Site   Web powered by
Weather or Not ~ Weather and musings from Keith Thompson.

I’m Still Saying Snow for the Holiday

November 19th, 2009, 8:54 am by keith

What looked like a vague possibility last Monday and Tuesday (see my recent blog post) is now looking a little more real.  The forecast model I typically view for 6 to 10 day periods continues to feature snow for Thanksgiving Day.  One subtle change to the model over the past 24 hours: the snow may begin a little early than previously thought.

Earlier this week, when I first mentioned the possibility of snow for the holiday, it looked like a rain event for Wednesday, becoming rain and snow, then snow during Thanksgiving Day as colder air moved into West Michigan.  Now, it seems the colder air might arrive earlier, so the rain/snow mix might begin as early as Wednesday evening.  That’s important news to those who will be driving over the river and through the woods to Grandmother’s house (or wherever else).

At this time, it’s a little early to predict travel trouble, and it certainly DOES NOT look like icy roadways are in the cards (thank goodness, temps Wednesday evening look to remain above freezing).  But for those traveling via car or air Wednesday, it will not be smooth sailing.  At best, we’ll have rain, and likely some gusty winds; not clear skies and dry roads.  At worst, we’ll have enough snow to stick on the roads. 

I don’t think we’ll have a “big” snow, and remember, the ground temps are still relatively warm as we’ve yet to have our first real winter chill.  As a result, a lot of the snow will melt soon after contacting the ground.  However, traffic (car and air) will likely have to slow a bit thanks to the adverse weather conditions, so that could make for a little more congestion on the highways and in the major airports that service our area ( O”Hare, Midway, and Detroit Metro), which of course could trickle down to our local airports.

The cold air coming in behind the system will likely give us a shot of lake effect later Thursday and Friday.  I’m talking seven and eight days out here, so obviously, this is subject to change.  I’ll continue to monitor the forecast model updates to see if any significant changes occur.  You can check my blog for further updates.  Also, follow me on Twitter (weathermankeith) and on Facebook (Meteorologist Keith Thompson Fans). 

You can also get the latest weather updates by watching meteorologist Jeff Porter, Monday through Friday on Newschannel 3 in the morning (5 a.m. to 7 a.m.) and at noon, and by watching meteorologist Wes Callison on Newschannel 3 Saturday and Sunday evenings.  I’ll see you in the evenings on Newschannel 3 at 5, 5:30, 6 and 11, and on Newschannel 3 Live at 10 p.m. on the CW 7.  Oh, and did I mention wwmt.com?  We’ve got you covered!

Snow for Turkey Day?

November 17th, 2009, 3:02 pm by keith

It looks like we might see a wintry change in our weather just in time for the Thanksgiving Day holiday.  The longer-range forecast model which stretches out 10 days shows an area of low pressure moving right over the Lower Peninsula next Wednesday, Thursday and Friday (November 25, 26, 27).  That low will tap into much colder air from Canada, pulling it into West Michigan.

In addition to being cold, the system will also be wet.  The result: a chilly rain Wednesday and early Thursday eventually turning to snow by late Thanksgiving Day, lingering through Friday morning.  It looks like the disturbance will be moving off to the northeast by Friday evening, so the snowfall won’t be too long lasting.  It is difficult to say how much accumulation we would see from the storm.

Remember, this outlook is based on forecast data that looks forward 10 days, and a lot can happen to change that forecast.  But at first blush, it certainly gives reason to pause.  If the forecast comes to pass, it would be the first serious intrusion of wintry air/weather to West Michigan this season.  I’ll be watching the forecast in the coming days to see if the snowy outlook changes.  Stay tuned!

Sunshine Soon in Short Supply

November 17th, 2009, 6:03 am by keith

Today (Tuesday) will be sunny in West Michigan, a real mid-November treat.  I suggest you soak it all in because the next few days, the sunshine will be on hiatus.  An area of low pressure that has been sitting, spinning over the Plains ande mid-Mississippi Valley the past few days will finally begin heading our way tonight.

The good news for us is that even though the low will be moving slowly, at least it will be moving, so it won’t be overhead too long.  As it approaches, we’ll see increasingly cloudy skies tonight.  Showers will be following tomorrow.  The rainfall tomorrow and Thursday will be on the lighter side, with about a tenth to a quarter of an inch possible over the two days.

