Final Exam (Quiz Questions) Flashcards
Tropical Cyclones_______________
Have no frontal systems attached, are warm core low pressure systems that form over subtropical oceans, produce persistent organized thunderstorm activity
What moth has the most hurricane activity in the North Atlantic Ocean
September
Which of the following is NOT a necessary ingredient for tropical cyclone development
Vertical wind shear > 20kt
Warm-core tropical cyclones form over sea-surface temperatures cooler than 26 C
False
The intensity threshold for a major hurricane is ______________
100kt
A major hurricane is defined as a category___________hurricane.
Three, four, and five
Major Hurricanes are responsible for_______ of all damage that occurs
90%
Wind pressure on structures is linear and is directly proportional to the wind speed
False
Tropical Waves are a combination of two wind fields: ________ and ________
Background easterly gradient flow, eddy flow
Since 1970, global tropical cyclone frequency and intensity have been increasing.
False
Which of the following weather systems is NOT a pre-existing disturbance that could trigger tropical cyclone formation:
Upper-level anticyclone
_______ is the most important genesis and intensity modulating factor
Vertical Wind Shear
A typical tropical wave is characterized by _______ located on the ______ of the wave axis
Low-level convergence, rising motion, and thunderstorms; east side
Which of the following parameters does not affect hurricane intensity: _________
Time of year
Which tropical cyclone hazard has the greatest potential to cause large loss of life:
Storm Surge
There have been _____ Cat 5 Hurricane landfalls in the United States
Four
“Storm Surge” is an abnormal rise of water generated by a storm, over and above the predicted astronomical tide, which typically occurs on the _______ side where the winds are blowing __________.
Right, onshore
Which of the following is NOT a significant factor in producing storm surge:
Central Pressure
In general, ______ -moving tropical cyclones tend to produce________ rainfall amounts
Slow; heavy
Relative to a landfalling tropical cyclone’s forward motion, the _______ quadrant is most favorable region for tornado development
Right-front
A hurricane reconnaissance aircraft penetrates the center of a tropical cyclone and measures a peak 850-mb flight-level wind speed of 80kt. The equivalent 1-minute 10-meter wind speed is approximately_____ and this system would be classified as a _________
Land-based weather radars can track the center of tropical cyclones and also provide rainfall information. Moreover, Doppler radars such as the NOAA/National Weather Service WSR-88D radars can also provide velocity data to assess the intensity of tropical cyclones
True
Although súrcate observation platforms/sites are not located at the same elevation above earth’s surface, the data can still be used as is without being adjusted to a standard altitude
False
Hurricane reconnaissance aircraft interrogating tropical cyclones obtain wind data at flight level(s), which are then adjusted down to a near-surface wind speed. In addition to flight-level wind data, dropwindsondes are released in the storm that measure: (a) the average wind speed in the lowest 500 meters (MBL), (b) the average wind speed in the lowest 150 meters (WL150), and (c) a 1-second-surface wind speed. However, the _________ wind data are considered to be the most accurate for determining an equivalent 1-minute 10-meter wind speed.
WL150
Weather satellites are the “first line of defense” for tracking assessing and forecasting tropical cyclones, especially when these storm systems are located over open ocean areas where reconnaissance aircraft data are unavailable for various reasons. Geostationary satellites can observe______ of the tropical regions at a __________ resolution , whereas polar orbiting satellites can observe_______ of the tropical regions at a ______ resolution
All areas, lower, limited areas, higher
The National Hurricane Center uses a _______ wind speed at _______ elevation to indicate the intensity of tropical cyclones.
1-minute average; 10-meters
A tropical cyclone is moving toward the United States, Using the Power Law Equation (below) for the boundary layer winds over the ocean, a 1-minute average wind speed of 100kt (U1) at 4.1 meters elevation is approx equal to a ________ wind speed (U2) at 10 meters elevation
U2=U1(Z2/Z1)^P
90 kts
A device called the Stepped-Frequency Microwave Radiometer (SFMR) onboard Hurricane Hunter reconnaissance aircraft indirectly determines near-surface wind speeds by measuring upwelled microwave radiation emitted by ocean foam that is created by surface winds. These wind data ________ be contaminated/inflated by rainfall.
Can
The Global Surface Observing System/Network ________ sufficient to accurately determine the intensity of tropical cyclones; in addition, the Global Upper-Air Observing Network________ sufficient to accurately determine the intensity of Tropical Cyclones.
