Scott's Jan 2007

Mid-Atlantic Radar

Scott's January, 2007 Blog
(blog descends chronologically)

Thurs-Friday Storm Update #2: So-So For Southeast/Mid-Atlantic.
Sweet for Northeast?
Wednesday, January 31

Quick blog as I'm on the road this afternoon and evening...probably no update here tonight but check our brand new RSS news feed for a quickie comment late tonight with full discussion here Thursday morning.

I've included some 12Z (7AM EST) models from this morning (click graphic for more maps):

A lot more gray hair than last week...this is a very challenging forecast! Two impulses coming up out of the south each bringing their own slug of precip (as noted previously). First comes up from the Gulf states (Slight Risk of severe wx Thursday from NOLA to JAX...click HERE), pushing plain rain into the Southeast States in the morning. Looks like ATL will get little to no frozen precip at this time. Snow for the lower 2/3rds of VA and NW NC before switching to some freezing rain then rain in NC...VA will transition to FZRA with plain rain south of I-64/east of I-95.

Precipitation will move at warp speed and I see nothing suggesting liquid totals will produce more that 3-5 inches of snow anywhere...in fact...there's strong reason to believe sufficient warm air advects to keep totals in the 1-3 inch range (if that) before the changeover. This looks like a quick hit system with insufficient time to put down sufficient moisture for Big Dog accumulating snow. General ideas presented here of lesser snow and potential for ice to rain seem the way to go; book remains open on the Northeast. Read on...

Model map depicts the second storm forming off the NC./VA border. Note the light blue line (color may actually have a different name but I'm partially color blind...really!). That line represents the NAM model and is probably the most accurate view of what will happen. The NAM takes the new coastal Low and zips it out to sea much further away from land than does the GFS and other models...including the European. This is bumming out snow lovers in the Northeast as warmer air and less precip probably get to interior NYS and New England. That comes Friday but for now, there remains some uncertainty as to how deep and how far inland snow gets for the Northeast.

Cold air drains into the region again this weekend and I am not yet sold on a likely solution for Sunday-Monday precipitation. I think the EURO model does have the right idea on a VERY impressive discharge of extremely cold air next week. Bitter cold may ooze from the Lakes and Northeast as far south as North Carolina. I want 70° January weekends back!

Looks like the Mid-Atlantic WX.com wx station will record a paltry 0.25" of snow for January and the entire season to date. Second half of the month will average out with daily highs about 10-12 degrees below normal.

If inclined, please check our new RSS feed tonight for a comment or two. RUC model will be in play by then and it'll be interesting to see if the NAM has the right idea...I discounted it until this morning which explains all the new gray hairs! It's been that type of winter.

Thursday-Friday Storm Update #1
And...Testing Our NEW RSS Newsfeed!
Tuesday, January 30

Latest Cold Front now crossing the Mid-Atlantic and Southeast, ending our one day break from the cold (although today's highs were mostly below normal). Winds quickly increasing and shifting back from the Southwest to the West and Northwest as arctic air again drains into the region. This ushers in another batch of snow and snow showers for the western slopes of the Appalachians tonight and Wednesday morning.

Low Pressure coming out of the Southwest will shoot quickly toward the Eastern US with a second Low firing up off the coast...effectively we'll have two batches of precipitation. Coastal Low gets going Thursday evening. First slug of precipitation gets into the region by early Thursday afternoon after bringing sleet and possibly freezing rain to Atlanta/north GA and light snow over central-eastern Tennessee Valley. Wintry mix invades SC on Thursday morning before changing to plain drizzle. Western NC starts as snow while central (Metro areas) sees a wintry mix...including pockets of freezing rain. Virginia should start as light snow (higher amounts in Extreme SW VA) and transition to sleet/freezing drizzle by late afternoon. The I-81 corridor north of Roanoke may hang onto cold air at the surface long enough for light snow to persist into Thursday evening while SE VA (east of I-95 goes to plain rain or drizzle. Again, this is a very close call on temperatures since warmer air will be moving in with the storm. North of the Old Dominion, the coastal storm starts pumping light snow near the coast with heavier, accumulating snow inland from Pennsylvania to Down East Maine.

As always, refer to your local forecast by typing your zip code into the box atop ever page at Mid-Atlantic WX.com and visit our Winter StormCenter for current info.

