The remnants of Typhoon Merbock have become a strong extratropical cyclone and is slamming in to Alaska today … here’s the GFS overlay showing the structure of the storm:
Alaska is pretty far north (duh). What that means is that the geosynchronous satellites (GOES – Geosynchronous Orbit Environmental Satellites) we rely on for near-instantaneous weather pictures are distorted since they are over the equator, and are looking at the state at a steep angle. Here is what the view from the GOES West satellite looks like right now …
Fortunately there is another family of satellites that is in a lower orbit and passes over the poles. These satellites, the NOAA Polar Operational Orbiting Satellites (POES) track over every point on the earth twice a day, and more frequently near the poles since they pass over each pole every 90 minutes. They give us a more overhead view. Here is the Alaska storm from NOAA-20, with a GFS forecast wind on top … notice the “swath” of the image as the satellite moves from north to south, and you can see the edges are a bit smeared since it is at a lower altitude.
There are also a set of NEXRAD radars across the state that are the same model we have down here in the lower 48. Here’s the view from Nome, which is closest to the storm center:
Lightning is one of those amazing and scary phenomena that nature uses to try to keep equilibrium – in this case, to equalize the static charge between clouds and the ground (link to Wikipedia article). While the displays can be beautiful, the sound it produces (thunder) isn’t much fun for a lot of dogs (and a few cats), and lightning causes on average around 30 deaths a year in the US. It also causes something on the order of two billion dollars in damage, a number that is increasing. No, not because of climate change, but because of all the electrical stuff we have today. Modern electronics is sensitive to both the static charge and the electromagnetic pulse (EMP) generated by a nearby strike.
Lightning damage is often strange. This weekend we had a strike hit a power pole a few hundred feet from the office. Why there, when the office has a big metal tower that sticks up at least as high, not to mention lots of higher trees and nearby cell towers? Probably something to do with the way the power lines are run in this neighborhood and the fact the cap wasn’t grounded on the pole. In any event, despite being on a different circuit than the hit pole, I had a lot of damage, all of it seems to be from EMP (the exception is the geophone in the seismometer). Essentially every Ethernet card with a cable run over 10 feet or so was damaged. For systems with embedded Ethernet ports that’s fatal. The numerous radios and antennas were not impacted at all as far I as I can tell, but they all have special protection, and of course the cluster computer uses high speed optical fiber so it’s ok. In any event, still sorting out the damage and figuring out what to do next. A bigger problem than the cost and paperwork hassle is the layout and design. While my systems were cutting edge a few years ago, it certainly isn’t what you would implement today given the changing pace of technology. So just replacing stuff isn’t really smart or even practical – I do have some spares but not enough to replace all that was damaged. But the core monitoring systems are hardened and generating data, so here’s a tropical update.
As expected, the strong tropical wave coming off the coast of Africa is now being tracked as Invest AL97 (or 97L). NHC gives it a 40% chance of developing before it encounters unfavorable conditions in a a few days. It looks to stay north of the Caribbean Islands, nothing to get excited about yet unless you’re on TV and need something to talk about 😛
Quite a few tornado reports across the southeast, as well as thunderstorm damage. Here’s the regional view …
… and zoomed in to the Savannah GA and South Carolina Lowcountry …
Storm Reports last 24 hrs
TSTM WND GST
TSTM WND DMG
HIGH SUST WINDS
NON-TSTM WND DMG
MARINE TSTM WIND
NON-TSTM WND GST
NON-TSTM WND GST
Reports from across the US yesterday (6am, 5 April to 6am, 6 April)
Some potential for more thunderstorms today, some may be pretty strong so keep your weather radios on this afternoon -and if you don’t have one, get one! Apps, etc. aren’t always as timely, and a good SAME radio can be had for about $30.
Today the much weakened system will be pushing east across Georgia/South Carolina and will be moving offshore this evening. It has lost a lot of energy but might still cause some strong thunderstorms, so keep your weather radios armed.
And of course the Ukraine thing grinds on. Hard to know what to say about that, the level of propaganda all around is insane, and there is virtually no reliable information in the public realm. So trust no one, and stay tuned … I suspect we are in that dangerous period where things are moving to a new equilibrium, but the people who don’t want or realize that may act to blow up (literally in this case) that trend. Perhaps by early April we will know.
There is a strong cold front sweeping through Georgia this evening, that will push our spring weather offshore for a couple days. The contrast in air (cold dry vs warm moist) is a good combination for very gusty winds, some thunderstorms, and maybe a weak tornado or two. Right on the coast the potential isn’t as high, but those on the GA coast (including down by Brunswick/Golden Isles) up through Charleston should keep the weather radios on just in case. Here’s the radar and warnings just before 4pm Sunday …
The orange hash is a tornado watch, the solid yellow lines mark out severe thunderstorm warnings, and the red box near Albany GA is a tornado warning, the radar indicated something rotating out there …
Update: at 5:15pm, tornado watch (watch means tornadoes are possible) until 10pm tonight for the coast. No active tornado warnings (warning means an actual tornado has been sighted or radar indicated). Here’s the updated radar and warnings (yellow boxes are severe thunderstorm warnings, hash orange is tornado watch area):
A strong cold front is running into unusually warm and moist air in the midwest, and whenever contrasting air masses collide you get severe weather … here is the radar and current warnings as of 6am this morning (Saturday):
The Alabama/Tennessee/North Georgia northwards into Ohio/West Virginia can expect to see thunderstorms today from this system, but for those in coastal Georgia, South Carolina, and North Florida, it should have lost a lot of energy and only a few rumbles are expected. Will post again if that changes.