Wind Speeds within the frictional boundary layer ________ with increasing altitude ________
Increase; logarithmically
On a non-rotating earth, a global Hadley cell forms as a result of cold air rising over the Poles and warm air sinking over the equator
False
Look at picture in #2 Quiz #3
The image below is a schematic of the northern hemispheric mid- and high-level flow pattern on Earth. Superimposed onto the global-scale, circular background flow pattern are _____________ circulations that produce ________ and ________ circulations that produce __________
Cyclonic eddy, troughs of lower pressure, anticyclonic eddy, troughs of higher pressure
A ______ cell is thermally________ circulation and a ________ cell is a thermally ________ circulation
Hadley, direct, Ferrel, indirect
The Walker Circulation is an east-to-west orientated Hadley Cell near the equator that forms as a result of _______ over the ________ Pacific Ocean and __________ over the __________ Pacific Ocean.
Cold air sinking, eastern, warm air rising, western
During El Niño warm-oceanic episodes in the eastern pacific, the Pacific Ocean Walker Circulation weakens and reverses the normal direction of the wind flow As a result, upper-level winds across the tropical Atlantic Ocean increase from a westerly direction, which acts to increase vertical wind shear and decrease tropical cyclone activity in the Atlantic basin.
True
Tropical waves originate of form over
The Ethiopian highlands
The African Easterly Mid-level Jet (AEMLJ) is a band of strong mid-level winds that blows from _________ and lies between the dry Saharan regions and moist sub-Saharan regions. This meteorological festutre result in the enhancement of tropical waves to the ___________ of the jet
Eats-to west, south
Horizontal cyclonic speed shear located on the southern, or equatorward, side of the Africa Easterly Mid-Level jet can _________ tropical waves after they develop and move ________ away from the Ethiopian Plateau
Strengthen, westward
Q9 Quiz #3
Correctly identify , in numerical order, the three weather features
1- extra tropical low pressure system, 2- tropical wave, 3- Bermuda-Azores high pressure system
Over Africa during the northern-hemisphere summer, the Monsoon Trough Lies to the _______ of the African Easterly Mid-Level Jet and within a ______ air mass
North; dry
For a low pressure system to be classified as a tropical cyclone, it must possess a ________ structure and have persistent __________ convection.
Warm-core, organized
A low pressure system that has a frontal system through the center of the low would be __________ cyclone
An extra tropical
Tropical Cyclones are generally only “warm core” above 925-mb level due to low-level diabetic cooling effects of rain, cool downdrafts, land, and ocean temps
True
Latent Heat released by deep convection that flows inward toward the center is concentrated near the convective comma head where upper-level convergences focuses the warmer and less dense air even more over the surface low, causing pressures to decrease and the tropical cyclone’s winds to increase.
True
The ________ of a hurricane is a thermally __________ circulation, while the ________ is thermally _________ circulation.
Eye, indirect, outer wind field, direct
A unique characteristic of a mature tropical cyclone is the formation of a generally cloud-free ‘eye’ where winds are nearly calm. Surrounding the eye is a ring of __________ called the ________.
Deep convection, eyewall
In a mature hurricane, the eye and eyewall slope __________ with height, producing a _________ effect.
Outward, stadium
Q8&9Quiz #4
Use the tropical cyclone “maximum potential intensity” nomogram below. Given an inflow temp of 25 degC and an outflow temp of -60degC, the minimum pressure that a tropical cyclone could theoretically achieve would be ________mb
960, (inflow for 9 is 30 deg C) = 930
Q10 Quiz #4
Use the tropopause temperature (TT) and the SeaSurface Temp (SST) maps below. Based on the availiable TT and SST data, identify the location where the minimum pressure for a tropical cyclone would theoretically be the lowest
D
The visible and enhanced infrared (EIR) Dvorak Satellite Intensity Estimation Techniques are objective processes that involve no user input
False
The Dvorak Satellite intensity estimation techniques provide a direct measurement of a tropical cyclones wind speed, providing output that is as accurate as surface observational or reconnaissance aircraft wind speed data
False
Of the various Dvorak satellite estimation technique cloud patterns/scene types, the _________ pattern is considered to produce the most reliable intensity estimates.
Eye
The advance Dvorak technique (ADT) utilizes long wave infrared, temperature measurements from geostationary satellites to estimate tropical cyclone (TC) intensity, and is __________ process that requires ___________ user input.
An objective, no
The CIMSS Satellite Consensus (SATCON) product only utilizes tropical cyclone intensity estimates from the ADT and AiDT objective intensity estimation techniques
False
Q7 Quiz#7
Use the enhanced infrared (EIR) curved band pattern shown in Figure A and the Data-T number (DT) scale in Figure B. The log 10 spiral band overlay depicts ________ banding, which yields a DT of __________.
