weather, weather safety/preparedness

Dangerous Irma Targeting Naples (H. Michael Mogil, CCM, CBM, NWA-DS*)

As of late yesterday afternoon, downtown Naples, U.S. Highway 41 (Tamiami Trail), and Naples/Collier County beaches resembled a ghost town. One could drive down Gulfshore Boulevard (a thoroughfare about a block or so from the beach) and perhaps see one or two cars. Fig. 1 shows the scene sans vehicles.

It was eerie.

But there was good cause for the lack of humankind. After a week of Hurricane Irma track uncertainty across the state of Florida (the large-scale storm track was “spot on;” the details across Florida, not so), computer and human thinking centered on a track along the west coast of Florida. Now, early Saturday morning (Sept. 9, 2017), the expected storm track is actually slightly west of Naples (i.e., with the center remaining over water). This is reminiscent of Donna (which destroyed the Naples Pier in 1960) and Charley (which slammed into Punta Gorda, north of Fort Myers in 2004).

This sets the stage for a worst-case scenario for Collier and Lee Counties.

Specifically,

high winds – much of Collier and Lee Counties will be impacted by triple digit sustained winds because the eye wall will be passing directly over both counties. Wind gusts can easily reach speeds that are 20 percent higher than sustained winds. Even though Irma has weakened slightly this morning (due in part to interaction with topography across Cuba), reintensification is expected later today (once Irma leaves Cuba).

heavy rainfall – since the right side (i.e., the wet side) of the storm will be affecting the two counties, roughly eight to 12 inches of rainfall (with locally higher amounts) is anticipated. Given recent heavy rainfall and flooding, these two-day rainfall totals may help replicate the recent flooding.

tornadoes – again the right side of the storm (mainly, the leading front right quadrant) is where tornadoes are most likely to form. That storm quadrant will be passing directly over Collier and Lee counties during the day on Sunday. Fortunately, most hurricane-generated tornadoes are weak and short-lived.

storm surge – is not an instantaneous (or wall-like) rise of water. Rather, it is the relentless onslaught of waves pushing water onshore, without the corresponding opportunity for water to flow back to the ocean. As a result, water levels can rise and push far inland.

Clearly storm surge will be a major risk for many areas. With a storm center over land, Naples and Fort Myers would not receive as much of an initial surge; with a storm offshore, an initial surge from the south is likely. Under either scenario, as the storm moves north of Collier and Lee Counties, hurricane force westerly winds will push additional salt water onto land areas for a longer period of time. Expected surge values will be in the six to 12 feet range.

High tides can add to the expected storm surge. Unfortunately, the turn to westerly winds will be occurring near the time of high tide (about 4:00p.m. E.D.T. on Sunday). Note that expected surge height values do not include any waves that may occur during the time of the storm surge.

Large areas of Collier County (and lesser areas in Lee and other west coast counties) are in the high surge flood risk. The map in Fig. 2 shows at surge risk areas due to a CAT 2 hurricane. Generally speaking the highest risk areas are south and west of State Highway 41.

This is a very large and very dangerous hurricane, one that can cause extensive damage to structures, trees, power lines and signs.

Since it’s too late to evacuate the area, it’s best for local residents and visitors to take shelter in sturdy structures or county-operated storm shelters. People living in mobile homes or manufactured housing should definitely leave these well in advance of the hurricane’s arrival.

© 2017 H. Michael Mogil

Originally posted 9/9/17

* 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

Getting Ready For A Hurricane and more… (H. Michael Mogil, CCM, CBM, NWA-DS*)

There are plenty of “to do” lists out there addressing what to do to prepare for a hurricane, undertake during a hurricane, and address following a hurricane. Some of the more detailed lists can be found at the following web pages:

Weather Ready Nation

FEMA – Hurricane Harvey

American Red Cross

• Your local TV stations (if you are in hurricane country)

At each of these, be sure to look for sub-page links that may provide even more detailed information. FEMA’s – Hurricane Harvey web page (found under the main page “Navigation” menu bar) provides considerable tailored information specifically for Texans. Look for a similar FEMA (Federal Emergency Management Agency) page to surface as Irma starts impacting the U.S. The Red Cross web site includes information about many topics, including how to locate loved ones who may be within a disaster area. In addition, many local TV stations distribute hurricane guides (Fig. 1), tracking charts and other informational items via local supermarkets and drug stores.

Today, I’m going to expound upon these lists a little, providing some insights as to WHY certain things are recommended. I’ll also add a few “out the eye wall” ideas. Note that no list can be totally inclusive.

