Record Highs, Temperatures 10-15 Degrees Above Normal to Begin October

FastCast—Saturday, Oct. 1 to Saturday, Oct. 8:

October will begin with record high temperatures that are 10-15 degrees above normal. Highs will reach 75º+ degrees for most of the first week of October in the lowlands. Highs on Saturday, Sunday, and Monday will potentially reach 80º+, which is quite rare for October. Sunday and Monday’s highs will likely challenge daily records. By Tuesday, a few more clouds will return, with conditions remaining partly cloudy to mostly sunny through next Saturday (Oct. 8th). Highs from Tuesday to next Saturday will be in the mid to upper 70s. Lows throughout the entire week will be in the low to mid 50s, except in the upper 40s in outlying locations. Most days will have a northerly breeze that will keep highs near Puget Sound in the low to mid 70s. In Eastern Washington and other traditionally warmer locations, October will begin with over a week of highs in the upper 70s to mid 80s. On the plus side, morning lows will be crisp, in the upper 40s to low 50s. We will have to watch for any degraded air quality due to the lingering smoke from the Bolt Creek Fire as flow is generally offshore. AQI may degrade due to near-surface smoke on Saturday.

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It will be an abnormally warm beginning of October, with many days above 75º expected. The European model forecast for temperature anomalies in the Pacific Northwest on Monday afternoon says it all.

Notice that highs in Western Washington will be 10-20 degrees above average on Monday. This trend of highs anywhere 5-15 degrees above average will be consistent through at least the first 8 days of October. 

Before we examine the upcoming high temperatures, the HRRR forecast for near-surface smoke on Saturday afternoon/evening is below.

This near-surface smoke is from the Bolt Creek and White River Fires in the Stevens Pass vicinity. Some will also come from lingering fires in the North Cascades. Expect air quality to degrade to the moderate category, with isolated locations reaching the unhealthy for sensitive groups category. This is possible on Sunday as well, but the HRRR model hasn’t done too well with these smoke forecasts in the past couple weeks. A good place to monitor hyperlocal air quality is the PurpleAir AQI map. It is updated frequently with AQI monitors all around the region, maybe even in your neighborhood!

Let’s take a look at the highs for this weekend. It will feel like late summer! The HRRR forecast for Saturday is below.

Expect lowland highs in the mid to upper 70s, except in the low 70s near the water. Areas near the Cascades may reach the low 80s due to downslope flow. Also, notice the downslope flow bringing significant warming to Abbotsford, BC and parts of Whatcom County. Highs up to the mid 80s are possible. Offshore flow will bring highs in the upper 60s to low 70s to the Washington Coast. Areas from Olympia south and in Eastern Washington will reach the low 80s on Saturday.

The HRRR forecast for Sunday is reminiscent of late August.

Sunday will be quite warm. Expect lowland highs in the upper 70s to low 80s. Areas near Puget Sound may only reach the mid 70s. Areas near the Cascades, downstream of the Fraser River valley, from Olympia south, and in Eastern Washington have a chance to hit the mid to upper 80s. Offshore flow will bring highs in the upper 60s to upper 70s (warmest inland).

Monday is expected to be as warm or slightly warmer than Sunday. High temperature records are possible on Sunday and Monday. Stay tuned for updates on Monday’s temperatures and the extended period of highs in the mid to upper 70s.

A good way to see the expected trend in temperatures is in the NWS Climate Prediction Center outlook. The graphic below shows the likelihood of above or below average temperatures for October 6-10 (Thursday to next Monday).

Wow…a huge area of an 80-90% chance of above average temperatures (darkest color). Most of Western Washington has a 70-80% chance of above average temperatures heading into the second week of October. 

Additionally, the much drier than normal September has prompted the US Drought Monitor to place almost all of Washington state in the “abnormally dry” category. 

This map, released on Thursday, shows about 92% of Washington state in the abnormally dry category, with large areas of Eastern Washington under “moderate drought.” Although this is not good, the huge snowpack and wet spring have kept Washington from being in worse drought. 

Stay tuned to the blog as record high temperatures are possible again on Monday, with warm weather expected for the next week or more.

