Irma Update – Sep 9, 8 am

Good morning,

Intense Hurricane Irma (185 mph sustained winds) is barreling through the northern Leeward Island, seemingly swallowing entire islands as it goes…

Latest Visible Satellite Loop via PSU Ewall

… and is expected to continue pushing west-northwest toward Florida.

The Billion-Dollar question (potentially) is when will Irma make the right hand turn. The NHC puts the storm on a track that takes it right up the Florida Peninsula, though the just-in computer model forecast data is edging the storm track a bit to the east, raking the eastern coast of Florida and then taking it right at Charleston, SC. The models that fall into this more eastern camp include:

00z & 06z Navy NAVGEM
00z European
00z & 06z GFS

The 00z UKMET model takes it a hair farther west right up the FL peninsula, but really is not that much different than the others. The oddball is the 00z Canadian Model, which takes it much farther east out in the Atlantic toward New England.

All folks in the Southeastern U.S. (or with family/friends down there) need to continue to watch this very closely.

The good news: The threat to the western coast of FL — while not over — has gone down a notch with this more eastern track. The bad news is this now puts the southern Carolina beaches (i.e. Charleston) in the bulls-eye for major impacts, and also ramps up the potential impacts for the Mid-Atlantic region.

Timing… Irma will head toward southern Florida over the weekend, but the models are much, much faster than the NHC’s official forecast. The NHC takes it into srn FL Monday. That seems a little slow, honestly. The European and GFS models bring it toward southern Florida Saturday night and Sunday morning; toward the SC/GA coast Monday into Monday night; then into the Mid-Atlantic region Tuesday into Wednesday. While I don’t want to diss the NHC, I’m inclined to go with the faster model forecast… and I’d plan accordingly. Plus, this way if it ends up being slower, you’ve got an extra day or two.

OK… that’s the latest.

Increasingly “interesting” Weather

Good afternoon,

While there’s nothing imminent just yet, wanted to provide an early FYI inre to some potential winter weather on the docket.

1)  Tomorrow (Thrs) morning, some snow is possible over nrn MD… ~ I-70/695 north.  Not an accumulation, but I wouldn’t be surprised if the early risers (includes me going to work) see wet snow.  Should change to rain by mid-day.  Rain from I-70/Baltimore south.

2)  New Years weekend looks pretty benign.  A cold front will swing thru Saturday night, perhaps accompanied by light rain.  New Years Day (Sunday) will feature a building high to our north (uh oh… (or woo hoo!)) but dry and cold.

3)  Early next week (Monday-Tuesday):  While we still have a storm track to our west (and Quebecian Lows), the pattern is beginning to change… and the first new wrinkle will be a high to our north, setting the stage for ice or snow on Monday.  Much of this will be contingent on how strong the high is (and how much cold air it pushes south into the region), but it’s starting to look dicey.  No other info beyond that… so pls don’t ask just yet.  The general theme I’m seeing is ice… and not so much snow.

4)  Longer term…. Jan 8-15:  A Negative NAO.  Long-time WxListers know I go on and on and on and on and on and on and on and on about blocking highs (or lack thereof) over the northern Atlantic.  There is an Index called the North Atlantic Oscillation (NAO for short, if you want to sound super cool) which measures this; a “negative” phase of the NAO means you’ve got a blocking high (or proxy) that ups our chances for cold and snow.  A positive NAO is the exact opposite, and I affectionately call it the North Atlantic Shop-Vac; it sucks all of the cold air out of North America.  Anyhow, models show a pretty strongly negative NAO for the second week of January, putting us in the cross hairs for some really cool (and cold) weather (and if you don’t think it’s really cool, then just simply respond to this email with “REMOVE” in the subject line!)

Anyway, the NAO is a really good indicator of “increased snow potential”.  It doesn’t guarantee snow, but it ramps us your odds a lot.

I’ll keep you posted.

