Storms Are Thunderstorms That Produce Tornadoes, Large Hail Or Are Accompanied by High Winds
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A Winter Forecasting Handbook Winter Storm Information That Is Useful to the Public
A Winter Forecasting Handbook Winter storm information that is useful to the public: 1) The time of onset of dangerous winter weather conditions 2) The time that dangerous winter weather conditions will abate 3) The type of winter weather to be expected: a) Snow b) Sleet c) Freezing rain d) Transitions between these three 7) The intensity of the precipitation 8) The total amount of precipitation that will accumulate 9) The temperatures during the storm (particularly if they are dangerously low) 7) The winds and wind chill temperature (particularly if winds cause blizzard conditions where visibility is reduced). 8) The uncertainty in the forecast. Some problems facing meteorologists: Winter precipitation occurs on the mesoscale The type and intensity of winter precipitation varies over short distances. Forecast products are not well tailored to winter Subtle features, such as variations in the wet bulb temperature, orography, urban heat islands, warm layers aloft, dry layers, small variations in cyclone track, surface temperature, and others all can influence the severity and character of a winter storm event. FORECASTING WINTER WEATHER Important factors: 1. Forcing a) Frontal forcing (at surface and aloft) b) Jetstream forcing c) Location where forcing will occur 2. Quantitative precipitation forecasts from models 3. Thermal structure where forcing and precipitation are expected 4. Moisture distribution in region where forcing and precipitation are expected. 5. Consideration of microphysical processes Forecasting winter precipitation in 0-48 hour time range: You must have a good understanding of the current state of the Atmosphere BEFORE you try to forecast a future state! 1. Examine current data to identify positions of cyclones and anticyclones and the location and types of fronts. -
January — March Year 2017
VOL 2 ISSUE 01 JANUARY — MARCH YEAR 2017 2016/17 DRY SEASON SUMMARY Dominica's dry season officially runs from December to May each year. The 2016 wet season, which prolonged into December resulting in a delay to the start of the 2016/17 dry season, was recorded as a normal season as it relates to rainfall amounts. A weak La Niña (the cooling of the Eastern Equatorial Pacific Ocean) was observed towards the end of 2016 and a transition to ENSO– neutral is expected during the period January to March 2017. La Niña tends to shift rainfall chances for January-February-March 2017 to above to normal in the southern-most is- lands of the Caribbean. With this occurrence, above to normal rainfall amounts are expected, resulting in less solar radiation and more cooling by clouds and more rainfall than last year. Temperatures are also expected to be closer to normal. IN THIS ISSUE Pg.1 2016/17 Dry-Season Dominica’s Climate Pg.2 Looking back at 2016 Pg.3 2016 Hurricane Season Looking ahead Pg.4 Seasonal Forecast Chart 1. Mid-December ENSO prediction plume DOMINICA’S CLIMATE Rainfall received during the dry season are usually generated by the annual migration of the North Atlantic Subtropical High, low level clouds which move with the easterly trade winds, southward dipping frontal boundaries and trough sys- tems. The dry season runs from December to May when the seas are cooler and thunderstorms and rainfall activity are relatively low. On average approximately 40% of the annual rainfall is recorded in elevated and eastern areas and ap- proximately 25% along the western coast. -
Subtropical Storms in the South Atlantic Basin and Their Correlation with Australian East-Coast Cyclones
