018
FXUS66 KPQR 182155
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
255 PM PDT Thu Jul 18 2024

.SYNOPSIS...High pressure continues to rebuild, bringing
above-average temperatures with mostly sunny skies inland and
morning stratus along the coast. Will see a cooling trend early
next week, lowering temperatures closer to seasonable normals.

&&

.SHORT TERM...Today through Saturday...High pressure over the area
today resulting in dry and warm conditions, expected to continue
into Friday. For today, temperatures are expected to warm back
into the upper 80s to lower 90s for the interior lowlands, with
onshore flow bringing cool breezes this evening. Friday will
have similar conditions, with marine stratus forming (morning)
and clearing (afternoon) along the coast, and highs in the low
90s inland. An upper level ridge will begin to rebuild on Friday
and amplify over the Pacific NW into Saturday. Saturday, highs
inland are expected to reach the mid 90s (60-80% probability),
with highs near Hood River pushing triple digits (40-60%
probability). This may lead to localized areas of major HeatRisk
from the Portland metro through the Columbia River Gorge.
-JH

&&

.LONG TERM...Sunday through Wednesday...Upper level ridge begins
to shift eastward on Sunday. Deterministic models show a weak
upper shortwave trough lifting north early Sunday, bringing a
slight chance of showers for the coast through Sunday morning.
Sunday may have a slight chance of thunderstorms but confidence
still remains low. Temperatures inland remain warm with highs
likely between upper and lower 80s Sunday through Wednesday.
Then, cooler weather likely early next week. WPC Cluster
analysis maintains good agreement among ensemble guidance as it
shows upper level troughing sliding into the Pacific NW. How
cool it gets will depend on the location of the upper low which
will be dropping down from the Gulf of Alaska. Most guidance
suggests it remains centered north as it moves into British
Columbia. Temps will likely trend closer toward seasonal
normals. Dry weather expected to continue.
-JH/DH

&&

.AVIATION...High pressure over the region, with weak southwest
flow aloft, will maintain widespread VFR through around 00Z
Friday. Inland locations will have a 25%-35% probability of MVFR
conditions with areas near KEUG having a 50%-60% probability for
MVFR conditions starting around 08Z-10Z Friday. IFR/MVFR marine
stratus will return to the coast around 00Z Friday and persist
overnight.

PDX AND APPROACHES...High pressure over region keeps the ops area
under clear skies. 30% probability of MVFR conditions in/around
KPDX to KTTD as well as across Clark County, WA starting around
10Z Friday. /42

&&

.MARINE...Weak high pressure, with light winds. However, a pattern
change and northerly wind shift is expected Friday. Still,
pressure gradients not all that tight until Saturday. This will
result in northerly winds gusting up to 25 kt this weekend. Seas
mostly stay in the 3 to 5 ft range, with a mix of variable period
swell.


&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...None.

&&

$$

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