So we got some snow after all!

After swinging wildly from model run to model run, alternating between 8" and 0" snow totals, looks like central and eastern NC got some snow after all this Dec. 26th. Just got in from outside playing with Maverick, Lambeau, Mike, Rhett, and Kendra- their backyard is a powder wonderland! Based on latest radar trends and upper-air analysis, looks like the heavy(ier) snow will be ending here within the hour. I measured 6" at 9 a.m.; the Raleigh NWS office shows similar totals all over the place. We should be piling into the 4Runner in a 15-20 mins and heading to Cary to visit with the other Barretts (those who could make it).

Enjoy the snow, all. Will post some pictures soon!

So just what is a white Christmas, anyway?

According to Wikipedia, a white Christmas "refers to a Christmas morning or Christmas Eve with snow on the ground." Others talk about snow actually falling on Christmas day. I'm pretty indifferent- either falling snow, or snow on the ground- both would count in my book! Since I'll be in Greenville on both Christmas Eve and Christmas day, this forecast will be KPGV-centric. Those who've been following me on FB and here have noticed a lot of back and forth with this snow forecast. Five days ago, the computer models were hinting at a major snowstorm for the entire east coast from SC north to Maine. Then about 3 days ago, the models started a 2-day trend of backing off the snow (both in warmer temps & less moisture) for all areas except down-east Maine. Then today the models have reversed again, predicting more snow both in accumulation and extent (snow as far west as Greensboro, NC).

We're about 30 hours out from the onset of precipitation- what can we expect? Based on a poor man's model consensus, I think the NWS forecast of 2-4" for Greenville is pretty accurate. The latest 18Z NAM forecast paints a much "wetter" picture for places west toward Raleigh... i.e., if it verified perfectly, Cary (where the Barretts will congregate on Sunday) would get 5" ending Sunday morning.

So here are the unknowns: atmospheric thermal structure (which usually has a margin of +/- 2 degrees F, not a problem unless you're talking about 30F vs 34F, which makes a big difference in terms of accumulating snows!) and moisture content (0.5" QPF vs 0.05" QPF, a pretty big difference that would give a range of 0.5"-5" of snow).

I'm going with the NWS here (always a good bet! www.weather.gov) and their 2-4" totals ending sunset Sunday. HPC has the area tasked in a low (10%) risk of 4" in the 24-hr period ending 7 pm Sunday (seems reasonable to me). See the attached graphics. In the images below, the shaded colors are 6-hr liquid-equivalent precipitation totals - so using a standard 10:1 snow:liquid ratio, 0.5" QPF = 5.0" snow. The dashed lines are thicknesses, and the general rule of thumb is that the "540 line" (the first blue dashed line) represents the rain-snow changeover boundary. The final graphic is the HPC snow probability.





Merry Christmas! Here are a few other pics from Christmas Eve: me with my great-aunt and great-uncle, Barretts at St. James Church for the Christmas Eve service, and me with my friends Sara Davis and Amanda Wooten.

Only cold... but a lot of it

This past weekend saw the continuation of the pattern that we've been locked in to for the entire month of December: cold and dry. Except for one quick warmup ahead of a cold front around 10 Dec, we've been below normal for every day of the month but two (01 Dec was also above normal, just before the deep freeze set in!) I guess I'm thankful that the below-normal temps are coming in Dec., leaving room for Jan & Feb to be back to normal (or even warmer!???)- below normal now means lows between 23-38F and highs 35-40F (instead of 18-23F and 30-35F, which we could have next month). Hopefully the pattern changes as we start 2011- a little warmer, and maybe some more snow!

So maybe it will after all?

The past week I've been following the potential for snow here in the mid-Atlantic for this upcoming weekend. The numerical guidance has been very interesting, mostly for its remarkable *lack* of agreement. Even now, 72 hrs out, you'd think that the general synoptic details would be clear -- i.e., where the sfc low will track, how amplified (phased) the 500 hPa trough will be, etc. I find it amusing that NCEP's HPC has discounted its own two high-quality NWP models (NAM & GFS) and instead gone for an ECMWF/Canadian/UKMET solution blend. For example, HPC predicts ~ 0.5" liquid-equivalent for Annapolis 00Z Sun-00Z Mon. Only tonight, for the first time, does the GFS start to hint at precip here (and even still QPF totals are 0.1-0.2" for the time period).

As I said earlier, it'll be interesting to watch what unfolds. This is what makes weather (its predictability) fun to follow!

First img: GFS QPF; Second img: HPC QPF

Looks like it wont...

After yesterday's post about possible accumulating snows this weekend in Annapolis, I've been underimpressed by the next sequence of model runs. Seems all solutions are now converging on a non-snow event for us... maybe still some snow for eastern New England as the surface low deepens and moves northward, but looks dry, windy, and cold for us. We'll see how it turns out.

So will it, or won't it?

For the past 4 days I've been entertained (and alternately dismayed) by the weather forecast for this weekend here. The GFS, NOGAPS, and ECMWF have been all over the place with their solutions as they attempt to predict where, how intense, and how "wet" the surface low will be as it heads from the Gulf coast. Obviously the favorable (for us, anyway!) solutions are for it to be very intense, very wet, and to take a northeast track hugging the coast. Of course it's dangerous to "cherry pick" one model solution and get excited about it, but that's what I'm doing here in this post (lol): this morning's 12Z GFS has a very deep, very wet, and very close low- prime position for a snow event in Annapolis. If this forecast were to verify perfectly, we'd have ~ 12" of snow here on Sunday. I'll be watching it intently, as always :)

Tick, tock...

