Short Spring Heat Wave for the Pacific Northwest

 FastCast--Thursday, May 9 to Tuesday, May 14:

A spring "heat wave" is ahead for the Northwest, with the warmest temperatures seen in months likely from Friday to Sunday. In the lowlands, expect sunny conditions through midday Sunday, before partly to mostly cloudy conditions take over from midday Sunday through Tuesday. Lowland highs will reach the low to mid 70s on Thursday. Friday and Saturday will be the hottest days since late last summer, with lowland highs reaching the low to mid 80s, hottest from Seattle southward. Cooler marine air will return on Sunday, with highs dropping to the mid 70s. Continued marine air will bring temperatures down to the mid to upper 60s on Monday and Tuesday. Remember, although temperatures will be warm, the water is NOT! Water temperatures across the region are in the 40s to low 50s, with some mountain-fed rivers in the 30s! These water conditions can cause severe health emergencies or even death. Be extremely careful around water during this warm spell.

----------------------------------------------------------------------------

Continue reading the full blog below!

Warm weather is here! The warmest temperatures of 2024 (so far) are expected over the next few days, from Friday to Sunday, depending on what part of the state you're in. Let's take a look at the forecast!

First, the NWS NBM model high-resolution forecast for highs on Thursday, seen below.

Expect lowland highs to reach the low to mid 70s, with areas east of I-5 and south of Olympia reaching the upper 70s. The coast will reach the mid 60s on the beaches to mid 70s just inland, and the Willamette Valley will reach the upper 70s to low 80s. Eastern Washington will reach the mid 70s to low 80s, warmest in valleys and around the Tri-Cities.

Next, let's take a look at Friday's forecast, also from the NWS NBM model.

Friday will likely be the first 80°+ day of 2024 for most areas from Everett southward. Expect highs in the low to mid 80s from Seattle southward, and in the mid 70s to low 80s from Everett northward. The hottest temperatures will be in the mid 80s, mainly in mountain valleys. The coast will reach the low 70s (hottest day in this stretch along the coast), while the Willamette Valley will reach the upper 80s, with an outside chance at the Portland area reaching the low 90s. Eastern Washington will also be quite warm, with highs across the region in the upper 70s to mid 80s, hottest in the lower Columbia Basin.

We'll continue into the weekend, taking a look at Saturday's highs below, from the NWS NBM model.

On Saturday, the lowlands will reach the mid to upper 70s north of Everett, and the low to mid 80s south of Everett. There is potential for low 80s to be more widespread across the North Sound. The Willamette Valley will reach the mid to upper 80s, while Eastern Washington will reach the low 80s near Spokane to the low 90s in the Columbia Basin. Cities like Yakima and the Tri-Cities will likely reach the low 90s. Notice that on the coast, temperatures will drop to the low 60s on the beaches and mid to upper 60s inland. That's the "natural air conditioning" of the Pacific Northwest moving in.

The effect of that "natural A/C" (and incoming clouds) will be seen west of the Cascades on Sunday, as the NWS NBM model forecast shows.

On Sunday, temperatures west of the Cascades will decrease noticeably. Expect the lowlands to drop to the low to mid 70s, while the Willamette Valley will drop to the upper 70s. The coast will be much cooler, with highs in the upper 50s to low 60s. However, notice that the cooler marine air hasn't reached Eastern Washington, where highs will remain in the low 80s near Spokane to upper 80s/low 90s for the Columbia Basin.

Temperatures statewide will decrease on Monday and Tuesday as cooler marine air moves through. However, rain remains unlikely for at least the next 7 days, possibly longer.

What is causing such a nice stretch in mid-May? That question is easily answered by looking at the European model forecast for Friday morning, showing atmospheric pressure at 18,000 feet (called 500 millibars in the weather world).

Notice the large high pressure ridge centered just offshore of the Pacific Northwest and over Southern BC. This ridge has the proper placement and strength to bring a short-lived heat wave to the region. In summer, the overall pattern favors ridges like this being larger, stronger, and lasting longer, contributing to more intense heat waves.

However, regardless of the strength of this heat wave, adverse impacts are still possible, especially if you are recreating in the water. Take a look at the very informative graphic below from NWS Seattle, showing the dangers of the region's very cold water.

Consider these reminders if you're around the water while it's hot outside. Remember how cold and dangerous our waters can be!

