Track & Intensity Forecasting

Question 1

Tropical Cyclone Motion

Answer 1

“A cork in a stream”

Question 2

Problem with Tropical Cyclone Motion

Answer 2

The “Stream Flow” or steering currents are not static, they are dynamic or always changing

Question 3

To a first- order approximation TC motion is governed by

Answer 3

Conservation of relative vorticity

Question 4

How does the vortex move

Answer 4

With the large-scale steering flow

Question 5

If a circulation has positive absolute angular momentum and it converges or contracts (diverges or expands) the it________ (slower) in the __________(negative)_________, and it will _______(lose) __________ absolute_______.

Answer 5

Must spin faster, positive, direction, gain, cyclonic, vorticity

Question 6

Do changes in TC inner-core structure have any influence on the future track?

Answer 6

No there’s little influence

Question 7

The Beta Effect or Beta Drift……..

Answer 7

Induces steering of 2-4 kt to the northwest

Question 8

The circulation of a TC, combined with the North-South variation of the Coriolis parameter, induces asymmetries know as Beta Gyres. These Beta Gyres produce a net steering current across the TC generally toward the northwest at a few knots

Answer 8

Beta Drift or Beta Effect

Question 9

Climatology and Persistence Model (CLIPER)

Answer 9

No longer provides useful operational guidance, but is used as a benchmark for other models and the official forecast. If a model has a lower mean errors than CLIPER it is said to be ‘skillful’

Question 10

The Beta and Advection Model (BAM): A class of simple _______ that utilize vertically averaged horizontal winds from the GFS to compute TC Trajectories. These trajectories include a ________ to account for the _____ of the earth’s __________(beta advection)

Answer 10

Trajectory models, correction term, impact

Question 11

BAM medium or BAMM/TABM (840-400 mb)

Answer 11

Default track model in the SHIPS intensity forecast model

Question 12

Global Models have _______________ to define the TC ___________ (eye and eye wall structure)
(Inner-core changes have virtually no effect on track)

Answer 12

Inadequate resolution, inner core

Question 13

Global models have no ___________conditions an therefore should have better ________ at longer ranges than the limites-area models

Answer 13

Lateral boundary, performance

Question 14

Limited-Area (Regional) models performance _________ at ________ ranges

Answer 14

Degrades, longer

Question 15

There is a ________ difference between _________ and __________ forecasts

Answer 15

HUGE, landfall, non-landfall

Question 16

The 2022 hurricane season was _____ than _____ to forecast at 96 and 120 h due ro the 2022 CLIPER5 errors being ________ than ______

Answer 16

Easier, average, lower, average

Question 17

Since 2016, NHC track forecast track errors……..

Answer 17

Have not changed

Question 18

Since 2016, NHC track forecast skill has basically

Answer 18

Not changed

Question 19

The ______(weaker) the TC, the ______ (worse) are NHC’s track forecasts at _____________

Answer 19

Stronger, better, all forecast times

Question 20

Often the _________ models are __________ formed from an ensemble of good performing _________ models

Answer 20

Most successful, consensus aids, individual

Question 21

Dynamical model consensus is an excellent……

Answer 21

First guess

Question 22

Continuity dictates that it must be considered in…….

Answer 22

The view of previous official forecasts

Question 23

Try to asses what so that you can understand and perhaps evaluate the model solutions?

Answer 23

Steering influences

Question 24

Compare the models’ ________ of the environments features, not just the __________

Answer 24

Forecast, TC tracks

Question 25

Evaluate the _________ of the ____ in the model fields. Unrealistic TC can affect the ______ of a successful forecast.