Regardless of what you read or hear, hopefully, you’ll employ common sense and logic to your actions. Also, be sure you get your information from reliable sources. It’s at times like these that well-thought out plans need to be put into play. And remember that governmental and volunteer service organizations may not have the resources or the capabilities to assist you for days, maybe even weeks, after a major hurricane strike.

• If you don’t have an emergency kit, create one. It should include items that can be placed in heavy duty, sealable, freezer storage bags. Group items to facilitate finding what you may need. For example, you might have individual, labeled, plastic bags that contain medical records, medicines (may not able to refill after the storm), identification (e.g., passports, birth certificates), small denominational cash (ATM machines may not be working, if power loss occurs), cell phones and electronic appliances (sealed to keep out water) and even food and snacks (to avoid contamination with ground water). If possible, put these smaller plastic bags into larger sealable plastic bags or sealable containers.

• Although many companies (e.g., banks, credit cards, utilities) may work with you after the storm to accept late payments (without late fees), it’s just easier to make payments in advance.

• You will want to ensure that certain food items are refrigerated and/or frozen even if you lose power. One way is to ensure that temperature settings in both fridge compartments are set as low as possible BEFORE the storm strikes. If you have created frozen plastic soda or water bottles or sealable containers/freezer bags in advance, these can be used to chill the refrigerator or freezer compartments. Large chunks of ice stay colder longer than bags of individual ice cubes.

Another way is to cook some of the frozen food beforehand. It will be easier for cold hamburgers to survive, for example, than to keep ground beef frozen.

• The same chilling factor can be said for your home. Chill your home as low as possible before power is lost so you’ll have at least a slightly more comfortable environment for a longer period of time.

• Stock up on non-perishables. This includes water, crackers, nutrition/energy bars, breads, cereals, pretzels, chips, snacks, chocolate (my favorite), canned food (e.g., tuna fish), peanut butter (doesn’t require refrigeration), and even astronaut food (possibly available at a local science store). Don’t forget toilet paper, tissues, paper towels and plasticware.

• Speaking about toilet paper, be sure to fill a bathtub or two with water to help with toilet flushing.

• If you lose power and want hot water for coffee, hopefully you’ll have an accessible natural gas line or propane canister. We have a small camping stove and some small propane canisters that we plan on using in an outside location, if needed.

• If you have power banks or power sticks, be sure these are fully charged before the storm strikes. These low-cost power supplies can help power smaller appliances during power outages. Be sure your appliances are fully charged in advance, too. If you have an emergency generator (note that many condo associations don’t allow these), be sure it is charged and/or you have fuel available.

• Bring any lose or liftable objects indoors. This includes hanging or potted plants, patio furniture, trashcans and toys.

• DON’T use any type of tape to protect windows. Most tapes are not strong enough to prevent glass breakage or shattering. Even if you aren’t in a flood zone, consider the flooding potential. Move valuable or important objects, non-refrigerated or non-frozen foods, furniture and electronics to higher levels in your home.

• If you need to evacuate (either by car, mass transit or plane), consider doing this during daylight hours. It is easier to see roads, obstacles and other vehicles, especially if you wind up on local roadways. Be careful of evacuating into the projected path of the storm. You might wind up leaving a secure structure only to stay the night in a less structurally secure motel or other building (or find yourself stuck on clogged roadways).

Also, turn off gas lines, water lines and electricity before leaving.

If you can’t evacuate (or chose not to), then plan to “hunker down,” hopefully in a safe place (e.g., non-flood zone) and with neighbors or relatives. Be sure to move your car to higher ground (away from trees and power lines), if possible.

• If you are elderly, or are in a senior facility, moving out of a flood zone early is better than waiting. Several such facilities in the Houston area failed to evacuate and were flooded, putting the elderly patients at risk.

• Before the rains arrive, consider cleaning roof gutters and downspouts to facilitate the moving of water away from your home. If there are storm drains near your home, take a few moments (even it’s not your responsibility) and clean out any leaves, twigs and other debris), to enable faster drainage.

• If you have kids or pets and evacuate (and you know that pets are welcome at the evacuation center), think about bringing games, toys, books and other items that can add fun and psychological stability to the situation.

• And, just in case, think about board games, cards, and jigsaw puzzles as things to do to pass the time in a potentially non-electrical home universe. This list is long and getting longer. I will be updating it periodically, including valuable suggestions that may come from my readers. In advance, thanks for your comments and feedback.

