Tag Archives: forecast

NASA-NOAA's Suomi NPP satellite passed over Joaquin at 06:10 UTC (2:10 a.m. EDT) on Oct. 1 as it was strengthening from a Category 2 to a Category 3 hurricane. Imagery showed cloud top temperatures colder than -63F/-53C (yellow).
Credits: NRL/NASA/NOAA

Satellites show Joaquin becoming a Category 4 hurricane:NASA

For details and related images CLICK HERE!

Hurricane Joaquin had become a Category 4 hurricane on the Saffir-Simpson Wind Scale by 2 p.m. EDT on October 1. At NASA, satellite imagery from NOAA’s GOES-East satellite was compiled into an animation that showed the hurricane strengthening. Earlier in the day, NASA-NOAA’s Suomi NPP satellite saw powerful thunderstorms within, indicating further strengthening.

The GOES-East satellite is managed by NOAA, and at NASA’s GOES Project at the NASA Goddard Space Flight Center in Greenbelt, Maryland, imagery from GOES-East we compiled into an animation. The infrared and visible imagery from September 29 to October 1 from showed Hurricane Joaquin become a major hurricane in the Bahamas.

NASA-NOAA's Suomi NPP satellite passed over Joaquin at 06:10 UTC (2:10 a.m. EDT) on Oct. 1 as it was strengthening from a Category 2 to a Category 3 hurricane. Imagery showed cloud top temperatures colder than -63F/-53C (yellow). Credits: NRL/NASA/NOAA
NASA-NOAA’s Suomi NPP satellite passed over Joaquin at 06:10 UTC (2:10 a.m. EDT) on Oct. 1 as it was strengthening from a Category 2 to a Category 3 hurricane. Imagery showed cloud top temperatures colder than -63F/-53C (yellow).
Credits: NRL/NASA/NOAA

Earlier in the morning, NASA-NOAA’s Suomi NPP satellite passed over Joaquin at 06:10 UTC (2:10 a.m. EDT) as it was strengthening from a Category 2 to a Category 3 hurricane. The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard captured an infrared image that showed cloud top temperatures colder than -63F/-53C, indicative of powerful storms within the hurricane. NASA research has shown that storms with cloud tops that high (and that stretch that high into the troposphere) have the capability to generate heavy rain.

On October 1, a Hurricane Warning was in effect for the Central Bahamas, Northwestern Bahamas including the Abacos, Berry Islands, Eleuthera, Grand Bahama Island, and New Providence, The Acklins, Crooked Island, and Mayaguana in the southeastern Bahamas. A Hurricane Watch was in effect for Bimini and Andros Island, and a Tropical Storm Warning was in effect for the remainder of the southeastern Bahamas excluding the Turks and Caicos Islands and Andros Island.

At 2 p.m. EDT (1800 UTC), the center of Hurricane Joaquin was located near latitude 23.0 North, longitude 74.2 West. Joaquin was moving generally southwestward at about 6 mph (9 kph), and the National Hurricane Center forecast a turn toward the northwest and north on Friday, October 2. On the forecast track, the center of Joaquin will move near or over portions of the central Bahamas today and tonight and pass near or over portions of the northwestern Bahamas on Friday, October 2.

Reports from an Air Force Reserve Hurricane Hunter aircraft indicated that maximum sustained winds have increased to near 130 mph (210 kph) with higher gusts. Joaquin is now a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some additional strengthening is possible during the next 24 hours, with some fluctuations in intensity possible Friday night and Saturday.

Hurricane force winds extend outward up to 45 miles (75 km) from the center and tropical storm force winds extend outward up to 140 miles (220 km).

The latest minimum central pressure extrapolated from Hurricane Hunter aircraft data is 936 millibars. For effects on the Bahamas, updates to forecasts, watches and warnings, visit the National Hurricane Center website: http://www.nhc.noaa.gov.

The NHC updated forecast takes Joaquin on a more northerly track from Saturday, October 3 through Tuesday, October 6 toward Long Island, New York. Tracks and forecasts are subject to change.

Source : NASA

 

Computerized model showing simulation of the city of Jeddah under flooding conditions. The cloudy sky indicates the spatial distribution of the amount of rain over Jeddah. Credit: KAUST

KAUST scientists developing models to predict extreme events

As KAUST celebrates its five-year anniversary, the community has a plethora of milestones to celebrate, not to mention more than a few memorable events to look back on. Interestingly, one of these noteworthy events, in the form of an unforeseen natural occurrence, still serves as the basis for ongoing interdisciplinary research at the University. Shortly following KAUST’s Inauguration, on November 25, 2009, over 140 millimeters of rain fell over the Jeddah region within a mere eight hours, causing in excess of 100 fatalities and resulting in an economic setback of over $100M.

