1. Forecast Verification time!?

2. 77 N

3. 77 3 N

4. VERIFICATION 77 3 N 1
SPC

5. WHAT IS CLIMATOLOGY ? How the weather behaves over
a long period of time.
Weather – Behavior of the atmospheric over a much shorter
period of time

6. NORMAL? CLIMATOLOGY 81 TEMPS Avg./mean: Median: Range: 82 90 - 68
30 year period - common 81
NORMAL?
TEMPS
Avg./mean:
Conforming to a
regular pattern;
typical
Median:
Range: 82
Std. dev. 7
60’s =
70’s =
80’s =
90’s = 2 8 18
RAIN
Avg./Mean:
Range:
% time:
0.15”
0-1.79”
43%

7. ASSUMES NO CHANGE ! WHAT HAPPENED … WILL CONTINUE TO HAPPEN
WHAT IS PERSISTENCE ?
ASSUMES NO CHANGE !
WHAT HAPPENED …
WILL CONTINUE TO HAPPEN

8. Climatology Forecast
Persistence Forecast
Key West Chicago
CLI 6/ 6/ 6/ 6/ 6/ 6/ 6/
AVG ERR.
1.3 9
Key West Chicago 6/ 6/ 6/ 6/ 6/ 6/ 6/
AVG ERR.

9. PSU SNOWFALL

10. Penn State Weather Camps
Basic Weather Forecasting Guidelines
Sat I – Sat II – Sat III - NWS – SPC - NHC – Radar - Radar - Radar
E-WALL - sfc. map 1 - sfc. map 2 - ltg

11. Traditional 4-Panel Model Output
SLP map + THK
500 mb
700 mb
Accumulate Precip

12. 500 mb map- GFS model. Valid 8 p.m. EDT
Trough
Shortwave/
JS Disturbance
Z = EDT
12z=8 am
18z=2 pm
00z=8pm
06z=?

13. SLP map- NAM model. Valid 8 p.m. EDTH

14. 500 mb map- GFS model. Valid 8 p.m. EDT
SPC

15. SLP map- NAM model. Valid 8 p.m. EDTH
SPC

16. Penn State Weather Camps
Basic Weather Forecasting Guidelines
Sat I – Sat II – Sat III - NWS – SPC - NHC – Radar - Radar - Radar
E-WALL - sfc. map 1 - sfc. map 2 - ltg

17. Jim Cantore 83 SW
PSU

18. Upper Level Map (i.e. 500mb)
Balance between 2 forces ….
Pressure Gradient + ??

19. SURFACE PRESSURE (SLP)? ? ?

20. SURFACE PRESSURE (SLP)? ?

21. Geostationary Satellite
22,000 miles above equator

22. De donde son ustedes?

23. JET STREAM This Afternoon
500 mb (~18,000 feet) L H

24. JET STREAM – LATER THIS WEEK

25. Basic Forecast Guidelines - TEMP
Cause of temperature to change:
Sunshine?
Wind direction?

26. Location – STATE COLLEGE TEMP – PRECIP – SKY COVER
WX CAMP - Forecasting
Location – STATE COLLEGE
TEMP – PRECIP – SKY COVER ?
90F
YES

27. Joe Smith 81
Yes 8

28. Basic Forecast Guidelines
What causes rain?
Need clouds!
Will any ole cloud do?
Moisture
Bodies of water – Moisture content of air

29. NORMAL
Conforming to a standard; usual, typical, or expected.

31. Basic Forecast Guidelines
What causes temperature to change?
How much sunshine?
How much precipitation?
Wind direction?

32. Basic Forecast Guidelines
Extrapolation= Look upstream to see what’s coming!
Sat IR - Sat II - Sat VIS - Radar - sfc. map 1 - sfc. map 2 – sfc map 3

33. Basic Forecast Guidelines
The “Models”
What are they?
Lower Res. (GFS)
Higher Res. (GFS)
Higher Res. (NAM)
Higher Res. (HRRR)
MOS - Statistical guidance

34. TROF AVIS PA
TROF AVIS

35. Cyclogenesis

41. Air Mass
Large volume of air with certain Temp and Moisture Characteristics
Continental Tropical, Maritime Tropical,
Continental Polar, Maritime Polar

42. Continental Polar
Maritime
Polar
Continental Tropical
Maritime Tropical

43. Summer - Day Winter- Day T = 105 TD = 38 T = 15 TD = -5 T = 67 TD = 58
Maritime Tropical
Maritime Polar
Continental Tropical
Continental Polar

44. RH Calculator Relative Humidity – How close the air is to saturation
- Varies between?
- If in a cloud ….. RH = ?
Dew Point – Absolute humidity (how much H20 v)
T = 85
D = 65
RH = 51%
How can we make a cloud?
RH Calculator

45. RH at 700 mb 18z WED
MOS - clouds
E-WALL - clouds

46. SFC Temperature Forecasting Techniques Climatology Persistence
Modified Persistence
Models
2 meter temp output
MOS (statistical)

47. Basic Forecast Guidelines
Climatology Forecast = averages for today
Persistence Forecast = yesterday’s values
Modified Persistence = Persistence + Any changes

48. Nighttime infrared satellite imagery suggests that the circulation associated with the low pressure area in the Gulf of Mexico is
gradually becoming better defined. However, the system is struggling to maintain organized convection near the center, and
the radius of maximum winds remains large. Based on this, the system is still maintained as a potential tropical cyclone.