Catastrophic Hurricane Ian Slams Florida, Impacts Across Southeast US

No FastCast tonight…check back on Friday for an update regarding the potential for record breaking 80º+ degree temperatures to begin October.

On Wednesday, catastrophic Hurricane Ian hit Florida, making landfall just north of Fort Myers (about 80 miles south of Tampa Bay). At landfall, Ian was a high-end Category 4 hurricane, with sustained winds of 150 mph, just 7 mph from Category 5 strength. Ian is tied with Hurricanes Charley (2004), Laura (2020), and Ida (2021) as the 5th-strongest landfalling hurricane in US history.

The radar photo above shows Hurricane Ian making landfall, viewed on the RadarScope app. 

The tweet below from NOAA Satellites shows Ian making landfall from the GOES-16 weather satellite. Notice the lightning in the top right of the eye. Lightning in a hurricane eyewall indicates that a hurricane is very strong/strengthening.

Ian began causing damage and devastation even before it made landfall. The tweet below shows downtown Fort Myers, FL, before the worst of Ian arrived. By the peak of the storm surge, the street signs visible in the photo were underwater.

The instances of damage from storm surge, wind, and flooding are far too extensive to cover on this blog. To see more photos of Ian’s wrath in Southwest Florida, click the link below.

The Weather Channel: Hurricane Ian Photos

While just offshore prior to landfall, Hurricane Ian’s winds reached a peak of 155 mph. This was much higher than the forecast of 130 mph. As expected, these winds have (and still are) producing widespread power outages across Florida. The PowerOutage.us Florida outage map is below.

Notice the dark red colors in SW Florida. Some counties have 90-100% of the population without power. 10-50% of the population is in the dark across much of central Florida, with a total of about 2.1 million Floridians without power. 

Ian’s peak winds were incredible, as seen in the National Weather Service graphics below.

On the coastline of SW Florida, winds gusted 70-125 mph, including gusts to 85 mph in Sarasota/Bradenton and 100-125 mph (not all shown due to power outages) from Port Charlotte to Bonita Springs. 

The Tampa Bay Area recorded hurricane-force gusts of 70-80 mph, including 73 mph at Tampa International Airport. As Ian moves inland, strong gusts are moving inland as well. Many inland areas, especially from Lakeland southeast toward Lake Okeechobee, have reached 60-90 mph.

So, what’s next for Ian? As of 9:45 PM PDT Wednesday, Ian is a 90 mph, Category 1 hurricane, moving NE across Central Florida. The official National Hurricane Center forecast is below.

Ian will move NE across Central Florida, moving into the Atlantic Ocean by Thursday night. Ian will make landfall near Charleston, South Carolina by Friday evening, as a 65 mph tropical storm.

The strongest winds now will be in Central and NE Florida, coastal Georgia, and the southern half of South Carolina. Those areas can expect winds gusting 50-70 mph. Storm surge of 3-6 feet is possible from Daytona Beach, FL to Myrtle Beach, SC, including the St. John’s River in Jacksonville. Other areas along the Atlantic coast from Cape Canaveral to the Outer Banks will have 1-3 feet of surge.

The European model forecast below shows expected rain totals through Sunday morning.

Areas that will receive the most rain (4-10 inches) will be Central and NE Florida, eastern Georgia, most of South Carolina, and parts of coastal North Carolina.

Finally, the chance of flash flooding will continue over the next few days, as seen in the NHC graphic below.

The highest chance for flash flooding remains in Florida (pink colors, 70%+ chance of flash flooding), with a moderate (40%+ chance) stretching along the coast into South Carolina. There is a risk of flash flooding for all parts of the Southeast US that are east of Atlanta and south of Roanoke or Richmond, Virginia.

For continued live updates on Hurricane Ian, use the links below (and stay tuned on Twitter).