2B.5 SUBTROPICAL STORMS IN THE SOUTH ATLANTIC BASIN AND THEIR CORRELATION WITH AUSTRALIAN EAST-COAST CYCLONES Aviva J. Braun* The Pennsylvania State University, University Park, Pennsylvania 1. INTRODUCTION With the exception of warmer SST in the Tasman Sea region (0°−60°S, 25°E−170°W), the climate associated with South Atlantic ST In March 2004, a subtropical storm formed off is very similar to that associated with the coast of Brazil leading to the formation of Australian east-coast cyclones (ECC). A Hurricane Catarina. This was the first coastal mountain range lies along the east documented hurricane to ever occur in the coast of each continent: the Great Dividing South Atlantic basin. It is also the storm that Range in Australia (Fig. 1) and the Serra da has made us reconsider why tropical storms Mantiqueira in the Brazilian Highlands (Fig. 2). (TS) have never been observed in this basin The East Australia Current transports warm, although they regularly form in every other tropical water poleward in the Tasman Sea tropical ocean basin. In fact, every other basin predominantly through transient warm eddies in the world regularly sees tropical storms (Holland et al. 1987), providing a zonal except the South Atlantic. So why is the South temperature gradient important to creating a Atlantic so different? The latitudes in which TS baroclinic environment essential for ST would normally form is subject to 850-200 hPa formation. climatological shears that are far too strong for pure tropical storms (Pezza and Simmonds 2. METHODOLOGY 2006). However, subtropical storms (ST), as defined by Guishard (2006), can form in such a. -
Weather Review and Outlook Towering Cumulus- Danny Gregoria by David Ross and Rob Molleda
Winter 2013 Welcome to this edition of Tropical Winds. Another hurricane season to be thankful for In This Issue… (…unless you are a hurricane junkie…). In Weather Review…………….….1 this edition, we will discuss what occurred Severe Weather Climo………...….7 during this year’s wet season and what to Hurricane Season 2013……………9 expect for the dry season. Also, we will talk about tornado climatology across South Employee Spotlight……………12 Florida. A look back at the 2013 Atlantic hurricane season will follow. To finish on a happy note, we will introduce you to another one of our devoted forecasters, Chris Duke. Happy Holidays!!! Weather Review and Outlook Towering Cumulus- Danny Gregoria By David Ross and Rob Molleda Looking Back at the Rainy Season May – October 2013 Synopsis The recently-concluded rainy season was wetter than normal across most of South Florida. It was very wet over most of southwest Florida where rainfall totals for the period from May 18th to October 10th (the duration of this year’s wet season) were in the 40 to 50 inch range, with a few spots exceeding 50 inches (Figure 1). This almost equals a year’s worth of rain in less than five months! Isolated spots in southeast Florida also recorded over 50 inches of rain, with most of this area receiving between 35 and 45 inches. Every month of the rainy season featured above normal rainfall over different parts of south Florida, with July being the wettest month overall due to a more widespread rainfall coverage, and August being the driest mostly across the eastern half of the peninsula (Figure 2). -
The Influences of the North Atlantic Subtropical High and the African Easterly Jet on Hurricane Tracks During Strong and Weak Seasons
Meteorology Senior Theses Undergraduate Theses and Capstone Projects 2018 The nflueI nces of the North Atlantic Subtropical High and the African Easterly Jet on Hurricane Tracks During Strong and Weak Seasons Hannah Messier Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/mteor_stheses Part of the Meteorology Commons Recommended Citation Messier, Hannah, "The nflueI nces of the North Atlantic Subtropical High and the African Easterly Jet on Hurricane Tracks During Strong and Weak Seasons" (2018). Meteorology Senior Theses. 40. https://lib.dr.iastate.edu/mteor_stheses/40 This Dissertation/Thesis is brought to you for free and open access by the Undergraduate Theses and Capstone Projects at Iowa State University Digital Repository. It has been accepted for inclusion in Meteorology Senior Theses by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. The Influences of the North Atlantic Subtropical High and the African Easterly Jet on Hurricane Tracks During Strong and Weak Seasons Hannah Messier Department of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa Alex Gonzalez — Mentor Department of Geological and Atmospheric Sciences, Iowa State University, Ames Iowa Joshua J. Alland — Mentor Department of Atmospheric and Environmental Sciences, University at Albany, State University of New York, Albany, New York ABSTRACT The summertime behavior of the North Atlantic Subtropical High (NASH), African Easterly Jet (AEJ), and the Saharan Air Layer (SAL) can provide clues about key physical aspects of a particular hurricane season. More accurate tropical weather forecasts are imperative to those living in coastal areas around the United States to prevent loss of life and property. -
