Tuesday, January 30, 2007

WHEN THE MOMENT IS RIGHT...
WILL YOU BE READY ?

Feb Storm 1

Storm #2 featured above is just a prelude to what's coming later in February. Though I will end up one day off for the projected arrival time (original call January 13 was for Storm # 2 to occur in the 1/29-31 time frame), it will be nice to finally have enough snow to cover the grass.

I know you want the full story on this storm, but a brief update is all I can do for now until tomorrow morning and then more tomorrow evening. But here's what it looks like to me:

1. CLIMATE TELECONNECTIONS point to a coastal storm: The Pacific North American (PNA) Index is positive, the North Atlantic Oscillation (NAO) is in a negative phase but driftly slowly toward neutral. That as some of you know is a key indicator for me, because when the NAO (a measure of air mass movement in the North Atlantic Ocean) backs off from strongly negative, it means there will be sufficient, if not fresh, cold air available as a coastal storm turns north.

2. ALL ABOUT THE TIMING. For the I-95 corridor from DC to Philly, the timing of this is terrible for commuters but wonderful for students and teachers hoping on a snow day, or at least some kind of something to give you a little time off. The NWS has been backing the temps down all day for Thursday, off from a high of 40 to now just 34 in the Dundalk area. I use my town as a gauge because we are southeast Baltimore County, right along the Chesapeake just east of 95. If the forecast HERE calls for snow/sleet/freezing rain, you can bet the rest of the Baltimore Metro area will see all frozen precip and coming at just the right (wrong) time.

3. WHERE'S THE HIGH? Some of you know the old rule: "Predict the High and you predict the storm." Problem this time around is there won't be a High Pressure system in the right place (SE Canada or upstate New York) to deliver fresh cold air. Instead the high moves off the Mid-Atlantic coast Wednesday, and the storm arrives on leftover cold air Thursday. Combine that with the expectation this will be a fast moving system, and you can see why snow amounts will stay on the low side, and this may wind up more of an ice event for many than snow.

WHAT ABOUT SCHOOL? For DC/Northern VA area schools, it looks more likely you'll be closed Friday due to the ice potential. For Baltimore Metro schools, this will be a tricky call at two different times:

- Thursday afternoon: Precip (mostly snow/some frozen mixed in) will start after lunch and spread northeast. Travel will deteriorate from 1PM on. Early dismissal? Don't count on it, because I doubt the radar will look so ominous so as to suggest school officials should pull the plug at 11AM based on a projection of something that's 2 hours away.

- Friday morning: Considering what the map above indicates, this will be a tough call. For everyone along I-95 and then to the north or west, snow will probably mix with sleet and freezing rain for a few hours overnight, then change back to snow in the morning. We are not talking much more than 3 inches for anyone. In fact, I'm leaning closer to 2 inches for most areas south of Mason-Dixon given that mixed precip will lower amounts. The kicker will be that blob of green you see wrapping back around the storm. For many Maryland districts: Balt Co, Harford, Baltimore City, Anne Arundel and Howard, I can see a scenario where everyone calls for a 2 hour delay, then 15 minutes later says they will reevaluate at 6:45 AM. If that band of wrap-around snow starts up right at the time of "reevaluation" you'll see schools change to closed. This happened twice in recent years...January 4, 2003 (snow) and February 6, 2004 (ice).

Finally, what is the point of my headline? No it has nothing to do with Cialis. It means that this storm will present only a few precious moments where the right decision can be made quickly and easily. Official forecasts will probably flucuate more in the next 24 hours, driving you crazy when you're looking for consistency and there is none to be found. A special note of warning to my teacher colleagues: A lot of things have to come together just right for this storm to deliver a day off, so maybe the headline should really say: "If the moment is NOT right, will YOU be ready?" (for class on Friday).

Next update in the comments feature Wed 5:45 AM, followed by Pre-Storm Report Wed evening after 9 PM.

18 comments:

terpguy said...

Thanks, Mr. F!

Looking forward to the variuos weather services being all over the place for the next 24-36!

TG

Mr. Foot said...

Hey BCPSers... looking more dicey with each forecast..now mixed/frozen Thu PM and Friday AM until noon.

You know what that means. Ahem.

Andy, Southern York County PA said...

NWS in State College and DC leaning toward most if not all snow call for Norther MD and Southern Pa. Just mention mix but seem to argue that is unlikely. My call is 3-6 inchesfrom Baltimore to Harrisburg, maybe more but too early to speculate on how strong the second coastal low will be.

Mr.B said...

Eh.

WEYTYN said...