National Hurricane Center: Hurricane Ian Hub

The Weather Channel

CNN Hurricane Ian Live Updates

NBC News Hurricane Ian Live Updates

Hurricane Ian Bringing Devastating Storm Surge, Wind, and Rain to Florida

FastCast—Wednesday, Sep. 28 to Monday, Oct. 3:

There is a decent chance of showers across Western Washington on Wednesday, mainly in the afternoon, through early Thursday morning. Rain totals will be sporadic, with totals varying from a trace to 0.3 inches across the lowlands. However, the incoming weak system will clear out surface smoke and drop high temperatures from the upper 70s/mid 80s to the mid to upper 60s, a refreshing break. Conditions will remain cool and partly cloudy on Thursday, with highs in the mid to upper 60s. Conditions will be sunnier on Friday, with highs reaching the low 70s. However, October will begin with temperatures 5-15 degrees above average. Expect lowland highs in the upper 70s with sunny conditions on Saturday, Sunday, and Monday. Warmer than average temperatures look to continue through the first week of October. Throughout the period, expect lows in the upper 40s to low 50s. Read below for an update on Hurricane Ian.

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Dangerous Hurricane Ian is approaching Southwest Florida, with devastating storm surge, winds, and rain ahead. This blog will take a look at the very dangerous impacts of Ian in Florida and the Southeast at large.

Below is the official forecast from the National Hurricane Center (NHC) as of 8 PM PDT Tuesday.

Ian will make landfall on Wednesday evening as a Category 4 hurricane, with sustained winds of 130 mph. Landfall is expected to be between Fort Myers and Sarasota, FL. By Thursday morning, Ian will be a tropical storm with winds of 70 mph, over the Orlando area. By late Thursday, Ian will likely move offshore near Jacksonville, then back onshore near the Georgia/South Carolina border by Friday evening.

The hazard with the greatest threat to life in Hurricane Ian will be storm surge. The NHC storm surge forecast is below.

The worst surge will be on the SW Florida coast, from Sarasota to the Naples/Marco Island area. Surge on this stretch of coast (red on the map) will be 8-12 feet above ground level. Surge of 4-6 feet above ground will impact the Tampa Bay area, and surge of 1-6 feet will also impact the Big Bend, and surge of 4-6 feet has been observed in the Florida Keys, exceeding forecasts. 

Notice the surge forecast for the Atlantic Coast, from Cape Canaveral to the Central South Carolina coast. This is due to Ian's onshore winds on Wednesday and the future Tropical Storm Ian's impacts when moving toward Georgia and South Carolina.

Another major and prolonged hazard with Hurricane Ian will be excessive rainfall. The European model forecast through Saturday morning is below.

A relatively narrow area of 15+ inches of rain will exist across Florida, with most of West, Central and NE Florida getting hammered with 5-10 inches. 

This will contribute to a high risk of flash flooding. The NHC graphic below shows the risk of flash flooding through Friday. 

Areas in pink have the highest risk of dangerous flash flooding. The major urban areas of Tampa Bay, Orlando, and Jacksonville are all in the “high risk” area, with a 70% chance of flash flooding. Virtually the entire state of Florida, except the Panhandle, has a 40%+ chance of flash flooding through Friday. 

Before we get to the wind forecast, it is important to remember that forecast models often have a difficult time with predicting hurricane winds as storms move onto land. That is especially true in areas like Western Florida, where the coastline is full of marshes and inlets.

We will use the European model’s forecast showing peak winds over 6-hour periods.

This first frame is for Wednesday morning to early afternoon. Winds will gust 80-100+ mph from Tampa southward, and 45-55 mph along the east coast, including 50-55 mph in the urban core of Miami, Fort Lauderdale, and West Palm Beach. 

The continuation is below.

This frame is for Wednesday afternoon to about an hour after sunset. During this time, winds will be gusting 75-120 mph along the west coast of Florida. The remainder of the state will have gusts of 40-60 mph.

Over the next 24-36 hours, strong gusts of 50-75 mph will occur in the Orlando and Jacksonville areas, along with the east coast cities, mainly north of Cape Canaveral.

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Summary of Impacts & How to Stay Updated: 

Although Ian will be weaker over the interior of Florida, significant impacts are expected, along the the closures of Walt Disney World and Universal Studios Orlando. Additionally, as of Tuesday night, operations at the Tampa Bay, Fort Myers, and Orlando International Airports have been stopped or will be stopped. Significant delays are ongoing at Miami International.

