It takes restraint to be a weatherman sometimes.
Last night was one of those times. Let's hope the restraint is justified in the long run...
Last night's 0Z (evening) GFS model run painted a really scary picture for a big Sunday rain storm, followed by several inches of heavy wet snow Monday. Today? We'll it would be too extreme to say "poof" it's gone, but not by much.
The overnight (06Z) GFS run is brining things back to reality a bit. It still spins up a low pressure system Saturday night into Sunday, but does not create the "bomb" fantasized by the earlier model run.
Talk about a sigh of relief. Whew...
GFS having a bad month:
I don't verify numerical weather forecast models for a living... (Believe it or not there are people at NOAA who do that!) but I do use them everyday. It seems to me that the GFS (the primary U.S. medium range forecast model) has been out to lunch lately.
Remember the "mega storm" about 2-3 weeks ago that lead to some alarming headlines of 1'+ snow totals...only to end up as 1" at MSP Airport? Thank the GFS.
To say we've been seeing a high degree of "variability" in the GFS solutions in the 3-10 day range would be putting it kindly. More like wildly inaccurate solutions...often brewing up monster storms that turn out to be highly overblown.
I can't say why this is happening for sure. But seasonal variations usually lead to model trouble. The models have trouble gauging the transitions during spring and fall.
I can tell you this, it's no fun to be a forecaster staring down the barrel of a (fictional?) 1' to 2" heavy rain followed by a 6"+ snow event in early April...and having to swallow hard and not publish it in hopes that the model was just going through some growing pains.
Let's hope today's runs confirm the idea that we will get some rain Saturday night and Sunday...but a more manageable amount under an inch in most locations...followed by a few wet, wind driven snowflakes Monday on the colder backside of the low.
Rivers dropping fast:
It's good to see river levels dropping fast west of the metro today.
The Crow is down around 1 foot in Delano since Sunday.
The Minnesota is down 1.5 feet in Mankato, and is now receding in Henderson.
The Minnesota is cresting today in Jordan.
The Mississippi is forecast to crest tomorrow in St. Paul well below the earlier threats of a flood rivaling the 1965 fiasco.
Two crests better than one?
There's plenty of talk about a "double crest" of 2nd crest for many area rivers this spring. This may be a good thing.
Moving 80"+ of winter snow melt down the rivers in two separate (but lower) surges may be a better outcome than having one big "mega crest" that could produce a flood of record for many river locations. Most flood protection can better handle two moderately high crests then one big flood that could top dikes & levees.
The double crests expected this spring may be a godsend.
Red River trouble?
The one exception to this scenario may be the Red River of the North. The big thaw never really hit the Red, and there's still plenty of water in snow to melt when things warm up later this week into the weekend. The Red may see one big crest...and the latest forecasts still put the chances high for a record flood on the Red at Fargo and other river points.
We'll watch as that story unfolds over the next two weeks.
Southern Minnesota river outlook better?
It still looks to this forecaster like we may be able to thread the needle on avoiding record flood levels for the next week at least, even with some hint of river rises next week due to melting and additional rainfall.
Let's hope so.
Signs of spring?
Yes, the forecast modles are hinting at more 40s & 50s the next two weeks. But this guy really caught my eye this morning. A sure sign of spring?
Posted at 5:45 PM on March 29, 2011
by Paul Huttner
Filed under: Winter/spring 2011
Forrest Gump may have said it best. "Life is like a box of chocolates, you never know what you're gonna get."
That's how meteorologists feel looking at each new forecast model run these days.
3" of snow Thursday or just a little slushy rain/snow mix? Heavy 1"+ rain & thunder Sunday? Heavy snow 6"+ Monday? Opps...storm tracking south, little or no rain or snow Sunday & Monday??
Various forecast model runs have painted all of the above scenarios over just the past two days, and it looks like we're not done yet!
After a sunny & milder Wednesday, it looks like Thursday may feature an almost "Alberta Clipper" like system riding along in northwest flow aloft. This seemingly weak system looks to produce light precip from a visual perspective on the maps. Still, forecast model output insists the system has enough oomph to produce precip on the range of .25" to .75" depending on which run & model you want to believe.
Rain or snow? Most of the model guidance would seem to suggest temperatures cold enough in the lowest mile of the atmosphere for snow Thursday. Still, temps should be close enough to freezing that daytime warming may cause some of the precip to mix. That may suggest a slushy mix of snow and rain Thursday.
Based on (the inconsistent) data so far, it looks like an inch or two of sluchy snow is possible Thursday and Thursday night into early Friday. If precip manages to stay all snow...there could be some 3" totals somewhere in the eastern half of Minnesota and western Wisconsin.
Expect some precip Thursday &Thursday night into Friday morning. It will probably be slushy snow but could mix with rain at times. An inch or two of slushy accumulation is possible, but not certain. This forecast still has a relatively low degree of confidence since the models continue to change with little "run to run consistency."
The "smell test" looking at the maps says to me the idea of heavy precip with this system may be overdone.
Saturday still looks like the nicest day of the weekend. It appears Minnesota will be in between weather systems, and it should be sunny and relatively mild with highs in the lower 50s possible!
Next system Sunday-Monday?
Here's where the forecast models are all over the map. Literally.
Overall tracks are trending south with this system. The latest GFS run still tracks a low close enough to Minnesota to produce soaking Sunday rains. The more southerly track also hints that colder air could come south...changing rain to possibly accumulating snow.
The European model suggests a more southerly track that could keep precip completely south of the metro.