Stay tuned for more information about the hot weather and extended forecast!

Brief Spring Atmospheric River Bringing a Wet Weekend

 FastCast--Saturday, May 4 to Thursday, May 9:

A fast-moving atmospheric river will bring a wet weekend to the Pacific Northwest. With the majority of the atmospheric river being aimed at Oregon, Washington's rain totals will be heaviest the further south you go. In the lowlands, generally expect 0.75-1.25" from Seattle southward, and 0.4-0.8" from Seattle northward. Expect rain at times from early Saturday through Sunday, becoming more showery on Monday. Some showers may linger into Tuesday. Conditions will change on Wednesday, turning partly sunny. Mostly sunny skies are likely by Thursday. Regarding temperatures, the weekend will be chilly around the lowlands, with highs in the low to mid 50s. However, Saturday's highs north of Everett will likely reach the mid 60s. Temperatures will be in the mid to upper 50s on Monday and Tuesday, before reaching the low 60s on Wednesday. By Thursday, a warmup is likely to begin, with highs reaching the upper 60s to low 70s. Expect lows through Thursday to remain in the low to mid 40s. Even warmer conditions, likely the warmest of 2024 so far, are possible for Mother's Day weekend, so stay tuned!

--------------------------------------------------------------------

Continue reading the full blog below!

A brief spring atmospheric river is impacting the Pacific Northwest, especially Western Oregon, with significant precipitation this weekend. Let's take a look at the forecast!

We'll start with the European model forecast for precipitable water late Friday night, showing the location of the heavier concentrations of water vapor (aka...the atmospheric river).

Notice how the highest concentrations of moisture are directed at Western Oregon, with some elevated moisture content making its way into Western Washington.

Now, let's look at rain totals. First, we'll take a look at the European model forecast for total rain through Monday night.

From Skagit County southward, this forecast shows 0.5-1" of rain, with areas from Olympia to Portland and on the coast getting 1.25-2", and the Willamette Valley and Oregon Coast being soaked by 2-2.5"! Whatcom and San Juan Counties will likely receive 0.3-0.5". Even Eastern Washington will get in on the rain, with most of the region getting 0.4-0.8", except 0.75-1.25" along and south of I-82.

We'll compare this to the NWS NBM high-resolution model forecast, seen below, also showing total rain through Monday night.

This forecast shows a similar picture for the lowlands and coast, with the Willamette Valley getting 1.4-2", and the Oregon Coast getting 1.5-2.5". Eastern Washington's highest amounts are confined to areas south of I-90 and near the Idaho border, with totals of 0.5-1.2", highest near Walla Walla and the Tri-Cities.

Temperatures will be on the cool side due to all the rain and cloud cover. Below is the NWS NBM forecast for highs on Saturday.

As rain and clouds will move from south to north, notice that highs increase as you move north through the lowlands. Areas from Everett to Tacoma will reach the mid to upper 50s, with areas north of Everett in the mid to upper 60s. From Tacoma south, expect highs in the low to mid 50s, except in the low 50s on the coast and in the Willamette Valley. Removed from the rain on Saturday, Eastern Washington will reach the upper 60s to mid 70s.

The entire region will be cool and cloudy on Sunday, as seen in the NWS NBM forecast below.

On Sunday, expect highs west of the Cascades to reach the low to mid 50s, with Eastern Washington reaching the low 50s near Spokane to low 60s near the east slopes of the Cascades. However, the Okanogan River Valley may reach the upper 60s to low 70s.

Here's the NWS NBM forecast for Monday, as the atmospheric river's associated rain begins to move out of the region.

Temperatures on Monday will remain on the cooler side, with highs in the low to mid 50s west of the Cascades, and in the upper 50s to mid 60s in Eastern Washington.

However, a significant change is possible as we move through next week. Below is the European model forecast for Thursday.

Notice the large ridge of high pressure located just north of Washington. This ridge, which will build from Wednesday onward, will set the stage for a warm end to the week and Mother's Day weekend, so stay tuned! There is a potential for the warmest conditions of 2024 so far!