From airports to highways, coastal communities to inland towns, and much more, Hurricane Ian will bring a plethora of devastating impacts to Florida. The biggest hazards are major storm surge, very strong winds, flash flooding and excessive rainfall, and a tornado threat in the outer bands of Ian. The storm’s slow speed will exacerbate all these impacts.

Hurricane Ian has already hit Western Cuba, crashing the entire country’s power grid, leaving 11 million Cubans in the dark. Key West, FL, has recorded its 3rd highest storm surge ever, and Ian is over 75 miles away. The worst has yet to come for Florida, sadly.

Stay tuned to Twitter, any national news outlet, The Weather Channel, FOX Weather, and of course the National Hurricane Center for all the latest updates throughout Hurricane Ian’s slow march through Florida, and keep all those impacted in your thoughts and prayers.

Record High Temperatures on Monday, Chance of Rain Midweek

FastCast-Monday, Sep. 26 to Thursday, Sep. 29:

Record high temperatures are ahead for Western Washington, especially on Monday. Highs in the lowlands will reach the low 80s, except cooler near the water. In Eastern Washington and the Willamette Valley, highs will reach the mid 80s to low 90s. Daily record highs will likely be set around the Pacific Northwest. It will only be slightly cooler on Tuesday, with lowland highs in the upper 70s, the low 80s in the Willamette Valley, and the upper 80s to low 90s again in Eastern Washington. From Sunday afternoon through late Monday, light winds will be fueling weak offshore flow, bringing a return of haze and surface smoke to the lowlands and Red Flag Warning conditions to the Cascades on Monday. Air quality may degrade to the Moderate or Unhealthy for Sensitive Groups categories, with areas near the Cascades potentially reaching the Unhealthy category. However, this will slowly change on Tuesday, as winds switch to light onshore flow. It will be much better by Wednesday, with clouds returning and highs dropping to the upper 60s. Then, from late Wednesday to Thursday morning, RAIN is in the forecast! Expect 0.2-0.4 inches of rain around the lowlands, the most since early July. Stay tuned for more information, and find an update on Tropical Storm Ian at the bottom of the blog.

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The hot and dry summer of 2022 just won’t stop! Yet another round of warm temperatures and offshore flow begun on Sunday and will continue through Tuesday.

Below is the NAM forecast for highs on Monday.

Expect highs in the lowlands (away from the water) to reach the low 80s. Some areas in mountain valleys may even reach the mid 80s. Eastern Washington and the Willamette Valley will reach the mid 80s to low 90s. While not unprecedented, these temperatures are rare for the last week of September.

Offshore winds on Monday will bring areas of surface smoke to Western Washington due to the Bolt Creek Fire. The areas with the highest likelihood of surface smoke are along US-2 and areas from Everett northward. Degradations of air quality is possible as well, especially near the Cascades and north of Everett. (A new air quality link has been added to the right side of the blog. Click “PurpleAir AQI Map” for a very accurate and hyperlocal look at the current air quality.)

The warm weather will continue on Tuesday, as seen in the NAM forecast below.

Expect Tuesday’s highs in the lowlands to reach the upper 70s to low 80s, wit 80+ degree readings being less widespread than Tuesday. Notice that the coast cools to the upper 50s and the Willamette Valley drops to the upper 70s to low 80s. However, Tuesday will be warmer in Eastern Washington, where highs across nearly the entire region will be in the upper 80s to low 90s.

Now…what we have all been waiting for…a big and very welcome change. RAIN is in the forecast! The large ridge offshore will break down by Wednesday, bringing a chance of showers by Wednesday evening. Rain will continue at times through early Thursday. The European model forecast is below for rain through 5 AM Thursday.

The European model shows 0.2-0.4 inches of rain in the lowlands and 0.5-1.25 inches in the mountains and on the coast! There is still uncertainty regarding the exact timing and amounts of rain, so stay tuned for more information.

Besides a chance of rain, Wednesday will also bring a big cooldown from Tuesday’s temperatures. The European model forecast is below.

In the lowlands, Wednesday afternoon will be 5-10 degrees cooler than Tuesday. In the mountains, it will be a whopping 20-30 degrees cooler! 

