Image courtesy cheddar.com.

Hurricane Dorian is moving up the coast and passing Florida, but there’s still a healthy amount of moisture being pulled into the storm. UF tropical storm expert Dr. Corene Matyas checked in with cheddar.com with the latest update on Hurricane Dorian, its impacts in Florida and projected conditions along the U.S. East Coast this afternoon. See the full interview here.

TANG, MATYASA Nowcasting Model for Tropical Cyclone Precipitation Regions Based on the TREC Motion Vector Retrieval with a Semi-Lagrangian Scheme for Doppler Weather Radar

Jingyin Tang and Corene Matyas

Article first published online: 21 May 2018 Atmosphere

DOI: 10.3390/atmos9050200

ABSTRACT: Accurate observational data and reliable prediction models are both essential to improve the quality of precipitation forecasts. The spiraling trajectories of air parcels within a tropical cyclone (TC) coupled with the large sizes of these systems brings special challenges in making accurate short-term forecasts, or nowcasts. Doppler weather radars are ideal instruments to observe TCs when they move over land, and traditional nowcasts incorporate radar data. However, data from dozens of radars must be mosaicked together to observe the entire system. Traditional single-radar-based reflectivity tracking methods commonly employed in nowcasting are not suitable for TCs as they are not able to capture the circular motion of these systems. Thus, this paper focuses on improving short-term predictability of TC precipitation with Doppler weather radar observations based on: a multi-scale motion vector retrieval algorithm, an optimization technique and a semi-Lagrangian advection scheme. Motion fields of precipitation regions are obtained by a multi-level motion vector retrieval algorithm, then corrected and smoothed by the optimization technique using mass and smooth constraints. Predicted precipitation regions are then extrapolated using the semi-Lagrangian advection scheme. A case study of Hurricane Isabel (2003) shows that the combination of these methods may increase reliable rainfall prediction to about 5 h as the TC moves over land.

Read the full publication at Atmosphere

 

 

 

 

 

MATYASTANGZICKUsing an Object-Based Approach to Quantify the Spatial Structure of Reflectivity Regions in Hurricane Isabel (2003). Part I: Comparisons between Radar Observations and Model Simulations

Corene J. Matyas, Stephanie E. Zick, Jingyin Tang

Article first published online: 25 APR 2018 Monthly Weather Review

DOI: 10.1175/MWR-D-17-0077.1

ABSTRACT: When a hurricane undergoes extratropical transition (ET), its rainbands evolve from a circular and compact shape to a more elongated, fragmented, and dispersed configuration with an exposed circulation center. This study calculates five metrics to measure these spatial changes in reflectivity regions as Hurricane Isabel (2003) underwent ET. A mosaic of observations from the Weather Surveillance Radar-1988 Doppler (WSR-88D) network is compared to reflectivity simulated by the Advanced Research Weather Research and Forecasting (WRF-ARW) Model. Six simulations are performed by varying the cumulus and microphysics parameterizations to produce a range of reflectivity configurations. A bias correction is applied to model-simulated reflectivity prior to the calculation of spatial metrics because lower reflectivity values are generally underrepresented, while higher values are generally overrepresented. However, the simulation with Kain–Fritsch cumulus and Morrison two-moment microphysics overpredicts reflectivity by 3–4 dBZ at all levels. We demonstrate that the spatial metrics effectively capture structural changes as reflectivity regions became more fragmented and dispersed and the center became more exposed. In this case study, the results were more sensitive to the choice of cumulus physics, compared with the choice of microphysics. The Kain–Fritsch simulations produce shapes that are too circular and solid when compared with WSR-88D observations, as the hurricanes lack distinct outer rainbands. Simulations with Tiedtke cumulus produce an elongated main reflectivity region as in WSR-88D, but with separate inner and outer rainbands that are too dispersed and fragmented. These results demonstrate the value in measuring spatial patterns rather than assessing model performance using visual inspection alone.