With regard to models, I'm watching the MM5 and the European while seeing how the GFS hones in on a solution...it still is jumpy and a bit too cold but the thinking behind this discussion is gaining confidence. Tomorrow I'll keep an eye on the MM5 and the RUC hoping they gel on a similar outcome. Wednesday's blog will include a look at how the models are converging...at least that is what I'm hoping for!

NEW NEWSFEED! We're currently testing a new newsfeed from Mid-Atlantic WX.com. As you probably know, newsfeeds provide quick hit information that appears in a news reader or other site. If you have a page at Google, Yahoo, AOL or many others you can subscribe to our feed and it automatically updates! If you read or bookmark any RSS feeds you can easily subscribe to ours by click here. I use and love Info RSS for Firefox; it's a tiny RSS scroll in the status bar of the browser and streams as many feeds as I select. Grabbing RSS feeds from NHC, SPC and now Mid-Atlantic WX.com ;) keeps you instantly informed on late breaking info. We will NOT use our feed for location specific warnings and watches but will let you know when the blog updates as well as quick comments about upcoming weather. Want to check it out? Click the XML logo to the left or click here.

Model Madness = Fickle Forecasts.
And...Rant Alert! Scott's Gloves Come Off About Global Warming.
Sunday, January 28

Cold Front crossing the region this morning quickly shifts winds and ends the brief balmy weather enjoyed yesterday. With another arctic front ready in the wings get ready for a renewed batch of cold air to rush across the Lakes and invade the Mid-Atlantic and Northeast on Monday.

A quick "Clipper" will enhance LES off Lakes Michigan and Erie, with cold air rushing in the snow will make it to the Appalachians with impressive totals along elevated western slopes of WV...lesser amounts for SW PA. Flurries/light snow could cross the ridges and approach the Blue Ridge Mountains as well as Virginia locations north of I-64, but low level air is dry and winds will shift out of the NW: not good for snow. Interesting comment this morning out of NWS Blacksburg suggesting a potent band of snow could cross into the Piedmont of VA tonight and with sufficient instability might even produce thundersnow! I'll be watching the Radar closely tonight. Winds will really crank up west of the Blue Ridge tonight...gusting to 45MPH, especially along ridge tops. Light snow also overspreads much of PA and Western/Southern Tier of NYS...as well as around Philly and into NJ where an inch or two is probable. Not a big storm but snow lovers should scream "Scooooore!", anytime a Clipper gets accumulation to I-95.

Computer models are having a tough time with the current set up as the onslaught of disturbances (short waves) is difficult to predict. We know it'll be cold (Polar Vortex in eastern Canada, upper level trof dropping down from the Great Lakes), but pegging the location and timing of each impulse is nerve-wracking to say the least! Models are focusing attention for a late week storm but there is not much agreement as to what develops. The GFS has been bringing a storm up into the Ohio Valley (read: rain for the Mid-Atlantic), but now is shifting to the east more in line with some other models. Perhaps some snow from the Georgia mountains up into the Mid-Atlantic, but at this time I'm unwilling to get more specific as this potential event is four days away. If (BIG "if") this storm does come up the coast we could have a significant snowstorm for the interior Southeast and the Mid-Atlantic/Northeast. There's just too many variables but I do like the idea of cold air locking down the East and a storm swinging out of the South as we enter the month of February. Stay tuned!

RANT ALERT! Well, be prepared for another full frontal assault about Global Warming as the UN's International Panel on Climate Change report comes out this week. Anyone who has read my email Updates and this blog knows I am not part of the Fanatic GW Crowd. Just last evening over dinner the subject of GW came up (mistake!) and upon rolling my eyes an argument nearly ensued. This is old hat to me now but over the next few weeks it'll be hard to keep my mouth shut. I certainly don't argue the Earth is in a warming cycle but truly tire of those who blame my Santa Fe (and your SUV) as the reason the Earth will be destroyed within a half Century. I have been consistently dubious of any claim of climate change solely being induced by humans; that's the principal and politically motivated position of the IPCC report. Across the entire planet we should have a serious and scientific debate...but I doubt that will happen as the topic has been hijacked by groups with political agendas. Is Al Gore scheduled yet on Oprah or Larry King? In 2005, I was savaged by some GW fanatics because I maintained there is no credible evidence an active hurricane season is a byproduct of Global Warming. So incensed by my position, three people cancelled their subscription to Mid-Atlantic WX.com Premium Service hurricane model maps. The quiet 2006 hurricane season doesn't seem to be addressed by the GW extremists...apparently because it did not suit their needs. I have a difficult time explaining to these people that weather is not the same as climate. As you hear media coverage of the IPCC report, ask yourself what is the motivation behind all the talking heads who solely blame humans, while refusing to consider the planet's natural cycles and ongoing solar activity research. The UN report exceeds 1,500 pages so there will be huge coverage (especially on CNN!) and I will do my best to muddle through the summary reports. But, my blood pressure won't handle the forthcoming cable TV hype, so I'll watch my new DVD of the second season of the TV show "F-Troop".

