Omega block expected across western North America… (H. Michael Mogil, CCM, CBM, DMS)

H. Michael Mogil September 19, 2016

Computer models keep suggesting the development of an “omega block” across western Canada by late this week. Such a block can involve a splitting of the overall upper level wind flow by a closed high to the north and a closed low to its south (Fig. 1). Alternatively, the pattern can involve a closed high sandwiched to its west and east by two closed lows. These situations split the flow (even if strong winds are involved), resulting in a slow-moving to stationary upper level pattern in the region of the block. “Omega blocks” are so-named because the northern part of the block resembles the Greek letter, Omega – Ω.

Although such “blocks” often persist for relatively long time periods (due to the aforementioned slow movement and blocking of the overall flow pattern), this particular system will break down by the early to middle part of next week as a deeper trough develops across the eastern U.S.

Originally posted 9/19/16

Tags: 3.14, 99L, AC, AccuWeather, ACE, ACT, advisory, Africa, agriculture, Air Force, air mass, air quality, aircraft, airline, airport, Alabama, Alaska, algal bloom, altitude, altocumulus, answer, Antarctica, anti-crepuscular rays, app, Apple, application, arctic, Arizona, Arkansas, ASD, ashcloud, Atlanta, Atlantic, Atlantic Ocean, autism, autumn, average, aviation, awareness, Bachmann, Bahamas, balloon, Barra, beach, beacherosion, Bermuda, BF, Big Bend, bing, biology, biomes, birds, Black Friday, blizzard, blocking, bomb, Bonita Springs, Boston, Bow, bow echo, brain, Broward, Buffalo, Business, California, calorie, Canada, Candy Crush, canyon, Cape Cod, Cape Verde, CapitalOne, car, Caribbean, Carolinas, Carson, cash back, CAT 1, CAT 5, CategoryFive, CategoryOne, Central Plains, Central U.S., Charlotte, check, checking, Chicago, chill, chilly, Christmas, Christmas Star, circles, cirrus, climate, climate change, climate zones, climatology, cloud, clouds, Coast, coastal flooding, COCORAHS, cold, cold front, college testing, Collier, Collier County, color-blindness, Colorado, Common Core, communication, computer, conjunction, contractor, convection, converge, convergence, cool, cooling degree days, Coronavirus, coverage, covid-19, covid19, credit, creditcards, crepuscular, crepuscular rays, crime, Cristobal, critic, CS/HB 7069, cumulonimbus, cumulus, current, Customer, customer service, cyclone, Dakotas, Darby, data, date, debate, deep south, degree days, Denver, deposition, Des Moines, desert, dew, Dew point, dewpoint, diameter, donut, Doppler radar, Dorian, Dothan, downburst, downdraft, downslope, drought, Dry, dry line, Drying, Dunkin’ Donuts, dust, e-mail, Earth, east, east coast, Eastern Pacific, Eastern Pacific Ocean, eastern US, eddy, Education, Emily, England, enhanced imagery, entrepreneur, equation, erosion, Eta, Europe, evacuation, evaporate, evaporative, eye, eye wall, fall streaks, family, fat, Federal, filters, fire, fire weather, fires, first responders, fish, FL, flash flood, flash flooding, flood, flooding, Florida, FLWX, focal point, fog, folder, folklore, forest fires, Fort Myers, freeze, freezing rain, frequent flyer, front, Frost, Ft. Myers, funnel, funnel cloud, gale, gale warnings, gales, game, garden, garden hose, Gaston, gauge, George Clooney, Georgia, geostationary, GLM, global warming, GM, gmail, GOES, GOES-16, GOES-R, GOESR, google, Gore, government, gradient, Great Lakes, Great Salt Lake, Greenhouse gas, ground fog, Groundhog, grushfire, Guadalupe Mountains, Guadalupe Peak, Gulf Coast, Gulf of Mexico, gust, gusts, hail, hair, Haiti, Harvey, Hawaii, Hawking, health, heat, heating degree days, heavy rain, heavy rainfall, heavy snow, hemisphere, Hendry, Hermine, High, High Plains, high surf, high temperature, high wind warnings, high-pressure, home, homework, Honolulu, hose, Houston, humid, humidity, hurricane, hurricane hunter aircraft, Hurricane Matthew, hurricanes, I75, Ian, ice, ice cap, ice storm, Illinois, image, images, inch, India, Indiana, Indianapolis, infrared, instability, Insurance, Intermountain, IOS, IOS 7, Iowa, iphone, IR, Ireland, Irma, IRS, isothermal layer, Jamaica, Japan, jet stream, Jupiter, Kansas, Karen, kitchen, koppen, Krispy