Is it still looking wet for this Memorial Day Weekend?

So a couple days have passed since our last blog post about the weather outlook for the Inland Northwest for the upcoming Memorial Day weekend. Consequently, our confidence in what sort of weather to expect should be increasing. Recall that in the last post, there were suggestions that this could be a very wet weekend. In fact, perhaps the wettest Memorial Day weekend since 1997 and the second wettest on record (since 1970). So is that still the case?

Saturday 500 mb height

Above is the 500 mb map for Saturday from the GFS. This is a similar setup to the maps we explored earlier this week with a deep low centered over the Pacific Northwest. So is this GFS run an outlier or do other model agree with the solution?

4 different models showing 500 mb heights for Saturday (upper left model did not come in fully)

Here's is a look at 4 models compared to each other and they all show a low focused somewhere over the Pacific Northwest on Saturday. So where is this low on Sunday?

500 mb maps for Sunday

Again there is great agreement that there will be a low focused somewhere over the Pacific Northwest. The top 2 models take the low into southern Oregon, whereas the bottom two models drop the low into southern Oregon. Now, what the positioning of the low on Memorial Day?

500 mb maps for Monday

Again all the models keep the low over the region, however, the consensus is to drop the low south of the Washington/Oregon border.

So our confidence in this event is quite high. We are certain this low will form and move over portions of the Inland Northwest however how long it will remain over the area and where its precipitation  band will set up is the big question. Looking at the GFS for the Saturday and Sunday yields a significant northwest to southeast orientated band of precipitation.

48 hr precipitation amounts for Saturday-Sunday (latest model run )

This is quite similar to the previous model run we looked at a couple days ago(see below). Both model runs show a similarly oriented band of precipitation, however,  the latest version has the band a little farther to the west leaving places such as Sandpoint and Colville much drier than the previous forecast.

Rainfall forecast for Saturday and Sunday (Monday's model run)

Obviously wherever this band sets up will determine who gets a lot of rain and who doesn't. If we decide to consult another model solution it also shows a similar NW-SE band setting up, but this time it's displaced even further west. If this solution were to pan out even Spokane would miss out on the bulk of the rain as would the Silver Valley. 

Another Saturday-Sunday 48 hr precipitation forecast

So given these uncertainties it will be hard to pinpoint exactly where the band will take up residence. This is where ensemble model forecast can sometimes help to pinpoint the band (s) of heavy precipitation. So once again referring to the GEFS/NAEFS ensemble forecasts we see that it maintains a NW-SE oriented band of heavy precipitation as well. However the model has backed off from previous runs which suggested this would be a 99-99.9 percentile event for this time of year. Nonetheless the model still suggests this is potentially a 90-97 percentile event which is still significant. 

NAEFS/GEFS Ensemble 48 hr rainfall Sat-Sun

So what about the temperature forecast? We are holding onto our thoughts of hitting near 70° each day in Spokane this weekend, however if the band hits our area what will our temperature be? To say there is some uncertainty in this forecast would be an understatement. The 12z run of the GFS (dark blue line) has our high hitting the mid-70s that day. How about the 18z run of the GFS? A chilly mid-50s! That is about as uncertain as things can get. Its pretty much the same story for other parts of the Inland Northwest including Moses Lake (bottom meteogram)

Meteogram for Spokane

Meteogram for Moses Lake

This forecast remains a problematic one. Suffice it to say a good portion of the Inland Northwest is going to see a soggy beginning to the holiday weekend. Specifically where that will be, we still can't say with good confidence.  We expect the wettest day of the three-day weekend will be Saturday with a gradual improvement expected after that.

How is this Memorial Day Weekend looking weather-wise?

Last year at this time, we composed an extensive blog discussing the connotations associated with Memorial Day weekends in the Inland Northwest.  In many parts of the country, this weekend typically kicks off the summer season. However here in the Inland Northwest that really isn't the case, due to continued cool and unsettled weather. So is this year going to fit the weather mold, or will we see warm and dry weather?