Earth Observing System Data and Information System (EOSDIS)
Importance and Incorporation of User Feedback in Data Stewardship Hampapuram Ramapriyan1,2 and Jeanne Behnke1 1Goddard Space Flight Center, 2Science Systems and Applications, Inc. Presented at SciDataCon 2018, Gaborone, Botswana, Nov. 5-8, 2018 1 Introduction Data stewardship - A long-term responsibility Long-lived systems must evolve On-Going user feedback is critical for understanding needs and evolving as needs change We illustrate this through NASA’s Earth Observing System Data and Information System (EOSDIS) 2 NASA’s Earth Observing System Data and Information System (EOSDIS) • Managed by NASA’s Earth Science Data and Information System (ESDIS) Project • Implements NASA’s free and open data policy in effect since early 1990s • Provides end-to-end capabilities for managing NASA’s Earth science data. Science Operations Science data processing Data management Interoperable distributed data archives On-line data access services Earth science discipline-oriented user services 3 Missions, Datasets and Disciplines Started in the 1990s, EOSDIS today archives and distributes over 11,000 data types • Atmosphere » Winds & Precipitation » Aerosols & Clouds » Temperature & Humidity » Solar radiation • Ocean » Surface temperature » Surface wind fields & Heat flux » Surface topography • Land • Human Dimensions » Ocean color » Cover & Usage » Population & Land Use • Cryosphere » Soil Moisture » Human & Environmental » Sea/Land Ice & Snow » Topography & elevation Health Cover » Temperature Distributed Active Archive Centers (DAACs) Alaska Satellite -
Lecture 15 Hurricane Structure
MET 200 Lecture 15 Hurricanes Last Lecture: Atmospheric Optics Structure and Climatology The amazing variety of optical phenomena observed in the atmosphere can be explained by four physical mechanisms. • What is the structure or anatomy of a hurricane? • How to build a hurricane? - hurricane energy • Hurricane climatology - when and where Hurricane Katrina • Scattering • Reflection • Refraction • Diffraction 1 2 Colorado Flood Damage Hurricanes: Useful Websites http://www.wunderground.com/hurricane/ http://www.nrlmry.navy.mil/tc_pages/tc_home.html http://tropic.ssec.wisc.edu http://www.nhc.noaa.gov Hurricane Alberto Hurricanes are much broader than they are tall. 3 4 Hurricane Raymond Hurricane Raymond 5 6 Hurricane Raymond Hurricane Raymond 7 8 Hurricane Raymond: wind shear Typhoon Francisco 9 10 Typhoon Francisco Typhoon Francisco 11 12 Typhoon Francisco Typhoon Francisco 13 14 Typhoon Lekima Typhoon Lekima 15 16 Typhoon Lekima Hurricane Priscilla 17 18 Hurricane Priscilla Hurricanes are Tropical Cyclones Hurricanes are a member of a family of cyclones called Tropical Cyclones. West of the dateline these storms are called Typhoons. In India and Australia they are called simply Cyclones. 19 20 Hurricane Isaac: August 2012 Characteristics of Tropical Cyclones • Low pressure systems that don’t have fronts • Cyclonic winds (counter clockwise in Northern Hemisphere) • Anticyclonic outflow (clockwise in NH) at upper levels • Warm at their center or core • Wind speeds decrease with height • Symmetric structure about clear "eye" • Latent heat from condensation in clouds primary energy source • Form over warm tropical and subtropical oceans NASA VIIRS Day-Night Band 21 22 • Differences between hurricanes and midlatitude storms: Differences between hurricanes and midlatitude storms: – energy source (latent heat vs temperature gradients) - Winter storms have cold and warm fronts (asymmetric). -
What Are We Doing with (Or To) the F-Scale?
