Thunderstorms: Could Be a Wild Afternoon

February 17, 2016

9:45am Wednesday…

I’ve got an important haircut to get to (critical for this job), but I wanted to let you know we could see some exciting stuff this afternoon first.  A cold front moves across our area this afternoon and along with warm southerly flow plus arriving cool air above, we could see thunderstorms pop up.  Models have been showing this for almost two days but this morning I see SPC (Storm Prediction Center) has put us in a MARGINAL threat area for severe thunderstorms west of the Cascades.

Capture

Highlights:

  • Expect warm temperatures midday/early afternoon as the south wind arrives…around 60 degrees.  Both our RPM model and WRF-GFS put us up to around 65 early afternoon!
  • A line of heavy showers/thundershowers develop and/or move from SW to NE across the Willamette Valley and SW Washington in the mid/late afternoon (3-6pm).
  • Thunder and/or hail is possible as this line of showers moves over.
  • A strong southerly wind burst may accompany the showers as well.  S/SW wind gusts 30-40 mph possible.  Likely just in spots where the showers are heavy.
  • It’ll finally feel like winter (the stormy part) for a few hours!

 

We have a nice low lifted index showing up on models at 4pm, lots of CAPE too.  HRRR has the CAPE up over 1000 j/kg in the Willamette Valley mid/late afternoon!

hrrr_cape_portland_9.png

Our RPM, which isn’t always a stellar performer, has that convective look to the cold front at 4pm:

rpm_precip

 

Here’s the SPC discussion:

...SUMMARY...
   ISOLATED THUNDERSTORMS ARE EXPECTED FROM SOUTHWEST WASHINGTON
   SOUTHWARD INTO CENTRAL CALIFORNIA...A FEW OF WHICH COULD PRODUCE
   LOCALLY DAMAGING WIND.

   ...SYNOPSIS...
   AMPLIFIED BUT PROGRESSIVE PATTERN WILL PERSIST ACROSS NOAM THROUGH
   THE PERIOD. DEEP LOW NOW CENTERED NEAR 42N/135W EXPECTED TO DEVOLVE
   INTO A STRONG...SLIGHTLY NEGATIVELY TILTED TROUGH THAT SHOULD EXTEND
   FROM CNTRL CA TO JUST OFF THE ORE CST BY 12Z THU AS DOWNSTREAM RIDGE
   ADVANCES E INTO THE PLNS.

   AT LWR LVLS...COLD FRONT/OCCLUSION WITH PAC SYSTEM SHOULD REACH THE
   ORE/NRN CA CST AROUND 21Z AND CONTINUE EWD ACROSS THE CSTL RANGES A
   BIT LATER WHILE WEAKENING. A SECONDARY FRONT/TROUGH LIKELY WILL
   APPROACH THE CST TOWARD 12Z THU.

   ...N PAC CST THROUGH PERIOD...
   MOISTURE AND DEEP SLY FLOW WILL SUBSTANTIALLY STRENGTHEN ALONG THE
   ORE/NRN CA CST LATER TODAY AS FRONTAL ZONE NEARS REGION. LOW TO
   MID-LVL LAPSE RATES LIKELY WILL REMAIN MODEST /JUDGING BY CHARACTER
   OF FRONTAL CLOUD BAND NOW OVER THE PACIFIC/. NEVERTHELESS...WITH PW
   INCREASING TO AROUND 0.75 INCH...POCKETS OF SFC HEATING...AND DEEP
   UPLIFT STRENGTHENING WITH THE ARRIVAL OF THE FRONT...ISOLD THUNDER
   MAY DEVELOP ALONG AND AHEAD OF BOUNDARY. STRONG LOW TO MID-LVL WIND
   FIELD MAY FOSTER DEVELOPMENT OF OCCASIONAL SMALL BOWING SEGMENTS AND
   SHORT-LIVED LOW-LVL ROTATION IN SHOWERS/STORMS...ESPECIALLY ALONG
   THE NRN CA/ORE CST...AND IN THE WILLAMETTE VLY. WEAK
   BUOYANCY...HOWEVER...SHOULD LIMIT INTENSITY/DURATION OF ANY
   ASSOCIATED SVR THREAT.

