Sunrise 5:50 AM   Sunset 8:28 PM Moonrise 4:24 AM   Moonset 7:32 PM

  Print   HELP   Reset   Save   Recall  New

PZZ255 Coastal Waters From Cascade Head To Florence Or Out 10 Nm- 847 Am Pdt Tue Sep 13 2022
.dense fog advisory in effect until 10 pm pdt this evening - .
Rest of today - SW wind to 5 kt. Wind waves sw 1 ft at 4 seconds. NW swell 2 ft at 9 seconds. Widespread dense fog and a chance of showers in the morning, then areas of dense fog in the afternoon. Tonight - N wind to 5 kt. Wind waves N 1 ft at 4 seconds. NW swell 3 ft at 9 seconds. Areas of dense fog in the evening. Patchy dense fog after midnight. Wed - N wind 5 kt. Wind waves N 1 ft at 4 seconds. NW swell 3 ft at 9 seconds. Patchy dense fog in the morning. Wed night - NW wind 5 kt. Wind waves W 1 ft at 4 seconds. NW swell 3 ft at 9 seconds. Thu - SE wind 5 kt, veering to W in the afternoon. Wind waves se 1 ft at 4 seconds, shifting to the W at 4 seconds in the afternoon. NW swell 3 ft at 10 seconds. Thu night - N wind 5 to 10 kt. Wind waves N 1 ft at 4 seconds. NW swell 3 ft at 10 seconds. Fri - N wind 5 to 10 kt. Wind waves 2 ft. NW swell 3 ft. Sat - NW wind 5 to 10 kt. Wind waves 2 ft. NW swell 4 ft.

PZZ200 214 Pm Pdt Tue May 7 2024
Synopsis for the southern washington and northern oregon coast - High pressure building across the waters brings more summer- like weather and breezy northerly winds through the end of the week.

FXUS66 KPQR 072147 AFDPQR

Area Forecast Discussion National Weather Service Portland OR 247 PM PDT Tue May 7 2024

SYNOPSIS
One more day of cool and unsettled weather today, then high pressure will bring a substantial drying and warming trend that will last through the end of the week. Before the warming trend, lingering cool air and clear skies will likely lead to frost in some of the outlying valleys, but urban centers should remain a few degrees above freezing. Record warm temperatures are possible Friday and/or Saturday, but rivers and lakes will remain dangerously cold.

DISCUSSION
Tuesday Afternoon through Monday...Radar imagery shows scattered showers continuing across NW Oregon and SW Washington Tuesday afternoon as a shortwave trough moves east of the region. Snow levels have risen to around 4000-4500 feet this afternoon, though webcams indicate snow is light and scattered enough that little to no snow is sticking to roads. Showers will end from west to east this evening as high pressure begins rapidly building east just off the coast.

With high pressure building in quickly, clear/calm conditions will lead to excellent radiational cooling within a chilly air mass lingering over the Pac NW tonight into Wednesday morning.
Nights are getting short, but it appears temps will have the opportunity to cool off enough for frost in the outlying valleys and possibly the suburbs. 12z HRRR and NBM guidance continues to show anywhere from a 40-80% chance of temps 35 deg F or cooler for most of the Willamette Valley excluding the PDX metro, whereas the suburbs generally have a 20-40% chance of temps 35 deg F or cooler. The inner Portland metro only has a 10-25% chance. A Frost Advisory remains in effect for lowland areas excluding the Portland Metro area north through the Washington I-5 corridor tonight through 8 AM Wednesday.

There is high confidence amongst ensemble guidance in a sharp warming trend and dry weather returning Wednesday into the weekend, with temperatures peaking Friday and Saturday. The chilly start on Wednesday will initially hobble the rise of temperatures, but strong May sunshine will eventually mix out any valley inversions and temps should climb well into the 60s (and possibly to 70 degrees) Wednesday afternoon. Low-level offshore flow will ramp up Wednesday night into Thursday, and with 850 mb temps +10 to +12 deg C by Thursday afternoon, it appears very likely inland areas and possibly even the coastal valleys will reach 80 degrees Thursday. Latest NBM probabilistic data show 60-85% chance of reaching 80 degrees Thursday for the entire Willamette Valley, with the chances exceeding 90% for the lowlands of the Portland metro area.