... so today I ordered most of my Christmas gifts for small group from Kohl's, not really realizing that the items would be shipped here. The status update says the "item should arrive by Dec. 24". In 13 days? Surely Kohl's warehouse can move faster than that! Oh well, hopefully the gifts will arrive before I head to Greenville for Christmas....?

Was I born a travelin' man?

If 2010 is any evidence, maybe I was born a travelin' man (I know the song is "ramblin' man"... but "travelin'" fits!) A quick run down for those who weren't following so closely:

Jan- Nicaragua
Mar- Caracus
Apr- Greenville (Easter)
May- SWIFT: 6800 miles through 16 states
Jun- NC for the Smoak wedding
Jul- Guadalajara / Colima
Aug- Beach & Tahoe
Sep- Greenville (cookout)
Oct- Retreat in W. Maryland & LBB
Nov- Madrid & Lisbon
Dec- Greenville & Chile

Whew, it's no wonder some days I'm just happy to stay home on the weekend! In total, I visited 20 states & 7 countries this year (counting Chile, which I plan to visit on 31 Dec)! Thanks to all who accompanied / accommodated me on one or more of these trips. Here's to 2011- whatever it may bring!

Lots going on: proposals, papers, and travel, oh my!

So after getting back from Spain & Portugal (I'll put up a blog post on here soon, don't worry!) last week, I had a very productive work week this week. I heard back from my paper submission to Journal of Hydrometeorology: accept pending revisions. The revisions look constructive & not too hard to tackle, which is great! I've also nearly gotten my ONR grant proposal finished, just waiting on a few institutional letters & tidying up the language. I'm also moving ahead with Chile trip plans; we're less than 4 weeks out from heading down on a Faculty-led cultural trip (am excited for sure!). Before heading to Santiago, though, I'll be spending a few days in Greenville & Cary for Christmas with family. I also heard that my research students are having a stellar semester: one was selected as a Rhodes Scholar, the other to replace her as Brigade Commander (equivalent position to Student Body president, but not a "popularity contest" like in other universities...) I hope to take him (the Brigade Commander-select) to an air quality conference in San Diego in March (pending funding availability), and I'm outlining a paper with him for his work. I also have another paper already outlined, and last week I lined up a great Chilean collaborator to work with me on interpreting the data. Finally, I'm working with my coauthor to finish up our J. Geoscience Education paper (need to "needle" him to get on it!), and have a J. College Science Teaching paper nearly ready to be submitted.

So these next 6 months are shaping up to be very active! For those keeping count:

- J. Hydromet paper (accepted)
- J. Geosc. Edu. paper (accepted)
- J. Coll. Sci. Edu. paper (in preparation, nearly ready for submission)
- J. Clim. paper (outlined; collaborator identified & eager to help)
- J. xxxx paper (not sure what journal, but the idea is clear, and could be a major contribution)
- ONR grant proposal (almost ready for submission)
- Chile trip with 4 students
- San Diego air quality conference (presenting w/ a student)

I think the only downside is that I haven't been able to put as much into teaching recently- which is ironic because the teaching is why this job was so attractive to me in the first place! Nonetheless I'm excited about all these opportunities! I am not so full of hubris as to think I'm a shoe-in, but if all these "irons in the fire" come to fruition, I don't think I'll need to sweat the tenure process when it comes up in a few years.

Stay tuned!!

Brrrrr.... and statistically cold, too!

Today's IAD sounding was very cold: except for a small blip just above the surface, the entire troposphere (and much of the stratosphere) was below freezing. The 500 mb temperature was -30C, which caught my eye: this early in the year (03 December), already -30C? How unusual is that? So I went looking in the sounding archive (IRGA), which fortunately for me I've been having one of my research students examine the data- so FORTRAN scripts were already written to quickly extract the data. The resulting histogram (see below) confirmed my suspicion: -30C *is* below average. Specifically, only 3.96% of all the November & December 500 mb temperature observations in the past 50 years at IAD had been colder than -30C. So we really are cold! Fortunately the ground (and nearby bodies of water) is still relatively warm- so our low this morning at the surface was still about 0C (and the high about 5C). If this same setup had occurred in late January, we would be COLD indeed, all the way to the surface. Now to hop on my bike and brave this statistically unusual chill.

5th busiest 6 months since 1930...

Back in mid-summer I posted about the 2010 North Atlantic Hurricane Season and how active it was to that point. The activity continued, and we ended up with 19 named storms, the 2nd most since 1933 (the most was in 2005). The storms were not incredibly intense (although Igor did reach 925 hPa, a strong Category 4 storm), and perhaps even more remarkable, no hurricanes made landfall in the United States, continuing a trend since Ike in 2008 (now over 2 years with no hurricane landfalls). The 2010 season still caused quite a bit of damage in the Caribbean, Mexico, and even Newfoundland!

(picture courtesy of Wikipedia)

It is worth noting that as of today, 01 December 2010, the global total number of tropical cyclones is at a near-record low-- a point all the more interesting because the Atlantic basin is at a near-record high in numbers of TCs. We have seen ~67 (65 if you use only the TCWC numbers) TCs in calendar-year 2010, with only one month to go. This would be the lowest # of TCs in at least 30 years.