2016 Tropical Weather Outlook

Size: px

Start display at page:

Download "2016 Tropical Weather Outlook"

Leo Fleming
7 years ago
Views:

1 National Weather Service Houston/Galveston TX 2016 Tropical Weather Outlook weather.gov/houston Social Media: NWSHouston 5/25/2016 5:51 PM

2 National Weather Service Houston/Galveston TX 2016 Tropical Weather Outlook In an average hurricane season one could anticipate: 11 named tropical storms (39-73 mph). Hurricane Alex January of which strengthen to hurricanes (74+ mph). 2 of which further strengthen to major hurricanes category 3-5 (111+ mph).

3 National Weather Service Houston/Galveston TX 2016 Tropical Weather Outlook Hurricane Season: June 1 November 30 th Historically, chances for Texas diminish in October after a couple fronts have passed through (storms tend to recurve)

4 From Phil Klotzbach

years) to La Nina (typically above normal tropical cyclone years) However, possible we are entering a

5 National Weather Service Houston/Galveston TX 2016 Tropical Weather Outlook During the summer 2016 several climate models indicate a transition from: El Nino (typically below normal tropical cyclone years) to La Nina (typically above normal tropical cyclone years) However, possible we are entering a less active phase of Atlantic Multidecadal Oscillation Fewer storms El Nino Neutral La Nina spring summer fall

7 Sum of squares of maximum sustained velocity for tropical cyclones every 6 hours More Active? Less Active? More Active? Now?

9 National Weather Service Houston/Galveston TX 2016 Tropical Weather Outlook What s expected this year? NOAA releases their 2016 outlook in late May. Consensus is for a near or slightly above normal season overall in the Atlantic but really no information about tropical activity in Gulf or Texas landfalls in particular Need to be prepared every year for a possible landfall

10 National Weather Service Houston/Galveston TX 2016 Tropical Weather Outlook The bottom line: The number of forecast storms doesn t matter!!! They don t tell you where a storm will hit, when it ll hit, or any details on its strength or expected impacts. It only takes one to make it a bad year!.

11 National Weather Service Houston/Galveston TX Misconceptions About the Cone Cone is shrinking as track forecasts improve. Three-day Forecast Cone with Rita 2005 How the cone would appear today X actual landfall X actual landfall Concern about misinterpretation with people thinking they are safe if outside the cone. Center tracks outside the cone about 1/3 of the time! The cone is not an impact zone! You can - and will - get impacts outside of it. What do you do? How would you plan? What if you are wrong? Is uncertainty taken into account for your hurricane plans/operations?

12 National Weather Service Houston/Galveston TX Misconceptions About the Cone Impacts Can be felt well outside the cone. High water levels occurred across a large portion of the Gulf coast in the case of Hurricane Ike

13 National Weather Service Houston/Galveston TX Storms Can Develop Quickly Near the Coast Sometimes tropical systems form close to the coast. Are you prepared to implement your plan quickly with minimal lead time? You make need to make important decisions based on a forecast before watches or warnings are issued! Tropical Storm Bill June 2015 Hurricane Humberto September 2007 Because Bill formed so close to land, tropicalstorm-force winds first reached the coast within about 12 hours of the issuance of the initial tropical storm warning. Humberto strengthened from a 30 mph low into an 90 mph hurricane within 24 hours right off the upper Texas coast!!

Graphical Tropical Weather Outlook: 5-day Shows chance of becoming a tropical cyclone over next 120 hours Hatching indicates areas where tropical cyclones could develop over next 120 hours Colors

14 Graphical Tropical Weather Outlook: 5-day Shows chance of becoming a tropical cyclone over next 120 hours Hatching indicates areas where tropical cyclones could develop over next 120 hours Colors indicate low, medium or high chance (X) indicates initial location of disturbance, if it exists at the issuance time Numbers assigned to each disturbance; each disturbance has separate display for clarity Arrows connect initial position of disturbance with area of formation potential

Bill did not become a tropical storm until just hours before Tuesday morning landfall Tropical Storm Bill Was forecast to likely become a tropical storm in outlooks 36 hours prior to being named NHC

15 Bill did not become a tropical storm until just hours before Tuesday morning landfall Tropical Storm Bill Was forecast to likely become a tropical storm in outlooks 36 hours prior to being named NHC working on plan to issue watches and warnings in certain cases where likelihood of development is high and impacts within 48 hours, yet TC not yet formed (pre-genesis) TS Bill Advisory 1, 10 pm CDT June

16 Photo credit: NASA, Scott Kelly

17 Tropical Storm Bill June 16 th, 2015

18 View from Matagorda/Palacios, TX Tropical Storm Bill winds gusted to 50 to 60 mph around Matagorda Bay Saw some minor wind damage near center, near eye wall Michael Kubecka

19 Tropical Weather H-92 H-68 H-44 Graphical Tropical Weather Outlook for TS Bill TC Formation not expected next 5 days 30% 60% H-20 H-8 H-5 TS Bill Advisory 1, 60 mph winds, 2 to 4 ft surge 80% 90% 11 pm EDT Mon Jun 15

20 Hurricane Humberto 2007 Newly Formed TD to Hurricane in 18 hours

21 National Weather Service Houston/Galveston TX 2016 Tropical Weather weather.gov/houston Social Media: NWSHouston 5/25/2016 5:51

22 Flooding Immediate concern: Flash Flooding! Rapid rise in water levels due to intense rainfall Thousands of high water rescues, people displaced; damages over 1b$? Flash Flood Emergency: Catastrophic, life threatening flooding underway Flash Flood Warning: Life threatening flooding Areal Flood Advisory: More nuisance level flooding (street and poor drainage flooding)

23 USGS Streamer Web Tool Can pick any point and get downstream or upstream trace Great way to view basins, understand where water is coming from

24 Brazos River Basin Upstream of Richmond

25 Buffalo Bayou, Houston

26 Radar Estimated Rainfall April 18th, Large Area 10 to 20 inches in <12 hours

27 Colorado River Basin

28 River at a Glance

29 Memorial Day Floods, 2015 Twitter Galleria, Twitter, KHOU Doublehornphoto.com

30 Flash Flood Safety Rules Turn Around, Don t Drown 2-3 feet will float most vehicles 12 inches of moving water can knock a person off balance Stay away from creeks or ditches Be especially cautious at night

31 National Weather Service Houston/Galveston TX 2016 Tropical Weather Outlook Forecast accuracy & other misc. slides

32 National Weather Service Houston/Galveston TX 2016 Tropical Weather Outlook Track forecasts (where the storm is headed) continue to improve. Not as rapid of success in regards to intensity forecasts. Forecast hour before landfall 2008 Error (nautical miles) 2016 Error (nautical miles) % change since (-2) (-3) (-5) (-6) (-7) (-5) (+12) -26

33 National Weather Service Houston/Galveston TX 2016 Tropical Weather Outlook

34 National Weather Service Houston/Galveston TX 2016 Tropical Weather Outlook Hurricane Return Period Last hurricane to hit the upper Texas coast was Ike in 2008.

35 National Weather Service Houston/Galveston TX 2016 Tropical Weather Outlook Questions? weather.gov/houston Social Media: NWSHouston 5/25/2016 5:51 PM

Lessons Learned from the Design of the Decision Support System Used in the Hurricane Katrina Evacuation Decision

PROCEEDINGS of the HUMAN FACTORS AND ERGONOMICS SOCIETY 51st ANNUAL MEETING 2007 253 Lessons Learned from the Design of the Decision Support System Used in the Hurricane Katrina Evacuation Decision Alex