Latest WPC cluster analysis remains confident in strong ridging building Friday into Saturday. All clusters suggest the ridge will eventually be worn down by a strengthening Pacific jet stream moving from the north- central Pacific into the NE Pacific, but most guidance holds on to the ridge long enough to keep Monday dry except perhaps for some coastal drizzle.

Deterministic models are depicting a fairly typical evolution for our anticipated warm spell: Offshore flow Thursday/Friday leading to unseasonably warm temperatures all the way to the coast, thermal low pressure shifting inland Saturday bringing cooler onshore flow to the coast and coastal valleys while inland valleys remain near 90 degrees, then more widespread cooling Sunday as thermal low pressure focuses on the Columbia Basin and pulls onshore flow all the way to the Cascades. The marine layer will likely remain too shallow for much in the way of morning cloudiness inland through Sunday, but the upper ridge may weaken enough for some low clouds to push into the inland valleys for a few hours Monday morning.

As for the magnitude of the warmth, the inner Portland metro appears the most likely to reach 90 degrees Fri/Sat based on NBM probabilistic guidance, with 80s a near certainty for all other inland valleys. Latest NBM prob guidance shows a 70-95% chance of reaching 90 deg F across the inner PDX metro and eastern Washington County as well as along the I-5 corridor in Washington south of Longview. South into the central and southern Willamette Valleys, these probabilities drop to 5-20%.
For now our forecast is around 90 degrees for the Portland metro Friday and Saturday, with mid to upper 80s for the remainder of the interior lowlands.

The unseasonably warm temperatures will no doubt cause people to flock to the rivers, lakes, and ocean beaches of SW Washington and NW Oregon. It is important to remember that rivers and lakes remain dangerously cold with water temperatures mainly in the 40s. Such temperatures can easily cause cold water shock for those without proper protective equipment. The bright sun and warm temperatures can make the cold water look refreshing, but the consequences of jumping in without the proper equipment could be deadly. Be sure to bring a life vest and be extremely cautious around area rivers. -Weagle/HEC

AVIATION
Northwest flow aloft continues today as high pressure ridge begins to build across the region. This will cause scattered light rain showers to gradually dissipate by this evening. Expect predominately VFR conditions today. Northwest winds at the surface begin to shift northerly later today through tonight.
Guidance then suggests stratus may rebuild by early Wed morning near the Cascade foothills with around a 30-50% chance of MVFR cigs creeping into the terminals through the Willamette Valley between 12-18Z Wed.

PDX AND APPROACHES...Predominately VFR expected with light scattered showers eventually dissipating by this evening. Chances for MVFR stratus creeping into the terminal increase after 12Z Wednesday to around 30-50%, but whatever does form should burn off quickly with increasing sun through Wed morning. Northwest winds increase to around 7-9 kt this afternoon. /DH

MARINE
Northwest winds 10-15 kt gradually shifts north overnight. Seas around 9 to 10 ft at 12 seconds are expected to persist through early this evening, barely meeting Small Craft Advisory criteria. Afterwards, high pressure begins to build across the waters, bringing more tranquil weather. Winds turn northerly as high pressure persists offshore and the thermal trough strengthens along the CA/OR coast. This summer like pattern will bring breezy north winds with gusts to 30 kt on Wednesday.
Have issued a Small Craft Advisory for this from Wed afternoon through Wed night. Winds ease somewhat Thursday morning, before pressure gradients strengthen again through Thu evening. /DH

PQR WATCHES/WARNINGS/ADVISORIES
OR...Frost Advisory from midnight tonight to 8 AM PDT Wednesday for ORZ104-105-109-114>118-121-123>125.

WA...Frost Advisory from midnight tonight to 8 AM PDT Wednesday for WAZ205-208.

PZ...Small Craft Advisory from 3 AM to 8 AM PDT Wednesday for PZZ210.

Small Craft Advisory until 8 PM PDT this evening for PZZ251>253- 271>273.

Small Craft Advisory from 2 PM Wednesday to 2 AM PDT Thursday for PZZ251-271.

Small Craft Advisory from 11 AM Wednesday to 5 AM PDT Thursday for PZZ252-253-272-273.

toggle option: (graph/table)

Portland, Morrison Street Bridge, Oregon, Tide feet

St. Johns, Willamette River, Oregon - IGNORE HEIGHTS, Tide feet

Full Color Weather Map

Link to Loop


Other links: GEOS-West     Contential US     Full GOES-East

Portland, OR,