Before we delve into this year's weather scenario, lets look at what the typical weather pattern is for this time of year. Looking at the mean 500 mb (18k ft MSL) maps below we see that the typical weather pattern is to see moist southwest flow pointed into the Pacific Northwest with a ridge setting up just downstream of the Continental Divide in western and central Montana. 

500 mb mean map 5/23-5/31

So what about the temperatures associated with this average pattern? Here's  the average temperatures for a couple locations as well as the average chance of precipitation:

So not bad. An average high around 70°F with rain expected on roughly 1 out of 4 days doesn't sound too terrible. But that's climatology and this weekend's weather could vary significantly from the norm. Why you ask? Well, let us take a look at the 500 mb pattern for this weekend to get an idea what sort of weather we might be dealing with. First off, here's a look at the weather for Saturday. 

GFS 500 mb heights for Saturday

This does not look promising if you enjoy plenty of sunshine and warmth. Note the closed low-pressure system (yellow L) centered over northwest Washington. Low-pressure systems like this are typically associated with cool and unsettled weather, especially if your are under or near the low. But this is only one model run. Surely there are other ideas out there in weather land. Well, here's a look at 4 distinct weather models for the same time period.

500 mb pattern from 4 different weather models for Saturday

Notice all these model runs place a low somewhere over the Pacific Northwest. That raises our confidence that the weather will be cool and unsettled over portions of the region, but maybe this unsettled weather will only last for a day. So let us take a look at the Sunday weather pattern.

500 mb pattern from 4 different weather models for Sunday

If the upper left model solution verifies (the GFS), the Inland Northwest could really be stricken with another cool and wet day. The other model solutions would hint at some modest improvements, but far from what we would deem summer like weather. How about Monday then?

500 mb pattern for Monday

The upper left solution (the GFS) still keeps the low parked over Washington while the others either drop it south of the region or weaken it. We shall see. But what if the GFS solution were to verify? What would our weather be like? If you love rain, well then you will love this forecast. Here's a look at the total precipitation forecast for Saturday and Sunday.

Rainfall forecast for Saturday and Sunday

The swath of red shading indicates rainfall amounts in excess of an inch. This includes Spokane, Kellogg, Coeur d'Alene, Pullman, Lewiston, Banks Lake, Lake Roosevelt, and Colville. If you look even closer there are a few locations which are expected to see in excess of 2 inches (shaded in tan)!
Now that is a lot of rain, regardless of the time of year. If the precipitation were to materialize, it would equate to our wettest Memorial Day weekend since 1997 and the second wettest on record (since 1970). So what is our confidence level in this precipitation panning out at this point?

Another tool we can look at in addition to just a few deterministic model runs is from an ensemble forecast approach. This is where you look at multiple model runs (initialized from the same model) and try to gather where the forecast confidence in the precipitation swath is greatest. Using this approach, the news isn't great either.

NAEFS/GEFS Ensemble precipitation amounts for the 48 hrs ending Sunday Afternoon

Without delving too deep into the specifics of the image above, the black lines depict the average precipitation amounts from the ensemble mean precipitation forecast while the green and blue shading (well any shading really) is bad if you like dry weather.  Notice the black lines hint at a swath of precipitation extending from southern British Columbia to the central Idaho Panhandle. The green and blue shading suggests the 48-hour precipitation amounts are in the 99-99.9% percentile for an early April-early July event. In other words, it is a 1 out of 100 or 1 out of a 1000 event for this particular time of year! There is even a small area of pale blue which hints that rain of this magnitude for this time of year has not been experienced since between 1985-2011!  This map suggests the GFS isn't entirely alone in forecasting a wet weekend, but we would like to see much better model agreement before buying off on this solution.

Now, if the rain does materialize, what impact will  this have on our temperatures?

7-day Spokane Forecast

Our current forecast is showing highs above average through the workweek with a cooldown by the weekend. Notice by the weekend we are forecasting highs right around 70 each day. That's not bad. Right around average actually. But we discounted the wet GFS solution. What if the GFS were to verify? How warm would it get then?

