Posted 9:30 AM Tuesday, 3/11/2008- Dave Longley - Another beautiful sunny day is on tap today, get out there and enjoy it.  You really notice the sun now in the evening, following the switch to eastern daylight time.  I noticed that cleaning up from dinner last night.

We're watching a cold front this morning just north of the US/Canadian border, northwest of the Great Lakes, that will be our next weather maker.  This front will bring an increase in clouds this evening (may marr our sunset) and some snow in here after midnight.  This thing is moisture starved, but we could still squeeze out a dusting to an inch or so of snow by the time we wake up Wednesday morning.

The real cold with this front should stay to our north, but we will get kissed by some colder air tomorrow, so temperatures will only make it to near 35.  Based on an analysis yesterday, Lake Ontario water temperatures have cooled to 36  degrees F, so we would need temperatures around 12 or 13 degrees F at 850mb over the lake to get lake effect precipitation.  We don't quite get there tomorrow, but there should be enough moisture to get some snow showers going.  I think we'll get some sun out tomorrow afternoon.  It should be breezy tomorrow afternoon, but at this point, it looks to be a longshot to get much more than an inch of new snow tomorrow.

Things will clear out Wednesday night, and we may see some sun Thursday morning.  A strong push of warmer air will be coming at us, and that will bring clouds and our next chance of precipitation Thursday.  We may be just cold enough for some snow at the start, but should change to rain in the afternoon.  Again, precipitation amounts look to be light.  With the clouds and precip., I lowered the high from the 47 down into the low 40s. 

Forcing for precipitation looks weak into Friday, and we should be warm enough for a mix of rain or wet snow showers.  Clouds may be pretty stubborn during the day Friday, which could keep temperatures a little cooler than what they might otherwise get to.

Now the weekend.  Of course, it's the St. Patrick's Parade in Syracuse.  All the models have been showing a system coming at us from the central US.  The GFS continues to be the most developed with this storm, placing a fairly deep storm over NYC by Sunday morning.  The GFS has some support from the ensembles and the UKMET.  The Euro is weaker, faster and farther south.  the trend that I've seen is for this storm to be slower and a bit farther south than earlier forecasts.  This would lead me to believe that we could see the first half to 3/4 of Saturday dry, with some snow flurries moving in late in the day.    This would be with either solution.

If the deeper GFS solution verifies, we would have wind and snow Saturday night and Sunday.  If the faster, weaker solution is the way to go, we would see just a few flurries Sunday.  Temperatures will be in the low 30s Sunday as some cooler air does get drawn down into CNY.

Beyond that we'll have 2 things we'll be watching.  1, which I've mentioned in earlier posts, is the NAO going negative.  Probably the most negative that we've seen since December.  This would lead to cooler than normal air being locked in across the Northeast US.  That's not to say we can't get mild, but the overall average over the next 7-10 days looks to be below normal.

The other thing we're watching is a very active southern branch of the jet stream.  At times this may lead to very unsettled weather in the southwestern US and an increase in severe weather across the southern Plains.  IF.  Notice that's a big IF.  IF something in the southern stream can get linked up with the rather persistent trough in the NE US, then we could have a storm of rain and snow in the eastern US.  If the phasing doesn't occur, then the southern stream system would likely harmlessly scoot off the mid Atlantic coast and not bother us.  Notice I said rain or snow.  There is no arctic air interaction at all, so these storms would have limited cold air to work with, and we'd be right on the fence of rain/snow.  A rather typical March scenario.

That should give you enough to chew on.  Comments as always are welcome.

Dave