weather, weather safety/preparedness

More Naples, FL area wildfires (H. Michael Mogil, CCM, CBM, NWA-DS*)

Late Thursday, Apr. 20, 2017, two wildfires of unknown origin broke out in the Golden Gate Estates area of east Naples, FL. Although fire fighters jumped into action quickly, dry and windy conditions allowed the fire to spread. By this morning, the combined blazes had grown to about 2,500 acres.

Collier County Emergency Management issued evacuation orders for some limited areas yesterday and expanded areas affected during today. As of late this afternoon, the boundaries of the evacuation area extended from the south side of Golden Gate Boulevard south to the east-west portion of I-75 and from Collier Boulevard east to Wilson Boulevard.

Jim Dickey, WZVN-TV (CH 7 – ABC, Fort Myers) Certified Broadcast Meteorologist, posted radar imagery at around 10:00 a.m. E.D.T. today of the dual fires at his Twitter page (@WxDockey). Dickey noted that “Now that A.M. inversion has lifted, smoke plumes from #30thStFire and #FrangipaniFire visible on radar” (Fig. 1).

     Images from the Immokalee Fire Control District showed the scope of the fires and their associated large billowing smoke clouds (Fig.2 and Fig. 3). Overnight and during Friday morning, the smoke reached the Naples City limits, lowering visibility at the Naples Airport (KAPF) to 3 miles. Based on the trajectory of the plume this morning (WZVN-TV radar imagery and video), and the fact that the smoke plume is still showing up on the Miami National Weather Service radar late this afternoon, most of western Collier County (including the city of Naples) and parts of southern Lee County are going to be experiencing smoky conditions through tonight and into early Saturday morning.

Thus, smoke from the fire will be affecting many more people than the fire itself. Small airborne particles from the fire may lead to respiratory problems, even for healthy people. Check out Fig. 4, a wildfire poster from http://www.ready.gov, republished by Florida Health. It contains some useful tips for dealing with smoky air.

© 2017 H. Michael Mogil

Originally posted 4/21/17

* The National Weather Association Digital Seal (NWA-DS) is awarded to individuals who pass stringent meteorological testing and evaluation of written weather content. H. Michael Mogil was awarded the second such seal and is a strong advocate for its use by weather bloggers.

weather

SWFL-GWCC South Florida’s Cowbell fire grows rapidly (H. Michael Mogil, CCM, CBM, NWA-DS*)

Discovered on Mar. 30, a relatively small brush fire in South Florida’s Big Cypress National Preserve (eastern Collier County) grew slowly during the following week. By Apr. 8, the Cow Bell fire (so named, because it is near the Cow Bell Strand within the Big Cypress National Park – Fig. 1) had consumed roughly 600 acres. On Sun., Apr. 9, thanks to an increase in easterly winds (and continued dry weather), the blaze exploded. By late Sunday, the blaze had consumed more than 8,000 acres. For comparison, this fire is slightly larger than the burned acreage from the Picayune Strand Fire (western Collier County) back in early- to mid-March. Fig. 2 shows the smoke plume from just north of the Cow Bell fire area.

During much of its lifetime, the fire has been moving westward across “Alligator Alley,” mostly parallel to Interstate Highway (I-75). Campgrounds in the Bear Island area, within the Preserve, are being evacuated. Due to the rapid spread of the fire, fire-fighting crews have had to reassess possible containment lines for stopping the fire’s westward movement.

Maximum smoke impacts were expected closest to the fire, with smoke also impacting I-75 between mile markers 55 through 80. On the evenings of Apr. 9 and 10, around sunset, smoke smell permeated the air in parts of North Naples (more than 50 miles from the fire). Smoke from the fire was also evident in the skies over North Naples. Fig. 3 shows the smoke plume as shown on the NWS Miami radar during mid-afternoon on Apr. 9.

Lacking any rainfall for the foreseeable future, and given the pineland and cypress habitat that is ablaze, the hundreds of fire-fighters engaged in battling the fire will have their hands full. Fortunately, there are only a few structures anywhere near the fire area, at this time.

Officials have urged all drivers on I-75 to use extreme caution and to check road conditions before starting travel across the “Alley.” The highest likelihood for experiencing roadway visibility restrictions due to smoke will be between 4:00 a.m. and 8:00 a.m. daily. This is the time window during which an inversion, a low-level temperature pattern with warmer air overlying cooler air, is most likely to trap smoke near the ground.