Arctic Attack...But No Big Snow Storms.
Thursday, January 25

Combining heavy work load, camping last weekend and the recent storm, I'm waaaay behind once again. Didn't Barry Manilow do a song titled: "Baby, it's cold outside"? Wow, I am tired if I'm quoting Manilow...I need to get back to my Springsteen stuff!

Arctic air that plunged temps in Ontario and Quebec below minus 30 degrees Fahrenheit continues to drain into the Northeast and will move over the Mid-Atlantic today and tonight. Here's this morning's 6Z chart for 500 millibars:

If we go down to 850 millibars (approx 5'000 feet) you'll see where the coldest air is situated:

Other than the North Pole, the Hemisphere's coldest air mass is located over Ontario/Quebec Provinces and Upstate NY. This core of cold will shift east slowly moderating the western Lakes but not until the Lake Effect Snow Machine cranks out hefty totals in favored LES locations.

A disturbance (short wave) along the jet stream is pushing some snow from the Ohio Valley into the Appalachians where several inches may accumulate...then...additional upslope snow on the western/northwestern slopes tonight and tomorrow. Bands of snow should cross the mountains and into Virginia today...generally west of the Blue Ridge, south of Winchester. Not looking for more than a dusting, except under persistent bands south of ROA where an inch or so is possible today. Friday's high temps will easily be 10 to 15 degrees below normal everywhere up from North Carolina. As this system pulls away the winds will rapidly ramp up; coupled with cold temps the wind chill will be savage on Friday over the Ohio Valley, Northeast and northern Mid-Atlantic.

Saturday brings a brief respite as the trof seen above shifts east and High Pressure briefly builds in over the area kicking temperatures into the upper 40's and mid 50's for the Mid-Atlantic. Awesome! Another Cold Front crosses the region to end the weekend...and the warmer temps :( Upslope snow will again develop over the western slopes of the Appalachians on Sunday.

Looks to me like next week a return to split flow can be expected. This is the case when the northern (polar) and southern (subtropical) jet streams do not phase/meet. While there's opportunity for a little snow late Saturday or early Sunday across the interior Carolinas, this cold High Pressure is very dry, so not much on the horizon in the way of snow.

Looking at the charts, the NAO appears to have about bottomed out this week but is forecast to stay slightly negative. The AO will be in free fall, finally dropping negative for the first time since last Thanksgiving...it is forecast to "dive, dive, dive" over the next week. These indicators certainly don't scream warm-up any time soon, so winter lovers will need wait for a good storm to crank over the Southwest. Given anticipated split flow...not encouraging until we get to February.

Next update here at the blog will be on Sunday. Bundle up!

Sunday - Monday Storm Update #3
Sunday, January 21

I was unable to find an Internet connection at camp yesterday and that's probably a good thing as my fingers were so numb that my typing would have been atrocious.

Light snow began at our wx station in Lexington, VA shortly after 9AM this morning (yes, this is sooner than my expectation over the past two days). The stage is set for a Cold air Damming (CAD) event, particularly across Virginia today as an oblong axis of High Pressure currently is over Rochester, NY to the Eastern shore of Maryland while the storm's Low Pressure center is near Oklahoma City, OK. Net result is north of the NC/VA border the low level cold air will hold over the region as warmer moisture streams up from the south. How deep the low level cold air will be determines what variety of winter precipitation you will receive.

Liquid totals from this event should be less than one-quarter inch north of the VA-NC border...more to the south. Snowfall now moving northeast across Virginia will reach NOVA and the Metro DC area by 1PM...Philly should also see some snow early this afternoon. As the warmer air overrides cold at the surface the precip will change to sleet and freezing rain before "dry slotting" shuts down precip to freezing drizzle or a cold rain.