© 2017 H. Michael Mogil

Originally posted 9/5/17

Uncategorized, weather

Tropical system affecting Florida (H. Michael Mogil, CCM, CBM, NWA-DS*)

While ex-hurricane Franklin dissipated quickly over Mexico yesterday, a much weaker tropical system began affecting Florida (Fig. 1). On Wednesday, the system was located over the Bahamas and all its storminess remained well east of Florida. In fact, thanks to the dynamics of these “tropical waves,” places west of the wave (in the Northern Hemisphere) are typically afforded sunny skies.

That was the dichotomy across Florida yesterday. The wave was located across southeast Florida late in the morning. As a result, southeast Florida was under a dense cloud canopy with numerous showers and thunderstorms (Fig. 2); at the same time, southwest Florida was experiencing scattered cumulus clouds and some high-altitude cirrus clouds, blow off from the storms to the east (Fig. 3).

East of the wave, southerly wind flow at low levels was convergent (winds blowing together). This forced air to rise, and rising air often yields clouds and precipitation. West of the wave, low-level northeasterly winds were divergent, yielding sinking air and clearer skies.

As of mid-morning yesterday (Aug. 10, 2017), Fort Lauderdale / Hollywood Airport (FLL) had logged record-breaking rainfall (at least 3.36” versus the old record of 3.35” set in 2003; records for FLL date back to 1912). To highlight the variability of rainfall, nearby Fort Lauderdale Executive Airport (FXE), just 9 miles away, received a scant 0.69” during roughly the same time period.

The “tropical wave” headed westward yesterday and brought some heavy thunderstorms to southwest Florida. One thunderstorm moved from north to south across Lee, Hendry, and Collier Counties, bringing  locally rainfall amounts, of an inch to more, to the area. The storm had a very pronounced outflow boundary, with a multi-layer “shelf cloud” marking its arrival (Fig. 4).

Today, with the tropical wave remaining over south Florida, more widespread shower and thunderstorm activity can be expected. Again, rainfall amounts may be locally heavy, with ponding of water possible in usually vulnerable low-lying areas and on roadways.

© 2017 H. Michael Mogil

Originally posted 8/11/17

* 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, weather safety/preparedness

Ground fog! (H. Michael Mogil, CCM, CBM, NWA-DS*)

Dense fog advisories (Fig. 1) as well as the fog they describe (Fig. 2), covered southwest Florida early this Friday morning (Jan. 6, 2017). Some places had 0-0 visibility (that is, zero feet both horizontally and vertically); other places had visibilities of several miles horizontally and several hundreds of feet vertically (Fig. 3). Visibility is defined as how far one can see cloud bases (vertically) or known ground-based objects (horizontally).

   

It is the variation in fog thickness horizontally (and associated visibility) that came to the forefront this morning as I walked my dog, Pepper, around our southwest Florida neighborhood.

  

First, looking up my street, visibility was about a half mile, the measured length of my street (Fig. 4). As soon as Pepper and I walked onto the golf course, fog density increased and visibility decreased (Fig. 5). As we approached the location of my COCORAHS (Community Collaborative Rain Hail and Snow Network) rain gage, which is adjacent to a large pond, the fog density increased further and visibility tumbled down to a few hundred feet (Fig. 6). All images were taken within 10 minutes of one another.

These three scenarios are described in the table below:

Location Fog density Visibility
Street light ½ mile
Golf course dense ~ ¼ mile
Near pond very dense few hundred feet

For the street, warmer air temperatures resulted in less dense fog. Over the golf course, temperatures were slightly cooler, allowing for somewhat dense fog to develop. In the pond area, cooler air temperatures and higher atmospheric moisture contributed to the densest fog.

Note that these conditions contribute to the formation of fog. But, local winds, drainage winds, and other factors can allow fog areas to move. Not surprisingly, this can result in highly variable fog density along roadways. Common sense dictates that motorists of all types of vehicles (cars, buses, trucks) drive more slowly and pay even greater than average attention to potentially rapidly changing visibility.

While the dense fog has lifted already, it will be back again, especially during the upcoming winter months.

– – – – –

© 2017 H. Michael Mogil

Originally posted 1/6/17

* 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

What a difference a wind direction makes (H. Michael Mogil, CCM, CBM, DMS)

The other day, I wrote about the arrival of a strong cold front in south Florida. That front arrived with a significant chill down. Low temperature readings, this Saturday morning (Dec. 31, 2016), were in the 40’s across many areas of southwest Florida. Even with relatively light north winds, wind chill readings dipped into the 30’s to the north of a Fort Myers-Lake Okeechobee line. Dew point readings tumbled into the teens and twenties in many areas (Fig. 1).