First Potential Winter Storm – 12/12/2016

Good afternoon,

Hope everyone enjoyed today’s spring-like warmth (at least that’s how it will compare to tomorrow). Strong cold front will produce some snow showers or light snow east of the mountains tonight, with the primary target for this north of DC and east of Frederick. Doesn’t look like much, but I don’t know how many times I’ve seen something like this… where a minor “event” precedes the “main” event and all eyes are on the latter and miss the former. Would not be out of the question to see a coating of snow for the morning commute, but this is not the big story.

Following the arrival of the chilly-jerry-carney air mass Thursday, we’ll get a taste of wintry pcp Friday night and Saturday morning as a warm front lifts north over the region. With no high to our north, the cold air will not hold… and any snow/sleet Friday night will change over the a brief period of freezing rain and then plain old rain by mid-day Saturday. Latest models are targeting northern and northeastern MD for the greatest chance of accumulating snow. South of I-70 and toward DC and nrn VA, the pcp kinda jumps over this area… so when the cold air is still around late Friday and early Saturday, the DC area won’t get much — if any — pcp, and by the time the pcp arrives, the warm air will be here (especially aloft) so I think for DC and environs up to ~ I-70/Baltimore Beltway, don’t expect much snow or sleet.

For nrn MD, models show a rather quick-hitting burst of moderate to perhaps even briefly heavy snow before the changeover occurs in the morning Saturday. In the counties along the PA border, latest models are showing “liquid precip as snow” totaling 0.40-0.60″… which if you go with a 10::1 snow-to-liquid ratio would get these locales a quick hitting 4 to 6″. I’d like to see tonight’s model data before offering up a forecast… but the overall ides of 2 to 4″, perhaps up to 6″ before a changeover occurs seems plausible. This is still 2+ days away, so a bit early to try and pin this down… and anyone who’s been on the list knows I’ve never been guilty of giving a precise forecast well in advance!

Will shoot out an update tomorrow.


Thanksgiving Wx

Good morning,

Thought I’d let you all know the weather leading up to Thanksgiving will not be a big factor in travel plans.  No rain expected today and Wednesday, as temperatures moderate into the lower to middle 50s ahead of a cold front set to swing thru Thursday.  This is a “meh” cold front.  There may be some light showers with the front Thanksgiving morning, but nothing major… and this front won’t hold a candle to the blast that came thru this past weekend (and also kicked off this season’s first sleet and wet snow last Saturday night).  In fact, the air behind this cold front won’t be any colder than what we have now, as the front will lose much of its umph as it marches east.

Longer term outlook does not feature much in the way of cold or interesting Wx.  Models, which had originally shown a trof (southward dip in the jet stream, usually associated with cold, often snowy weather) over the eastern U.S., now have shifted this trof for next week west over the Great Plains, leaving us a predominant southerly flow next week and warmer temperatures.

Commuters:  Send this out every year… it has become my experience that today, the Tuesday before Thanksgiving, has the WORST afternoon commute of the year (outside of weather-related delays).  It’s gotten so bad that when the opportunity comes, I take the day off or leave early.  If you’re at work and can do the latter, it would serve you well.

Hope everyone has a safe and enjoyable Thanksgiving!

10/7/2016 – Whew! (Finally)

Good afternoon,

Whew. Thankfully, those oddball mid-morning model forecasts were not matched by their more reliable counterparts that rolled in over the past hour (GFS, NAM, and Canadian)… so I feel better about giving the all-clear.

For Saturday, a chance of some light showers or plain old light rain during the mid-day hours, but amounts should be light (less than a quarter inch). Rain could be heavier down at the DE/MD beaches, but even here they should stay out of the deluge that appears headed toward the Carolina beaches.

Sunday, sunny but breezy west of the bay, while morning clouds give way to sun at the MD/DE beaches… but a strong north wind (20-30 mph, higher gusts). Temperatures in the 60s

I hope this is it until it snows…

Hope everyone has a good weekend. Go Ravens!