7-day temperature meteogram for Spokane

See the green line on the chart above? That is our official NWS forecast. However the blue lines (from the GFS) show the highs on Saturday could struggle to escape the mid-50s on Saturday and then slowly rebound into the lower to middle 60s for Sunday and near 70 on Monday.

Stay tuned to later forecasts this week to see how wet this weekend might really get. In the meantime, you might want to procure yourself one of these if you have camping plans this weekend.

How unusual will this next episode of warm and wet weather be for the Inland Northwest?

By now you have likely heard that this is going to be a wet and warm remainder of the week across the Inland Northwest. This wet spell of weather is expected to continue into early next week. So why is this? Well, most of it can be attributed to yet another atmospheric river event. While most atmospheric rivers come and go, this event will be a little different, as we will likely be impacted by a trio of rivers. The first arrived yesterday into last night. The next is expected to unleash its torrent of moisture on Friday and the last will likely impact the region on late Sunday. The video below shows the expected sequence of events. The atmospheric rivers are denoted by the blue, purple and red colors

So what does this mean for the area. Well, it will translate to several things. The most obvious is it will result in very wet weather. Here's the estimated rainfall we are forecasting between today and Sunday night.

Rainfall forecast between today-Sunday night

These are some pretty hefty totals. Notice the reds and oranges spread across the Cascade Crest and extreme northeast Washington/north Idaho. These locations could potentially amass a few spots of 3-6" of precipitation, most of which will fall as rain. While these amounts are impressive, the question is just how rare are they? We get atmospheric rivers all the time this time of year. Certainly it can't be that unusual, can it? Well, if put into perspective for the time of year and amount of precipitation it actually turns out to be a very rare event. One of the new tools in our weather toolkit consists of quantifying an event based on climatology. In other words, how common is a weather event for a given time of year? For this event, we will look at the amount of rainfall expected over a 3-day period (between today-Sunday). Below you will see an image from one of our ensemble models showing the approximate amount of precipitation (black contours or isohyets) combined with the rarity of the forecast amount (the color shading). What's interesting, in this case, is northern California is covered with isohyets in excess of 3 inches, while over the Inland Northwest we see a small area of 1.5"-2+"  inches over extreme northeast Washington and north Idaho (the amount is smoothed and will not catch the locally higher amounts we forecast over the mountains). Despite the lighter rain totals over our neck of the woods, it's actually a less common event as shown by the blue and dark green shading. The blue shaded areas are locations where this event places in the 99.9 percentile (or 1 out of 1000 events)  for all rainfall events between December 22 and March 22nd (between 1985-2012). The dark green shaded areas, which cover a good portion of the Inland Northwest represent a 99.5 percentile event (1 out of 500 events). So technically speaking we will experience the most unusually heavy precipitation in the western US this weekend.

Ensemble precipitation forecast (Thu-Sun) combined with the relative rarity of the amount.

The other unusual weather phenomena we are expecting this weekend will be the warmth. If we once again choose to utilize a percentile ranking of the warmth for this event it's rare, but nowhere close to as rare as the rainfall. Here's a look at the forecast temperature and the respective percentile (for the period between January 27-February 17)  for the temperatures at 850 mbs (around 4500' above sea level) on Friday afternoon. The image below is showing temperatures in the lower to middle 40s (4-6°C)  pale yellow which indicates roughly the 90th percentile (1 out of 10 events). So really it's not rare at all. Temperatures at this level will be significantly cooler than what we experienced on the 25th of January when our 4500' temperature surged into the lower to middle 50s.

Climatology rarity of 850 mb temperature for Friday afternoon (2/6/15)

What will make this an unusual event though is the duration of the mild temperatures. Right now for the Spokane area we are forecasting 4 consecutive days of high temperatures right around 50° (see image below). The last time we saw that many 50°F or warmer days between December and early February (2/10) was in 1963! The longest stretch on record is 6 days set in 1917. A 3-day stretch of low-temperatures of 40°F or warmer is also rare for this time of year. Between tonight and Saturday night, we are forecasting lows at or above that mark. Surprisingly, the last time we saw three nights of lows ≥ 40°F was earlier this winter (in early December). Before that, we had only seen 3 or more consecutive nights of 40°F or warmer lows 7 times since 1881.