The cloud shield with the low will likely linger over West Michigan through a portion of Friday.  But here’s a silver lining on the cloudy outlook: forecast models show a dry air mass moving in later Friday, bringing sunshine back to West Michigan for the weekend.  Temps will continue near average to slightly above average.

If you’re wondering when we’ll first feel winter’s first chill, it may be about a week away.  I’ve been looking at some longer range forecast data which indicates some colder air may arrive in about a week, specifically, next Wednesday and Thursday.  The chill will last a few days, and maybe will come with some snow, perhaps our first accumulating snowfall.   It looks to be a sign that we’re turning the corner from fall to winter in West Michigan.  Remember, that feature in the forecast is still a week away, and a lot can change from now to then.  Stay tuned!

Weather for the Week: Most Un-Novemberlike

November 16th, 2009, 7:08 am by keith

A “cut off low” is spinning around in the mid-Mississippi Valley, just off to our southwest.  What is a “cut off low?”  It is a low pressure center that is cut off from the jet stream.  The jet stream moves and guides areas of low pressure across the globe.  Sometimes, when the jet stream isn’t very strong and/or is moving in a west-to-east flow (called a “zonal flow”), an area of low pressure can become separated.  When that happens, the low just sits and spins, not moving much for days.

If you’re stuck underneath a cut off low, that’s bad news because the weather will be cloudy, damp and often chilly for days.  That’s the forecast for the next couple of days for the region of the country just to our southwest.  Forecast models show the cut off low eventually moving our way, bringing a threat for showers Wednesday and Thursday.  By then, the low will be on the move, so no problem with it hanging out over West Michigan for too long.

In the meantime, the weather here will be much quieter than what is typical for this time of year.  We’ll have lots of clouds interspersed with periods of sunshine.  That’s not so abnormal for November.  But our temperatures will continue to be a little warmer than normal — with highs in the lower 50s all week long.  The combination of no storms on the horizon and slightly warmer than average temperatures is why I say this pattern is a surprise for this far into the month.

The “worst weather of the week” award easily goes to the Pacific Northwest — specificially, Seattle, Washington.  A powerful Pacific storm is slamming into the coast today and tomorrow, bringing rain and strong winds.  The storm is expected to keep rain around for a while.  The Seattle weather forecast calls for rain every day this week — that’s every day from today through next Sunday!  There’s a reason that part of the country is renown for gray skies and rain!

Strong El Nino, Warmer Winter?

November 6th, 2009, 6:55 am by keith

The latest update on El Nino from the U.S. Climate Prediction Center (CPC), issued Thursday, says the phenomenon is strengthening.  El Nino is the term used to describe the unusual warming of the surface water of the equitorial Pacific Ocean.  The warmer water causes weather patterns to shift around the world, sometimes with disastrous results.

Not all El Ninos (or La Ninas, the name for the atypical cooling of the equitorial Pacific) have dramatic effects on weather.  History (in weather terms, called climatology) has shown that the impact(s) of the phenomena are often dependent on location and strength.  Remember, the Pacific Ocean is a huge body of water, and usually, the warming doesn’t occur across the entire mass, but a portion of it.

The current El Nino is strongest in the central Pacific, where in October, sea surface temperatures were 1 to 1.5 degrees Celsius warmer than averge.  That’s a moderately strong El Nino.  The strongest El Ninos — which have produced the most catastrophic aftereffects — have temperature deviations of greater than two degrees Celsius. 

A moderately strong El Nino is historically correlated to certain weather outcomes in the United States, among them, warmer than average winters in the northern Plains and western Great Lakes.  Temperature patterns evident from analyzing the last 13 El Nino events (information available at the CPC’s El Nino site, if you want to see more) show the greatest effects in the northern Plains, beginning in December.  Here in West Michigan, the effects don’t typically begin to show until January, lasting through March.