Temperatures look good from previous discussions here. Click map to enlarge and get interactive current conditions:

Using our Mesonet map and the 14Z RUC model as a backdrop, here are my revised totals from north to south:

Delmarva Peninsula/Metro Philly/NJ: 1" with some sleet before freezing rain/drizzle.

NOVA: 1-2" snow before change to freezing rain...some sleet possible.

Virginia:
Along and east of I-95 and north of I-64: 1" snow and some sleet, then freezing rain tonight.
I-95 and south of I-64: Light snow, generally less than 1", then freezing rain changing to rain.
Tidewater/Norfolk/VAB: rain with the chance of freezing rain pockets.
I-95 west to the Blue Ridge: 1-2" snow then freezing rain overnight.
Highlands, Shenandoah, Roanoke and New River Valleys: 1-2" snow with sleet then freezing rain with ice accumulation expected.
NOTE: Ice Storm Warning roughly from Boone, NC-Roanoke-Lexington (lower Shenandoah Valley)

North Carolina:
Asheville up to Fancy Gap/I-77 area: sleet and freezing rain changing to rain later this afternoon.
North central NC: rain...some sleet may mix in during the afternoon.
Elsewhere: rain.

Our Winter StormCenter is full speed ahead and you can also check your local forecast here at Mid-Atlantic WX.com.

I'll have an update this afternoon around 5PM. We'd love to share any pictures you have from this storm at our Photo Gallery. Cell phone or digital camera pictures can be sent to weather@midatlanticwx.com. Thanks!

UPDATE 4:55PM: Snow continues the transition to sleet and freezing rain except areas of NC and SE VA this has been an all rain event. Looks as though few, if any, areas see in excess of two inches of snow especially with compaction from freezing rain. Warm air advects over much of the region and we'll see a transition to freezing rain as the primary precipitation type tonight. At least a light ice glaze will develop with totals between one tenth and one quarter inch into the early morning hours.

Areas of rain over NC should remain as such and not freeze although some light ice is occurring over northern interior NC and this will continue into the evening before changing to cold rain.

Little temperature change overnight before precipitation wanes by sunrise on Monday. Clouds will be tough to scour out but there may be a few rays of sunshine. Temps will only reach the mid 30's to the lower 40's (from north to south).

Attention will quickly shift to Wednesday night and Thursday as the next system takes aim on the Mid-Atlantic region and the Northeast.

Sunday - Monday Storm Update #2
Saturday, January 20

This will be short as I'm going camping this weekend (don't ask! LOL).

Other than ongoing precipitation type challenges, no big changes in thinking how this goes. High Pressure near the Great Lakes will will slide East today and center over the Northeastern US on Monday. Current surface map below:

Once the High moves to New England, surface winds will shift out of the east (since winds blow clockwise around high pressure)...this sets up a probable Cold Air Damming (CAD) situation for Virginia and possibly North Carolina.

Precip should overspread the region by early/mid Sunday afternoon. I will note the 6Z run from the MM5 model continues the trend of keeping snow north of the VA/NC border and I think this is correct given anticipated warming in the lower and mid levels by Sunday night.

From north to south:

Delmarva Peninsula/Metro Philly/NJ: trace with no accumulation.

NOVA:1" snow before change to freezing rain.

Virginia:
Along and east of I-95: Rain/drizzle with pockets of freezing rain. No accumulation.
I-95 west to the Blue Ridge: 1-3" snow then freezing rain overnight.
Highlands, Shenandoah, Roanoke and New River Valleys: 2-3" snow then freezing rain with some ice accretion likely.

North Carolina:
Along and east of I-95: rain. No accumulation.
Freezing rain with some wet flakes or ice pellets...especially NW of Charlotte. Changeover to rain expected Sunday night.

Again, I have low confidence in snow totals but that's what everyone wants to know. This will not be a big SNOW storm (6+ inches) anywhere unless there is strong CAD producing upslope snows...I doubt this as the liquid totals from this storm won't exceed .60 inches in Virginia.

Stay close to our Winter StormCenter and check your hometown forecast here at Mid-Atlantic WX.com. This event is highly dependant upon temperatures, so keep an eye on the region with our exclusive Mid-Atlantic "meso" map featuring dozens of weather observations across the area, updated every 30 minutes. Shameless plug: I know of no other place on the web offering more current temps and conditions than Mid-Atlantic WX.com! As the precipitation moves in, check conditions and the Wet Bulb temperature here at our weather station.