Answer 25

Initialization, TC, likelihood

Question 26

Spread of ______ can dictate forecaster ________

Answer 26

Models, confidence

Question 27

Sometimes the forecaster might want to exclude certain models from a “selective consensus”……. If _________ amoung the models can be ________

Answer 27

Discrepancies, resolved

Question 28

Previous official forecast exerts a strong _______ on the current forecast

Answer 28

Constraint

Question 29

NO_________(1)

Answer 29

Windshield Wipering

Question 30

NO…..(2)

Answer 30

Tromboning

Question 31

‘Smart’ models have to _______ during the course of a new seasons and, thus, can be _________early

Answer 31

Re-learn, unreliable

Question 32

Accurate estimate of ________ and _____ is extremely important

Answer 32

Initial location, motion

Question 33

TC forecasters ________ and _________ these wobbles in order to mitigate large track forecasts errors

Answer 33

Must anticipate, smooth through

Question 34

Initial motion estimates should ____ reflect ______ track wobbles that will not persist

Answer 34

Not, short-term

Question 35

NHC philosophy is that it is better to ___ events a little bit than to be going ________ with analyses of forecasts

Answer 35

Lag, back and forth

Question 36

Intensity Output initial conditions: tropopause:

Answer 36

-70 deg C

Question 37

Minimum attainable surface pressure (mb) as a function of surface air temp (Ts) and weighted mean outflow temperature (Tout) assuming ambient surface pressure of 1015 mb, ambient surface RH of 80% 20 deg latitude, outer radius of 500 km and __________

Answer 37

No vertical wind shear

Question 38

The _____ the ______ temperature and the ____ the surface _______ temperature the _________ a hurricane can become

Answer 38

Colder, outflow, warmer, inflow, more intense

Question 39

We can only sample a _____ of the TC each observation has strengths and weaknesses we want a value that is __________ of the TC’s mean circulation

Answer 39

Part, representative

Question 40

Always weigh the more accurate _______ data over remotely sensed data

Answer 40

In situ

Question 41

Sea Surface Temperatures: _______(cool) SSTs generally produce _______(weaker) hurricanes

Answer 41

Warm, stronger

Question 42

Ocean Heat Content: the greater the depth, more available heat can be potentially converted to energy and also_________

Answer 42

Prevent cold upwelling

Question 43

_______ in the low-levels results in a ________ and ________

Answer 43

Drier Air, Higher LCL, Higher LFC

Question 44

If lifting mechanism is weak, then low-level air parcels may not reach the LFC and release the conditional instability resulting in ___________

Answer 44

No deep convection

Question 45

Tropical cyclone intensity change can be caused by inner-core processes such as

Answer 45

Eyewall replacement cycles (ERC) or concentric eyewalls

Question 46

In major hurricanes, we often see an _________ eye wall occur at larger distances from the center than the radius of the original eye wall

Answer 46

Outer concentric

Question 47

The occurrence of ERC’s appears to be at least partly related to the _______ and _______(RMW)

Answer 47

Hurricane’s intensity, radius of maximum winds

Question 48

The more intense hurricane and smaller the RMW, the more likely that an ERC will occur; this is due to ________ winds in the ________ flowing ______

Answer 48

Supergradient, inner eye wall, outward

Question 49

When this outer eye wall becomes ________, weakening ________ occurs

Answer 49

Dominant, invariably

Question 50

Winds weaken over land due to lack of………

Answer 50

Latent heat and increased friction

Question 51

Terrain and Higher Elevations: These wind speeds are not considered to be

Answer 51

Representative of a TC’s actual tangential winds

Question 52

SHIPS forecasts are _______ to interpret

Answer 52

Easier

Question 53

Experimental tests using GOES lightning in the _________ in RII show improved skill

Answer 53

Inner-core region

Question 54

Lightning is a _____ for ____ strength owing to lightning generation mechanisms

Answer 54

Proxy, updrafts

Question 55

Problems with representation of shear; regional models such as HWRF, HMON, HAFS-A/-B models are

Answer 55

To shear resistant

Question 56

Dynamic models are more _______ for basin-wide ______ forecasts

Answer 56

Skillful, intensity

Question 57

Statistical methods more _______ skillful for identifying ________

Answer 57

Generally, RI cases

Question 58

Extreme events are almost

Answer 58

Never forecasted