Sunrise 5:57 AM   Sunset 8:19 PM Moonrise 1:35 AM   Moonset 10:01 AM

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PZZ210 Columbia River Bar- 218 Am Pdt Tue Apr 30 2024
.small craft advisory in effect through this evening - .
In the main channel -
General seas - 6 to 8 ft subsiding to 3 to 4 ft Wednesday morning.
First ebb - Ebb current of 4.71 kt at 941 am Tuesday. Seas 8 ft.
SEcond ebb - Ebb current of 2.28 kt at 1055 pm Tuesday. Seas 6 to 7 ft.
Third ebb - Ebb current of 4.39 kt at 1056 am Wednesday. Seas 4 ft.

PZZ200 218 Am Pdt Tue Apr 30 2024
Synopsis for the southern washington and northern oregon coast - Weak low pressure will continue to move across the northern waters through Tuesday morning. High pressure brings calmer conditions Tuesday night into Wednesday morning. Another system approaches later Wednesday.

FXUS66 KPQR 301030 AFDPQR

Area Forecast Discussion National Weather Service Portland OR 330 AM PDT Tue Apr 30 2024

SYNOPSIS
Another relatively cold weather system will move through the region today, bringing rain showers, Cascade snow showers, and a 15-30% chance for thunderstorms. Potential hazards with any thunderstorm development include lightning, small hail, heavy rain, and gusty winds. Very brief drying and warming arrive on Wednesday before the next system arrives on Wednesday night to Thursday. Unsettled weather likely continues this weekend into early next week.

SHORT TERM
Now through Wednesday night...An upper level trough is making its way toward the Pacific Northwest this (Tue)
morning. Satellite imagery as of 3 AM PDT shows the associated surface low centered around 47.14N 127.39W, just off the coast of Washington. This system is already returning shower activity across northwest Oregon and southwest Washington this morning.
Expect rain showers, Cascade snow showers, and a 15-30% chance of thunderstorms today as the low progresses southeast and makes landfall along the north/central Oregon coast. Snow levels in the Cascades will be around 3000 to 3500 feet.

Any thunderstorms that do develop today could bring moments of lightning, small hail, heavy rain, and/or gusty winds. We'll see an unstable environment today as the aforementioned upper level trough advects positive vorticity and cold air into the region.
This is often associated with upward motion (lifting) of air. NBM and HRRR guidance shows CAPE values ranging between 150-400 J/kg across the area today. Models also show 500 mb temperatures as low as -30 to -35 deg C with lapse rates of 7.5-8.5 deg C/km.
This will help with the formation of small hail.

The latest CAMs show the heaviest showers generally north of Lane County. 24 hr QPF amounts ending 5 AM Wednesday are forecast around 0.20-0.50 inch for the coast, Coast Range, and inland valleys. Meanwhile, forecast QPF in the Cascades will be between 0.75-1 inch, especially north of Lane County. The current Winter Weather Advisory for the Cascades between the South Washington Cascades and Marion/Linn County Cascades remains in effect through this evening, as convection may bring heavy snow showers at times. With snow ratios around 10:1, forecast snow amounts will generally be between 2-8 inches above 3000 ft, with the heaviest amounts above 3500 ft. Those traveling through the passes (highways 20/22/26) today should prepare for winter weather conditions.

Tonight into tomorrow (Wednesday), conditions dry as this system pushes east and upper level high pressure builds. We could see some clearing or cloud breaks Tuesday night, which would help with radiational cooling and thus frost development.
NBM/HRRR probabilities for Wednesday morning lows below 36 degrees are around 60-80% in the Coast Range, Willapa Hills, and Upper Hood River Valley, and 20-40% in the Willamette Valley.
However, there remains uncertainty with frost development since most model guidance is not showing complete clearing. In addition, winds Tuesday night don't go completely calm, so that could inhibit cooling as well. For now, a slight chance (15-24%) for patchy frost was kept in the forecast Tuesday night.