I hope to be able to get online for a quick update tonight and expect to have another full discussion on Sunday afternoon as the event gets underway.
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Sunday - Monday Storm Update #1
Friday, January 19

Things are coming nicely together for a winter weather event but precipitation types still being debated. Next storm will develop Low Pressure near the Southwest Four Corners and should be a prolific snow producer up into Oklahoma and perhaps Missouri. Folks in those areas should keep tabs with reliable local media and check into our Winter StormCenter.

For the Eastern US I am using the European and Air Force MM5 models as I think they've trended with some logic. Need to keep an eye on things but this storm should track across the Tennessee Valley before ejecting out to sea, most likely near the VA/NC border. This is critical as the rain/mixed/ snow line will ebb north and south based largely on the track. I'll use the VA/NC border as the dividing line for Sunday's event. Right now, thinking is a quick period of snow north of the border while freezing drizzle/rain will predominate NC and northern SC. Precip should move into the region early-mid Sunday afternoon but may be delayed by low dew points. South of upper SC...all rain.

Snow changes to freezing rain and perhaps some ice pellets across Virginia and the Eastern Shore on Sunday night with precipitation ending from north to south. Tennessee Valley and Carolinas could see liquid totals around one-half inch so there's the possibility of a moderate icing event in North Carolina.

As noted, the track is important but so is placement of High Pressure as this feature could set up a Cold Air Damming (CAD) scenario across VA/NC. Models aren't screaming about this but they often miss CAD until very close to an event. Essentially, if the High pushes cold air into the lee side of the Blue Ridge and Alleghany Foothills, surface temps may stay very close to freezing and a wide variety of location dependant precip would follow. The other obvious variable is the actual track; some guidance is nudging the storm slightly north...this would expand likewise the "non-snow" area to the north, meaning the rain/snow line is subject to change.

I don't think the storm gets precipitation north of the PA Turnpike as it isn't going to head up the coast...but will scoot away an an ENE course...away from land.

Looks like a trof sets up over the Eastern US and so the cold will remain for another week. Pretty good bet next Thursday-Friday we contend with another event with a Clipper coming and another disturbance shooting out of the Southwest. Too early to get specific but the next storm probably will come up the Northeast coast...perhaps cranking up in a big way! No shortage of cold air so we'll watch and wait out this new threat.

I am away most of the weekend but will attempt to get at least one quick update here on the blog. Depend on our Winter StormCenter to keep you informed with real-time information.

Thursday Storm Update
Thursday, January 18

Quick post to update today's event. Both the 18Z and 19Z RUC model runs have a good handle on current storm.18Z NAM currently out only to 12 hours but much the same. Low Pressure will pull away from OBX this evening and isn't expected to push much additional precipitation west or NW of current Radar returns. As such, not expecting much along and west of the Blue Ridge where dew points generally remain in the teens. Freezing drizzle should wane this evening for North Carolina and the lower Piedmont of VA...plain rain and drizzle for eastern VA. Show showers will continue across PA and Upstate NY this evening. So far, so good on thinking this is a nuisance variety storm...not much accumulation but enough to get folks thinking about winter.

Low Pressure will crank up and then crash into the Maritimes early Saturday producing very strong winds, rough seas and significant snow accumulations Down East and the "Upcountry" of Maine.

Next storm coming Sunday and Monday should be more formidable with the distinct possibility of shovelable snow from interior NC up into New England. Many variables to work out but "storm #2" could be the Mid-Atlantic's first real winter storm.

Back tomorrow.

Pesky Storm To Produce First Snow For Mid-Atlantic,
Next Storm COULD Be Different!
Wednesday, January 17

Late update tonight as I wanted to see the 00Z models and I was attending my son's wrestling match tonight. Like a wrestling referee (real wrestling, not the WWF and WWE gibberish), I call 'em as I see 'em. Last Monday, I opined the pending system would amount to very little and track too far off shore to through wintery precipitation inland. While weaker than what the GFS was gloom and dooming a couple days ago, this Low will produce "nuisance variety" winter weather to the interior Southeast and lower Mid-Atlantic.

