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Area forecast discussion 
National Weather Service Medford or
258 am PDT Thursday Jul 24 2014

Short term...the upper low centered just to the north will
quickly shift northeast today...and expect some continued below
normal temperatures today. Also a surface thermal trough will
build along the coast today bringing gusty north winds to the
coastal waters and along coastal areas. The strong surface thermal
through will persist into the weekend...weakening slightly on
Sunday. Inland...building heights will bring warming temperatures
on Friday. Temperatures will continue to increase across inland
areas Saturday and Sunday as a high pressure ridge builds over the
region.

The upper low is currently centered to the north over western
Washington. Models indicate that this low will quickly track
northeast this morning. Some light precipitation is forecast along
the coast during the morning hours but this is expected to stay
north of the Coos and coastal Douglas County area. Although some
light drizzle is possible, mainly along the coast from North Bend
northward. Overall, for most the area expect dry conditions today.
Morning low clouds along the coast and inland across Douglas
County and in other west side areas will clear this afternoon.
During the afternoon, expect sunny skies with mild temperatures.
Highs are expected to only reach the 70s to 80s across much of the
area. With the developing thermal trough along the coast, gusty
north winds will develop at coastal locations this afternoon into
this evening. Also offshore flow with the surface thermal trough
is expected to bring a mild Chetco effect to the Brookings area.

Dry and warming conditions will continue on Friday with
temperatures warming 7 to 10 decrees across inland areas...and
high temperatures expected in the middle 80s to 90s. Gusty winds will
continue Friday along the coast. This pattern will continue
Saturday into Sunday with temperatures warming further as an upper
ridge strengthens across the western US. By Sunday, highs in the
90s to low 100s are expected for most inland valleys. Also on
Sunday, models begin to track shortwave energy into the area from
the south-southwest. This shortwave is forecast to reach the area
during peak heating and models show weak instability over inland
areas as well as some moisture moving into the area from the
south. Although moisture is somewhat limited, have decided to add
a slight chance of thunderstorms to inland mountains given the
model consistency in depicting this shortwave. Since forecast
steering flow is light, expect any storms that develop would most
likely stay locked on terrain features.



Long term...Monday through Thursday...hot conditions continue
across the area with a ridge forecast to strengthen Monday and
Tuesday then persist through late in the week. Models show good
agreement with a strong ridge developing early next week. So have
bumped up temperatures slightly with highs expected to reach the
upper 90s to middle 100s by Tuesday in west side valleys and reaching
the middle 90s for east side valleys on Tuesday. Hot temperatures
continue Wednesday and Thursday...possibly lowering a couple
degrees though. In addition to hot weather, expect a continued
slight chance for thunderstorms for inland areas Monday through
Thursday as shortwave energy and moisture moves into the area from
the south and combine with daytime heating and instability. Expect
the best chance for any thunderstorms will be from the Cascades
east in Oregon and over northern California. However, on Tuesday
and Wednesday there is the potential for thunderstorms west of the
Cascades in Oregon as models show flow aloft becoming more
southeasterly. So have introduced a slight chance for
thunderstorms west of the Cascades in southern Oregon on these
days.



&&

Aviation...based on the 24/06z tafs...conditions will transition
from a moist northwest flow to a subsident northeast over the next
12 to 24 hours. Clouds tonight will continue mountain
obscurations from the Oregon Cascades and Siskiyous, and Marble
Mountains westward overnight, diminishing some toward and after
sunrise as light offshore flow begins mostly south of the Umpqua
Divide. Areas of MVFR ceilings will persist along and near coast
this morning. Isolated MVFR ceilings may spread into Douglas County
and the krbg area but confidence is low and have kept MVFR out of
the krbg forecast taf. Overall, anticipate most west side valleys,
except along and near the northwest slopes of the Cascades and
Siskiyous, to remain primarily VFR. By late morning expect most
locations will become VFR under a progressively drier and warmer
air mass. Btl



&&

Marine...updated 230 am PDT 24 July 2014...

There is high confidence in the marine forecast through Saturday
night. A thermal trough will rapidly develop over northern
California today then persist through the weekend and likely into
early next week. This will result in moderate to strong north winds
and steep wind driven seas with the strongest winds during the
afternoon and evening hours in the outer waters south of Cape
Blanco. The upper ridge moves inland Sunday with the thermal trough
weakening...resulting in decreased winds and wind waves into the
early portion of next week. The main uncertainty with the forecast is
the extent of this weakening. A model blend of the dgex and the
stronger 00z GFS was utilized. /Dw

&&

Mfr watches/warnings/advisories...
or...none.

California...none.

Pacific coastal waters...Small Craft Advisory for winds from 11 am this morning to 11 am
PDT Sunday for pzz350-356-370-376.
Small Craft Advisory for hazardous seas from 11 am this morning
to 3 PM PDT Sunday for pzz350-356-370-376.
Hazardous seas warning from 11 am this morning to 3 PM PDT
Sunday for pzz356-370-376.
Gale Warning from 11 am this morning to 11 am PDT Sunday for
pzz376.

$$

Cirrocumulus

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