Mostly Dry to Begin May, Rainy Weekend Likely

 FastCast--Wednesday, May 1 to Sunday, May 5:

After a few days of showers, a relatively dry remainder of the work week is expected. Partly sunny conditions are expected on Wednesday, with highs reaching the upper 50s to low 60s. Thursday will be the best day of the week, with mostly sunny skies and highs in the mid 60s across the region. Clouds will return on Friday, but highs will remain in the mid to upper 60s. However, rain will move in by late Friday evening, continuing at times through late Sunday. Precipitation totals look to be on the heavier side for this round of rain, with amounts of 0.5-1.5" possible, depending on which forecast we look at. Temperatures on the weekend will decrease to the mid 50s, with lows from Friday to Sunday in the mid 40s. Notably, lows on Wednesday and Thursday will be in the mid to upper 30s, with a slight chance for frost in some outlying areas on Wednesday morning. Stay tuned over the next few days for more information about the weekend forecast.

----------------------------------------------------------------------------

Continue reading the full blog below!

A couple nicer days are ahead across Washington, following a few days of showers. Let's take a look at the forecast, and a look ahead to a potentially wetter weekend.

Below is the forecast for morning lows on Wednesday from the NWS NBM model.

Expect morning lows in the mid to upper 30s outside the metro area, with the cities remaining in the upper 30s to low 40s. Eastern Washington will drop to the low to mid 30s. Any areas below approximately 35-36° have a potential for frost, so be aware of this possibility.

Highs on Wednesday will be an increase from Tuesday, as seen below in the NWS NBM forecast.

On Wednesday, expect lowland highs in the upper 50s to low 60s, coastal highs in the mid 50s, Willamette Valley highs in the upper 50s, and Eastern Washington highs in the upper 50s near Spokane and Ellensburg to the mid to upper 60s in the Columbia Basin.

Next, let's take a look at highs on Thursday, which will be the sunniest day in Western Washington, albeit not the warmest. The NWS NBM forecast is below.

On Thursday, the lowlands will reach the low to mid 60s, with the Willamette Valley and coast reaching the upper 50s to low 60s. Eastern Washington will reach the low 60s near Spokane to upper 60s in the Columbia Basin.

Friday will be the warmest day for awhile, but Western Washington's skies will be mostly cloudy as our wet weekend system moves in. Below is the NWS NBM forecast.

Expect highs on Friday to reach the mid to upper 60s in the lowlands, with the coast reaching the upper 50s, the Willamette Valley reaching the upper 50s to mid 60s, and Eastern Washington reaching the mid 60s to mid 70s.

Quite a wet weekend is possible, especially on the European model forecast. We'll look into the weekend forecast more over the next few days, but below is the forecast for total rain in the 48-hour period from Friday evening to Sunday evening.

This forecast shows heavy rain totals of 1-1.5" from Seattle southward through the Willamette Valley, with 0.3-0.9” from Seattle northward. This forecast doesn’t necessarily encompass rain totals for the whole region over the entire weekend, so stay tuned for more information over the next few days!

Lowland Showers & Mountain Snow to End April

 FastCast--Monday, April 29 to Friday, May 3:

Showers will continue on Monday and the first half of Tuesday across Western Washington. Generally, expect 0.3-0.6" of additional rain, most under Convergence Zone bands and from Olympia south. Some areas may get over 0.6" of rain through Tuesday. There is also a region-wide chance of thunderstorms on Monday and Tuesday, specifically in the afternoons. Remember that any showers have the potential to produce thunder, lightning, and gusty winds. Be prepared if you are outside. Snow levels in the mountains will decrease to 2,000-2,500 feet on Monday and Tuesday. Expect higher passes like Stevens and White to receive up to 8" of snow, with Snoqualmie Pass picking up 2-4". Some winter driving conditions are possible, so don't be caught off-guard by late April snow! Regarding lowland temperatures, Monday and Tuesday will be on the chilly side for April, with highs in the low to mid 50s both days. Wednesday will be mostly sunny, with highs increasing to the upper 50s to low 60s. Clouds and showers will return on Thursday, but temperatures will remain in the upper 50s to low 60s. Friday will be the nicest day of the week, with mostly sunny skies and highs likely in the mid to upper 60s! Expect overnight lows to generally be in the upper 30s to mid 40s, coldest on Monday and Wednesday mornings.

------------------------------------------------------------------

Continue reading the full blog below!