Kreme, lake, lake effect, Lake Erie, Lake Ontario, Lake Tahoe, lake-effect snow, latitude, law, LD, learn, learning, Lee, Lee County, life, lift, Lightning, lightning detection, logic, Long Island, longshore current, Louisiana, low, low temperature, low-pressure, low-pressure system, low-pressure systems, lows, luggage, Macy's, mail, Maine, mall, Marco Island, Mars, Maryland, Massachusetts, math, Mathworks, Matthew, Maui, MCC, MCS, media, Memorial Day, mentor, mentoring, meso-cyclone, mesocyclone, mesoscale, Mesoscale Convective System, meteorological bomb, meteorologist, meteorology, Mexico, Miami, Michigan, microns, mid-atlantic, Midwest, military, Minneapolis, Minnesota, Mississippi, Mississippi River valley, Mississippi Valley, misture, mixing, models, moisture, monsoon, Montague, Montana, moods, moon, mountain, mountains, movie, Naples, NASA, Nate, National Climatic Data Center, National Hurricane Center, natural world, nature, Nebraska, Nevada, New England, New Jersey, New Mexico, New York, news, Newton, NHC, NOAA, nor’easter, North Carolina, Northeast, northern, northern hemisphere, Northern Plains, number, numbers, NWS, Oahu, Obamacare, observation, observations, observe, observer, Ohio, Ohio Valley, Okeechobee, Oklahoma, omega, omega block, omega high, online, Ophelia, order, organize, organizing, OS, outbreak, outflow, outflow boundaries, outflow boundary, outlook, Pacific Northwest, Palm Beach, Panhandle, paper, parade, parent, pattern, patterns, Pavlof, pedometer, Pennsylvania, Philadelphia, photographs, photography, Pi, PiDay, Plains, polar, polar vortex, political, ponding, precipitable water, precipitation, preparedness, pressure, pressure gradient, primary, problem, Puerto Rico, Punxsutawney Phil, question, radar, radiosonde, radius, rain, Rain shadow, rainbow, rainbows, raindrop, raindrops, rainfall, rainshadow, rainy, record, records, Red Flag Warnings, red tide, responsibility, review, reward, rewards, Rhode Island, ridge, ridges, rip current, ripple, risk, Rockies, Rocky Mountains, RSW Airport, Russia, safety, Saffir-Simpson, San Diego, San Francisco, Sandy, Santa Ana, SAT, satellite, Saturn, scandal, school, science, Scotland, SDO, sea breeze, sea surface temperature, seabreeze, seas, Season, seasonal, seasons, service, severe, severe thunderstorms, severe weather, shadow, Shinseki, shower, showers, shutdown, Sidewalk, Sierra Nevada, Sky, sky awareness, sky awareness week, sky optics, sky watching, sleet, small craft advisory, smoke, snow, snow removal, snowfall, Snowstorm, social, sounding, south, South Carolina, South Dakota, Southeast, Southeast U.S., southern Plains, southwest, southwest Florida, space, space weather, Spaghetti plot, SPC, spiders, spiral bands, spirals, spotters, spring, St. Cloud, Starbucks, statistics, Steps, StevenHawking, stock, storm, storm damage, storm surge, storm warnings, storms, Stormsurge, STRIIV, structural current, student, students, study, sub-freezing, sublimation, subsidence, summer, summer camp, summer camps, sun, sun dog, sunset, sunspot, Super Tuesday, supercells, supercomputer, surge, SW Florida, Swells, Tampa, technology, teen, temperature, Tennessee, Tennessee River Valley, Tennessee Valley, test, test-taking, tests, Texas, thanksgiving, The Perfect Storm, The Weather Channel, think, thinking, thundersnow, thunderstorm, thunderstorms, tides, time, tornado, tornado warnings, tornado watches, tornadoes, train, training, transportation, travel, tropic, tropical, tropical cyclone, tropical storm, tropical storms, tropical wave, tropical weather, tropicalstorm, tropics, troughs, Tug Hill Plateau, tutoring, twas, TWC, twilight, typhoon, U.K., U.S., UK, unenhanced imagery, updraft, Upper level, upper low, Upper winds, upper-level winds, US, Utah, vacation, vegetation, Venus, veteran, virga, Virginia, virtual, virus, visibility, visible, vocabulary, volcano, vortex, voting, Waikiki, walk, warm, warmth, warning, warnings, warranty, Washington DC, watch, watches, water, water cycle, water vapor, waterspout, Watertown, wave, waves, weather, weather camp, WeatherNation, west, West Coast, West Virginia, Wet-bulb effect, wildfire, wind, wind chill, wind shear, winds, windy, winter, winter storm, Wipha, Wisconsin, word, work, WRN, WV, Wyoming, Yucatan Peninsula,