Big Cypress National Preserve officials have instituted the following closures:

  • Gator Head Campground
  • Bear Island Campground
  • Jeep Campground
  • The road leading into the Sanctuary except to residents
  • All trails between state road 29 and L-28 Canal including the Florida Trail
  • All public lands west of the L-28 Canal
  • All public lands east of state road 29
  • All public lands south of the Preserve boundary
  • All public lands north of Alligator Alley

In addition, a temporary flight restriction has been placed over the Cowbell Fire (ground level to 3,000 feet mean sea level) to provide a safe environment for fire-fighting aviation operations. In addition to 17 fire engines, at least seven helicopters and two water tanker aircraft are involved in firefighting efforts. The area will likely be expanded to accommodate increased fire growth.

© 2017 H. Michael Mogil

Originally posted 4/11/17

* The National Weather Association Digital Seal (NWA-DS) is awarded to individuals who pass stringent meteorological testing and evaluation of written weather content. H. Michael Mogil was awarded the second such seal and is a strong advocate for its use by weather bloggers.

 

weather

Description of the four-panel GWCC home page display (H. Michael Mogil, CCM, CBM, NWA-DS*)

The GWCC home page contains a four-panel graphic containing satellite and radar observations and a severe weather outlook (all from NOAA). The following is a brief overview of these graphics (organized by column from left to right):

  • GOES Enhanced Infrared satellite image (upper left) – This image, obtained by a GOES (Geostationary Operational Environmental Satellite) measures the “heat” given off by clouds, large water bodies, land surfaces, and clouds. Using a special “enhancement” scale (see color bar at the bottom of the image, just below the NOAA logo), warmer colors appear as blues and greens and colder temperatures appear as yellows and reds. Note, that GOES satellite images on different web pages (or in different GWCC posts) may use different enhancement or “false color” image temperature scales. Colorized images, such as these, should always have their own color key.
  • GOES Water Vapor satellite image (lower left) – This geostationary satellite image also measures “heat,” but the satellite sensors used are more sensitive to the amount and distribution of atmospheric water vapor. When the atmosphere at the middle and high altitudes is dry, infrared energy from lower altitudes (where temperatures are normally warmer) is able to escape to space and be detected by the GOES (Geostationary Operational Environmental Satellite) sensors. This image has been false-colored using a special “enhancement” scale: dry (black and orange), mid- and high-level moisture (white), and cloud-laden at mid- and high-levels (blue and green through red and purple).
  • Storm Prediction Center (SPC) convective outlook (upper right) – SPC issues a wide array of severe weather and other thunderstorm-related guidance and outlook products. They also issue tornado and severe thunderstorm watches and fire weather outlooks. This image, which is often updated several times a day, shows expected thunderstorm and severe thunderstorm activity for “Day 1.” “Day 1” extends from the forecast time until the next 1200 GMT (Greenwich Mean Time or 8:00 a.m. E.D.T / 7:00 a.m. E.S.T. Favored areas for thunderstorm / severe thunderstorm activity are depicted as, “to the right of a line,” as shown by an arrow at the end of any line.
  • National radar composite image (lower right) – This image brings together radar reflectivity data from some 100 plus radar sites throughout the contiguous 48 states. Radars measure how much energy atmospheric solids and liquids (hydrometeors such as snow, hail, and rain, as well as particles such as dense smoke and volcanic ash) reflect back to a radar site. The greater the reflectivity value (shown in dBz units), the greater the concentration of so-called “hydrometeors,” solids and other objects (e.g., birds, bats), the radar beam may intercept. The color scale ranges from blues and greens (the lowest reflectivities) to reds and purples (the highest reflectivities).

© 2017 H. Michael Mogil

Originally posted 4/7/17

* The National Weather Association Digital Seal (NWA-DS) is awarded to individuals who pass stringent meteorological testing and evaluation of written weather content. H. Michael Mogil was awarded the second such seal and is a strong advocate for its use by weather bloggers.

weather

Heavy rainfall gradients and rainfall rates (H. Michael Mogil, CCM, CBM, NWA-DS*)

Across Louisiana, Mississippi and parts of far East Texas, torrential rainfall occurred Sunday and Sunday night. Widespread one to four inch rainfall amounts were reported, with some locations noting amounts of six, eight and even ten inches (Fig. 1). Alexandria, LA, in the west-central part of the state, reported more than nine inches over a nearly 12-hour period, with nearly continuous thunderstorm activity for a roughly 8-hour period (Fig. 2).