10/7/2016 – alarming SREFs

Highly confident this is a very low confidence forecast. I’m not providing a forecast here… sorry. Just some behind the scenes info, and a serious muddying of the waters for us locally.

First, Matthew is right on the FL coast… see it here on this nice radar loop provided by the Univ of Wisconsin.

Early morning prelim model data offers an All Or Nothing take on our weather forecast for Saturday. The data I’m talking about is called the Short-Range Ensemble Forecasts (SREFs), and these are high-resolution short-term models, but largely experimental, that are the first to roll in. While there is often some “Take these with a grain of salt” to them, it’s a bit alarming to see such a huge disparity for a forecast that’s essentially valid 24 hours from now. The SREF forecast charts valid for tomorrow feature everything from dry, perhaps even sunny weather to torrential rain, strong winds, and coastal flooding along the Bay and at the Mid-Atlantic beaches.

Click here to see a snapshot of the SREF forecast for 5 pm tomorrow evening. Each panel is a different model, the lines denotes pressure, and the shaded colors denote 3-hour rainfall (green is moderate, yellow is heavy, red is very heavy, white/grey is extremely very incredibly heavy). There are some that clearly keep Mathew to the south and out of the picture (literally), and there are others that are like “Meh… let’s bring it up I-95…”

I will shoot you an update when the rest of the data rolls in, but this is certainly a bit of an alarming twist.


10/6/2016 – Matthew Approaching Florida

Good afternoon,

Sorry for the delay. Matthew appears to be strengthening as it crosses the open water between the Bahamas and Florida. The latest satellite imagery is impressive, with a compact but intense core of the hurricane showing better symmetry over the past several hours. The radar loop is likewise impressive, and provides a very nice way to follow the storm in near-real-time: Click here for the latest Radar Loop (via Univ Wisc).

Models have settled down, and Matthew does not pose a threat to the Mid-Atlantic, at least not directly. The storm will essentially follow the FL/GA/SC coast – give or take 50 miles – and produce heavy rain and strong winds along its path. The good news is Matthew is a small storm, and the hurricane-force winds only extend out ~ 60 miles from the center, and most of this is likely on the east side of the storm. The heavy rain from the storm will spread northward up toward the Outer Banks, and perhaps graze the lower Eastern Shore. Matthew will turn northeast and remain south of Cape Hatteras, and then get nudged out to sea over the weekend. However, a strong high behind this weekend’s cold front will enhance the winds at the beaches from DE to NC on Sunday… with a strong pressure gradient (and strong winds) developing from the strengthening high to our north and the hurricane to the south. I suspect Sunday at the beaches will feature howling north winds, but the rain will remain south of MD/DE. It looks to be a brutal weekend at the Outer Banks, altho the core of the hurricane will not make it that far.

Up here… I don’t think we’ll see much, if any, rain up this way. Hurricanes have a lot of sinking air around their perimeter (aka subsidence)… which helps to squash any rain that might be approaching. As a side note, this subsidence… sinking air… is nature’s answer to what goes up, must come down… with tons of rising air at the center of the storm balanced by sinking air around the perimeter of the storm. This is often why those just outside the hurricane have beautiful, sunny, dry weather, while 100 miles away it’s a living hell.

Well, expect lots of wind at the beaches, especially on Sunday. Rain could make it as far north as the MD-DE beaches, but up this way we’ll stay mostly dry. At least that’s my hope. Some models still suggest some rain Saturday morning, but not heavy.

If anything changes, I’ll let u know asap.

10/5/2016 – Some Models Doing a 180

S F D…. make of those letter what you will.

Note: This is just an FYI.. some behind-the-scenes info. I’m not ready to bail on the “Matthew will stay offshore” idea just yet, but I’d be doing you a disservice if I didn’t let you know this could change, and without much notice.

