Friday Thaw; Window rattling Arctic front Saturday; NWS new “warning” language?

36F high temp at MSP Airport at 12:12pm Wednesday

7F low at MSP so far Thursday

Arctic sideswipe - brief glancing blow of arctic air today

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Friday thaw milder Pacific air returns briefly Friday as temps crack the thawing point

Siberian Express rolls across Minnesota Saturday as temps plunge toward zero and northwest winds gust over 30 mph

Life on the temperature roller coaster:

We're getting used to this in Minnesota these days. Rising temps before sunrise? Falling temps during the "warmest" part of the afternoon? It's what meteorologists call "advection."

As Arctic and Pacific air masses battle for control of Minnesota through Saturday, expect more unusual temp swings at odd times of day.

Thursday will feel like Old Man Winter. Friday may tease "hints of March" by late afternoon. Saturday will leave no doubt that it is still mid-January.

Arctic Invasion: Still on track

Okay, so it won't get that cold in Minnesota next week...but you have to appreciate the youthful sense of fun when temps drop at UAF.

We shouldn't be surprised that a sub-zero arctic outbreak is on the way to Minnesota in mid-January. What's surprising is that we have avoided a sub-zero daytime high at MSP Airport for a record 4 year stretch.

It's going to get very cold starting on Saturday night...and lasting into most of next week. The only question appears to be...how cold?

Image: NOAA GFS MOS output via SUNY-Albany

The magnitude of arctic outbreaks is often hard to gauge before the fact. Models generally have trouble with precision on extreme events...those that stray far from "climatology."

Arctic air is sometimes underestimated...and usually reluctant to leave as fast as the models would like once the heavy, dense arctic air is in place.

The lack of deep snow cover across Minnesota is one factor working against prolonged, extreme cold.

The Twin Cities Urban Heat Island...with MSP Airport on the southern end of a light northwest flow on cold nights...is effective at keeping temps in the central urban core and MSP Airport as much as 10 to 15 degrees warmer than the outlying suburbs/exurbs like Lakeville and Glencoe.

-10F at MSP Airport? -15F? We'll probably bottom out somewhere in between those two numbers Monday or Tuesday morning.

It's increasingly rare for us to hit -20F in the inner metro core. The last time we saw -20F was 4 years ago in 2009 on January 16th when the mercury plunged to a respectable -22F.

As of now...I don't think we'll get that cold this time.

Cue applause.

Word games - NWS looking at options for more effectively communicating weather warnings

It was riveting to sit at the Hurricane Sandy Town Hall and listen to National Hurricane Center Rick Knabb and Weather Channel Hurricane Specialist Bryan Norcross talk about "messaging" with Hurricane Sandy.

As the ferocious and devastating hurricane approached the Jersey Coast, NHC was wrestling with a decision. Do we drop "Hurricane Warnings" as Sandy hits shore and become "post tropical?"

There are debates about what kind of storm Sandy was "meteorologically speaking" as she slammed into New York and New Jersey. But there is no questions that the effects were those of a hurricane.

I've gone on record as saying that after an excellent, life saving forecast and warning scenario in the days leading up to Sandy, I think NHC dropped the ball on communication and messaging by dropping "hurricane warnings" as Sandy roared ashore.

Everyone knows what a "hurricane warning" means. Few have ever heard of a "post tropical cyclone."

It sounds like a broken beach amusement park ride...and certainly doesn't convey an immediate sense of urgency... or the imminent emergency conditions Sandy was about to unleash on the most densely populated coastline in the USA.

I was encouraged to hear at the meeting that NHC has a proposal that will allow them to retain "hurricane warnings" for future storms as they come ashore...even if they are in transition to "post tropical" or "hybrid" systems.

Now NWS is looking at "simplifying" terminology for all weather warnings, and Minnesota is in the Guinea Pig zone for this test.

My initial read?

The term "Warning" has credibility and conveys a sense of action, and should be retained.

I'll need some time to take a look at the rest of the proposals here. But I thought this would be a great opportunity for you as astute Updraft readers to take a look at the proposed changes here and give your opinion to NWS.

What do you think?

PH

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