By early Tuesday, the large-scale storm system responsible for the storminess has moved well to the northeast and the heaviest rainfall had moved well to the east of The Pelican State. In the wake of the Sunday rainfall activity, flood warnings remain in effect for many areas in Louisiana that received excessive rainfall or are downstream from these areas (Fig. 3).

Two things are striking in Fig. 2. First, there are numerous bands of heavy rainfall aligned southwest-to-northeast. These mark the locations in which thunderstorm lines became at least somewhat stationary. Then thunderstorms, moving along the line, dumped successive bursts of heavy rainfall. This scenario, in which numerous storms move across the same area, is known as “training.”

The second thing of note is the large precipitation gradients in areas near the heaviest rainfall. One only needed to have traveled a relatively short distance to go from eight to ten inches of rainfall to amounts of around an inch.

A similar, albeit greater, rainfall gradient occurred in my backyard, Collier County, in southwest Florida, on Sunday. A small convective weather system (without thunder and lightning), developed along the sea breeze front and moved slowly northwestward across parts of north-central Collier County. Heavy rainfall (between 1.47 and 1.78 inches according to two nearly co-located reporting stations) fell just two miles to the northeast of my rain gauge. According to a high school student interested in meteorology (and one

who attended a Naples weather camp last summer), most of the rainfall that he measured fell in just under 20 minutes (Fig. 4). That translates to an hourly rainfall rate of 4.5 inches to 5.5 inches. I measured a scant 0.07 inches of rainfall, although I did briefly experience gusty outflow winds from the convective weather system. Fig. 5 shows radar-based rainfall estimates for southwest Florida on Sunday.

While these situations were somewhat similar in their excessive rainfall and localized rainfall gradients, one was linked to a large-scale low-pressure system and the other to a small-scale sea breeze zone. This is testimony that different meteorological scenarios can yield similar meteorological outcomes.

© 2017 H. Michael Mogil

Originally posted 4/4/17

* The National Weather Association Digital Seal (NWA-DS) is awarded to individuals who pass stringent meteorological testing and evaluation of written weather content. H. Michael Mogil was awarded the second such seal and is a strong advocate for its use by weather bloggers.

geography, weather

A Look at GOES Water Vapor Imagery (H. Michael Mogil, CCM, CBM, NWA-DS*)

This feature is about GOES (Geostationary Operational Environmental Satellite) Water Vapor (WV) imagery. This type of satellite imagery (just one of many) is based on a specific band of data within the infrared radiation (IR) spectrum. It is collected from a geostationary satellite positioned roughly 22,000 miles above the Equator near the longitude of Florida and a longitude just west of the U.S. West Coast. With the satellites racing around their larger orbit path at an angular speed that matches that of the Earth’s surface, the satellite never sees the earth moving (hence, geo- or Earth- stationary). As a result, animations show cloud and/or moisture movement only. These two U.S.-operated satellites are part of a global network of satellites supported by several Nations and/or organizations.

I’m a big fan of WV imagery because it allows meteorologists and others to see the motions (called animations) of clouds and locations of moist/dry areas. Even when the image is not color-enhanced, the various white to black grey shades provide important discrimination. Thunderstorms, with cold, high, cloud tops appear as the brightest white; cirrus (ice crystal) clouds are white, but typically not as bright. Moist areas are generally grey; dry areas are black (see scaling, warm to cold, at lower left of Fig. 1). It would be easy to see this representation as something similar to a topographic or relief map, with thunderstorms representing the mountains and dry zones representing dried lake beds.

In this image (Fig. 1) and associated animation, there is a lot to see. For example, there is a bright area that develops across eastern Oklahoma and moves into southeast Missouri. To its north, it is easy to see a small-scale swirl in the clouds and moisture areas. Further northwest, a larger swirl (the center of the main storm system) was moving into southwestern Minnesota.

