Sunday. Sunday will also be a few degrees cooler than today.
.LONG TERM...Sunday night through Saturday. Upper level low is
expected to continue tracking southeast then east across the
Idaho/Nevada border by Monday morning. Showers can be expected in
the southeastern two thirds of the CWA, and mainly in the mountains.
By Monday afternoon models differ slightly in placement of the low,
as the ECMWF and Canadian models are a bit faster than the GFS and
NAM. However, wrap around moisture looks to impact the eastern
edges of the CWA in each solution through Monday evening. For
Tuesday and beyond, a northwest pattern with embedded shortwaves
looks likely, however, the GFS is much wetter with widespread
showers than the ECMWF. THe current forecast is trended drier for
now. The next pattern change is depicted in both models with a
trough passing through late in the period, but confidence is low in
the feature. Temperatures expected to be around 10 degrees below
normal Monday and Tuesday, then gradually warm to near normal
through the rest of the week.
.AVIATION...VFR with cloud cover decreasing from west to east
through the morning. Ongoing showers and thunderstorms and cold
front this morning expected to be out of the area by 01/15Z. Surface
winds: West-northwest around 10 kts with afternoon gusts to around
20 kts. Winds aloft near 10 KFT MSL: Southwest 30-40 kts decreasing
after 01/21Z to 15-20 kts.