0.60 or 6/10’s, 3
Q8 Quiz #5
Use the enhanced infrared (EIR) shear pattern shown in figure A and the Data T number (DT) scale in Figure B. Relative to the center position, the shear pattern yields a DT of___________.
<3/4 degree or <45 nmi; 2.5
Q9 Quiz#5
Use the Enhanced Infared (EIR) embedded center pattern shown in figure A and the Central Feature number (CF) scale in Figure B. Relative to center position, the embedded center pattern yields a CF and Data T-number (DT) of ___________.
4.5
Q10 Quiz #5
Use the Enhanced Infrared (EIR) Eye pattern shown in figure A and the eye adjustment charts in Figure B. Assume an eye temp of +5 degrees C or Off white (OW) shade. This Eye Pattern produces a Central Feature (CF) and Data T-number (DT) of __________.
6.0
Which of the following is NOT a characteristics of passive microwave satellite imagery:
Provide direct measurements of hurricane-force wind speeds
Although surface observation platforms/instruments are not located at the same elevation above Earth’s surface, the data can still be used as they are without being adjusted to a standard height
False
Wind speeds within the frictional boundary layer ___________ with increasing altitude___________
Increase, logarithmically
Active microwave satellites called scatterometers are essentially radars that transmit microwave pulses down to Earth’s surface, and then measure the power that is returned back to the instrument by small capillary waves moving across the top of larger ocean waves.
True
A device called the Stepped-Frequency Microwave Radiometer (SFMR) onboard Hurricane Hunter reconnaissance aircraft indirectly determines near-surface wind speeds by measuring upwelled microwave radiation emitted by ocean foam that is created by surface winds. These wind data cannot be contaminated or inflated by rainfall
False
Scatterometer-derived surface wind data (ASCAT) are useful for assessing the peak intensity of strong (> or equal to 55 kt) tropical storms and hurricanes, especially if the radius of maximum winds is small (<25 km) due to the ~25km resolution or “footprint”
False
ASCAT-derived wind speed data can be contaminated by “rain splash” and breaking waves, causing a low-speed bias.
False
________ is not a necessary ingredient for tropical cyclone development
Vertical wind shear >30 kt
Major hurricanes are responsible for _______ of all damages that occurs
90%
Wind pressure on structures is _________ proportional to the square of the wind speed (V^2), which means that a _________ change in pressure on structures or objects
Directly, small, large
Tropical waves are a combination of two wind fields; ________ and __________
Background easterly gradient flow; eddy flow
___________ is not a pre existing disturbance that could trigger tropical cyclone formation
Upper-level anticyclone
The most important genesis and intensity modulating parameter is ___________
Vertical Wind Shear (VWS)
A typical tropical wave is characterized by ________ located on the _________ of the wave axis.
Low-level convergence, rising motion, and thunderstorms, east side
Which of the following parameters is NOT a significant factor in producing storm surge
Central Pressure (mb/HPa/ in Hg)
In general, _____ moving tropical cyclones tend to produce ________ rainfall amounts
Slow, heavy
A good estimate for a 24hr rainfall total for a tropical cyclone forecast to move across an area at a forward speed of 20 kts would be ______in
5
Q29 Midterm
Relative to this landfalling tropical cyclone’s motion, location _________ is the most favorable region for tornadoes to occur
A
For a low pressure system to be classified as a tropical cyclone, it must possess a ________ structure and have persisted _________ convection.
Warm inner-core, organized
Q39 Midterm
Consider the two passive microwave satellite images below. The 37 GHz microwave channel represents the _______ of a tropical cyclone and the 85 GHz channel is representative of the ________ of a tropical cyclone.
Low-levels, mid levels
Consider the two passive microwave satellite images below. This is a classic example of the “stadium effect,” where the eye and the eyewall slope ________ with _________ height
Outward, increasing
The Dvorak Satellite Intensity Estimation Technique is an subjective analysis process that requires no user input
False
To a first order approximation, tropical cyclone motion is governed by the conservation of relative vorticity, which means that the TC vortex moves with the large-scale steering flow _________
Like a cork in a stream or river
Changes in the inner core structure of a tropical cyclone play a significant role in a TC’s future track
False
Tropical cyclone (TC) intensity forecasting, similar to track forecasting, requires proper positioning of the center, especially when the only available intensity estimation technique is derived from Dvorak subjective and/or objective (ADT) satellite data.