   WDLY SCTD TSTMS SHOULD FOLLOW FRONTAL BAND OVER A LARGER REGION FROM
   SW WA SWD INTO CNTRL CA THIS EVE AND TNGT...AS MID-LVL TEMPS COOL TO
   AOB MINUS 25C AND ONSHORE MARITIME FLOW STRENGTHENS IN WAKE OF
   FRONT. SMALL HAIL MAY ACCOMPANY STRONGER/LONGER-LIVED UPDRAFTS.


Of course now that I've brought this to your attention, we'll probably only see a few heavy showers and nothing happens.  Or...we'll see! 

Chief Meteorologist Mark Nelsen

Winter Is Over In The Lowlands

February 15, 2016

Fork2

It’s overdue, I’ve held out as long as I can, but I can’t stand it any longer.  I’m sticking a fork in winter because it’s quite obvious winter is over here in the lowlands of western Oregon and SW Washington.  Luckily John Rinier from Forest Grove made me the nicely stained solid wood fork for these big weather days.

I know what you’re thinking…one of 3 things:

“What Winter?  I only saw snow once!”

Or…

“Yeah, real tough forecast…after 5 days in the 60s this month!”

Or…

“Are you nuts?  Winter doesn’t end until the 3rd week of March!”

We did actually have quite a bit of winter this year.  All of it was in December and the first few days of January.   Looking back, winter more or less “ended” for us west of the Cascades after the 1st week of January.  This winter will be remembered for one month only…DECEMBER.  Flooding rains, high winds, storms, mudslides etc… Before December 1st and after the first week of January nothing of interest occurred.  Due to this, as of mid-February we are in our 4th warmest winter on record here in Portland:

MarkWinter_Over1

Here in the lowest elevations of the Pacific Northwest, west of the Cascades, almost all our significant winter weather events happen between mid-November and mid-February.  Snowstorms, windstorms, ice storms, & flooding.  You get the idea…it’s rare to have these events (not so much with wind) outside of this time period.

Looking ahead to the next 15 days it appears the warm pattern will hold.  We can see general weather patterns on our models a good 10-15 days in the future and no models are showing a stormy or cold pattern through the first few days of March.  I see more of the same for the next two weeks.  So…

WINTER IS OVER IN THE LOWLANDS OF WESTERN OREGON AND SOUTHWEST WASHINGTON

What does that statement mean?  These points apply to anywhere west of the Cascades (including the Coast) below 1,000′.

1. You can take your snow tires off IF you plan to stay in the lowest elevations (below 3,000′) for the next few weeks.  Wayne Garcia was the smartest…he gambled and didn’t bother putting them on!

2. You can unwrap your pipes, or any plants that need to be protected from temps below 25-28 degrees.

3.  More school snow days or delays are unlikely in these lowest elevations.

4.  Strong and cold east wind episodes are finished in the Gorge.  Still windy at times, but not the really cold stuff we saw in January.  The east wind always disappears in early March and then reappears in the fall.

5.  Dense and widespread valley fog is unlikely between now and October.  Inversion season is just about over.

Here’s a good idea of what we won’t see again until next winter and what is still possible:

MarkWinter_Over2

Of course we all remember March of 2012 when wet snow fell several times in March. That’s always possible, but we’ve only seen March snow in the lowest elevations 3 times in the past 20 years!  And each time it’s been the wet/slushy overnight and morning stuff in the metro area.  Plus, we haven’t seen March snow in a strong El Nino winter since 1966.

What about Cascade Skiing?  We should be fine through Spring Break (late March), but it’s pretty obvious now that the best skiing was in December.  That’s perfectly normal in an El Nino year when most weather action in the Pacific Northwest tends to happen early.  Then winter gradually fades away in January and February.