7-day outlook for the Spokane area Thursday (on left) through Wednesday (right)

Just the latest chapter in what has been an unusually mild and relatively snow-free winter.

Severe Weather Tomorrow??? It's a Possibility.

We have all heard of the calm before the storm, today could be just another chapter in that book. This afternoon will feature highs in the 70's and 80's under mostly sunny skies. Come tomorrow the chance for showers and thunderstorms will be on the rise as an area of low pressure approaches the Inland Northwest. Temperatures will continue on the warm side of normal, but increased moisture will push ahead of the low pressure center increasing our chances for convective activity or thunderstorms. In this post we will evaluate the chances for thunder around the region and the potential timing through various weather maps and products.

So lets start out with today and move forward from there. Our current pattern has a ridge of high pressure directly over the Inland Northwest keeping conditions calm and pleasant. The ridge also allows for warm southwesterly flow to advect into our area bringing above normal temperatures today. We will take a look at the current set up in the following image.

 11am PDT Infared satellite map with 500mb heights

From the image we can see the area of low pressure to our west and the current ridge over us. The ridge is also diverting much of the cloud cover to our north. As the low slowly moves onshore the ridge will continue to be shifted to the east allowing clouds to move east of the Cascades. Not only will this bring increased cloud cover for tomorrow afternoon, but also increased moisture through the atmospheric column allowing better instability. So lets take a look at the increased moisture moving in. This can be accomplished in a couple of manners, but we will look at Precipitable Water or PWATs in the atmospheric column.

Precipitable Water values from 11am today (left image) and 5pm Thursday (right image)

The images above show the increase in atmospheric moisture from today to tomorrow from the North American Model (NAM). For much of the Inland NW we will see an increase of nearly a quarter of an inch of precipitable water. Another method to address the amount of moisture would be the change in forecast soundings which show temperature and dewpoints up through the atmosphere. Next we will examine the forecast soundings to see the change in moisture from today to tomorrow.

NAM forecast soundings from 2pm today (left image) and 2pm Thursday (right image)

From the sounding you can see the major differences in the amount of moisture present. The red line would indicate the temperatures and the green indicates the dewpoint which reflects the amount of moisture in the atmosphere. For the left image a dry layer is noted around 500mb (where the green line moves away from the red) whereas for tomorrow (right image) much more moisture is present (green and red lines are closer throughout the image). So from these two examples the change in moisture can easily be noted, but will we have the instability to promote the thunderstorms? We will now at these parameters that promote thunderstorms.

For thunderstorms to occur, many things need to be present including lift (forcing), moisture and instability (atmospheric stability). We will first look at the lift for the area and the one way to do this is to compare from today's conditions to tomorrow. Below is an image looking at the Q vector convergence in the upper atmosphere or Div-Q. Div-Q is a generalized way to assess the lifting potential in a portion of the atmosphere.

Upper level Div Q from 11am today (left image) and 5pm Thursday (right image)

From comparing the images we can see the major differences concerning forcing. Tomorrow the low will move onshore bringing a good amount of forcing ultimately aiding in thunderstorm development. With the right image being for 5pm tomorrow, we will most likely be looking at a case that will unfold more in the late afternoon and evening hours rather than early in the afternoon. Would this be a good or a bad thing with it unfolding in the evening? For now it looks good. We have been hitting our high temperatures in the late afternoon/early evening which would be the best time for the stronger storms, so this would also would aid in thunderstorm development. We have already looked at the moisture profiles for the area and have concluded that higher amounts of moisture will be in place. Finally we will look at one of the convective parameters that are normally consulted to address thunderstorm potentials which is CAPE or the Convective Available Potential Energy. First we will once again look at the NAM model. It has been the most aggressive when it comes to CAPE values, but paints a similar picture to the others as to the areas with the best chances for seeing thunderstorms.