Along the coast south of the Chesapeake Bay, all rain as High Pressure migrates east and sets up a brief period of return flow from the South. Certainly now warm air but warm enough to keep the coast wet, not white. For the Carolinas, west of the I-95 corridor: light precip Thursday may begin as sleet but should change to wet snow...possibly some pockets of freezing rain. Slight accumulations, especially north central NC. A mixed bag for Virginia on Thursday, where rain should fall along the coast back to I-95. A little sleet may fall across the Piedmont before changing to light snow. Right now it doesn't look like much precipitation west of the Blue Ridge...or north of Harrisonburg...although some sleet/snow/drizzle may fall along the mountains, the Shenandoah and Roanoke Valleys. Overall, I do not believe there will be much in the way of accumulation for the Southeast or Mid-Atlantic however, slick roads and some ice (especially northern and interior NC) could quickly make driving hazardous.

I think Philly has a decent shot at mixed precipitation with some accumulation. A trace to 1.5 inches along and just west of the I-95 corridor from Baltimore to Metro NYC.

The storm could bomb out on approach to the Gulf of Maine on Friday and may become a significant for interior New Hampshire and Maine. Folks there should monitor local forecasts.

With cold air now firmly entrenched and an active southern Jet Stream, storms now have the opportunity to produce winter weather for the region. That could happen early next week! Low Pressure near Four Corners should begin to pull together near the Texas Coast this weekend. Potential track would put the storm off Cape Hatteras on Monday and well off the New England coast next Tuesday. While I am sold the storm will develop, I am offering this suggested track with some uncertainty. Precipitation type is extremely sensitive to the actual storm track so we'll closely watch how the models handle the system. Something to keep an eye on is the strength of the first storm on the weekend; if this indeed bombs out south of the Maritimes, chances improve for the second storm to be a snow maker across the Mid-Atlantic and Northeast. Two decent storms certainly will help to usher in fresh cold air for later next week. For the short and medium range, winter is here!

I am away for much of the weekend but will have another update here on the blog Friday evening.

Ice, Ice, Baby. And...The Cold Cometh!
Monday, January 15

You know things are weird when Houston gets freezing rain and sleet while it is raining in Boston, MA! Another curiosity: it was nearly twice as warm in Richmond today as it was in Houston (RIC: 71°, HOU: 37°). Low Pressure now over Northern New England is dragging a Cold Front across the Eastern US tonight and this feature will be the focus of precipitation. Northern New England is seeing a combination of ice and snow...the white stuff will continue tonight with several inches accumulation.

As an aside, Portland Head Lighthouse is one of my favorite places on the planet. Here's the web cam view atop the lighthouse tower (visible during daylight hours):

Along with a decent storm for the northern half of New England, the Lake Effect snow machine gets going with modest (less than 4 inch) totals.

For the Mid-Atlantic and Southeast the front is bringing a weakening band of showers but no frozen precipitation today. For those of you (like me) who have delighted in this variety of winter weather...the joyride is over. High Pressure and colder air builds into the eastern US once the frontal boundary passes tonight and Tuesday morning. The Northern Jet Stream is *finally* winning the day and it will dive down across the Great Lakes, Mid-Atlantic and Northeastern US this week. Temperatures heading into the weekend will be close to or slightly below normal...however...20 to 30 degrees colder than the past few days! Add in the gusty winds behind the front and it will feel brutally cold! On Thursday, the High will shift east offshore but this time it will be different since this winter we've seen return flow always pumping in warmer air from the South. The pattern change continues with a new batch of Arctic air coming down from Canada on Thursday into the weekend (translation: no balmy warm-up this time!).

Now things get interesting! As mentioned yesterday, Low Pressure may develop just off the Mid-Atlantic coast, perhaps east of Norfolk/Virginia Beach. This probably will have marginal effect on the Mid-Atlantic BUT that could change. Computer guidance is bullish on a trof swinging down across the Great Lakes with a booster shot of cold air may get some snow/wet snow/sloppy mess into Baltimore, Philly, interior New Jersey and Metro NY. This would be overnight Thursday into Friday morning. The potential is there for a snow/mixed event on Friday along the I-95 corridor from NY to Boston. I am not buying the GFS model solution of pushing the trof excessively south and I am not sold on its big Florida to Virginia storm this week, therefore Virginia and points south stay cool and dry later this week. But, the cold will hold into the weekend.

Next update here at the blog on Wednesday. Bundle up!

Ice, Freezing Rain and Snow Moves Northeast. What's Next For The Mid-Atlantic?
Winter Coats? Yes. Snow Shovels? Don't Think So.
Sunday, January 14

Quick note about no blog updates last week. I attended a two-day conference and was unexpectedly on the road most of the week. I'm back at the WeatherCenter just in time for the arrival of winter temperatures; but is winter really on the way?