Since the WV imagery is based on IR (temperature) data, it is easy to ascertain ground-based features when very dry air covers a region (such as west Texas, New Mexico, Colorado, and western Kansas). Notice the roughly north-line that separates a light grey region to the west and a dark area to the east. This marks the front-range of the Rocky Mountains, with snow-covered, colder mountains to the west and low-altitude, warmer, plains to the east (Fig. 2).Near the end of the animation, a cloud rapidly develops over far west Texas, just to the northeast of El Paso. The western edge of the cloud stays locked in place, as nearby clouds continue to move by from the west. This cloud feature formed as moist air bumped into the Guadalupe Mountains (and Guadalupe Peak, 8751 feet elevation) and was forced to rise (Fig. 3). Rising air cools by expansion (lower pressure as one goes up in the atmosphere) and this often leads to condensation and cloud formation. Since the feature causing the cloud to form doesn’t move, the cloud feature continually reforms on its western edge. From the ground, this would likely appear as a standing wave cloud,

Finally, across New Mexico, notice that some grey clouds move over the snow-covered, colder ground areas. These clouds are warmer than the underlying ground and provide some information about the vertical atmospheric temperature profile in the area.

The bottom line to all of this is that GOES weather satellite imagery allows meteorologists and others to view larger geographic regions and both large- and small-scale weather features.

And this limited perspective of satellite capabilities is just with current GOES capabilities and just one IR channel. Wait until GOES R, launched last November, gets fully checked out and starts to deliver operational data and images. The WOW factor will likely be incredible!

© 2017 H. Michael Mogil

Originally posted 3/1/17

* The National Weather Association Digital Seal (NWA-DS) is awarded to individuals who pass stringent meteorological testing and evaluation of written weather content. H. Michael Mogil was awarded the second such seal and is a strong advocate for its use by weather bloggers.

weather, weather safety/preparedness

The winds win! (H. Michael Mogil, CCM, CBM, NWA-DS*)

Today through tomorrow evening, large areas of the Nation and some nearby ocean water areas are under various types of wind warnings. From hurricane-force wind warnings in New England’s offshore waters (large-scale winter storm and intense pressure gradient) to Santa Ana (canyon-channeled) winds in southern California (Fig. 1), the winds win!

In New England, for added measure, heavy snow and bitter cold will add to the misery. Across parts of west Texas, a wintry mix will develop. In the mid-Atlantic, it’s a combination of large-scale vertical mixing (high speed winds from higher altitudes mixed down to the ground) and the effects of downslope winds.

In all of these land areas, winds will be high enough to affect the travel of high-profile vehicles and even passenger cars. Offshore from New England, waves will build to heights of more than 30 feet. As noted in National Weather Service marine warnings, “seas are given as significant wave height…which is the average height of the highest 1/3 of the waves. Individual waves may be more than twice the significant wave height.” Hence, if a 60-foot wave does form, it would take on the scope of the self-proclaimed “George Clooney Memorial Wave” in “The Perfect Storm” movie.

Winds will die down in many locales by Tuesday, as a more tranquil weather pattern establishes itself. Until then, drive safely, act cautiously, and stay in safe places.

© 2017 H. Michael Mogil

Originally posted 2/12/17

* The National Weather Association Digital Seal (NWA-DS) is awarded to individuals who pass stringent meteorological testing and evaluation of written weather content. H. Michael Mogil was awarded the second such seal and is a strong advocate for its use by weather bloggers.

weather, weather safety/preparedness

One New England Blizzard…Two New England Blizzards… (H. Michael Mogil, CCM, CBM, NWA-DS*)

On Feb. 9, 2017, southeastern New England experienced a significant snowstorm. Within the storm’s circulation, blizzard conditions lasted for some three to almost six hours and affected many areas. The National Weather Service (NWS) Office in Taunton, MA summarized the storm in a lengthy weather release on the evening of Feb. 9, 2017. Excerpts from that release have been provided here (all times Eastern Standard Time).

The storm responsible for the blizzard (Fig. 1 – left) was a “meteorological bomb,” a storm that undergoes rapid pressure falls (or “explosive deepening”) of at least 24 millibars (0.71 inches of mercury) in 24 hours. Bombs typically contain some “thundersnow,” which often means locally heavier snowfall. This bomb was no exception.