Temperatures warm up slightly on Wednesday, with highs in the upper 50s along the coast and Coast Range, low 60s for inland valleys, and 40s in the Cascades. The next system looks to arrive Wednesday evening into Thursday, bringing another round of precipitation, including Cascade snow. -Alviz

LONG TERM
Thursday through Monday...Most ensemble guidance suggests another trough will push through the region Thursday, bringing additional lowland rain and Cascade snow. The latest NBM shows a 30-40% chance that inland valleys receive 0.25 inch or greater of 24 hr QPF ending 5 PM Thursday. For the coast, Coast Range, and Cascades, this probability is around 40-60%.
Advisory-level snow is currently not expected in the Cascades, as NBM shows less than 5% chance of 4 inches of snow or more during this time frame.

Friday looks relatively drier as the majority of WPC clusters suggest transient ridging; however, the ridging doesn't look particularly strong. This may allow for some shortwave troughing to push through and bring some precipitation. The majority of clusters (at least 75%) still show precipitation on Friday, despite them also showing ridging.

Unsettled weather continues Saturday to Monday as WPC cluster analyses show a troughing pattern over the weekend and into early next week. There is some uncertainty with the weekend trough - Currently, about 65% of ensemble members show the trough pushing through the Pacific Northwest. In this scenario, we would receive another decent around of precipitation.
Meanwhile, 25% of members show the weekend trough dipping south toward the central coast of California. If this pans out, we would remain relatively drier. Finally, 10% of members depict a middle-ground scenario with the trough axis taking aim toward southern Oregon and northern California. We'll see how this shapes up later in the week. In general, the long term forecast does not depict any overly impactful weather. -Alviz

AVIATION
Generally VFR across the airspace, with a mixture of low-end VFR to high-end MVFR through at least 03Z Wednesday as showers and thunderstorms move across the airspace. Showers will continue to produce mountain obscurations through at least 03Z Wednesday. 15-20% probability for thunderstorms through 03Z Wednesday as showers diminish in a west to east direction. Any thunderstorms or heavier showers could result in small hail. After 03Z Wednesday expect improvement towards predominately VFR which should persist through the remainder of the TAF period as weak high pressure builds across the airspace.

Generally westerly winds with gusts up to 25 kt along the coast and southerly winds inland with gusts up to 20 kt. Expect a windshift around 18Z Tuesday to a more northerly wind pattern along the coast and more westerly inland around 21Z Tuesday along with gusts diminishing.

Notes: The ASOS at KTTD is only available via the dial in option.
The AWOS at KMMV is still out of commission, but a tentative work around has been implemented. There is no estimated time of full repair and restoration for either of these locations.

PDX AND APPROACHES...Generally VFR, with a mixture of low-end VFR to high-end MVFR through at least 03Z Wednesday as showers and thunderstorms move across the airspace. 15-20% probability for thunderstorms through 03Z Wednesday. After 03Z Wednesday expect improvement towards predominately VFR. Southerly winds inland with gusts up to 20 kt, with winds becoming more westerly around 21Z Tuesday. /42

MARINE
Gusty west/northwest winds and scattered showers continue across the coastal waters through this afternoon, maintaining low end Small Craft Advisories as winds occasionally gust to 25 kt and seas linger around 8 to 10 ft with a dominant period of 10 to 12 seconds through this evening. Weak high pressure will bring a brief lull in conditions tonight into Wednesday morning. More active weather then returns later Wednesday into Thursday as another low approaches the waters. /42

PQR WATCHES/WARNINGS/ADVISORIES

OR...Winter Weather Advisory until 6 PM PDT this evening for ORZ126- 127.

WA...Winter Weather Advisory until 6 PM PDT this evening for WAZ211.

PZ...Small Craft Advisory until 11 PM PDT this evening for PZZ210- 251>253-271>273.

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