As a result, I wouldn’t be surprised to see a continuation of the colder than average temperature pattern which began here in late September.  That might mean we get an early start to the snowfall, making it appear that we’re on the way to a cold and snowy winter.  But if history serves as an accurate marker, between January and March, the snowfall will be below average levels, as temperatures run slightly warmer than average.  By the way, you can read how my forecast stacks up against my TV competitors, and the climatological guru (Bill Marino) at the National Weather Service office in Grand Rapids, in the Sunday Grand Rapids Press.

Back to the CPC El Nino forecast.  The Thursday report from the CPC notes that forecast models (of which there are about a dozen) indicate the current El Nino will remain moderately strong (central Pacific equitorial sea surface temps about 1.25 to 1.50 degrees Celsius above average) through March.  After that time, the models show the phenomenon slowly disappearing, with surface water temps returning to normal/near normal levels by next summer.

One word of caution: the historical correlation between moderately strong and strong El Ninos and warmer winter weather is convincing, but not perfect.  There have been El Ninos that did not produce warmer winters.  But they are the exception to the rule.  Interestingly, a forecast for warmer winter temperatures in the northern Plains and Great Lakes goes against the Farmers Almanac forecast, which is for a very harsh season.  Time will tell!

October Weather Recap: Brrr!

November 3rd, 2009, 3:09 pm by keith

You don’t need me to tell you that last month was unusually cold.  But now that the month has ended, we can say just how cold it was.  Last month’s average high temperature was just 55.3 degrees, a full seven degrees colder than the long term (30 year) average.  Deviations of a couple of degrees from the long term average is considered substantial, so to be a full seven degrees off is incredible.

Low temperatures weren’t nearly as cold, thanks largely to the abundant cloud cover we had most of the month.  Clouds typically keep temperatures up a little at night, so cloudy nights should be a little warmer.  Even so, last month’s average low — 40.2 degrees — is a couple of degrees colder than the long term average. 

The temperature wasn’t the only unusual thing about last month’s weather in West Michigan.  We also were shorted on the sunshine…by a lot!  Typically, we see about 55% of the available sunshine in the month of October.  But last month, we managed to see just 22%.  Of course, lack of sunshine goes hand in hand with colder daytime temperatures, so that makes sense.

Mea Culpa

October 29th, 2009, 2:06 pm by keith

me·a cul·pa (mā’ə kŭl’pə, mē’ə) n.  An acknowledgment of a personal error or fault.

Remember today’s forecast?  “Best weather day of the month with abundant sunshine,” I recall someone saying Wednesday.  There were a few sunny spots in West Michigan: Calhoun, Branch, Jackson and Hillsdale counties saw a few hours of el sol.  But the word that best sums up the cloud cover over West Michigan today is “overcast.”  Certainly not sunny!  And, without the help of the sun, temps only reached 60 degrees, several degrees short of the forecasted middle to upper 60s.

So what happened?  The first hint that we might see only limited sunshine actually came Wednesday morning, when areas of dense fog developed right around day break.  The fog didn’t last long, but was significant (in hindsight) because it indicated what might happen this morning, since atmospheric conditions were largely similar.

Sure enough, in the pre-dawn hours this morning, fog and low clouds began to form, just like Wednesday night.  By sunrise, a relatively strong ”stratus deck,” solid, low-hanging, thick clouds,  were in place.  In order to get rid of the deck, we needed the atmosphere to “mix,” with columns of warmer air rising, eroding the clouds.  But the relatively low angle of sunlight this time of year means that the mixing process is somewhat stunted.  And, bottom line, there just wasn’t enough heating to get that mixing going.  By late this afternoon, the clouds from the next system heading our way were moving in, effectively ending our hope of seeing the sun.

The forecast models typically don’t do very well with situations like this morning’s.  Fog is often a rather localized condition, and forecast models work at a more macro level.  Even so, there were some indicators from various models that there could be some low clouds lingering in our area at least through the morning.  But in making today’s forecast, I chose instead to give more credence to the indicators of sunshine.  By mid-afternoon, I knew the forecast was a bust.  Ouch! 

I’ve filed the experience in my brain.  You can bet the next time a similar scenario presents, I’ll give those fog/low cloud indicators a little more weight.