For those of you on on the Georgia Coast and South Carolina Lowcountry a storm system is brewing up that threatens some gusty winds and coastal flooding. In fact, if the forecast holds, the water levels at the Fort Pulaski gauge are predicted to be in the top five water levels in the last 80 years, beating the October 2015 storm for the number four spot (10.6 is forecast for around 10am Saturday; the October 2015 storm reached 10.43 feet above MLLW). Here is the tide forecast for this weekend …
These water levels are about two feet lower than the modern records of 12.6 feet set by hurricanes Irma (2017) or Matthew (2016), so while high, and the usual coastal places that flood will see water, that couple of feet makes a difference given the low terrain. And while the wind will be a bit gusty, nowhere near dangerous levels, so don’t use those storms as reference points!
Tides tonight should also be quite high, into the moderate flood stage. There are several reasons for this. First, the moon is near new, so the pull of the sun and moon are lined up creating higher tides. Second, the winds have been blowing onshore, so that “stacks up” water in the marshes – water levels have been running about a foot above normal. The storm, a fairly classic nor’easter like system forming out of a frontal system, is currently (Friday Morning) over the Gulf, but by Saturday morning will be just offshore …
This will mess with the Rock and Roll Marathon in Savannah, with temperatures at race time in the upper 40’s (good you’re running) and 80% chance of rain showers (not so good). The entire coast from Jacksonville up to the other side of Charleston will see impacts … the weather service office in Charleston has a briefing up at this link. To be clear, aside for folks in the usual places that flood with higher than normal tides this will just be a cold, wet, windy day, but if you do live on the water it may get uncomfortably high.
There is a messy storm system crossing the US, and it is reaching the Georgia/South Carolina coast this afternoon. Here’s the 8am radar, and a tornado warning in the BigBend of Florida …
As has been the case with these things lately, the focus of the potential for the most severe thunderstorms and possible tornadoes are in South Carolina, right now looks like between Hampton and Charleston, but everybody especially east of I-95 in Georgia and SC should keep their weather radio’s on this afternoon.
Only one tropical system of interest, Hurricane Rick (EP17) should hit the west coast of Mexico Monday (more below), but there are two big non-tropical storm systems impacting the US today. Here is the TAFB surface analysis this morning, showing Hurricane Rick off of Mexico, the tangled fronts and low pressure in the middle of the country, and the big Pacific storm system starting to stream moisture into California …
Two areas are of concern in the US – the first is in the middle of the country, where a complex system is likely to produce some strong thunderstorms today. But the big Pacific storm (just under the label in the upper left of this graphic) has been getting media attention with the usual breathless headlines like “Atmospheric river, high winds to wallop California and Pacific Northwest” and talk of “Bomb Cyclones.” The terms “Atmospheric River” and “Bomb Cyclone” both have specific meanings and really aren’t necessarily scary or destructive unless you say them in the right tone of voice.
The more accurate term for “Bomb Cyclone” is “Explosive Cyclogenesis.” There is in fact a technical definition, that a storm decreases in minimal surface pressure by at least (24 sin φ/ sin 60°) mb in 24 hours, where φ represents latitude in degrees. I never liked the term “bomb” as being overly dramatic, but it has been in used in meteorology for a long time. They do have the potential to cause a lot of damage – the one approaching the Pacific Northwest has winds of hurricane force and higher. In addition, a second phenomena called an atmospheric river (AR in NWS abbreviations) is setting up over California today. That stream of moisture will drop a lot of rain there, which has the potential to cause flash flooding and over a foot of snow at higher elevations since in combination with the approaching cold fronts (the saw-toothed lines in the upper left of the above map) there will be a big temperature drop because, well, WINTER IS COMING! This year there is another factor, the large burn scars from this year’s wild fires. That means the vegetation that normally helps slow down or hold back rain is gone, so the potential for epic mudslides is present. You can get accurate and relatively drama free (and totally advertising free since you already paid for it!) reporting on all this at the National Weather Service web site (link). The short range weather discussion is always a good place to check for the “big picture” …
For those in Mexico, here is the damage swath expected from Rick:
NHC’s Key Messages regarding Hurricane Rick caution that as is typical for landfalls in Mexico, inland flash flooding and mudslides in the mountains are always a risk with this storm in addition to the threat of storm surge and wind on the immediate shoreline.