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Tropical Storm Ian:

As of 9:20 PM Sunday, Ian is a strengthening tropical storm located SW of Jamaica in the Caribbean Sea. On Monday, Ian will begin rapid intensification, becoming a 115 mph Category 2 hurricane by Tuesday. Ian will cross Western Cuba, bringing storm surge of 9-14 feet and winds over 100 mph. By Wednesday morning, 130 mph Hurricane Ian will be off the west coast of Florida. Although Ian will weaken prior to landfall, it will also slow down. Major storm surge is likely for Western Florida.

The National Hurricane Center forecast for Ian is below.

Notice how Ian slows down (“M” icons closer together) from late Tuesday to late Thursday as it moves into Western Florida. This will likely create significant damage along Florida’s West Coast, as Ian’s storm surge and expanding wind field keep Florida in their crosshairs for over 24 hours.

However, substantial uncertainty remains. The “spaghetti model” probability plot from the incredibly helpful Tropical Tidbits website by Dr. Levi Cowan is below.

This forecast shows the potential tracks of Ian from many different forecast models. The models range from a disastrous landfall near Tampa Bay to a landfall near Pensacola, nearly 340 miles away.

For updated information on Ian, stay tuned to Twitter (right side of the blog) and the National Hurricane Center. 

Hurricane Fiona Bringing Major Impacts to Atlantic Canada

One of the strongest storms to impact Atlantic Canada in history is just hours from landfall in Nova Scotia.

Hurricane Fiona, now a post-tropical cyclone, has sustained winds of 105 mph, the strength of a Category 2 hurricane. 5-10 inches of rain will fall, and significant storm surge is likely in the many bays and inlets along the coasts of Nova Scotia and Prince Edward Island.

Below is the European model forecast for late Friday night, showing Fiona’s approach to Nova Scotia.

The European model gives Fiona an incredible central pressure of 925 millibars, which would be the all-time record lowest pressure in Canadian history. 

The incredibly close lines of constant pressure represent the very strong hurricane-force winds that will impact Atlantic Canada.

Below are wind gusts at 10:20 PM Pacific Time (2:20 AM in Nova Scotia).

Winds are gusting 50-75 mph across most of Nova Scotia and Prince Edward Island. Winds are highest on the immediate coastlines of Nova Scotia and Prince Edward Island (upper left), including large lakes, with hurricane-force gusts of 75-100 mph.

Peak winds across most of Nova Scotia and Prince Edward Island will be sustained 40-70 mph, with gusts of 75-110 mph, strongest on the coast. Extreme wind damage will be widespread, including power failures.

The duration of the winds will also be an issue. The European model forecast below is for 5 AM PDT.

This is about 6 hours after the forecast model shown earlier in the blog. In those 6 hours, Fiona will weaken, but hurricane-force winds will continue impacting a large area. 

Additionally, strong and prolonged onshore winds will bring significant storm surge to many bays, inlets, and large lakes in Nova Scotia and Prince Edward Island. This will cause significant coastal erosion and damage, including potential major impacts to the only causeway connecting Cape Breton Island to mainland Nova Scotia. 

The National Hurricane Center (NHC) forecast for Fiona shows the expanse of Fiona’s wind field (brown/orange shading around the storm center).

The NHC’s latest advisory reports that hurricane-force winds (74+ mph) extend 185 miles from the center in all directions, essentially the distance from Seattle to the Tri-Cities or Salem, OR.

Although Fiona’s forward speed will slow substantially on Saturday, impacts for Nova Scotia and Prince Edward Island should end by late Sunday, with wind speeds substantially lower even by Sunday morning.

However, we are not done talking about hurricanes. In fact, you will hear much more about an upcoming hurricane than you have about Hurricane Fiona. 

Tropical Storm Ian formed on Friday evening. Ian is currently over the Caribbean Sea, south of Haiti and the Dominican Republic.

Ian is forecast to pass south of Jamaica as a tropical storm, then pass near the Cayman Islands as a hurricane. It will make landfall in Western Cuba as a Category 1 or 2 hurricane late Monday. Ian will re-strengthen on Tuesday and Wednesday, and is currently forecast to make landfall on the east coast of Florida on Wednesday night as a 115 mph Category 3 hurricane.