NAM CAPE values for 5pm Thursday

From the NAM we can see a broad area with values surpassing 1000J/kg and localized areas greater than 1500J/kg (blue and green shading). If you remember around a week ago on the afternoon of June 3rd we had thunderstorms for much of the area. These storms were also working with around 1000J/kg of CAPE. With the NAM being on the upper end of model perspective lets take a look at another one. Next we will examine the model often used by the Storm Prediction Center (SPC) in Norman, OK which is the SREF or the Short Range Ensemble Forecast.

SREF CAPE values for 5pm tomorrow

Although not as colorful as the NAM, the SREF is also showing higher values for eastern Washington and into the Idaho Panhandle. It also has peak values in the 1000J/kg to 1250J/kg range. So we do have some consistency among short range models of the potential for higher amounts of CAPE. So with all of this in mind, now comes the million dollar? will we see thunderstorms and if so, how strong will they be? Concerning the chance for thunderstorms, it is a given. We will see thunderstorms tomorrow. The next question is where? As we can see, the best forcing will be in the eastern third of Washington and the Idaho Panhandle so these are the locations with the best chances. We do not want to omit the chance for the east slopes of the Cascades or the Basin, but the threat will not be as great as the other locations. From the SPC, they create a calibrated outlook of the thunderstorm chances for a location so lets take a look at what they think.

SPC calibrated thunderstorm probabilities between 5am-5pm Thursday

So from the SPC, they highlight a 40% chance for much of northeast Washington into the Idaho Panhandle.  These are some of the higher values I have seen from this for our area so it would lead me to think the chance for thunderstorms is essentially a slam dunk.  Finally the big one.....will any of the storms be severe? Here at the office we seem to think the potential is definitely there for strong storms. Comparing to last week, we had similar CAPE values, but tomorrow we actually have better dynamics to support storms. The SPC also does a product for the chances of severe storms and here it is.

SPC severe thunderstorm probabilities for 5pm Thursday

While the chances for severe storms do not look very high, they still highlight the potential for portions of the area. This product usually only has slight chances for us when severe events do occur, so the potential is there. The region will want to keep an eye on the skies tomorrow as active weather looks to be a given.

Unusually wet February and March

Greetings folks, sorry it's been a while since we last posted to this blog, but we have been focused on implementing a new computer system for our office used to compose our complete suite of products and weather grids. Now that we have gotten our feet wet, it's time to discuss the unusually wet February and March the Inland Northwest endured.

So the weather pattern that took a dramatic shift in February unexpectedly continued into March. What was the cause? Recall that a highly anomalous ridge was fixed over the extreme eastern Pacific through the first half of the winter. Here's what it looked like on a 500 mb chart (approximately 17-18k ft). Notice the strong buckling in the flow just off the west coast. This is rather unusual and resulted in almost a record breaking dry spell for the first half of a winter.

500 mb mean map for 10/1/13-1/15/14

Well as the calendars changed to February, the unrelenting ridge gave way and opened the doors to countless storms which surged through the Pacific Northwest for the following 2-month period.
The mean 500 mb charts for February and March exhibited this ridge flattening.

500 mb mean map for 2/1/14-3/29/14

Notice although the ridge is still present (albeit flatter), its actually a much more favorable setup for precipitation since the amplitude of the ridge allows sub-tropical moisture to be wrapped into passing weather systems. Here's is what the anomaly of the atmospheric moisture (called precipitable water) looked liked for the period. Notice the well defined connection of moisture extending from southwest of the Hawaiian Islands northwest to the coast from northwest California to southern Washington (red, orange and green shading).

Precipitable Water Anomaly 2/1/14-3/29/14

So how wet was the two month period? Very was the answer. The map below shows the departure from normal of precipitation for February and March. Every location saw wetter than normal conditions, with the Cascades and Idaho Panhandle mountains leading the pack with well over 10" more than the normal amount of precipitation.

Rainfall departure from normal February & March 2014

From a percentage standpoint vs. normal it was also an impressively wet period. Note the dark blues and purples over the Cascades and north Idaho mountains, indicating where precipitation amounts were 2 to 4 times the normal for that period.