Best Weather Day of the Month Today

October 28th, 2009, 10:25 pm by keith

I think you can make a good argument that today’s weather will be the best we’ve had so far this month.  Temps this afternoon will rise to the middle and upper 60s.  It will likely be the second warmest day of October.  The warmest day so far was October 21, when we made it to 68 degrees.  But on that day, we only had about 40% of available sunshine, as skies were partly to mostly cloudy.  Today, in addition to the warmth, we’ll have much more sunshine.  Hence, why I think it will be the “best” weather day we’ve had so far this month.

Better enjoy it, because the sunshine will be gone tomorrow.  In fact, tomorrow may be the wettest day we’ve had so far this month.  We got a real soaker of a storm through here last Friday, dumping between one and two inches on West Michigan.  Forecast models show rainfall coming in advance of a cold front that will pass over the Lower Peninsula late Friday may produce one to two inches of precipitation.  What a way to end this odd month of October (first in National Weather Service Grand Rapids history to not have a 70 degree day): the best day of the month followed by the soggiest!

But it looks like Mother Nature will throw a bone to the trick-or-treaters.  Rain should be winding down early Saturday, and the winds will quickly subside as well.  It will be much cooler Saturday evening, but not cold, with sunset temps in the middle to upper 40s.  Of course, the best news is that the weather should be dry.  Sunday, however, is another story.  Another system moving in will bring a chilly rain for the first day of November.

No Trick, Late Month Warm Treat

October 27th, 2009, 6:25 am by keith

Not that we need any proof that the weather in West Michigan can be wacky, but how about this:  the warmest day of this month may come just a couple of days before it ends.  October is typically the month when temperatures fall the most from beginning to end, as we say goodbye to the last vestiges of summer and hello to the earliest visits from Old Man Winter.

But this October has been strange from the get go.  Temperatures have been anything but “normal.”  The first three weeks were unseasonably chilly, and the warmest temps were just last week, when we finally put together three 60 degree days.  We’re still on track to set a record for the first October on record (going back to 1892) without at 70 degree reading.  Who knew that when we said goodbye to September, we said goodbye to anything above 69 degrees?  Probably better we didn’t know that.

But it ain’t over yet!  In a development so appropriate for this strange weather month, we have one more crack at reaching 70 degrees, though I think it is unlikely we’ll get so warm.  A shot of warmer air will be moving into West Michigan ‘Wednesday and Thursday, ahead of a strong area of low pressure moving across the Plains.  Forecast models are hinting that there may be enough warmth pulled in to the southern Great Lakes to push highs to 70 degrees Thursday — middle 60s look to be a sure bet.

Unfortunately, the nice weather won’t hold for the trick-or-treaters Saturday night.  A cold front will pass over West Michigan Friday, accompanied by rainfall which might be heavy.  The scenario is similar to last weekend, when a windy and wet Friday was followed by a breezy, gray and chilly Saturday.  Early precipitation forecasts show an inch of rain possible here Friday.  Temps will be much cooler with a blustery west wind Saturday.  Stay tuned!

Active Weather Week, But Same Old Weekend Story

October 26th, 2009, 2:12 pm by keith

As you might expect at this time of the year, the weather in this part of the world is getting more active.  Gone are the quiet weather patterns where little changes over several days, replaced by disturbances which cross our region every few days.  Typically, this pattern change doesn’t happen until late October or into November.  This year, the change seemed to take hold earlier in October — hence the unusually damp, chilly weather we’ve had.

This week, a couple of areas of low pressure moving through will bring showers — one tonight (Monday), and a second tomorrow night.  These lows will be moving relatively fast, so the showers won’t last long.  And in their wake, dry air will bring some sunshine, Tuesday afternoon, then again Wednesday afternoon through Thursday.

Unfortunately, it looks like the pattern setting up for the late part of the week will bring another round of gray, chilly weather to West Michigan.  A strong area of low pressure will be moving across the Lakes Friday, bringing blustery, chilly and likely wet weather Friday and Saturday, with the chilly air lingering through Sunday.  So, again, it looks like the weekend (including Halloween) will be cool and damp.  Stay tuned!

Weather
Daily WWMT weather forecast
7 Day Forecast
ADVERTISEMENT 
ADVERTISEMENT 
  • Archives

  • Categories

  • Tag Cloud

powered by
google
Search
        Search: Web    Site