Thursday, January 10, 2013

Still Concerned About Ice Next Week

3PM Thursday Update... Here's a video update using the latest look at the European model and my thoughts on it.


 

You may have noticed I didn't update the blog Wednesday after my initial morning post.  The data throughout the day suggested more rain than anything next week with the only chance for any wintry weather across the far northwest.  While that scenario is still quite possible, the overnight run of the European model throws a curve ball in many forecasts.... IF TRUE.  I alluded to the possibility the models just don't have it right yet and I still don't think they have it right.  You have to be kidding yourself if you looked the models Wednesday as said, "yep, that's what's going to happen next week." 

Remember the Christmas Day storm?  Some models several days prior to the event showed severe thunderstorms here ( I never bought into that thank goodness).  Each day was a different track, even the day before.  The NAM was horrible in that forecast.  Again, my point, confidence is low in this type of pattern as each run of the model shows different solutions.

Here's what we do know from history.  Arctic air is usually shallow by the time it gets to Arkansas, the Ozarks CAN delay the subfreezing air from getting into central Arkansas, and a southwesterly flow aloft usually is unsettled!

I want to make it very, very clear that what I'm posting here is NOT our forecast, but just things we watch in the weather center.  Once confidence builds on any given solution, I'll let you know.  This could turn out to be just plain rain, ice, or NOTHING!  I hate to sound so vague, but it's the truth.  The European model sounded alarm bells last night and let me show it to you.

This is the European model valid at 6PM Saturday showing you surface temperatures.  The white line is the freezing line.  Look at the contours tightly packed over NW Arkansas.  The front is located there with readings in the 40s, but it's near 70 across the southeast.
On Monday morning at 6AM, a good bit of the state is covered up with precipitation.  The rain/snow line is the blue dashed line up north so NO snow according to this.  The cold surface high is near Des Moines, Iowa.  This is bringing in an east-northeast wind at the surface allowing low level cold, dry arctic air to move in and it's raining on top of that.  The front has slowed down just east of the state due to ridging in front of it.  This allows a wave of low pressure to develop in the northern Gulf of Mexico and you can see that with the black line labeled "1014".
This is the alarm bell the European model  sounded.  Look at the white line through Arkansas.  Everything along and north of that is 32 degrees or colder at the surface.  This runs from near Waldron to near Little Rock over to Memphis.  If this is true, we're talking about freezing rain and maybe some sleet.
But wait, there's more.  Another wave late Tuesday could move through southeast Arkansas, however, the Euro shows most of the state ABOVE freezing at this point.
This is the 500 mb pattern late Wednesday next week from the Euro.  Look at those orange's over the southwestern United States.  That's a strong storm I'm not writing off.  It's very much in the long range.  The model dampens this out as it moves east, but I don't trust that at this time.
And here's the GFS next Monday morning.... NOTHING!!!! It's cold and dry.  See the forecasting challenges now!?!?  Where's the advil?
In summary, I'M NOT CALLING FOR ICE RIGHT NOW!  I want you to know that the possibility is at least on the table, but so is the GFS's dry solution.  BTW, the GFS does bring a wave of moisture in Tuesday so we'll watch that as well.  Once confidence grows in the forecast, I'll let you know.

Thanks for reading!

2 comments:

Will said...

Morning thoughts....Euro trending much colder than previous runs. GFS is not as cold but also trending colder. The GFS is good with sniffing out possible trends in the long range but normally not very consistent with day to day runs. This is what happened with the Christmas storm I first mentioned 10 days before it actually happened. The GFS was the first hint at that storm and then it vanished for a couple of days only to return. The Euro was late to come on board with that storm and I think that's the case with the upcoming cold snap. The GFS started showing this cold, along with some other indicators, (SWM, MJO, etc..) several days ago but backed off. I would tend to agree with Todd that because the Euro, (Todd's favorite) is showing some substantially colder air coming we might need to watch out for some icing, which as I have said previously is the more common precipitation form during an arctic plunge.

What say ye Snow Bird Bob??

Sarah Robertson said...

Whew, to be a meteorologist in Arkansas, tiring!!!