The prolific, deadly ice storm is moving to the Northeast and continues to impact the lower Plains and Mid Mississippi Valley today. Folks in the affected areas should continue to closely monitor local forecasts and travel conditions. A nearly stationary Front is hung across Texas, up into the Ohio Valley and east to the Atlantic and New Jersey. The Mid-Atlantic and Southeastern US again are under the influence of High Pressure over the Western Atlantic Ocean (note widespread barometer readings exceeding 30.20"), so this Front is deflected away from the area. We've beaten to death discussing how Ridging off the Southeast US keeps winter away and that will be the case...but only for another two days. The pattern IS changing!

As the Frontal Boundary ebbs to the east, Low Pressure will track from Kentucky to Pennsylvania before crossing Long Island and heading out to sea. You can see the projected track in the Ensemble 00Z model runs below:

Areas south of the storm track will be in the warm sector and precipitation will fall as rain and showers through Martin Luther King Day. To the north and west, colder air in Canada will move in and produce a stripe of frozen precipitation from Illinois to the Southern Tier of NYS and into central Massachusetts and southern New Hampshire. Sleet accumulations should not be significant (less than one inch) however there will be areas of freezing rain before a changeover to snow. As always, check your local forecast for information specific to your area (type your zip code in the box atop every page here at Mid-Atlantic WX.com for current information). Accumulating snow will pile up in areas north of this "frozen band" of precipitation.

MEDIUM RANGE: Delayed but not denied. Faithful readers of the blog know I have been very slow on the trigger regarding a pattern change. One week ago even I thought that arctic air would be on the doorstep by now...yet it remains a couple days away. It IS coming, but the questions remain: how long does it stay and will there be snow?

High Pressure fills in behind the Frontal Boundary and brings with it a return to near normal temperatures...Monday's 60s-lower 70s will be replaced by 30s and 40s by Wednesday).

Low Pressure depicted on the above model map will be off the Canadian Maritimes later in the week while High Pressure dominates the Central US. This will bring much colder temps to the region on Wednesday and they will likely remain to the weekend. With the Cold Front languishing off the East Coast we need to watch the Carolina coast for development of Low Pressure on Wednesday...I'm thinking if this pans out it is too far offshore but we'll see what perks up along the front.

Ridging over the central US should keep things high and dry over to the Mid-Atlantic and Southeastern US as we approach next weekend although another Cold Front will cross the Lakes and Northeast late Friday or early next Saturday (1/20). This, coupled with the possibility of Low Pressure off the Delmarva Peninsula makes things interesting as we approach the weekend. I am not sold on a winter storm or snow in the east next weekend! To truly get the region in a winter pattern we need sustained/reinforced shots of cold air and precipitation...I do not see that combination in the medium range. Sure, the next 60 hours bring frozen precip and snow north of the Mid-Atlantic but nothing beyond that in the following several days.

Darn, when it comes to sub-tropical Ridging, I do not trust the models and continue to watch closely the Arctic Oscillation (called AO).

It is easy (not to mention spurious) to simply look at this chart and think that's how to forecast winter weather; this is one of a dozen tools used to get a glimpse of the future. But, the sub-topical Ridge (High Pressure over the SE US and western Atlantic) does correlate to the Arctic Oscillation. Positive AO helps to drive storms to the north...generally there is sub-tropical High Pressure off the SE US...not always, but certainly that's been the case this winter. Note the AO's solid black line has been in a positive phase roughly since Thanksgiving weekend. Despite one intrusion of cold air in early December, temperatures have consistently averaged above normal during this ongoing positive phase. The 14 day forecast clearly shows the AO dropping and this translates to the evolving pattern change underway in the Pacific. Will it hold? Will the sub-tropical (SE US) Ridge get beaten back and go into hibernation? I don't know. As I said one week ago, the second half of January will not resemble the first half, but I can't tell you the cold air will couple with an active storm sequence.

Next update here at the blog will be Monday when we'll look at what's next for the ongoing ice storm.

