390
FXUS66 KPQR 171052
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
352 AM PDT Mon Jun 17 2024

.SYNOPSIS...One more seasonably cool day across the region as
showers continue to taper off behind departing low pressure.
Temperatures rebound back to normal on Tuesday, with high
pressure then bringing a stretch of hotter weather from
Wednesday through Saturday.

&&

.SHORT TERM...Now through Tuesday Night...Early morning radar
imagery shows shower activity mainly confined to the Casacdes
and the north Oregon/south Washington coast as the upper level
trough which has dominated the pattern for the past several days
shifts east of the Cascades. Showers will continue to taper off
across most of the area today as the region settles into drier
northwest flow in the wake of the trough. A few showers may
linger as long as this evening along the Cascades, with
additional model QPF amounts ranging from a tenth to a quarter
inch. Temperatures will remain below normal for one more day as
850 mb temps of 2-3 C correspond to highs in the mid to upper
60s in the interior lowlands. Showers will come to an end across
the area and temperatures will rebound back to seasonal normals
in the low to mid 70s on Tuesday as the influence of the upper
trough continues to diminish and 850 mb temps climb to around 8
C by Tuesday afternoon. /CB

.LONG TERM...Wednesday through Sunday...A stretch of
hotter weather begins on Wednesday as ensemble clusters and
deterministic solutions continue to depict a Rex Block type
pattern developing over the West Coast with an upper level ridge
over western Canada and a trough over California. Ensemble
solutions show good agreement on highs in the mid 80s across
much of the area on Wednesday afternoon, though low level
onshore flow will continue to moderate temperatures along the
coast. Temperatures look to peak Thursday into Friday as
probabilistic guidance continues to trend slightly higher, now
showing a 60-70 percent chance to reach 90 degrees from Portland
to Salem on both days and around a 35 percent chance to hit 90
at Eugene on Friday. The upper end of the guidance envelope has
also trended upward, as the chance to reach 95 degrees from
Portland to Salem has increased to 10-15 percent on Thursday and
around 30 percent on Friday. Despite these higher
probabilities, a look at individual ensemble members from the
GFS, Euro, and Canadian model suites still point to highs
ultimately maxing out in the low 90s both Thursday and Friday.
That said, the possibility for temperatures to reach as high as
the mid 90s later in the week can`t be discounted, particularly
for Friday. Guidance then indicates the start of a downward
trend on Saturday as temperatures drop back into the 80s, with
highs falling off into the 70s by Sunday as ensemble clusters
show good agreement on the next trough arriving over the region.
There is still uncertainty as to if this feature will be
accompanied by any meaningful precipitation, with the latest NBM
guidance holding onto a 20-30 percent chance of rain for the
northern coastal areas by Sunday. /CB

&&

.AVIATION...An upper level trough over the Pacific NW will
slide east of the Cascades this morning bringing northwesterly
flow aloft today. Isolated showers expected to continue to
decrease as well, with predominately VFR conditions likely by
this afternoon. Highest chances for MVFR cigs this morning at
the coast (60-80%), while inland terminals have closer to a
20-40% chance of MVFR cigs between 12-18Z today.

PDX AND APPROACHES...There is around a 30-40% chance of MVFR cigs
developing between 12-18Z this morning. Otherwise, expect
predominately VFR conditions through the period. Northwest winds
increase to around 6-8 kt this afternoon. /DH

&&

.MARINE...High pressure offshore is expected to persist through
the week. Northwest winds 10-15 kt across coastal waters today
becoming northerly on Tuesday. North winds begin to increase later
Tuesday afternoon as a thermal trough strengthens from northern CA
into southern OR. Expect will see periods of winds gusting up to
25 kt through Friday during the late afternoon and evenings. Seas
around 4 to 6 feet will generally be wind driven through the week.
/DH

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...None

&&

$$

www.weather.gov/portland

Interact with us via social media:
www.facebook.com/NWSPortland
www.twitter.com/NWSPortland