Ian’s final outcome is incredibly uncertain, so stay tuned to my Twitter (accessed from the Twitter logo on the right side of the blog) for updates.

Brief Cooldown, Much Above Average Temperatures Next Week

 FastCast—Friday, Sep. 23 to Tuesday, Sep. 27:

Onshore flow on Thursday brought much-improved air quality and cool, breezy conditions in Western Washington. Highs dropped from the upper 70s to the upper 60s/low 70s. Cooler conditions, with highs in the upper 60s to low 70s, will continue on Friday and Saturday. On Sunday, it will be mostly sunny, with highs increasing to the mid 70s. Monday and Tuesday will have highs of 10-20 degrees above average in the Pacific Northwest, reaching the upper 70s to low 80s in the lowlands and the mid 80s to low 90s in the Willamette Valley and Eastern Washington. This is very abnormal for late September, and daily records may be broken around the region. Additionally, flow will again turn offshore by late Saturday. This will potentially bring smoke from the Bolt Creek Fire back into the lowlands. Stay tuned for more information about smoke, air quality, and high temperatures. I will have an update on Friday night regarding Hurricane Fiona and its historic impacts to Atlantic Canada.

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After a couple very smoky days around Western Washington, fresh marine air returned on Thursday, bringing cooler temperatures, improved air quality, and a marine breeze (gusts 20-30 mph). Expect cooler temperatures in the upper 60s to low 70s on Friday and Saturday!

However, that cool and seasonable weather won’t last for long. A robust high pressure ridge will bring much warmer temperatures to the entire Pacific Northwest on Monday and Tuesday. Below is the European model, showing temperature departure from average on Monday afternoon.

On Monday afternoon, temperatures in the entirety of the Pacific Northwest will be 10-20 degrees above average. Western portions of Washington and Oregon will have highs an amazing 15-25 degrees above average. 

So…what will those highs be? The European model forecast for Monday is below.

Highs in the lowlands will be in the upper 70s to low 80s, a bit cooler near the water. Eastern Washington and the Willamette Valley will be quite hot, with highs in the mid 80s to low 90s. 

For the lowlands, temperatures over 80 degrees in the last week of September are rare, but not unprecedented. If you were wondering, “average” highs in the lowlands in late September are in the upper 60s.

It is more likely than not that above average temperatures will continue into October. Extremely above average temperatures like Monday and Tuesday don’t look likely as of now (but that can always change). The NOAA Climate Prediction Center outlook for September 28th to October 2nd is below.

There is a 40-60% chance of above average temperatures in Western Washington into the beginning of October. 

Stay tuned for a Friday night update on the historic impacts of Hurricane Fiona in Atlantic Canada, especially Nova Scotia. Updates on Fiona can be found at the National Hurricane Center and on all major news outlets.

Stay tuned this weekend for updates on the potential return of surface smoke with upcoming offshore flow.

Smoky & Warm on Wednesday, Cooling Ahead

FastCast—Wednesday, Sep. 21 to Sunday, Sep. 25:

Smoke has caused air quality issues around Puget Sound due to the Bolt Creek Fire as offshore flow brings easterly winds. It was also quite dry on Tuesday, with relative humidity dropping to the 20-35% range. On Wednesday, surface smoke will continue around Puget Sound. Although there will not be much smoke, it will be enough to degrade air quality, especially from Wednesday morning to mid afternoon. Highs will be on the warm side for late September, in the mid to upper 70s. A weather shift will occur late Wednesday through Thursday, with increasing clouds and decreasing temperatures. From Thursday to Saturday, expect partly to mostly cloudy conditions with highs in the mid 60s to low 70s. Temperatures increase with sunnier weather by Sunday, and highs will reach the mid to upper 70s. Lows through the week and the weekend will be in the low to mid 50s.

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Offshore flow has brought surface smoke into the lowlands at times on Monday and Tuesday, especially to the west of the Bolt Creek Fire. Air quality has been degraded around the region, sometimes into the “unhealthy” category.