First, it’s important to reiterate what a blizzard actually is. According to the NWS, a blizzard involves falling and/or blowing snow, sustained or frequent wind gusts of 35 miles per hour or more and visibilities frequently reduced to less than a quarter of a mile. All of these conditions must last for three hours or more.

For purposes of this summary, the NWS meteorologists used only official airport reporting stations (since all of the above weather conditions are routinely reported at these). For visibilities, they decided to use reported values of one-quarter mile or less since, “…that is quite low for an automated sensor to detect.” Obviously, blizzard conditions occurred elsewhere across the area.

  • Providence, RI wins the competition with 5 hours and 18 minutes of blizzard conditions (10:51 a.m. to 4:09 p.m.).
  • Hyannis, MA was a close second with 5 hours and 4 minutes (12:56 p.m. to 6:00 p.m.).
  • Boston, MA netted blizzard conditions for 4 hours and 34 minutes (12:20 p.m. to 4:54 p.m.).

Other locations reporting blizzard conditions (in decreasing length of time of blizzard conditions) included Martha’s Vineyard, MA; Block Island, RI; Beverly, MA; Marshfield, MA; New Bedford, MA; and Westerly, RI.

As the region digs out, another storm system looms on the western horizon. This one, much like its predecessor, promises to involve “explosive deepening” as it passes by the region from late Sunday into late Monday (Fig. 1 – right). However, its movement will be significantly slower, allowing heavy snowfall and blizzard conditions to last longer. Already, local snowfall forecasts are pegged at approaching two feet.

This will be a “hunker down” storm. So stay home, dress in layers if you venture out, and, unless you have a snowblower, consider letting a local teenager shovel your driveway.

© 2017 H. Michael Mogil

Originally posted 2/11/17

* The National Weather Association Digital Seal (NWA-DS) is awarded to individuals who pass stringent meteorological testing and evaluation of written weather content. H. Michael Mogil was awarded the second such seal and is a strong advocate for its use by weather bloggers.

photography, weather

Nephelococcygia from space (H. Michael Mogil, CCM, CBM, NWA-DS*)

On Sat., Feb. 4, 2017, I gave a talk to the Friends of Barefoot Beach. The talk centered on “Celebrating The Weather.” I decided to use cloud photography to focus the talk on the sky.

As part of the talk, I shared some cloud photography of things familiar to us. One image was a happy dog (ground perspective); another was a flying goldfish (taken from an airplane window over London).

Last evening, I was perusing some GOES (Geostationary Observational Environmental Satellite) images and came across an interesting cloud pattern, one the showed a smiley-faced storm just offshore from Washington State (Fig. 1). I’ve rotated the image clockwise 90-degrees to make the image easier to view (Fig. 2).

The term for viewing shapes in clouds is “nephelococcygia.” Loosely translated from Aristophanes’ play, “The Birds,” it means “cloud cuckooland.” Since Aristophanes lived around 400 B.C.E., I am 100 percent certain that he never considered cloud watching from some 22,000 miles above the Earth in his literary repertoire. However, interpretations from his writing indicate that Nephelococcygia was a utopian city in the clouds.

Stay tuned for more nephelococcygia stories.

© 2017 H. Michael Mogil

Originally posted 2/5/17

climate, humor, weather

Southwest Florida winter to continue (H. Michael Mogil, CCM, CBM, NWA-DS*)

BULLETIN: Four Naples groundhogs spied their shadows early Thursday morning. Hence, look for six more weeks of south Florida winter. Yahoo!

Punxsutawney Phil does not have a sterling record of furcasting the weather for the last six weeks of winter, even though the official Punxsutawney web site says otherwise. I know because an intern and I analyzed about 100 years of Phil’s forecasts in the late 1990’s. During our research, we discovered that, at best, Phil was accurate only about 10 percent of the time. Phil just kept getting it wrong…and getting it wrong…and getting it wrong, much like Bill Murray did in the movie, Groundhog Day.

Phil’s forecast accuracy is far below chance and offers stark testimony to the inability of the Groundhog legend to really offer any hint about upcoming weather. Still, the legend is fun and offers a great escape for mid-winter blues. And even with a spate of Johnny-come-lately Marmota Monax’s (Phil has many ancestors and bretheren), groundhog weather prediction simply doesn’t cut it.