Rainfall % of normal February & March 2014

The unusually wet period has also brought the snow water equivalent (amount of water in the mountain snow pack) to normal or just above normal over the entire region. Note that although conditions were moist over Washington, Idaho, and western Montana, things were still quite dry across Oregon and California (not shown).

Not only did a considerable amount of precipitation fall, but it also did so on an unusually high number of days. Here's a look at the numbers compared to the normals.

Days of measurable rainfall for various locations across the Inland Northwest Feb-Mar 2014

Over locations where the temperature was cold enough, most of this equated to snow. In Holden Village, WA the snowfall for the two-month period was 180.7". That shattered the old record of 166.7" (set in 1999). Not quite as impressive was the 14.0" which fell in Lewiston, ID. This was the most since Feb-Mar in 1985.

So will this unusually wet weather continue? Showers are still fairly common this time of year. In Spokane we typically see some precipitation about 50% of the time during the first half of April. That number drops to around 40% of the days by the end of the month.  In Wenatchee and Moses Lake, the percentage of wet April days is a mere 25%!

The 8-14 day outlook for precipitation shows near normal conditions for most of eastern Washington and north Idaho.

8-14 day precipitation outlook. 

Well that was a quick recovery!

Our blog posted on 2/6 hinted that changes were coming which would be conducive for snowfall across the Inland Northwest. While that prognostication proved true, we had no idea just how much snow was going to fall. Since February 7th the region has been pummeled by a relentless parade of storms. Just look at some of these snow totals below.

All of these locations have seen more than the normal amount of snowfall for February in the brief two-week period. Some locations much more. The hardest hit locations have been near the Cascades with most locations seeing 2-3x the monthly normal already. While the 100" that fell at Holden Village was not a record (117.2" fell in February 1999), there is still more snow expected through the remainder of the month. The record could also be attained at Plain (66.5" in 1937). The Lewiston number isn't a record either but it is the most amount of snow that has fallen during the month of February since 1985. Below is a picture of what the snow depth looked like in western Chelan County.

Buried pickup truck in western Chelan County...care of Chelan County Sheriff Office. 

So how has this snow impacted what was nearly a record low snow pack earlier this winter. First lets take a look at some individual SNOTEL sites and then a broader scale map of the region. For those not familiar, a SNOTEL is a site, typically set in a remote mountain location which measures things such as temperature and snow depth. You can check this link for more details.  So here's the data from Harts Pass SNOTEL located in western Okanogan County at an elevation of 6490'. If we just look at the blue dotted line it suggests that since the 9th of February nearly 40" of snow has accumulated. While 40" is a good amount of snow it is a large underestimation since the snow undoubtedly compacted from the shear amount that's fallen. Since February 6th, nearly 8" of precipitation has fallen (red line). If we use a climatologically average snow to liquid ratio of 14:1 that would yield around 112 inches of snow.

Hart's Pass in western Chelan County. 

Now if we look at a different site, (Blewett Pass in Chelan County) in a different format we can compare how we stack up compared to normal conditions. The important lines to look at are the navy one which shows the snow water equivalent for the 2014 water year (October 2013-current) and the lavender line which show the median conditions. Notice the navy line almost went straight up over the past couple weeks, falling just shy of the median. That is an awfully swift recovery.

Blewett Pass SNOTEL 

Now lets zoom out a little and look at things from a regional perspective. Below is a look at the snow pack as of the middle of January. Notice the widespread yellow and orange shading over the Cascades and some reds over the Olympics and Oregon Cascades. This denoted near record dry conditions over much of the region.

Snow water equivalent as of 1/14/14

Now fast forward just over a month later and the recovery has been rather impressive. Most of the Washington Cascades have now nearly attained a normal water equivalent in the snow pack, while the Clearwater Mountains of north-central Idaho have actually exceeded normal. Meanwhile the mountains stretching from the Okanogan Highlands to extreme northern Idaho have generally kept pace since mid-January.