Luckily we had a ton of snow in December and it returned over several weekends lately.  That snow is going to be very slow to melt even with these warm systems and above freezing temperatures.  That said, the weekend rain did continue the melt in the lower Cascades, mainly below the 4,000′ elevation.  I see a few (only a few) rocks at 5,000′ from our Skibowl Camera that I haven’t seen since before Christmas.

Chief Meteorologist Mark Nelsen


Warmest February On Record…So Far

February 15, 2016

As of 5pm Monday we haven’t seen the temperature even get DOWN TO OUR NORMAL HIGH since early Sunday morning!  That’s right, even last night it was warmer than what we would typically see in the afternoon.  Feels like spring is trying to move in and we hit 61 today, our 5th 60 degree day this month.  Take a look at the numbers for the past 12 days here in Portland:

MarkTemp_Last12Days

As a result, the average temperature for February 2016 is now slightly warmer than February 2015, which is the warmest on record in Portland.  That’s warm!  Will it remain that way the 2nd half of the month?

MarkFebruary_TempLast8Years

In general the pattern remains quite warm, so if we don’t stay at record levels we’ll most likely be close in the end.

More later as winter ends…


Skiing/Snowboarding: Avoid Sunday

February 12, 2016

7pm Friday…

We have two good days for hitting the mountain this 3 day weekend, which of course leaves one that definitely won’t be so great.  That would be Sunday.

MarkSkiWeekend_3Days

Why the rain on Sunday?  A warm front with steady rain pushes into the Cascades after sunset Saturday.  That will be followed by snow levels up around 8,000′ (way above the tree line) through Monday.  The flow of air at 5,000′ will be straight from the west at 35-50 mph all day Sunday; that means moist air runs right into the Cascades, is forced to rise, and dumps rain over and west of the Cascade crest.  That’s called orographic lifting and will give us some big rain totals for about 24 hours.  It appears this event is going to be quite extreme with respect to the rain totals…unusually light in the valleys and unusually heavy in the mountains.  Our RPM shows 3-5″ of precipitation in the south Washington and north Oregon Cascades over the next few days…much of that falling in the form of rain after sunset Saturday.

RPM_12KM_Precip_NWOR.png

The good news is that the band of rain lifts north Monday and should leave us with a dry and spring-like day on the mountain.  Hopefully the snow won’t be too saturated with water; most likely it’ll be okay since we have 4 to 8 feet on the ground at the base of the ski areas.

Here in the valleys the weekend will be wet, with most rain during the midday/afternoon Saturday.  Sunday’s rain should be lighter.

We may have a 60 degree day (or warmer?) on tap for Monday.  If clouds lift far enough north we will be in the sweet spot with some sunshine, very warm atmosphere, and light southerly breezes.

Chief Meteorologist Mark Nelsen


Mild Weather Continues

February 11, 2016

We’ve been busy the past two days here at FOX12 in a telethon raising money to support the Childrens Cancer Association.  Luckily the weather has been dead so I can focus on other things…Daria and 105.1 The Buzz have been our partners in this endeavor and this was a nice photo moment:

mark_ladies

Moving along, take a look at the 00z GFS ensemble chart…above normal through almost the entire 16 day period.  Remember the blue line is the actual operational model, the red is the average of all the ensembles, and green is the average for the date.

tseries_850t_000-384_Portland

This says it’ll be tough to get snow down to Government Camp much in the next two weeks.  The snowpack below 4,000′ will continue to slowly melt.  The 12z ECMWF is a little cooler in the middle of the period, but plenty warm early and later:

tseries_850t_000-360_Portland

I’m dusting off the fork this evening…

Here are the 4 weekly maps from last night’s run of the ECMWF.  That takes us through the 2nd week of March, showing higher than normal heights through the period:

 


Downpours in Vancouver

February 11, 2016

3:28pm Thursday…

It’s wet, but warm out there this afternoon!  Check out the radar:

KPTV_Default

And a little closer you can see heavy rain moving through Vancouver,

KPTV_Default2

This stuff is moving quickly to the northeast so the rain won’t last long.  Expect showers to pretty much end after sunset.  But don’t worry, rain will be back just in time for the Friday AM commute.