5.6 What Are We Doing with (or to) the F-Scale? Daniel McCarthy, Joseph Schaefer and Roger Edwards NOAA/NWS Storm Prediction Center Norman, OK 1. Introduction Dr. T. Theodore Fujita developed the F- Scale, or Fujita Scale, in 1971 to provide a way to compare mesoscale windstorms by estimating the wind speed in hurricanes or tornadoes through an evaluation of the observed damage (Fujita 1971). Fujita grouped wind damage into six categories of increasing devastation (F0 through F5). Then for each damage class, he estimated the wind speed range capable of causing the damage. When deriving the scale, Fujita cunningly bridged the speeds between the Beaufort Scale (Huler 2005) used to estimate wind speeds through hurricane intensity and the Mach scale for near sonic speed winds. Fujita developed the following equation to estimate the wind speed associated with the damage produced by a tornado: Figure 1: Fujita's plot of how the F-Scale V = 14.1(F+2)3/2 connects with the Beaufort Scale and Mach number. From Fujita’s SMRP No. 91, 1971. where V is the speed in miles per hour, and F is the F-category of the damage. This Amazingly, the University of Oklahoma equation led to the graph devised by Fujita Doppler-On-Wheels measured up to 318 in Figure 1. mph flow some tens of meters above the ground in this tornado (Burgess et. al, 2002). Fujita and his staff used this scale to map out and analyze 148 tornadoes in the Super 2. Early Applications Tornado Outbreak of 3-4 April 1974. -
Storm Data and Unusual Weather Phenomena ....…….…....……………
MAY 2006 VOLUME 48 NUMBER 5 SSTORMTORM DDATAATA AND UNUSUAL WEATHER PHENOMENA WITH LATE REPORTS AND CORRECTIONS NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION noaa NATIONAL ENVIRONMENTAL SATELLITE, DATA AND INFORMATION SERVICE NATIONAL CLIMATIC DATA CENTER, ASHEVILLE, NC Cover: Baseball-to-softball sized hail fell from a supercell just east of Seminole in Gaines County, Texas on May 5, 2006. The supercell also produced 5 tornadoes (4 F0’s 1 F2). No deaths or injuries were reported due to the hail or tornadoes. (Photo courtesy: Matt Jacobs.) TABLE OF CONTENTS Page Outstanding Storm of the Month …..…………….….........……..…………..…….…..…..... 4 Storm Data and Unusual Weather Phenomena ....…….…....……………...........…............ 5 Additions/Corrections.......................................................................................................................... 406 Reference Notes .............……...........................……….........…..……........................................... 427 STORM DATA (ISSN 0039-1972) National Climatic Data Center Editor: William Angel Assistant Editors: Stuart Hinson and Rhonda Herndon STORM DATA is prepared, and distributed by the National Climatic Data Center (NCDC), National Environmental Satellite, Data and Information Service (NESDIS), National Oceanic and Atmospheric Administration (NOAA). The Storm Data and Unusual Weather Phenomena narratives and Hurricane/Tropical Storm summaries are prepared by the National Weather Service. Monthly and annual statistics and summaries of tornado and lightning events -
Probable Maximum Precipitation Estimates, United States East of the 105Th Meridian
HYDROMETEOROLOGICAL REPORT 'N0.53 L D ..... 'C..,p "\ ..u o tM/ 'A1 ws/t.d/M 'b !>"'"'"' , , 1 1 ~, 5 E.~..~t:-west J/.,e; h~ s,J~ ..s, .... ~ ,41'b ~·qto Seasonal Variation of 10-Square-Mile Probable Maximum Precipitation Estimates, United States East of the 105th Meridian ,_ U.S. DEPARTMENT OF COMMERCE, , -- NATIONAL OCEANIC AND ATMOS~HERIC ADMINISI'RATION U.S. NUCLEAR REGULATORY COMMISSION - , - Silver Spnng, Md , , Apn11980 U.S. Department of Commerce U.S. Nuclear Regulatory National Oceanic and Atmospheric Commission Administration NUREG/CR-1486 Hydrometeorological Report No. 53 SEASONAL VARIATION OF 10-SQUARE-MILE PROBABLE MAXIMUM PRECIPITATION ESTIMATES) UNITED STATES EAST OF THE 105TH MERIDIAN Prepared by Francis P. Ho and John T. Riedel Hydrometeorological Branch Office of Hydrology National Weather Service Washington, D.C. April 1980 TABLE OF CONTENTS Page Abstract. 1 1. Introduction . 1 1.1 Authorization. 1 1.2 Purpose. 1 1.3 Scope ••... 1 1.4 Definitions .. 2 1.5 Previous study 2 2. Basic data . 2 2.1 Background • • • • • . 2 2.2 Available station rainfall data •• 3 2.2.1 Storm rainfall • • • • • 3 2.2.2 Maximum 1-day or 24-hour values, each month ••••••• 3 2.2.3 Maximum 6-, 12- and 24-hr values, each month . 3 2.2.4 11aximum recorded rainfall at first-order stations. 3 2.2.5 Data tapes, selected stations. 3 2.2.6 Data tapes, 1948-73 •. 5 2.2.7 Canadian data. 5 3. Approach to PMP. • ••. 5 3.1 Summary. 5 3.2 Selected major storm values •. 5 3.3 Moisture maximization. -