More showers are expected on Monday and Tuesday, along with a region-wide chance of thunderstorms. Additionally, snow levels will be down to 2,000-2,500 feet on Monday and Tuesday, bringing a chance of late April snow at the passes.

Let's start with the snow forecast. Below is the NWS NBM high-resolution snow forecast through Tuesday evening.

This forecast shows the higher passes (Stevens & White) getting 6-10" of snow, with Snoqualmie Pass getting up to 3-5", Paradise and Crystal Mountain getting 6-10", and Mount Baker and the North Cascades Highway getting 4-5". This event shows that mountain snow is still possible at the passes into April. Be prepared for potential winter driving conditions over the passes, especially on Monday.

Now...back to the lowlands. Let's take a look at expected rain through Tuesday night. Most showers will be on Monday, with showers decreasing in coverage on Tuesday. Below is the European model forecast for rain through Tuesday night.

Generally, expect an additional 0.3-0.5" of rain across the lowlands. However, with the showery nature of the incoming precipitation, totals will likely be a bit more scattered. This forecast shows areas of higher rain totals between Tacoma and Mount Vernon, due to Convergence Zone bands (0.5-0.9"), and areas south of Olympia getting 0.6-0.8". The coast gets 0.5-1.5" through Tuesday, with parts of Eastern WA near the Cascades and near the Idaho border getting 0.2-0.4". 

Let's compare this with a higher-resolution forecast, which will show the potential areas of heavier precipitation due to showers and thunderstorms. Below is the NAM high-resolution forecast for total rain through Tuesday night.

This forecast shows areas of showers producing paths of increased precipitation, on both sides of the Cascades. Overall, the lowlands receive at least 0.25" of rain, with areas of heavier showers getting up to 0.8", with isolated higher totals, especially in Convergence Zone bands and on the coast.

The cause of these strong showers that could bring high rainfall totals is a region-wide chance of thunderstorms, on Monday and Tuesday, but with the higher chance being on Monday. Below is the NAM high-resolution forecast for CAPE (instability in the atmosphere) on Monday afternoon.

This forecast shows CAPE values of 200-500 across Washington on Monday afternoon. While these values would be considered quite low in the Midwest, they're at least respectable for Washington.

Another way of looking at thunderstorm potential is lightning flash density, essentially the chance of lightning at a given spot over a certain time period. In this case, we're looking at 3-hour lightning flash density on Monday afternoon, forecasted from the European model.

This forecast shows a lightning potential for most of the lowlands, with the highest potential in Eastern Washington, especially around the Tri-Cities, Walla Walla, and the Eastern Columbia River Gorge. The thunderstorm chance in Western Washington is going to be highest around the Convergence Zone, so likely somewhere between Seattle and Skagit County.

Any strong showers or thunderstorms that do develop will bring heavy rain, gusty winds, a potential for small hail, and of course, a chance of thunder and lightning. Visibility will likely decrease while driving, and areas of standing water are possible too.

There's a good amount of weather going on through Tuesday, with mountain snow, lowland showers, and a statewide chance of thunderstorms! Be prepared out there!

Wet Weather Returns to Western Washington

 FastCast--Thursday, April 25 to Monday, April 29:

After a relatively dry month, by Seattle standards, a rainy pattern will return to Western Washington to round out April. Thursday will be the rainiest day of the pattern, with 0.4-0.8" of rain across the lowlands. A chance of showers will persist every day through at least Monday, and likely beyond. Conditions will be overcast, except for some potential sunbreaks on Monday. High temperatures will be below average, with highs on Thursday only reaching the low to mid 50s, and remaining in the mid to upper 50s through Monday. Wetter and cloudier conditions will keep lows in the upper 40s through Sunday, decreasing to the upper 30s to low 40s by Monday. Despite a wetter pattern, snow will remain mostly above 5,000 feet, with a trace to 1" of snow possible at the higher passes through early next week.

--------------------------------------------------------------

Continue reading the full blog below!

A wet pattern is returning to Western Washington after a relatively dry past few weeks. Let's take a look at the forecast!

We'll start with the European model forecast for rain through midday Friday.

This forecast shows areas from Seattle south and Mount Vernon north getting 0.5-0.8" of rain by midday Friday, with a rain shadow from Seattle to Mount Vernon, and west along the Strait, where 0.3-0.5" of rain is possible. The coast and mountains will receive 1-2" of rain, most in the Olympic Mountains. Parts of Eastern Washington, mainly mountainous areas, will get 0.1-0.3" of rain.

