It looks like La Niña is on her way out, with neutral conditions expected to develop by February. The engine of ENSO is the temperature of the ocean surface in the equatorial central and eastern Pacific. Since late summer 2016, the Niño3.4 region has been cooler than the long-term average. December was -0.72°C below average, a slight uptick relative to the month before. Taking a look at the global ocean map (Figure), you can see the small patch of cooler waters that is powering our La Niña is still embedded in a very warm (compared to average) Pacific Ocean.

Since ENSO is assessed on seasonal timescales, it’s more relevant to examine the average for the October – December period, which was -0.8°C. We now have four consecutive seasons with an average cooler than the La Niña threshold of -0.5°C. Five successive seasons are required to officially qualify as a La Niña event. Forecasters are confident that the November – January period will qualify as continuing the La Niña, but predict that the next period, December – February, will be warmer, and likely end up in neutral territory (between -0.5°C and +0.5°C).

There were also still consistent signs in December of a weak atmospheric response to the cooler equatorial ocean, with reduced cloudiness and rainfall over the tropical central Pacific, and more over Indonesia. La Niña conditions mean the winds in the tropical Pacific (east-to-west in the lower atmosphere, and west-to-east in the upper atmosphere) are stronger than average, an effect we also saw at times during December.

The Aviation Weather Center’s Impacts Terminal Aerodrome Forecast (TAF) Board became an operational web service on November 28th.

This product provides the aviation community with a time series display of weather conditions at select airports across the United States. The board is a visualization of the “impacts catalog” – a database designed to reflect weather conditions that could impair arrivals and/or departures (or airport closure) based on specific criteria to each airport.

On October 31st through November 5th, AWC's International Branch Chief Matt Strahan and AWC's Cooperative Institute for Research in the Atmosphere (CIRA) associates Jung-Hoon Kim and Brian Pettegrew visited the Korean Meteorological Agency (KMA) and attended their 5th Aviation Weather Workshop in Jeju, South Korea. This increased the collaborative ties between KMA and the AWC on turbulence forecasting methodology. KMA will also soon join the global Significant Weather Chart online coordination chats.

Following this trip, five forecasters and scientists from the KMA also visited the AWC and the Kansas WFO, RFC, and Olathe CWSU December 6-8. During their visit, they learned about the tools and techniques for aviation weather forecasting. They also worked with members of AWC’s Support Branch on improvements to turbulence forecasting for the World Area Forecast System.

Benjamin Friedman, NOAA Deputy Under Secretary for Operations, visited the Storm Prediction Center on October 19th. During the visit, SPC Director Dr. Russell Schneider provided an overview of the SPC mission, history, and staffing. Bill Bunting, Chief of Forecast Operations, provided a briefing on daily forecast operations, and Lead Forecaster Rich Thompson highlighted some of the challenges in severe storm forecasting. The importance of the NOAA Hazardous Weather Testbed as a conduit between research and operations was also emphasized. During the visit, several SPC staff interacted with Deputy Under Secretary Friedman and described the data sets and software used to prepare convective and fire weather outlooks, mesoscale discussions and severe thunderstorm and tornado watches.

On November 15, 2016, NBM version 2.0 went into the Weather and Climate Operational Supercomputer System production cycle with the 12z run. Developed by the NWS Meteorological Development Lab (MDL), the NBM project produces a nationally consistent and skillful suite of calibrated forecast guidance from a blend of both NWS and non-NWS models for use in forecasting at the National Centers and local field offices. This development will leverage a common data assimilation analyses for calibration and verification, ensemble guidance which enables the estimation of uncertainty in the forecast, and emerging statistical post processing techniques to calibrate and blend model output and the forecast guidance more useful.

Version 2.0 includes the following:

• New input models for CONUS and OCONUS domains:

• NAM
• NAM Nest
• New output domains:
• Alaska
• Hawaii
• Puerto Rico (No GMOS input for this version)
• Oceanic (Winds Only)
• Temperature, Dewpoint, Daytime Max Temperature, Nighttime Min Temperature
• CMCE DMO, GEFS DMO, GFS DMO, GMOS, EKDMOS, NAM-Nest DMO, and NAM DMO (NAM and NAM-Nest not used for MaxT and MinT)
• Bias-corrected relative to URMA
• Compute MAE of bias-corrected components
• MAE-based weights (unique for each gridpoint)
• Relative Humidity
• Derived from NBM T and Td via gridpost
• Wind Speed
• CMCE DMO, GEFS DMO, GFS DMO, GMOS, NAM-Nest DMO, and NAM DMO
• Bias-corrected relative to URMA
• Compute domain-wide wind speed MAEs relative to URMA
• Blended wind speed based on domain-wide MAEs
• Inflates speed based on topography and GFS gust
• Wind Gust
• Wind gust derived from blended wind speed using gustmod subroutine in grblend (Tattelman’s equation).
• Wind Direction
• Wind direction computed from GEFS ensemble mean U and V
• Sky Cover
• CMCE DMO, GEFS DMO, GFS DMO, GMOS, NAM-Nest DMO, and NAM DMO
• CONUS:
• Compute domain-averaged MAEs relative to URMA
• Weight model components based on MAEs
• OCONUS:
• Models are equally weighted since URMA does not generate sky cover analyses. (GMOS not used for HI and PR.)
• Apparent Temperature
• Derived from final blended T, Td, and wind speed via grblend
• 12-hr Probability of Precipitation (POP) and 6-hr Quantitative Precipitation Forecast (QPF)
• Precip Amount forecasts used from: CMC Deterministic, CMCE, GFS, GEFS
• 6- and 12-hr Precip Amount "observations" from Climatologically Calibrated Precipitation Analysis (CCPA) from Jan. 2002 to present; stored in NetCDF
• CDF Creation:
• CDF created for CCPA
• POP: CDFs created individually for CMCD, CMCE, GFS, GEFS
• QPF: CDFs created for a Grand Ensemble Mean (GEM)= CMCD + CMCE + GFS + GEFS
• Blended POP and QPF generated via stochastic quantile mapping and statistical downscaling

Upcoming implementations for the NBM and their planned releases are:

• NBM v2.1 (winter 2017)
• Upgrades the CONUS PoP12/QPF06 guidance by introducing stochastic quantile mapping
• NBM v3.0 (summer 2017)
• Increased temporal resolution (hourly) to 36-hours by adding short- term models (HRRR, GLMP, SREF, etc.) to NBM over the CONUS
• Add FNMOC NAVGEM 20 member ensemble to CONUS and OCONUS
• Add ceiling and visibility grids over the CONUS
• Add QPF01 and PoP01 to 36-hours for CONUS
• Add PoP12 and QPF06 grids over Alaska, Hawaii and Puerto Rico
• Create blended inputs to support production of NDFD Weather, Snow Amount, and Ice Accumulation grids

On the early morning of October 7, Hurricane Matthew was centered just of the east-central Florida coastline and moving north. Hurricane warnings extended all the way to South Carolina. National Hurricane Center (NHC) Director Dr. Rick Knabb expressed concern that many of the people who were being told to evacuate were not doing so, and wondered how to drive the point home. NOAA/NHC Communications Public Affairs Officer Dennis Feltgen proposed to have a special broadcast at 8:30 a.m. EDT aimed at all of the TV stations from Northeast Florida to S. Carolina to make the plea. A blast e-mail was sent to these coastal stations and to the national cable networks, urging them to take the feed. Dr. Knabb stood in the NHC operations area, flanked by NHC staff members, and made a personal plea to those in harm’s way to evacuate if being told to do so by emergency officials. The five minute broadcast was carried live by CNN, The Weather Channel, and many local outlets, drawing an immediate and positive reaction, particularly on social media.

A NOAA small-business innovative research (SBIR) project was recently completed with a focus on space weather products to support the commercial satellite industry. The project titled "A Satellite Charging Assessment Tool (SatCAT)" was led by Space Hazards Applications, LLC. The goal of this project was to evaluate the needs of the satellite industry and to develop new products targeting those needs. Satellite systems are susceptible to the low-energy and high-energy particle environment in space, which can cause satellite impacts ranging from anomalous system behavior to satellite failure.

Currently real-time data, such as from NOAA’s Geostationary Operational Environmental Satellites (GOES), and numerical models are available to provide information on the conditions in space that could be responsible for spacecraft impacts. Through discussions with satellite industry representatives, the SBIR team was able to clarify how space weather impacts are managed and they identified gaps where new services would be beneficial. It is expected these results will lead to improved services to support the satellite industry with the potential for new public-private partnerships.