We look for model trends when giving you a fcst. The models have been trending for the last two days farther south and east with Matthew, easing any concerns locally as well as for those traveling south. To my dismay, the latest model runs – using the balloon data launched at 12z (GMT, or 8 am, EDT) – are rolling in, and there are some serious Oh $#its in the group. I’m not gonna bail on the idea that Matthew is going to stay offshore just yet and remain well to our south, but I’ve got one foot off the ledge…

The early model data has come back markedly closer to the coast. In fact, some are suggesting that Matthew actually interacts with the cold front, as opposed to being bounced by it, and just trudges right up the I-95 corridor; this idea seems a bit far fetched… but not out of the realm of possibility.

Nevertheless, Florida, which appeared to be primed to escape this, now appears to be at the greatest risk. The Carolinas, especially from Cape Hatteras south, also now appear to be back in the crosshairs. For now, I think we’re fine up this way… but we’ve definitely inched back closer to “Uh oh” for the Mid-Atlantic Beaches as well.

I really want to see what the Intermediate Advisory at 2pm by the NHC, two hurricane models (GFDL and HWRF ~ 3 pm), and perhaps even the NHC Full Advisory at 5 pm, before making a final call. That will follow.

Talk soon.

10/5/2016 – Matthew No Longer An Immediate Threat

Good morning,

Short version for the ADD crowd: Matthew will not impact our weather this weekend (at least not directly), with a vastly improved forecast for the Mid-Atlantic.

Will spare you all my typical diatribes; appears our cold front will do the trick, and keep Matthew away from the area. Matthew will still pose a threat Florida and the Southeast Coast, but even the Outer Banks seem to be emerging from under the “threat umbrella”. In fact, the sinking air around the perimeter of the hurricane (aka “subsidence”) may actually end up squashing our cold-front showers on Saturday, so we could end up with really nice weather, in a great sense of irony, courtesy of Hurricane Matthew.

I’ll add that the same cold front expected to suppress Matthew to the south may ultimately “miss” the storm… leaving it behind to meander off the Southeast Coast for days and days. The European Model started showing this yesterday, as well as some of the GFS Ensemble model runs. So this means we may not be done with this storm just yet.

Talk to u all later.

10/4/2016 – Threat Diminishing for MD

Good morning,

We are getting more clarification on where Hurricane Matthew is headed after its journey through the Bahamas. In short, the storm will stay to our south and east, but we may still feel the impacts. Anyone thinking about going to the Carolinas should keep a very close eye on this, while the MD/DE beaches will likely be spared… though these folks should also still closely watch the storm.

Latest models are in much better agreement that Matthew will turn northwest toward the Southeast Coast this week, then turn back to the northeast, paralleling the Carolina Coast before tracking out to sea. As per usual, the final track will determine who gets what… and as I keep saying over and over, we’re far from being in the clear – or vice versa – with this one.

If the current model forecasts hold… (and I still like the GFDL and HWFR hurricane-specific forecasts)… we will see increasing winds and periods of rain Saturday. Rain could be heavy if Matthew tracks far enough west, but right now, it looks like the heavy rain will stay to our south and east on Saturday. Winds will continue gusty Saturday night as Matthew accelerates away from the region. Sunday will be breezy but pleasant. Overall, the threat of major impacts from Mathew appear to be going down somewhat… though I do caution this could be a “blip” in the forecast models, or we could very well trend toward sunny skies if the forecast track keeps shifting south and east.

For the beaches…

MD/DE: Some coastal flooding likely with a persistent east wind in advance of the storm enhancing the water build up on the coast. Current model wind forecast suggests wind speed of 20-30 mph sustained on Saturday, with higher gusts. However, the strongest winds will actually develop after the center has passed, when the wind direction will switch to northwesterly. This will help mitigate the coastal flooding threat somewhat. If the storm recurves more to the east, the beaches may very well end up with nice weather… albeit windy.

Carolinas: Hurricane or Tropical Storm conditions are likely. However, the storm’s rapid movement should make this a quick hitter, and I’m beginning to think that outside of a few rough hours, these folks too may be spared a huge impact. But if I had to pick anywhere within driving distance that is still quite vulnerable, it would be here.

Anyway, I have to get back to work. Will keep you updated