Let's compare this forecast to the high-resolution NWS NBM forecast, also showing total rain through midday Friday.

This forecast largely agrees with the European model, except it shows a lesser rain shadow, which is mainly confined to areas west of Whidbey Island. This forecast shows 0.5-0.9" of rain in the lowlands, with 1-2" on the coast, and up to 3.75" in the mountains, most in the Olympics and Southern Cascades.

What about mountain snow? Below is the European model forecast for total snow through midday Friday.

As we get later in spring, it gets harder to get significant snowfall. The winners for snow will be the volcanic peaks, with Paradise and Mount Baker being the only recreation areas to get some snow, as the snow level remains around 5,000 feet.

You'll definitely notice that temperatures will be on the cooler side, as seen below in the NWS NBM forecast for Thursday's highs.

This forecast shows highs on Thursday only reaching the low to mid 50s west of the Cascades. Eastern Washington will reach the low to mid 60s. Expect temperatures across the state to warm a few degrees on Friday.

We'll end this blog by taking a look at the extended outlooks for the end of April and first few days of May. These outlooks are from the NWS Climate Prediction Center (CPC). 

First, the CPC temperature outlook.

For April 30-May 4, this outlook shows a 50-70% probability of below-average temperatures in Washington, highest for Western Washington.

Next, let's see how the temperature and precipitation outlooks correlate.

This outlook shows a 40-50% probability of above-average precipitation for Washington through the first week of May. 

Stay tuned for more information, and enjoy the rainy weather while we have it! All the rain counts toward more water for the summer!

Warm Tuesday, Wetter & Cooler Pattern Ahead

FastCast--Tuesday, April 23 to Friday, April 26:

A warm day is ahead on Tuesday, with highs in the lowlands reaching the upper 60s to low 70s, under partly to mostly sunny skies. However, a major pattern change is ahead, with a shift to cooler and wetter conditions. Highs will drop to the upper 50s to low 60s by Wednesday, with overcast skies. Rain will move in on Thursday, continuing at times through Friday. Through late Friday, most of the lowlands will receive 0.4-0.8" of rain. High temperatures will also be on the cool side, only in the low to mid 50s. Expect lows in the low to mid 40s. (Check the bottom of the blog for a list of peak winds from the stronger-than-expected Saturday storm).

To see some video of the gusty winds and a timelapse of the Saturday storm, check out my YouTube channel by clicking the YouTube logo to the right!

-----------------------------------------------------------------------

Continue reading the full blog below!

For the last time in awhile, the lowlands will have a warm and pleasant day, with highs likely reaching into the 70s. However, big changes are ahead, with a pattern change likely. Let's take a look at the forecast!

Let's start with the NWS NBM high-resolution forecast for high temperatures on Tuesday.

Tuesday will be warm and pleasant across Washington. Expect lowland highs to reach the upper 60s to low 70s, except in the mid 60s from Everett northward. The coast will reach the upper 50s to low 60s, the Willamette Valley will warm into the low to mid 70s, and Eastern Washington will reach the mid 60s to low 70s.

Temperatures will begin to cool down on Wednesday. Below is the NWS NBM forecast for highs on Wednesday.

Lowland highs will drop to the upper 50s to low 60s on Wednesday, with the coast dropping to the mid 50s and the Willamette Valley dropping to the mid 60s. Eastern Washington will warm into the mid 60s to mid 70s, getting warmer instead of cooling down as the high pressure ridge moves eastward.

Temperatures will cool further by Thursday, as seen in the NWS NBM forecast.

Highs across Western Washington and Oregon will drop to the low to mid 50s. Eastern Washington will drop to the low to mid 60s, except the upper 60s around the Tri-Cities. 

As the temperatures cool across the region, weather systems will begin to move in. A system will spread rain across Western Washington on Thursday, with showers continuing on Friday, and likely into the weekend. The European model forecast below shows total rain through Friday night.

This forecast shows the lowlands getting 0.5-0.8" of rain, except some areas north and east of the Olympics will get less rain in a rain shadow. Areas from Olympia south will receive 0.8-1.3", and the coast will get 1.3-1.6". Even Eastern Washington will get in on the rain, with 0.1-0.3" for most of the region. The mountains of NE Washington will get up to 1" of rain.