Snow Water Equivalent as of 2/20/14

So will this wet trend continue? If we look at some of the model prognostications the answer is a resounding yes. Below is a look at precipitation forecast using some ensemble model data and associating it with similar weather patterns from the past (termed an analog). This analog suggest that from now through the end of the month, up to another 1-2" of precipitation can be expected near the Cascades with just a little bit less for the Idaho Panhandle.

Precipitation analog through 4pm  2/26

Snow, Rain, Wind, (and Thunder?)

Yesterday's weather system brought a nice 1 to 3" of snow to many locations.  You can see an extensive list of snow reports on the National Weather Service website.  Now we have Storm #2 arriving 24 hours later.  This one will be a little different in a couple of ways.  First, this storm is a little wetter and more extensive than the first.  This means more people will see precipitation.  Here's the radar forecast from the HRRR model valid at 5pm this evening:

5pm radar forecast from the HRRR model

This is a forecast from a computer, not an actual radar image.  But it gives you an idea what the radar will look like around 5pm.  And just about everyone in the Inland NW will be seeing some sort of precipitation at this time.  Which leads us to the other difference.  While Storm #1 was all snow, this one will be more of a mixed bag of rain and snow.  The HRRR forecast for precipitation type at 5pm is shown below.

5pm precipitation type forecast from HRRR

This graph is a little hard to read, but the horizontal blue lines represent snow, while the vertical green lines are for rain.  The HRRR expects the precipitation by 5pm to be rain south of a line from Deer Park to Grand Coulee.  This includes Spokane and the Palouse.  The precipitation may initially start in the metro area as wet snow, but it won't be able to accumulate much and will change to rain later this afternoon. Also notice there are some small pockets of red scattered around the region. This represents a chance of freezing rain. If freezing rain really does occur it will be rather isolated and likely quite brief. 

Here's the storm total snow forecast from the National Weather Service.

Storm total snow ending 4pm Thursday

Most of the valleys across the north (Republic, Colville, Sandpoint) will see all snow and pick up 2-6" of snow, while the mountains will receive up to a foot.

Storm #3 will follow on Thursday afternoon/evening this will be a weaker system.  It will once again bring rain or snow to Spokane and the Palouse while the northern valleys will pick up a little more snow.

Storm #4 is still taking shape but it consistently looks like it will be the strongest of the bunch.   Today's GFS model forecast backed off a little from it's previous forecast, while some of the other models came out a little stronger today.  As a result, they're all in very good agreement at this time.  We often take this as a sign to increase our confidence in the forecast.  Even though they all agree, could they all be wrong?  Yes, but the odds are growing increasingly slim.  

Here's a breakdown of how this storm will unfold:

• Precipitation will spread over the area on Friday around or shortly after sunset.
• Spokane and the Palouse will see rain from this storm, with a possible mix of snow at the onset.
• Saturday morning will be rainy and breezy.  Spokane will be in the lower 40s by sunrise and top out in the mid 40s during the day.
• The northern valleys will start as snow and will accumulate a few inches.  They will gradually change to rain overnight.  Colville will probably change to rain before midnight, while Bonners Ferry could hold on to snow until Saturday morning.
• The cold front will move through the area during the middle of the day.  Behind the front winds will really blow.  Below is our forecast peak winds for Saturday.  Areas in white can expect gusts in excess of 50 mph.

Peak wind gusts expected on Satuday

We will likely be issuing Wind Advisories for much of the area and possibly High Wind Warnings.  You'll want to stay tuned to this forecast.

Here's a couple of other things to consider with this storm.  The rain along with the melted snow won't be able to soak into the ground since the ground is solidly frozen (from our early December cold snap).  So expect some water  ponding, even on your lawn.

The other interesting tidbit is the outside chance of a thunderstorm.  Thunder?  In early January?  Yes, it's happened before, and this is pretty much the classic set up for it:  warm moist air ahead of a strong cold front.  Below is the SREF model probability of thunderstorms. 

24 hr thunder chances ending 10pm Saturday. 

You can see a small area of 10% over southeast Washington.  If thunder does occur, we don't expect to see hundreds of lightning strikes. However a few claps of thunder are a possibility especially over southeast Washington and the southern Idaho Panhandle, including Pullman and Lewiston.