Hey there
FOOT FORECASTFanatics/Powderhounds/
blogspotters/enviro-gurus/
democrats/republicans/
soothhsayers/apocolyptical laisons/and anyone else I have forgotten-

WEYTYN here- I have been reading and analyzing the weather in my own little postage stamp of the world.

For those that question global warming/climate change and have extra time on your hands...do a google search of this-
solar activity vs global warming

and check out some of the interest info available on the subject.
specifically the solar activty levels vs global temperature changes

some fun reading.
ya'll better be thinking how to saty warm instead of how to stay cool!

happy shoveling

Anonymous said...

ohh goody goody... here is to HoCoPS'ers enjoying a lil time off.. THANKS MR. FOOT!!

I NeedaSnowday!!!

E.H. Boston said...

BOS gets screwed this morning when 2-4" of snow was forecasted last night at 11PM and we didn't even get 2-4 flakes of snow to fall from the sky.

BOS will be screwed again as the late week storm goes OUT TO F****** SEA. The story of my winter!

Anonymous said...

Hey EH.. I recall last year when everyone wanted to pack their bags and move to Boston! This winter has been discouraging huh!

E.H. Boston said...

That was two winters ago. Boston finished the season at 36" last year and spent most of JAN in the 60's. We got all our snow in two storms, each of which had all their snow melt in less than 5 days.

BOSTON SNOWFALL SO FAR...1.5"

Mr. Foot said...

Mr. E.H.:

February hasn't even started. Relax. You'll get your snow, I promise.

E.H. Boston said...

In all do respect Mr. Foot...I'm sorry for the anxiousness. People from Massachusetts, especially near Boston, are the most wound up worry-some who cant spell, people that you will ever encounter. I know. We walk fast for no reason. You can't understand us when we talk. We misunderstand Cartoon Network Billboards for bombs? I DUNNO??

Boston is a city where we would take a New Yorker and spit them back out.

We have Puritan roots, we love to suffer...Red Sox until 2004, and like to complain.

I could never make it in California.

Oh yeah...this winter s*cks!

Bring on the RED SOX BABY...Celtics are going for 12 or 13 in a row (losses) tonight. I NEED SOME SNOW!!!!!!!

Andy, Southern York County PA said...

This storm looks like a bust, but in a year of busts if we get 2 inches it will be the largest single snow of the season so in a sense it's a step in the right direction. Also, goes to show you not to rely on the models too much. Even if the models don't show snow for next week, does not mean we can't get a heck of a storm. WE ARE WAY OVERDUE SO I'LL BE POSITIVE!

Andy, Southern York County PA said...

Henry M. from accuweather says:

"THE GFS PLAYS IT'S NORMAL GAMES...

I said from the start of this, the models will play the game of taking the storm east then pulling it back west in the end, and if you look at the GFS, it is doing just that...The latest run, and I know it's the 18z run, does pull the storm back toward the coast Friday which would mean snow for the major cities instead of nothing as per recent runs. The Carolina's still get the ice and New England still gets a few inches of snow.

The Monday storm is showing up too again, no surpirse there...but lets get through Thursday before I get into that next and the one aftyer that. Oh, did I tell you, there's even another storm after that next week...."

DOES ANYONE REALLY KNOW WHAT THIS STRANGE STORM WILL DO? HAVE NOT SEEN THIS MUCH UNCERTAINTY THIS CLOSE TO AN EVENT FOR A LONG TIME!

E.H. Boston said...

Have the model suites gotten worse over the past few years or am I mistaken? It seems like there was much more reliable forecasts in the early 2000's.

Mr. Foot said...

Yes, I have been looking at all that and in the face of intense public scrutiny, believe that the Baltimore/Washington NWS is ignoring this storm at their own peril. Not even issuing a Special Weather Statement when all other area NWS Offices have done so. I am concerned this storm will be one where the data and observations continually outstrip what the models were projecting for that time and place. What I see is more moisture and colder air than was anticipated at this point. I'll be posting another update this evening, and sticking to my forecast. If I'm wrong and we're in school Friday, then I'll be happy to wear the bag and explain to you (and my disappointed students) why it happened. But I just feel confident the dynamics will play in our favor.

Mr.B said...

Radar 1

Models 0

Models underdoing current radar.

Andy, Southern York County PA said...

Current radar is very interesting. We have very cold air in place and warm sea surface temps. Curious to see how this storm evolves and interacts in this environment. At this point no one seems to be confident of anything. So keep an eye to the sky!

Frank said...

Thanks Mr. Foot. Looking forward to your update, and glad to see that you are not model hopping like all the mets. that I have watched. Weather (haha) you are right or wrong, I always like how you make your calls. Good luck with this one!