“All this rain coming at the same time, in a matter of few hours, meant the water had nowhere to go; so it went into the streets,” said KAUST’s Ibrahim Hoteit, Associate Professor of Earth Sciences and Engineering and Principal Investigator of the Earth Fluid Modeling and Prediction group. Flash floods present a particular challenge in arid areas with limited sewage systems.

Computerized model showing simulation of the city of Jeddah under flooding conditions. The cloudy sky indicates the spatial distribution of the amount of rain over Jeddah. Credit: KAUST
Computerized model showing simulation of the city of Jeddah under flooding conditions. The cloudy sky indicates the spatial distribution of the amount of rain over Jeddah. Credit: KAUST

“The rain doesn’t get quickly absorbed in this region.” As Prof. Hoteit further explains: “We’re trying to reconstruct the rain event that happened during the 2009 and 2001 floods using modeling and observations.” As he emphasizes, “models predict the future data and the data guide the model toward the truth.”

He points to an impressive computerized model of Jeddah on his monitor, capturing over 20,000 buildings, complete with surrounding mountains and estimated paths taken by the water as it flooded the city.

Constructing Predictive Models for Jeddah Flooding

“In order to build a local model at the level of Jeddah, we downscale from global to regional MENA (Middle East & North Africa)-wide models all the way down to a few hundred meters over Jeddah,” as Hoteit outlines. To obtain the MENA region data, his team used data from satellites and international sources.

As they eventually zoomed in over the Jeddah region, the local data was provided by Presidency of Meteorology and Environment (PME) and the Jeddah Municipal government. The data collected is then used to complement and guide the atmospheric and weather models employed to forecast.

“Using all available observations and state-of-the-art weather forecasting models, our simulations suggest that we could predict these devastating extreme rain events one or two days in advance. So we can greatly improve the prediction of these events and issue timely warnings,” said Prof. Hoteit.

The rain is then used as input in developing very high-resolution models to simulate street flooding in the city of Jeddah.

It’s important to keep in mind that environmental fluid models are not perfect, and as such their outputs can be modeled as random variabilities with some distributions. “The question of how good or certain our forecast is dependent on a complex mathematical and computational problem. We strive to compute the best possible representation of the distribution of the system state given the models and available data.”

These sophisticated models, taking into account input and modeling uncertainties, are achieved through highly multidisciplinary work involving various teams at KAUST. Prof. Hoteit closely collaborates with KAUST’s Prof. Omar Knio, a world expert in the field of uncertainty quantification. He also relies heavily on collaborations with the high performance computing and visualization teams. “Visualization is very important for us as a way to communicate our scientific concepts to people and users,” explained Hoteit.

Ocean Modeling and the Impact of Sea Currents

In an effort to build forecasting models meant to predict extreme marine and weather events, Prof. Hoteit and his group also rely on ocean and atmospheric observations. For any environmental model to be effective, it’s important to complement it with actual data collected from the whole region and locally.

Working with data sets collected from Saudi Aramco, from PME, as well as from satellite data, KAUST was able to develop a 14-year reanalysis (from the years 2000 to 2014) of atmospheric conditions over the Red Sea at a 10-kilometer resolution – one of the highest and most accurate of its kind in the region.

As they eventually zoomed in over the Jeddah region, the local data was provided by Presidency of Meteorology and Environment (PME) and the Jeddah Municipal government. The data collected is then used to complement and guide the atmospheric and weather models employed to forecast.

“Using all available observations and state-of-the-art weather forecasting models, our simulations suggest that we could predict these devastating extreme rain events one or two days in advance. So we can greatly improve the prediction of these events and issue timely warnings,” said Prof. Hoteit.

The rain is then used as input in developing very high-resolution models to simulate street flooding in the city of Jeddah.

It’s important to keep in mind that environmental fluid models are not perfect, and as such their outputs can be modeled as random variabilities with some distributions. “The question of how good or certain our forecast is dependent on a complex mathematical and computational problem. We strive to compute the best possible representation of the distribution of the system state given the models and available data.”

These sophisticated models, taking into account input and modeling uncertainties, are achieved through highly multidisciplinary work involving various teams at KAUST. Prof. Hoteit closely collaborates with KAUST’s Prof. Omar Knio, a world expert in the field of uncertainty quantification. He also relies heavily on collaborations with the high performance computing and visualization teams. “Visualization is very important for us as a way to communicate our scientific concepts to people and users,” explained Hoteit.

Ocean Modeling and the Impact of Sea Currents

In an effort to build forecasting models meant to predict extreme marine and weather events, Prof. Hoteit and his group also rely on ocean and atmospheric observations. For any environmental model to be effective, it’s important to complement it with actual data collected from the whole region and locally.

Working with data sets collected from Saudi Aramco, from PME, as well as from satellite data, KAUST was able to develop a 14-year reanalysis (from the years 2000 to 2014) of atmospheric conditions over the Red Sea at a 10-kilometer resolution – one of the highest and most accurate of its kind in the region.

Source: KAUST