So...what's the cause of this pattern change? Take a look at the European model forecast below, showing the high and low pressure systems at around 18,000 feet late Thursday.

This shows a broad area of troughing over the Pacific Northwest by Thursday. Troughing will likely continue across the Northwest through the end of April...so stay tuned!

------------------------------------------------------------

Saturday Peak Winds:

NAS Whidbey: 49 mph

Shelton: 46 mph

Port of Tacoma: 44 mph

Bremerton: 43 mph

Camano Island: 42 mph

Lake Stevens: 40 mph

Tacoma Narrows: 39 mph

Boeing Field: 38 mph

Sea-Tac Airport: 37 mph

These winds caused over 22,000 PSE customers to lose power, with over 10,000 customers losing power in the Seattle City Light and Snohomish PUD service areas as well.

Rapid Saturday Evening Cooldown to End Warm Stretch

FastCast--Friday, April 19 to Tuesday, April 23:

Friday will be a warm and beautiful day across Western Washington. Highs will likely reach the upper 60s to low 70s, with easterly gap winds bringing warming and gusts of 30-40 mph for the foothills. High clouds will move in on Saturday, with highs reaching the upper 60s to low 70s by mid-afternoon. Then, a strong marine push combined with an incoming cold front will bring a rapid cooldown, with temperatures dropping 15-20° within 3 hours by early evening. Winds will briefly gust 30-40 mph across the region, and showers will move through. A Convergence Zone setting up between Northern King and Skagit Counties will bring a chance of thunderstorms north of Everett on Saturday night. By Sunday, conditions will be partly cloudy, with highs in the mid 50s to low 60s. Monday will be partly cloudy, with highs increasing to the upper 50s to low 60s, followed by mostly cloudy skies and highs increasing further to the mid to upper 60s on Tuesday. Overnight lows through Tuesday will be in the low to mid 40s. By the middle of next week, we'll likely start to cool down again.

---------------------------------------------------------

Continue reading the full blog below!

A warm and pleasant day is expected on Friday, followed by another warm day on Saturday, with a marine push/cold front combination on Saturday evening bringing a major cooldown, gusty winds, and showers. Let's take a look at the forecast!

We'll start with the NWS NBM model high-resolution forecast for highs on Friday.

Expect highs in the lowlands to reach the upper 60s to low 70s, with some areas in the North Sound remaining in the mid 60s. The coast will reach the mid to upper 60s, the Willamette Valley will reach the low to mid 70s, and Eastern Washington will reach the mid 50s to low 60s in the north and mid to upper 60s in the south.

Part of the reason that the lowlands will be much warmer than Thursday will be the presence of easterly gap winds (known as "Cascadia" winds). The NAM high-resolution forecast below shows the expected wind gusts through early Saturday.

Notice gap winds gusting 30-35 mph for parts of the lowlands, roughly from Federal Way to Seattle, with areas such as North Bend and Enumclaw reaching 35-40 mph. Also notice that the Portland metro area will have easterly gusts of 35-45 mph, strongest near the Gorge.

Now, let's take a look at Saturday's highs, also from the NWS NBM model.

Saturday will be warmer for most of the region, despite there being near 100% cloud cover due to high clouds. Expect the lowlands to reach the mid 60s to low 70s, with the coast only reaching the low 60s, the Willamette Valley also reaching the mid 60s to low 70s, and Eastern Washington reaching the mid 60s to low 70s.

However, this forecast is somewhat deceptive. Saturday's highs will occur around 2-3 PM, earlier than typical highs. Below is the NAM forecast for temperatures at 2 PM Saturday.

At 2 PM, the lowlands are in the upper 60s to low 70s. However, notice that the coast has dropped to the low 50s. Highs on the coast will occur around midday.

Around 2 PM, a marine push/cold front will be located between the coast and the lowlands, moving quickly eastward. To see this, let's take a look at temperatures by 5 PM Saturday.

By 5 PM, the marine push/cold front will have hit the lowlands, with temperatures dropping rapidly, all the way down to the low 50s in Olympia, the mid 50s to low 60s along the I-5 corridor. Notice how the foothills are still in the mid 60s at 5 PM.