But, with brilliant sunshine and a wind shift to the southeast, temperatures soared into the 70’s across most of south Florida by mid-day Saturday (Fig. 2) and into the mid- to upper- 70’s across southwest Florida by Saturday afternoon. Of even more significance was that dew point readings jumped from the 20’s into the low and mid 50’s in most places (Naples shown in Fig. 3).

This transition was linked to a change in wind direction. During the day on Friday and into Saturday morning, winds arrived from the north and northeast (Fig. 1); this kept the trajectory of the arriving continental Polar air mass passing over land. On Saturday, the trajectory of air was from water first and over the Florida peninsula next (Fig. 2). The result was that a continental Polar air mass had been replaced quickly by a maritime Tropical one.

And the trend will continue. By today, New Year’s Day, highs across southwest Florida reached the low- to mid- 80’s. Morning lows only dipped into the mid 60’s to lower 70’s along the southeast coast and low 60’s in most other coastal locations. These warmer day- and night- time readings should be the rule (plus or minus a few degrees) for most of the upcoming week.

I hope to be writing, soon, about examples in which wind direction and/or variations in wind direction play a significant role in an evolving weather event. Other GWCC writers have already posted regarding lake effect snow showers and squalls. Stay tuned!

© 2017 H. Michael Mogil

Originally posted 1/1/17

weather, weather safety/preparedness

Chilly wind chills for south Florida (H. Michael Mogil, CCM, CBM, DMS)

Once a strong Pacific cold front barrels through south Florida later today, attention will shift to windier weather and much chiller temperatures. The combined effect of wind and temperature will contribute to unusually low wind chills for the area. Wind chill is a measure of heat loss from exposed skin.

For Friday morning, wind chills across south Florida will range from the mid 40’s in more northern inland locales to the lower 60’s along southeast and southern locations (Fig. 1).  By Saturday morning, wind chills from Collier County northward, along the west coast, will likely dip into the 30’s and lower 40’s. The combined effect of nearby warm Atlantic waters and a northerly wind flow across Lake Okeechobee (whose waters are still quite warm) will keep East Coast southeast inland locations mostly in the mid 40’s to near 60 degrees (Fig. 2).

Then the chill vanishes, almost as quickly as it came.  Winds will quickly turn to east and allow warmer, more humid air from over the Atlantic to move back into the area. Hence, by Saturday afternoon, many western areas of southwest Florida will see temperatures skyrocket into the mid 70’s.

As noted in yesterday’s post, for the fireworks and other outdoors activities on New Year’s Eve, look for temperatures across southwest Florida to fall back into the mid to upper 60’s with light (5 to 10 mile per hour) southeasterly winds.

© 2016 H. Michael Mogil

Originally posted 12/29/16

weather

THEWEATHERMOGIL:: More heavy rainfall still on tap for southwest Florida

Yesterday morning, I provided information about the flooding potential for southwest Florida. At the time, I indicated that rainfall totals for the upcoming 36 to 42 hours would be in the two to five inch range and that this was atop the nearly two inches that fell across Collier and Lee Counties overnight into Wednesday morning. So far (Fig. 1), total storm rainfall based on radar estimates is in the two and half to four inch range with additional heavy rainfall expected today.

SWFL001-MIA-radar-rainfall-thru-160128-0551amEST

With the stationary front still lingering (today it is across south Florida between Naples and Miami), abundant tropical moisture, and a nearby very strong jet stream, more heavy showers and thunderstorms are in the offing. Additional rainfall totals could reach or exceed three inches according to computer and forecaster guidance. With individual showers and thunderstorms moving over the same areas (an event known as “training”), flooding is possible. Hence, a flood watch has been posted for today across much of south Florida (Fig. 2).

SWFL002-Flood-watch-graphic-160128

Once the front clears the area (and the upper level jet stream moves slightly to the east), skies will clear (at least partially) and temperatures will drop back below seasonal levels…for at least a day or two. With the jet stream nearby, don’t surprised if there is more cloudiness than sunshine during the next five to six days.