Read the full publication at Monthly Weather Review

 

 

 

 

 

irma0001, Air Force Magazine. Hurricane Irma passes Cuba and approaches southern Florida on Sunday, Sept. 10, 2017, in a NASA satellite captured a night-time image of the storm in the Florida Straits and identified where the strongest storms were occurring within Irma’s structure. NOAA’s GOES-East satellite provided a visible image at the time of Irma’s landfall in the Florida Keys. NASA photo

Geography’s Dr. Corene Matyas and Dr. Joann Mossa recently spoke to several new outlets about the cause and result of Hurricane Irma.

9/7 Dr. Corene Matyas explains the mechanics of a Catergory 5 storm at HowStuffWorks.com

9/7 Dr. Corene Matyas talks to Canada’s CTV News channel about what #Florida can expect from Hurricane Irma

9/7 Dr. Matyas talks to BBC 5 Live (1h18m) about the impact of Hurricane Irma

9/7 Dr. Corene Matyas talks to David McCullagh about the projected #hurricane path of Hurricane Irma

9/8 Dr. Corene Matyas tells the BBC what might happen during Hurricane Irma

9/19 Dr. Joann Mossa explains why Florida flooded during Hurricane Irma on INTERSECTION: WHY FLORIDA FLOODS 

 

 

 

 

 

HERNANDEZ AYALA, KEELLINGS, WAYLEN, MATYASExtreme floods and their relationship with tropical cyclones in Puerto Rico

José J. Hernández Ayala, David Keellings, Peter R. Waylen & Corene J. Matyas

Article first published online: 12 SEPT 2017 Hydrological Sciences Journal

DOI: 10.1080/02626667.2017.1368521

ABSTRACT: An extreme value analysis (EVA) point process approach has been implemented to examine the flood characteristics of Puerto Rico when tropical cyclones (TCs) are present in the discharge series and when they are removed from it. Mean daily discharge values that exceeded the 99th percentile thresholds were used in both the TC and non-TC data series. In nine of the 12 stations the maximum discharge was associated with a TC, with hurricanes Hortense (1996), Georges (1998) and Eloise (1975) responsible for most of the maximum peaks at each site. Percentage changes in the generalized extreme value parameters, which include location (central tendency), scale (variance) and shape (skewness), between the TC and non-TC data exhibited a decrease in the majority of stations. Stations in the eastern interior and central region of the island showed the largest decrease in all parameters, in flood occurrences and in return periods when TCs were removed from the series.

Read the full publication at Hydrological Sciences Journal

 

 

 

 

 

Hurricane Matthew composite radar 07-10-2016 0848UTC.png
Hurricane Matthew. Image courtesy WikiMedia Commons.

Hurricane Matthew’s near miss of Florida may result in more widespread damage than a direct hit – according to UF’s Dr. Corene Matyas – who was quoted in an October 7th Tampa Bay Times article. Dr. Matyas’ National Science Foundation (NSF) funded research focuses on rainfall from tropical cyclones.

From the Tampa Bay Times:

“But Florida’s near miss may simply have spread the damage and flooding over a wider swath of the state than a direct hit, warned Corene Matyas, a UF associate professor of geography who investigates the frequency and intensity of hurricanes.

Matthew knuckled along the coast for hundreds of miles, increasing the areas exposed to tropical storm-force winds, storm surge and rainfall, she said.

“The complete picture of damage has yet to emerge,” she said.

Dr. Matyas clarifies that the “Hurricane Matthew tracking parallel to the coast has increased the areas exposed to tropical storm-force winds and water rise from storm surge and wave energy, plus rainfall.”

Read the entire article at the Tampa Bay Times.

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In a recent Forbe’s article, recent Geography alum (and Assistant Professor at Virginia Tech) Dr. Stephanie Zick helped explain ‘Why have we seen a ‘blob’ east of Hurricane Matthew’s eye and why it should concern us‘.

In the article, she was quoted as saying: “I think there are multiple factors: 1) the stationary band complex, so there would be confluence downshear (east of the TC center), but combined with, 2) a surge in the trade winds and 3) confluence downstream of the South American landmass/terrain.” and “another factor (albeit more speculative) that I think might be enhancing the convection is a working hypothesis that asymmetries can develop during landfall as drier air from over land moves over the moist boundary layer (modifying moist static stability).”

Read the entire article to see more of Dr. Zick’s analysis.