Offshore flow will bring more surface smoke into the lowlands on Wednesday. The surface smoke forecast for 10 AM Wednesday from the HRRR model is below.

While this isn’t much smoke in the forecast (it has been underplaying it at times), it will be enough smoke to degrade air quality and bring a smell of smoke to the region.

In addition to surface smoke, Wednesday will bring above average temperatures to the region. The NAM forecast is below.

Expect highs in the mid to upper 70s in the lowlands. Eastern Washington and the Willamette Valley will reach the upper 70s to low 80s. 

Flow will switch to onshore by Thursday, pushing smoke out of Western Washington and bringing cooler temperatures. 

Temperatures will be 5-10 degrees cooler around the lowlands and Willamette Valley. Thursday’s highs from the NAM model are below.

Highs in Western Washington will only reach the upper 60s to low 70s. It will feel more like September.

However, that won’t last long, as the NOAA Climate Prediction Center is forecasting above average temperatures for the entirety of the Pacific Northwest for September 26th-30th.

There is a 50-70% chance of above average temperatures to close out September in Western Washington. Southeastern Washington has a 70-80% chance of above average temperatures. It appears likely that crisp fall weather won’t make it to the Pacific Northwest until at least early October.

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Puerto Rico Update:

Hurricane Fiona, now a strengthening Category 3 hurricane (125 mph winds) north of the Turks & Caicos, has left devastating flooding in Puerto Rico. The graphic below shows rain totals in the past 72 hours.

Many areas on the southward facing slopes of the island received an astounding 15-30 inches of rain in just three days. Even areas on the less-exposed northern side of the island have received 4-8 inches. Flooding has been catastrophic.

Additionally, most of the island remains in the dark, as the PowerOutage.us map from Tuesday night shows.

There is good news though…as officials estimate that power will be restored to most of the island within the next few weeks (much sooner than in Hurricane Maria).

Warm & Breezy In Western Washington, Hurricane Fiona Hits Puerto Rico

FastCast—Monday, Sep. 19 to Saturday, Sep. 24:

It was a relatively typical late summer weekend in Western Washington, with a mix of sun and clouds, breezy conditions at times, and even some brief showers in the South Sound early Sunday morning. Temperatures will increase to 5-10 degrees above average on Monday, Tuesday, and Wednesday. Expect lowland highs in the mid to upper 70s, hottest east of I-5 and south of Tacoma. Due to slight offshore flow, expect northerly winds along Puget Sound gusting 20-30 mph, especially later Monday through Tuesday afternoon. The same offshore flow will bring gap winds gusting 20-25 mph and stronger Fraser River outflow in Whatcom and San Juan Counties, with NE winds gusting 25-40 mph. There is potential for localized areas of higher fire danger, and potentially for areas of smoke due to the Bolt Creek Fire (which has burned 10,220 acres and is 79% contained). Flow will switch back onshore by Thursday, with cooler temperatures through Saturday. Expect lowland highs in the mid to upper 60s. Lows from Monday through Saturday will be in the upper 40s to mid 50s. 

Keep reading below for information about Hurricane Fiona, currently impacting Puerto Rico and the Dominican Republic.

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Weak offshore flow will develop in Western Washington to start this week. The main impact will be warmer than average temperatures and breezy offshore winds. There is a chance of some areas of higher fire danger and localized smoke (especially near the Bolt Creek Fire). 

Offshore winds will be strongest from Monday evening through early Tuesday afternoon. The HRRR forecast for gusts at 9 AM Tuesday is below.

The HRRR shows the strongest winds in the Fraser River Gap, impacting Whatcom and San Juan Counties with NE wind gusts of 30-40 mph. Winds will gust 20-30 mph near Puget Sound and in the Cascades (where isolated higher gusts are possible). 

Offshore flow also brings higher temperatures than usual, as we will see in Western Washington through Wednesday. The NAM forecast for Monday’s highs is below.

Expect lowland highs in the mid to upper 70s. Eastern Washington and the Willamette Valley will make a return to the low 80s. Even the coast will reach the upper 60s, due to offshore flow. Some areas along Puget Sound, especially Everett northward, will remain in the upper 60s to low 70s.