However, by 8 PM (seen below), the marine push/cold front will have advanced through the entirety of Western Washington, bringing much cooler temperatures in its wake.

By 8 PM, all of Western Washington has dropped to the mid 40s to low 50s, with Eastern Washington cooling rapidly into the low 50s to low 60s.

A great visualization of the rapid temperature decrease is found on this map below, showing the NAM model forecast for temperature change from 3 PM to 6 PM Saturday.

This shows that as the marine push/cold front moves across Western Washington, temperatures will drop 15-20° within 3 hours. This temperature drop will occur across the entire region as this feature moves through.

Another impact of this feature will be a brief shot of wind through the region. In addition to strong westerly winds through the Kittitas Valley and some gusty winds across parts of Eastern Washington, gusty southwest winds will move through the lowlands on Saturday evening. Below is the NAM high-resolution forecast showing gusts at 6 PM.

Around 6 PM Saturday, as the marine push/cold front moves through the lowlands, expect winds to increase, with brief gusts of 30-35 mph, with some areas gusting up to 40 mph, especially near the water and in the San Juan Islands.

One final weather impact to be aware of with this feature is that in addition to bringing a brief round of showers from late Saturday afternoon through the evening, a Convergence Zone band between Northern King and Skagit Counties will bring a slight chance of thunderstorms late Saturday night. Below is the European model lightning forecast for Saturday night.

This forecast shows lightning potential over Island, Skagit, and Snohomish Counties. This outlines the potential for thunderstorms in this Convergence Zone band. There is also a very low, but non-zero chance for isolated thunderstorms along the main marine push/cold front as it moves across the lowlands on Saturday evening.

Stay tuned for more information via Twitter and Pacific Northwest Weather Watch YouTube (link on right side of blog) about this dynamic feature on Saturday, and enjoy the sun & warmth while it lasts!

Chilly Start to Wednesday, Warmup Ahead

 FastCast--Wednesday, April 17 to Sunday, April 21:

After a couple showery and cooler days on Monday and Tuesday, a warmup and transition to mostly sunny conditions is expected through Friday. Wednesday morning will be quite chilly across the region, with lows in the low to mid 30s in the lowlands. Afternoon highs will reach the mid 50s in the north to the upper 50s to low 60s in the south. Lows on Thursday morning will reach the upper 30s, followed by highs region-wide reaching the low to mid 60s. Friday will be the nicest day of this stretch, with highs reaching the upper 60s across the region, with sunny skies. Clouds and a chance of showers return on Saturday, with highs likely dropping back to the upper 50s to low 60s. Sunday looks to be partly cloudy, with highs again in the upper 50s to low 60s. Expect morning lows from Friday to Sunday to be in the low to mid 40s.

------------------------------------------------------------------

Continue reading the full blog below!

Cooler and showery weather will soon be replaced by a few days of sunshine, with temperatures warming each day through Friday. However, before we get there, we will have a chilly morning, with frost possible across some parts of the region. Let's take a look at the forecast!

Below is the NWS NBM model forecast for low temperatures on Wednesday morning.

Expect lows in the lowlands to reach the low to mid 30s, likely coldest from Tacoma southward. Eastern Washington will also have lows in the low to mid 30s, coldest in the Palouse and near the Cascades. Any frost that forms at this time of year can damage sensitive plants. If you have sensitive plants, be sure to move them inside for Wednesday morning's lows, and for Thursday morning's lows in Eastern Washington.

Under mostly sunny skies, Wednesday will be warmer than Tuesday was, as seen below on the NWS NBM forecast.

Expect highs across Western Washington to reach the upper 50s to low 60s, with some areas remaining in the mid 50s. The Willamette Valley will reach the low to mid 60s, while Eastern Washington will reach the mid 50s around Spkane and the Palouse and the low to mid 60s in the Columbia Basin.

Further warming is expected on Thursday, as seen in the NWS NBM forecast below.

On Thursday, expect highs in Western Washington to reach the low to mid 60s, with the Willamette Valley reaching the upper 60s to low 70s. Eastern Washington will be a bit slower to warm up, with highs in the mid 50s around Spokane and the mid 60s in the Columbia Basin.

Finally, let's take a look at highs on Friday, which will be the warmest day of the week.

Friday will be quite nice across Western Washington, with highs reaching the mid to upper 60s (possibly the low 70s in the metro areas). The Willamette Valley will reach the low to mid 70s, while Eastern Washington warms up to the mid 50s to upper 60s.