49. The low is moving erratically northwestward around the southwestern portion of a deep-layer ridge located over the western Atlantic and Florida. The large-scale models suggest this ridge will strengthen some during the next 36 hours or so and cause the low to turn a little more westward. This would be followed by a northward turn around the western end of the ridge and eventual recurvature into the westerlies. Overall, there has been a left shift of the track guidance models since the previous advisory. The new forecast track is also shifted left, but it is to the right of the model consensus, especially at h. Given the nature of the circulation, though, and the fact that the wind and rain hazards extend well north and east of the center, users are encouraged to not focus on the details of the track forecast.

50. The initial intensity remains 35 kt based on partial scatterometer overpasses and continuity from the previous advisory. Significant strengthening is unlikely due to strong vertical shear caused by an upper-level trough over the northwestern Gulf of Mexico and entrainment of dry air into the system. However, the large-scale models suggest slight strengthening before landfall, and thus the intensity forecast is unchanged from the previous advisory. One change from the previous advisory is that it now appears more likely that the system would become a subtropical cyclone rather than a tropical cyclone due to the current structure of the low and interaction with the aforementioned trough. That being said, development into a tropical cyclone remains possible. The primary hazard from this disturbance is expected to be heavy rainfall over portions of the central and eastern Gulf Coast.

51. FORECAST POSITIONS AND MAX WINDS
INIT 20/0900Z 24.8N 90.1W 35 KT 40 MPH...POTENTIAL TROP CYCLONE
12H 20/1800Z 25.7N 91.0W 35 KT 40 MPH...SUBTROPICAL CYCLONE
24H 21/0600Z 26.6N 92.1W 40 KT 45 MPH
36H 21/1800Z 27.5N 93.0W 40 KT 45 MPH
48H 22/0600Z 28.9N 93.5W 40 KT 45 MPH
72H 23/0600Z 32.5N 93.5W 25 KT 30 MPH...INLAND
96H 24/0600Z 36.5N 88.0W 20 KT 25 MPH...POST- TROP/INLAND

52. Our friends …. Storms Prediction Center

53. NAM MODEL – 4 panel map
Valid at 8 a.m. (12z) YESTERDAY

54. L H H NAM MODEL – 500 mb. map Valid 8 a.m. (12z) YESTERDAY Ridge
Trough

55. NAM MODEL – SFC map
Valid 8 a.m. (12z) YESTERDAY

56. NAM MODEL – SFC map
Valid 8 P.M. (00z) YESTERDAY

57. LIFTED INDEX
Valid 2 P.M. (18z) YESTERDAY

58. 5 a.m. (09z)

59. NAM MODEL – 4 panel map
Valid at 2 p.m. (18z)

60. NAM MODEL – sfc map
Valid at 2 p.m. (18z)

61. NAM MODEL – 500 mb
Valid at 2 p.m. (18z) L
Trough
axis

62. LIFTED INDEX
Valid 2 P.M. (18z) TODAY

63. Penn State Weather Camps
Basic Weather Forecasting Guidelines
Sat I – Sat II – Sat III – Sat WV - NWS - NHC – Radar - Radar
sfc. map 1 - sfc. map 2 – sfc map 3

64. NAM MODEL – Precip. map
Totals (2 pm – 8 pm)
(18z – 00z)
GFS MODEL – Precip. map
Totals (2 pm – 8 pm)
(18z – 00z)

65. NAM MODEL – Precip. map
Totals (2 pm – 8 pm)
(18z – 00z)
GFS MODEL – Precip. map
Totals (2 pm – 8 pm)
(18z – 00z)

66. SURFACE PRESSURE ? ? ? ? ?

67. SURFACE PRESSURE

68. Warm Sector vs. Cool Sector

71. MOS – Model Output S …
Accu Friends
Wx Channel Friends
NWS Friends

72. Know what to expect! = Climo.NH RH NL RL
Know what to expect! = Climo.

75. Big Picture …. Then details 
Soundings ?
Model soundings
Other fun output
Meteograms

76. Big Picture …. Then details 
Temps + Clouds
Soundings – What are these?
Model soundings
Other fun output
Meteograms