In early December 2016, NOAA's Space Weather Prediction Center (SWPC) successfully implemented a new experimental test product to specify the harsh radiation environment inside of geosynchronous orbit. Currently, for space weather operations, SWPC provides forecasters and satellite operators with the intensity of the greater than 2 MeV electron flux at geosynchronous orbit as measured by NOAA’s GOES satellites. Electron event alerts are issued when the flux of these electrons exceeds 1000 particles per centimeter squared per second per steradian, and the Relativistic Electron Forecast Model (REFM) provides a forecast for the electron levels for the next 3 days. These observations and model predictions are useful for satellite operators because satellite operations and survivability can be affected by the deep dielectric charging (and discharging) caused by these relativistic electrons.

For decades, NOAA's observations and model results of MeV electron levels have supported the services provided by the billions of dollars of satellite assets in geosynchronous orbit; however, there was a gap in support for the large number of satellites that operate closer to Earth, in medium Earth orbit (MEO), where the radiation belts are most intense. Now, using observations from NASA's Van Allen Probes research satellites, and in collaboration with scientists and software developers at the Johns Hopkins Applied Physics Laboratory, we fill the gap inside of geosynchronous orbit, in Earth's near equatorial plane, from about 3 Earth radii to 6.6 Earth radii (geosynchronous).

Figure 1 below illustrates one of the products now available on the SWPC website, for forecasters and outside users, that shows 1-year of 2 MeV electrons measured by the Van Allen Probes and the huge variability of the electron intensity in the region from about 3 to 6 Earth radii, just inside of geosynchronous orbit (L-shell 6.6 on this plot). The Van Allen Probes, also called the Radiation Belt Storm Probes (RBSP) are in a geosynchronous transfer orbit that allows them to sample the radiation belts twice (inbound and outbound) during each approximately 10-hour orbit. While the data in this figure provide forecasters and users with the recent past history of the radiation belts, other products provide details about recent levels and comparison to those at GOES at geosynchronous altitude. The test product will evolve to accommodate forecaster and user experience and results of this work will contribute to the implementation of similar results from radiation belt models.

Hurricane Matthew brought strong winds, devastating flooding and damaging storm surge to the southeast U.S. from Florida to Virginia - killing 49 people at least $6B in damages in the U.S. Among the many hazards of Matthew, of particular note was extreme rainfall in the Carolinas and Virginia with catastrophic flooding over the Coastal Plains of eastern North Carolina not seen since Hurricane Floyd (1999). Rainfall in many areas of the Carolina coast plain was a 1/500 year event, or a 0.2% chance of occurrence in a given year.

Hurricane Matthew touched nearly every aspect of WPC operations, from the International Desks, Medium Range, Quantitative Precipitation Forecast, Meteorological Watch, Short Range, Surface, Social Media, and Tropical Backup Desks. Of particular success was forecasts of extreme rainfall and 'High' risk of flash flooding 2 days in advance (Figure). This was only the second time in WPC history that a 'High Risk' was issued 2 days in advance. The High Risk area was expanded to include the entire coastal plain 1 day in advance of the extreme rainfall. WPC lead collaboration among local Weather Forecast Offices and River Forecast Centers to ensure a consistent public message and also briefed key decision makers, such as FEMA and State Emergency Management Offices. Such action prompted the prepositioning of resources, such as swift-water rescue units, which helped mitigate a larger loss of life from this historic event.

NWP guidance has advanced to the point where NWS can provide partners a heads-up of hazardous winter weather as much as a week in advance. After testing and refinement based on partner and WFO feedback, the NWS has included the Weather Prediction Center’s (WPC) Days 4-7 Winter Weather Outlook in the National Digital Forecast Database (NDFD) on an experimental basis during the 2016-17 winter season. This is the first WPC product in NDFD, and joins other outlook products in NDFD issued by NCEP.

The Winter Weather Outlook shows the probability for a plowable snowfall (~ greater than 3 inches) for the contiguous United States 4 to 7 days in advance, and can serve as the basis for collaboration among all NWS forecast offices and National Centers. The product is novel, as it uses the deterministic forecast created by forecasters and pairs it with an automated multi-model ensemble to provide the daily probability of exceeding 0.25" liquid equivalent snowfall. The product has two key features – extending daily winter weather forecasts out to a week, and doing so in a probabilistic manner. Combined, these features give emergency managers, the media, and the public information to mitigate issues that may arise from hazardous wintry conditions.

Ongoing survey results indicate people feel the product is useful, easy to use, and a great majority check it daily.