The best thing about Wednesday, Thursday, and Friday is that skies will be almost 100% clear, save for some areas of morning clouds, especially along the coast. What is causing these clear skies and warmer days? Take a look at the European model forecast below.

Notice a large ridge of high pressure over Alaska and Northwestern Canada, with troughing over the Midwest US, and a subtle ridge over the Northwest. That ridge, in combination with the larger-scale pattern, is bringing our brief warm spell.

Stay tuned for more information about the weekend forecast and what's ahead next week!

Early Week Cooldown Followed by Midweek Rebound

 FastCast--Monday, April 15 to Friday, April 19:

Sunday was warm and beautiful across much of Washington state, with lowland highs reaching the mid to upper 60s! However, significant changes are ahead, with a large cooldown on Monday and Tuesday. Breezy westerly winds will gust up to 40-45 mph along the Strait and in Island County through midday Monday, with gusts of 20-30 mph possible around the lowlands through Monday evening. Monday will be mostly cloudy, with lowland highs in the low to mid 50s. Highs on Tuesday will be relatively similar, but clouds will decrease throughout the day. Temperatures rebound on Wednesday, with lowland highs increasing to the upper 50s to low 60s. Of note is that Wednesday morning lows will likely drop to the low to mid 30s across the lowlands, meaning that localized frost is possible. Be aware of this if you have sensitive plants. Highs will increase to the mid to upper 60s on Thursday and Friday. Expect conditions to be mostly sunny from Wednesday to Friday!

-----------------------------------------------------------------------------------

Continue reading the full blog below!

After a beautiful weekend, a cooldown is in store across the state to begin the work week.

Let's start with the forecasted temperature change from Sunday afternoon to Monday afternoon, seen below in the European model forecast.

Almost the entire state will see a 10-20° drop in temperatures on Monday compared to Sunday. The coast will see a lesser drop since marine air had already moved in earlier on Sunday. 

This temperature decrease is being driven by gusty westerly winds, that increased late Sunday evening, and will continue at times through Monday. Let's take a look at the NAM high-resolution forecast, showing peak wind gusts through Monday.

This forecast shows westerly winds along the Strait of Juan de Fuca and in Island County gusting 40-45 mph, strongest on Northern Whidbey Island and near Port Angeles. The coast and lowlands will gust 20-30 mph at most. Eastern Washington is a different story, with most areas near the eastern slopes of the Cascades gusting 40-50 mph, strongest in wind-prone gaps such as the Kittitas Valley, and in wide, flat areas downwind of gaps, such as the Waterville Plateau. The Palouse region and areas east of the Columbia River Gorge will also see gusts of 35-40 mph.

These winds will usher in cooler temperatures across the entire region. Below is the NWS NBM high-resolution forecast for highs on Monday.

Expect lowland and coastal highs to drop to the low to mid 50s, warmest from Tacoma to Olympia. The Willamette Valley will drop to the upper 50s. Eastern Washington has one more warm day, with highs remaining in the low to mid 60s, except in the upper 60s in the lower Columbia Basin.

By Tuesday, most of the state will be on the cooler side, as seen below.

The coast and lowlands will again be in the low to mid 50s, with the Willamette Valley in the mid to upper 50s. Eastern Washington will cool dramatically, with highs only in the low 50s near Spokane to the low 60s in the Tri Cities.

Conditions will begin to get warmer by Wednesday, but before we get there, we'll have a chilly morning, with some frost possible. Below is the NWS NBM forecast for Wednesday morning's lows.

On Wednesday morning, lows will drop to the low to mid 30s in Western Washington and the Willamette Valley, and will also drop to the low to mid 30s in Eastern Washington. This means that some frost is possible across the state. This is a threat to sensitive plants, so be aware of this frost possibility on Wednesday morning.

Finally, here's a look at highs on Wednesday, as temperatures begin to rebound across the state. 

Highs in the lowlands and along the coast will increase to the upper 50s to low 60s under mostly sunny skies. The Willamette Valley will warm into the mid 60s, with Eastern Washington increasing to the mid 50s around Spokane and the low to mid 60s in the Columbia Basin.

Stay tuned for more information on what looks to be a warm and sunny end to the week!