 |
| An immense area of the the U.S. is under fire danger alerts today. The dark red and especially pink areas of the map are at particular risk for erratic, fast moving wild and rangeland fires that could blow into towns. |
That storm is planning some real havoc.
Maybe the most impressive part of this storm is the huge areas that are subject to the three main hazards from this system - tornadoes and severe thunderstorms; high winds not associated with thunderstorms and wildfires.
The overall forecast hasn't changed much since I described this looming storm yesterday. It's just that the predictions have become more certain, and in some cases more threatening than we thought just 24 hours ago.
HIGH WINDS
The high wind warning and watch zone is just immense, extending from New Mexico to North Dakota and east as far as Ohio.
Through this whole area, winds are expected to gust to 60 mph, with several areas forecasting gust to 70 or even 80 mph. Given the vast population affected, you're going to see an incredible number of power outages, trees down, that sort of thing.
WILDFIRES
Worse, an immense portion of the high wind zone is also incredibly dry as the storm rushes arid air out of the Desert Southwest and northern Mexico.
The result is a very dangerous wildfire situation, and I can't recall seeing anything quite like this. The area with a wildfire risk today is immense, covering New Mexico, Texas, Oklahoma and Kansas and extending in a broad band all the way to southern Michigan and Ohio.
Experts are most concerned about Texas, Oklahoma and parts of Kansas, where the wind will be particularly strong, humidity especially low, and a landscape that was parched even before this new threat came along.
As I mentioned yesterday, today's wildfires won't necessarily be contained to open rangeland with no buildings. The areas with the highest fire danger today have a total population of more than 25 million. You can see how a rangeland fire can sweep into exurbs and suburbs of larger cities like Oklahoma City or Dallas or San Antonio or Wichita.
Worst case scenario is we could lose a lot of homes to fires today.
As a prelude, a fast-moving rangeland fire near Colorado Springs forced temporary evacuations and burned three outbuildings on Wednesday. Firefighters were able to keep the flames out of nearby homes.
Another unusual aspect of this is the risk of "dry thunderstorms" in parts of Kansas and northeast Oklahoma. Dry thunderstorms are practically rainless storms that spit out lightning which in turn causes fires.
Dry thunderstorms are fairly common during fire season in the Rocky Mountains and West, but very rare in the Plains.
These dry thunderstorms will be the beginning of an immense outbreak of dangerous storms and tornadoes.
TORNADOES/SEVERE WEATHER
Easily the biggest threat from this storm is what looks like will be a massive outbreak of severe thunderstorms and tornadoes.
 |
| Another huge area is under the gun for tornadoes and intense, dangerous thunderstorms today. The orange and red areas are most at risk. This is just for today. Another huge area of the South and Midwest can expect more tornadoes and intense storms on Saturday and maybe Sunday, too. |
Those dry thunderstorms today will be the opening salvo into what might become one of the largest March outbreaks of severe storms and tornadoes we've seen in years.
Those "dry storms" will move into a more humid environment, and more storms will blossom today. Meteorologists with NOAA's Storm Prediction Center expect an intense squall line or derecho to form this afternoon and sweep quickly across the Mid-Mississippi valley.
Wind gusts with the storms could reach 70 to 90 mph. This squall line will probably have some tornadoes embedded within in, too. Its forward motion will be very fast, too. That means there won't be much time to hunker down as the storm races toward a particular location.
As you get down into eastern Arkansas, Missouri and southern Illinois, forecasters expect supercell thunderstorms to form and quickly produce tornadoes. Some of the tornadoes could become quite strong, so it wouldn't be just a matter of a couple damaged barn roofs and trees.
If one of these strong tornadoes hits a town, there'd be a ton of destruction and the risk of some deaths. The risk of these twisters will extend well after dark, which makes them more dangerous. People often are unaware of warnings at night, and of course can't see a tornado coming at night.
Today, unfortunately is just the beginning.
A renewed wave of storms and tornadoes is likely Saturday, focusing on the Gulf Coast states and on north into Tennessee. Mississippi and Alabama appear to be particularly in the crosshairs with this one. "Multiple, long-track, high-end tornadoes will be possible," NOAA' Storm Prediction Center said I'm their latest briefing.
Alabama tornado expert James Spann this morning was telling people in the threatened area to not to turn on their "do not disturb" feature so that you get warnings.
He also told people to have bicycle, baseball or motorcycle helmets ready to wear when taking shelter from a potential strong tornado. That'll help protect your head from flying debris. He also suggested carrying an air horn to your save place. If the house collapses and you can't get out, use the air horn to alert rescuers.
The threat of severe storms and tornadoes will move on to the East Coast on Sunday.
On top of all this, parts of Kentucky, Tennessee and West Virginia that saw severe, deadly flooding in February look poised to endure yet another flood with this upcoming storm.
VERMONT EFFECTS
For us, too the forecast is essentially unchanged, with a flood threat unfolding Sunday into Monday.
Rivers will start to slowly rise today and tomorrow as highs in many towns get well into the 50s and in many cases low to mid 60s. No flooding is expected through Saturday, except possibly near ice jams.
We'll have to keep our eyes on those existing ice jams starting later today and through the weekend. They could move, or get worse, causing some local flooding here and there. Parts of the Winooski, Lamoille and especially Missisquoi rivers are jammed up with ice at the moment.
Sunday into Monday will bring the highest threat. It's still a little soon to predict how high most Vermont rivers will get, but minor flooding at least seems a good bet. There could be areas of moderate flooding, which is the level at which you start seeing some real damage.
Remaining snow will melt super quickly Sunday, as conditions will be perfect for getting rid of snow. Temperatures will be in the 60s, humidity will be high for this time of year and gusty winds will drive that warm, humid air into the snowpack, causing that rapid meltdown.
The vast storm's cold front arriving in Vermont should also add a half inch to an inch of rain to the mix Sunday and Sunday night. Which is another reason why we have the flood threat. There could even be some heavy downpours from embedded thunderstorms with this thing.
The ice jams will be the thing to watch most carefully Sunday and Monday. The ice will tend to move as them melt continues and water levels rise. Those jumbles of ice could perhaps get stuck at times in different locations, causing sudden floods just upstream from the new ice jams.
It looks like it will stay unseasonably mild most of next week, but by then so much of the snow will have melted that the flood threat should diminish. Unless we get another round of heavy rain later in the week. We don't yet know whether that would happen, so we'll just get through the next few days for now.
No comments:
Post a Comment