Another Significant Rain Storm Approaching (Severe Possibilities) Before Brief Cool Down...Winter MAY Arrive Next Week.
Sunday, January 7

SHORT TERM: Low Pressure over the Gulf of Mexico is organizing and will track into the Tennessee Valley and west of the Alleghenies. Here's this morning's models showing good agreement on the storm track (click graphic for more maps):

Abundant moisture from the GOM and the Atlantic will be enhanced as a trof rotates down through the Lower Plains and shifts east. This set up is excellent for producing another bout of severe weather today for SE VA, the Carolinas and northern portions of GA and MS. Tornadoes and severe storms again possible today!

Heaviest rainfall will be along and east of the storm track shown above. Liquid precipitation overspreads the Southeast and Mid-Atlantic this afternoon with heavy rain a good bet for the interior Southeast and Mid-Atlantic...as forecast here:

Note the expansive coverage area of 1 inch plus rain across VA (south of I-64) and NC (west of I-95), these areas already are saturated from precious rainfall and Flood Watches are now in effect.

As the storm moves out, colder air builds in and low level moisture may change to snow along and near the mountains late Monday into Tuesday. This is when an Alberta Clipper is due to scoot another batch of moisture into the region. It looks like this feature could bring accumulating snow to the western slopes of the mountains (north of NW NC) on Tuesday...and with cold air settling in some white stuff could cross the mountains and make it to the Blue Ridge. Leeward eastern Great Lakes should get some snow from this and upstate NY and the PA Northern Tier may also get some snow or perhaps freezing drizzle on Tuesday.

MEDIUM RANGE: Cool High Pressure will not reside over the region but it will be much colder Tuesday and Wednesday...temps 5 to 10 degrees below normal and 20 to 30 degrees below the delightful high temperatures of this past Friday and Saturday. With a fairly progressive weather pattern, this High should slide off the East Coast , setting up return flow from the southwest on Thursday. As a result, temps will again rebound later this week into next weekend.

LONG RANGE: I won't pretend to tell you I have a firm grip on the pending medium-long range synoptic weather. If fact, I do not believe anyone does! The recently concluded hurricane season dealt everyone a near unending sequence of "curve balls" (better understood now, but not completely) while this pattern that began in mid-October has been absolutely exciting to observe, learn from and endeavor to forecast. I am a big fan of the Southeast Ridge (a variant of the loosely called Bermuda High) for two reasons: one, I don't hide the fact I detest winter and two, when the Ridge is persistent, it is often underestimated. For three months it has continually bounced back to deflect storms away from the Mid-Atlantic and pump in warm air that enthuses the lunatic Global Warming crowd. Several features must unfold before the Ridge takes a beating and retreats for an extended period. I believe we now are one week away from the best opportunity this winter. But...the devil is in the details and until the Polar Vortex has an exit ramp to unload some truly cold air I can't get hyped on a prolonged major shift in this pattern. And cold air does not automatically mean snow storms...it just means cold. That said, my opinion is the second half of January will not repeat the first half of the month. As Mr. Spock would say; this weather pattern is "fascinating".

SC Tornado Produces Multiple Injuries As Line of Storms Crosses Carolinas.
Friday, January 5

Quick post concerning the tornadic line of storms across upper SC and southern NC. Several injuries in Pickens County, SC where cars were piled up at an Elementary School. Click HERE for storm reports. As this is written (4:55PM), two new Tornado Warning in effect just west of Charlotte, NC. Damaging winds and additional tornadoes possible this evening across western/central SC and up into the Charlotte Metro area. Very juicy air (dew points in the upper 50's and mid 60's) are helping to fuel severe storms. Isolated pulse or Supercells are not expected...storms generally are confined to a strong line racing across the Carolinas. Check our Radar links (to the left) for local Radar images. Heavy rains, thunderstorms and straight line winds are primary threats however tornadoes are a possibility. These storms should survive past sundown and threaten central NC and SE Virginia this evening...keep an eye on this as additional strong storms and Tornado Watches seem likely tonight. Refer to our Severe WeatherCenter for real-time information.

I'll have another update here at the blog on Sunday morning...when we'll look at an anticipated change...perhaps a BIG change...to the current weather pattern!

UPDATE: 940PM. I'm being treated to a nice little thunderstorm here in Lexington, VA! Our wx station is located under the "b" in "Rockbridge" on the graphic below. The white blocks depict lightning strikes in the past 10 minutes.

Can't recall the last time we had a thunderstorm around here in January. What fun. Fortunately, the strong storms across the Carolinas are weakening. Cold Front crosses the region on Saturday morning but WELL above normal temps will hold through the weekend. I'm going to enjoy the thunder...and will be back on Sunday.

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