Region-wide, temperatures will be 5-15 degrees above average. The European model forecast below shows temperature departure from average on Tuesday afternoon.

Temperatures in Western Washington and Oregon will be 5-15 degrees above average, while Northern California is 5-25 degrees below average! What a change of events! This is due to a persistent upper-level low off Northern California that will bring cooler temperatures and a much-needed 0.5-2.5 inches of rain.

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In Puerto Rico, there is devastation due to Hurricane Fiona, which is currently impacting Puerto Rico and the Dominican Republic as an 85 mph Category 1 hurricane. (RadarScope radar image below from Sunday morning)

The entire island was impacted by heavy rain and gusty winds from the core of Fiona, and the southern half of the island, including the major city of Ponce, was impacted by Fiona’s northern eyewall.

Below is the NWS map showing peak gusts in Puerto Rico on Sunday.

Notice the peak gusts on the southern and western parts of the island, reaching 60-100 mph. The highest gust was 103 mph on an exposed headland near Ponce. Gusts in the capitol and largest city of San Juan, on the northern shore of the island, reached 50-60 mph.

As you would expect on a heavily forested tropical island, the power grid was severely impacted. As of 9:30 PM (Pacific Time), the entire island of Puerto Rico has no power, although some isolated areas are reported to have power again. The PowerOutage.us map shows that 100% of Puerto Rico (1.4 million customers) has no power.

The grid did not take as big of a hit as it did from Category 5 Hurricane Maria’s 100-160 mph gusts in September 2017, and power should be restored within weeks instead of within months or years.

The National Hurricane Center forecast for Hurricane Fiona is below.

Fiona will make landfall in the Eastern Dominican Republic and will impact the eastern Turks and Caicos as a high-end Category 1 to Category 2 hurricane (winds 90-105 mph), before strengthening to Category 3 (120-125 mph) while making a very close pass to Bermuda. Stay tuned on Twitter and national news outlets.

Localized Chance of Rain on Friday, Changes Ahead

FastCast—Friday, Sept. 16 to Wednesday, Sept. 21:

There is a localized chance of rain in the Central Puget Sound area on Friday, especially in the afternoon and evening due to a potential Convergence Zone. Rain will likely be on the light side, totaling 0.1-0.25 inches. Some areas, particularly the Cascades, will get higher totals, up to 0.5” in isolated areas. Friday and Saturday will be on the cool side, with highs in the low to mid 60s for the lowlands. Temperatures will increase a bit as clouds decrease to begin next week. Expect highs from Sunday to Wednesday in the low to mid 70s, with lows in the upper 40s to low 50s. 

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A weak weather system moving by Western Washington on Friday will bring a chance of a Convergence Zone in Central Puget Sound on Friday, particularly from mid morning to evening. We will take a look at the high-resolution rain forecasts below.

Starting with the NAM model, we see total rain through 12 PM Saturday.

The NAM model shows as much as 0.25” in the Seattle area, with up to 0.5-0.75” in the Cascades and Olympics (potentially higher). However, notice that this rain is confined to a narrow area between approximately Tukwila and Everett, with 0.05-0.1 inches possible from Everett north to Bellingham.

Let’s see what the HRRR forecast says. This is also for rain through 12 PM Saturday.

The HRRR shows much less rain, with totals in the Convergence Zone and associated rain bands only 0.05-0.15 inches, with some areas in the mountains getting closer to 0.2 inches.

This weak system will bring overcast days on Friday and Saturday, with cooler temperatures expected. The NAM high temperature forecast for Friday is below.

It will be one of the coolest days in months for Western Washington, with highs in the low to mid 60s, with some areas (mainly Tacoma southward) potentially reaching the upper 60s. Eastern Washington will only reach the 70s, with a slight chance of the Columbia Basin reaching the low 80s. Statewide temperatures will be below average through Saturday, but that trend will change soon.

The NWS Climate Prediction Center outlook for September 23rd-29th is below.

This outlook shows a 60-70% chance of above average temperatures for the majority of Washington and Oregon. Some extended forecasts have been suggesting temperatures in the upper 70s and potentially the low 80s in late September. Stay tuned for more information!