True
The best way to forecast tropical cyclone intensity is to use the
Consensus of the best performing statistical-dynamic and dynamic intensity models
Power returned (Pr) to a radar is _________ related to the Power Transmitted (Pt) and _______ related to the target range (R^2)
Directly, inversely
Wavelength λ, is a key design consideration for weather radars because ________ wavelength radar signals require a _______ diameter antenna in order for the radar signal to remain concentrated
Long (λ>10 cm), large
Electromagnetic Energy (E-M) emitted by weather radars is ionizing radiation that can adversely affect DNA and other genetic material in your body
False
A _________ wavelength (λ) radar can suffer from precip attenuation, resulting in the displayed intensity of storms appearing to be ______ than their actual intensity. This is a particular problem with aircraft weather-avoidance radars
Short (λ<5 cm), weaker
Power Returned (Pr) to a radar is directly related to the Target Reflectivity (Z). As a result of this physical premise, ________ targets return ______ power compared to ______ targets
Larger, more, smaller
Q6 Quiz #8
Consider the reflectivity image below. Assuming a near-surface standard lapse rate, the altitude of the target(s) at location “A” _______ the altitude of the target(s) at location “B”
Is lower than
Q7 Quiz #8
The radar equivalent reflectivity at location “A” is 30 dBZ which is the same equivalent reflectivity at location “B” Assuming that the dropsize distribution is the same at both locations, the rainfall rate at location “A” would be ___________ the rainfall rate at location “B”.
Identical to
Q8 Quiz #8
The positive velocity value at location “A” indicate target motion _______ the radar site while negative velocity values at location “B” indicate target motion _______ the radar site
Away from; toward
Q9 Quiz#8
The Doppler velocity values at location “C” are -20kt. Based on this information, a forecaster could accurately assume that the actual wind speeds at Location “C” are at least 20 kt
True
Dual-polaraization radars can better determine if the precip particles are rain or hail by comparing the difference between the horizontal power returned and the vertical power returned, which is called Differential Reflectivity or Zdr. This feature of the WSR-88D weather surveillance Doppler radar is helpful in distinguishing between rain and the large water-coated hailstones due to rain drops returning more power and reflectivity in the vertical plane (Zv) than the horizontal plane (Zh)
False
To a first order approximation, the primary factor affecting TC rainfall total is ______
Movement-forward speed
Different precip regimes accompany the seasonal Indian-Asian wind shifts ______ season with _______ flow in the summer and a _______ season with ________ flow in the winter
Rainy, onshore, dry, offshore
One of the four classical criterion for a monsoon, as specified by Ramage (1971), is a shift in the direction of the prevailing winds by at least ________ degrees between January and July
120
A monsoonal wind flow pattern is not a giant Hadley Cell Circulation
False
Q5 Quiz #9
The hemispheric surface flow pattern depicts a typical _______ hemisphere ______ monsoon pattern and a typical ________ hemisphere ________ monsoon pattern
Northern, dry, southern, rainy
Q6 Quiz #9
The hemispheric surface flow pattern depicts a typical ________ hemisphere __________ monsoon pattern and a typical _______ hemisphere ________ monsoon pattern
Northern, rainy, southern, dry
In the western North Pacific basin, there is a tendency during El Niño years for tropical cyclones to be ___________ and ______________ than during La Niña years
More intense, longer lived
A cat 5 hurricane makes landfall along the gulf coast at 10 kt and then moves inland/overland at 5kt. The estimated total max rainfall that can be expected (storm total rainfall = 100/storm motion)
Aprox 20 inches
In the Atlantic Ocean basin, there is a tendency during El Niño years for tropical cyclones to be _________and _________ than during La Niña years
Less intense, shorter lived
The monsoon Trough Patterns over the Western North Pacific, Western South Pacific, Northern Indian, and Southern Indian Ocean basins are not affected El Niño southern oscillation (ENSO) or Madden Julian Oscillation (MJO) events due to the monsoon circulations very large size
False
Unlike homes and businesses located on barrier islands, civilian and military airport complexes near the U.S coastline are not susceptible to storm-surge flooding
False
Tropical cyclones, especially major hurricanes/typhoons do not produce severe turbulence outside of the intense eyewall convection
False
Medicanes are tropical cyclones that develop over the Mediterranean Sea, primarily during the warm and summer season
False
Medicanes are generally smaller than Atlantic subtropical cyclones typically having asymmetric cloud pattern in satellite imagery, and occasionally possess a distinct round eye encircled by atmospheric convection
True
Although medicanes are similar in appearance to tropical and subtropical cyclones they are not capable of producing hurricane force winds due to the surface cyclones forming beneath large upper-level cold low-pressure systems
False
The primary hazard associated with medicanes is
Rain-induced freshwater flooding