The Population Bias of Severe Weather Reports West of the Continental Divide
THE POPULATION BIAS OF SEVERE WEATHER REPORTS WEST OF THE CONTINENTAL DIVIDE Paul Frisbie NOAAlNational Weather Service Weather Forecast Office Grand Junction, Colorado Abstract and had 'significant consequences. Lightning from thun derstorms that afternoon sparked the Marble Cone fire Many severe storms in the West may go unreported or (several miles south of Camp Pico Blanco) that burned unobserved, and therefore, the severe weather climatology 177,866 acres - the third largest wildfire in California's is not fully understood. However, as the population has history (California Department of Forestry and Fire increased in the West, so has the number of severe weath Protection 2004). er reports. To check if a population bias exists, correlation The aforementioned cases illustrate the challenges of coefficients are calculated with respect to population for establishing a relevant severe weather climatology for tornadic and nontornadic severe storm activity. The sam the western US. Since no one knows how many severe ple size for tornadic storms is too small to draw any con storms go unreported or unobserved, there is uncertainty clusion. To calculate the correlation coefficients for non regarding the number of severe storms that actually do tornadic severe storms, population and severe weather occur. People have been gradually moving into areas that data are used for every county in each western state were once unpopulated, and are now observing severe between the years 1986-1995 and 1996-2004. The calcu storms that would not have been observed beforehand. To lated correlation coefficients reveal that population and provide a better understanding of how often severe the number ofnontornadic severe storms are significantly weather occurs, trends for tornadic and nontornadic correlated which indicates that a population bias does severe storms will be examined. -
ESSENTIALS of METEOROLOGY (7Th Ed.) GLOSSARY
ESSENTIALS OF METEOROLOGY (7th ed.) GLOSSARY Chapter 1 Aerosols Tiny suspended solid particles (dust, smoke, etc.) or liquid droplets that enter the atmosphere from either natural or human (anthropogenic) sources, such as the burning of fossil fuels. Sulfur-containing fossil fuels, such as coal, produce sulfate aerosols. Air density The ratio of the mass of a substance to the volume occupied by it. Air density is usually expressed as g/cm3 or kg/m3. Also See Density. Air pressure The pressure exerted by the mass of air above a given point, usually expressed in millibars (mb), inches of (atmospheric mercury (Hg) or in hectopascals (hPa). pressure) Atmosphere The envelope of gases that surround a planet and are held to it by the planet's gravitational attraction. The earth's atmosphere is mainly nitrogen and oxygen. Carbon dioxide (CO2) A colorless, odorless gas whose concentration is about 0.039 percent (390 ppm) in a volume of air near sea level. It is a selective absorber of infrared radiation and, consequently, it is important in the earth's atmospheric greenhouse effect. Solid CO2 is called dry ice. Climate The accumulation of daily and seasonal weather events over a long period of time. Front The transition zone between two distinct air masses. Hurricane A tropical cyclone having winds in excess of 64 knots (74 mi/hr). Ionosphere An electrified region of the upper atmosphere where fairly large concentrations of ions and free electrons exist. Lapse rate The rate at which an atmospheric variable (usually temperature) decreases with height. (See Environmental lapse rate.) Mesosphere The atmospheric layer between the stratosphere and the thermosphere.