By the way, another very warm day out there; temperatures close to 60 degrees again

PLOT_Highs_ORWA.png

Chief Meteorologist Mark Nelsen


A New First Live Local Weather Face

February 9, 2016

I have a new co-worker in the FOX12 weather center!

Liana3

Meteorologist Liana Brackett has been with us since early January; getting on-air just in the past few days.  She’ll be getting you all your weather information during the 8pm and 9pm shows on PDX-TV.  Of course she’ll be working on other shows as well.  Our company owns both FOX12 and PDX-TV and we produce newscasts for both stations.  It’s all the same in that the signal just goes to one transmitter or the other; the same graphics and FOX12 branding is used in all shows.  We produce 6 evening newscasts so that’s a lot of weather content to fill!  We do a lot of this:

Liana_chroma

There are generally two ways a person gets into broadcast meteorology (television weathercasting).  The first is most typical: you get a broadcast journalism degree, start as a reporter, get some weather knowledge, and become a weathercaster.  The second path is to get a degree in Atmospheric Sciences or Meteorology and then become an on-air meteorologist.

Here in the Portland television market there are 4 weathercasters with a degree in meteorology and we now have 3 of them!  Brian MacMillan and I both have degrees along with Liana.  She graduated from UC Davis with a degree in Atmospheric Sciences.  Liana spent the past 6 years working here in Portland right under our noses…at the Portland National Weather Service office.  As a result she knows our weather well which is quite a plus.  To be honest, it’s a bit of a pain to teach someone from another part of the country how our weather works; it takes awhile to get used to all our terrain and the effects it has on day to day conditions so we got lucky to find someone local.

I asked her a few questions…

What’s the hardest part of changing from a non-TV job to “on-air”? Using less technical meteorological terms! That was a tough one for me because I was used to using “orographic lift” and other terms daily. But, I love explaining weather terms so that will be fun to do on-air.

What’s the best part? I love explaining weather to people so now I get to do it every day! That, and the dressing up part and the fun people I get to work with.

Have you been surprised by anything/something? I didn’t realize how long I can spend looking at the weather! At the NWS, you’re constantly watching the weather so I can easily spend 3-4 hours just trying to get the forecast “just right.” But, now in TV, I have to manage my time between forecasting, getting camera ready, and actually doing the show. I just need to get some more programs on my home computer then.

What’s it like to tell a weather “story”, have a producer talk in your ear, change graphics, and smile all at the same time?  Tougher than it looks or no? Oh. My. Goodness. It is way tougher than it looks! There is an art to it all, and that’s when things go perfectly. It’s even more challenging when you throw in any malfunctions like you can’t see yourself, but you still need to talk into the camera and smoothly go through your weather story. But, I’m loving the challenge and know it’ll just get easier and smoother. I seriously love this job!

Anything else you want to add? 
This job is amazing! Well, I get to work with Mark every weeknight
so how can it not be? Lol, he’s sitting nextto me so I have to say that. J 

Because I’m such a mean guy…that’s right…
We’ve all enjoyed getting to know Liana over the past month and look forward to many more months/years with her!
Here is some contact info for you:

BIO: http://www.kptv.com/story/31094017/meteorologist-liana-brackett

Follow on Twitter: https://twitter.com/LianaBrackett

Like on Facebook: https://www.facebook.com/lianabrackett/?fref=nf

By the way, in case you are wondering who is leaving or getting fired?  No one.  Nora Hart has been doing weather for the past 16 months but is now a news anchor again.   She’s leaving us in the weather center and moving about…15 feet away.
Chief Meteorologist Mark Nelsen