One reason these groundhogs keep getting it wrong is because of media coverage. No, the furry critters aren’t creating fake news. Rather, as Al Roker noted on the Today Show, Thursday morning, there are simply too many camera lights. Hence, the only forecast possible is ongoing winter. Not surprisingly, even with cloudy skies (Fig. 1), Punxsutawney Phil saw his shadow on Thursday (Fig. 2). I didn’t even bother to see what the other nationally known groundhogs predicted. I knew the answer.

Instead, my focus was on four Naples groundhogs. Okay, so they are Ty babies™. They are still groundhogs! And I can report, unequivocally, that no camera lights were at play. It was pure sunshine that allowed these marmots to see their shadows (Fig. 3).

While folks in northern climes are dreading six more weeks of winter, we in Naples are thrilled about winter’s continuance. The reason is that in southwest Florida, winter means lovely weather. Average daily climatological temperatures start in the mid-60’s in early February and only rise into the lower 70’s by the end of March. The daily range spans about ten degrees above and below these values. In short, it’s almost like late Spring in northern states. With minimal rainfall chances, it’s the weather southwest Floridians crave.

The only drawback to the lovely weather is that southwest Florida could use a few days of steady rainfall. Southwest Florida and much of the Florida peninsula, according to the National Drought Mitigation Center, has been (and is expected to continue to be) abnormally dry.

Wherever you may live, and whatever the weather brings, please, enjoy. Summer heat and humidity, for most of us, are just over the distant horizon.

© 2017 H. Michael Mogil

Originally posted 2/4/17

* The National Weather Association Digital Seal (NWA-DS) is awarded to individuals who pass stringent meteorological testing and evaluation of written weather content. H. Michael Mogil was awarded the second such seal and is a strong advocate for its use by weather bloggers.

weather, weather safety/preparedness

Long duration lake-effect snow event underway (H. Michael Mogil, CCM, CBM, NWA-DS*)

The National Weather Service has issued “lake effect” snow warnings and advisories for areas to the east of Lakes Erie and Ontario through Sunday evening (Fig. 1). These forecasts call for locally heavy snow and wind-blown snow with associated hazardous driving conditions. Forecasts for areas in New York State downwind of these lakes indicate that snowfall amounts will be within a 15 and 40 inch range (locally higher amounts expected) along with wind gusts to 45 miles per hour. The heaviest snowfalls are expected in the Tug Hill Plateau area (downwind from Lake Ontario, near Watertown and Montague, NY), with 12-hour snowfalls, throughout the period, frequently in the six to 12 inch range. Already, early this Friday morning, Watertown reported wind gusts in excess of 40 miles per hour.

While not yet issued, look for similar forecasts to be posted for other downwind areas of the entire Great Lakes region during the next several days.

This entire weather scenario is linked to a quasi-stationary surface and upper air low-pressure system across eastern Canada (Fig. 2). The system’s counter-

clockwise circulation will send winds across the Great Lakes, mostly from a west to northwest direction.

With the Great Lakes mostly ice free (Fig. 3), colder air, moving over relatively warmer water, can gain heat and moisture. This allows clouds (often low-topped) to develop in bands across the lakes (Fig. 4). As these bands make landfall, the air they are riding on experiences increased frictional drag

(friction is higher as winds blow over land than water). The result is a low-level convergence effect, adding uplift to the clouds. In areas where terrain increases inland, there is an added orography-lift effect (e.g., the Tug Hill Plateau area). In a snowfall event earlier this winter season, parts of the Tug Hill Plateau were targeted with over four feet of snow in a three-day period.

Due to the nature of “lake effect” snow events, the National Weather Service in Buffalo, NY noted early this Friday morning that, “…in lake effect snow, the weather can vary from locally heavy snow in narrow bands to clear skies just a few miles away. If you will be traveling across the region, be prepared for rapid changes in road and visibility conditions.”

© 2017 H. Michael Mogil

Originally posted 1/27/17

* The National Weather Association Digital Seal (NWA-DS) is awarded to individuals who pass stringent meteorological testing and evaluation of written weather content. H. Michael Mogil was awarded the second such seal and is a strong advocate for its use by weather bloggers.