© 2016 H. Michael Mogil

Originally posted 1/28/16

weather

THEWEATHERMOGIL:: More heavy rain on tap for southwest Florida

A quasi-stationary front to the north of Naples, FL will be hanging around Florida at least until Thursday evening (Jan. 28, 2016). To the north and south of this frontal boundary, periods of rain, locally heavy, can be expected. Since individual showers and thunderstorms will be moving over the same areas (an event known as “training”), rainfall totals for the upcoming 36 to 42 hours will be in the two to five inch range. This would be atop the nearly two inches that fell across Collier and Lee Counties overnight. Localized, mainly urban, flooding and ponding could occur.

Extensive cloud cover and reduced daytime solar heating should keep the risk of severe weather low. However, a strong upper level jet stream across the “Sunshine” State, linked to El Nino, could allow some storms to intensify to near or above severe levels.

It is easy to see the extensive amount of mid- and upper-level moisture to the southwest and west of the Florida peninsula on this water vapor satellite image (Fig. 1).

SWFL001-GOES-E-WV-160127-1645Z

Once the front clears the area (and the upper level jet stream moves to the east), skies will clear and temperatures will drop back below seasonal levels…for at least a day or two.

© 2016 H. Michael Mogil

Originally posted 1/27/16

weather

THEWEATHERMOGIL:: Yet more severe weather possible for southwest Florida

It just keeps coming. Earlier this month, an EF-2 tornado struck Cape Coral, FL (near Fort Myers, FL). The storm produced significant damage and injured three during its nearly three and a half mile trek through Lee County. On Fri., Jan. 15, an EF-1 tornado struck parts of Lee County damaging a few buildings and causing sporadic power outages. A few severe storms accompanied this tornado yielding damage to pool cages and other easily airborne outside items.

Then on Jan. 17, 2016, the third such event in roughly a week impacted south and central Florida. First, a tornado touched down near Sarasota, FL. damaging some condos and mobile homes and killing two. Then, within hours, a strong downburst moved across Collier County, FL inflicting widespread tree and fence damage across a 4-mile wide path that extended some 30 miles in length. This event impacted parts of Naples.

And now, the National Weather Service (NWS) has advised that all of south Florida is under the risk of some severe weather and heavy rainfall on Wednesday, possibly extending into Thursday (Fig. 1).

SWFL001-svr-wx-otlk-160126-earlyAM

While the projected impact level is low at this time, today is the day to start monitoring the weather developments more closely. Given that storminess could develop early on Wednesday, be sure to take a final check of the forecast (NWS and/or television) before bedding down tonight…just in case the activity arrives earlier than expected.

© 2016 H. Michael Mogil

Originally posted 1/26/16

weather

THEWEATHERMOGIL:: More stormy times followed by chilly weather for southwest Florida

With a potentially crippling snowstorm/blizzard set to affect the mid-Atlantic states today and Saturday, it would be easy to lose a local focus. However, since I am slated to give a weather talk at the Friends of Barefoot Beach Lecture Series tomorrow (Jan. 23, 2016), keeping atop of local conditions is uber-important.

Let’s face it, the weather this month across Florida has been quite interesting. And the next 36 to 48 hours will keep that trend intact, according to the National Weather Service in Miami, FL (Fig. 1).

SWFL001-weather-impacts-160122-160124

Today, showers and thunderstorms (some storms strong to possibly severe) should move across the area. Winds will be increasing from the south to southeast with gusts up to 30 miles per hour. As dew points rise into the middle 60’s and a very strong upper level stream flies past at some 30,000 feet or so above sea level, conditions continue to move toward a severe storm set up.

Once the storms exit, winds will shift to the northwest and remain gusty in the 25 to 30 mile per hour range over land. Over water areas, winds are expected to reach gale force, even near the store. This will set the stage, yet again, for strong wave action and rip currents along Florida west coast beaches. Local beach erosion and considerable sand transport can be anticipated.

Look for temperatures to tumble across southwest Florida with highs over the weekend only rising into the lower 60’s with overnight lows dropping into the lower and middle 40’s. Inland locations could see some readings in the upper 30’s.

As next week unfolds, temperatures will rise back to near or slightly above seasonal averages.

As for my talk tomorrow, I am nearly 100 percent certain that I will be leading my audience to the beach to look at wind and wave action at work. We should also have ample low-level cloudiness in place which will allow me to explain winds aloft.

My talk starts at 10:00 a.m. E.S.T. at Barefoot Beach Park, entrance off Bonita Beach Road, Bonita Springs, FL (address 503 Bonita Beach Road, North Naples, FL 34134).

© 2016 H. Michael Mogil

Originally posted 1/22/16