TECHNIQUES DEVELOPMENT PROGRAM (H. Glahn)

The primary objective of the Techniques Development Program is to develop analysis and forecast techniques which, when implemented, will help improve forecast accuracy and service to the wide range of users of NWS products. These techniques are implemented on NOAA's computer system, when appropriate, and guidance products disseminated via AFOS, facsimile, or other NWS distribution systems. Techniques are produced for basic weather elements used in public and aviation forecasts, such as temperature and visibility. Also, special emphasis is given to marine-related forecasts and to those forecasts especially associated with mesoscale processes. For many synoptic-scale forecasts, the output of operational numerical models is used to produce forecasts of weather elements of interest to users. When dealing with forecasts of shorter time and space scales, more use is made of data sets rich in information on those scales; for example, hourly and automated surface reports and radar, satellite, and profiler data. For marine-related forecasts, numerical and statistical models relate elements of interest, such as storm surge, to atmospheric analyses and forecasts.

This quarter we were heavily occupied with converting software to the CRAY, which is necessary because the HDS computers are to be discontinued. NGM-based equations for identifying regions favorable for aircraft icing during the cool season were developed. The thunderstorm identification algorithm initially developed within the Eastern Region is being ported to an AWIPS environment and is being enhanced. LAMP forecasts are being generated and provided to four forecast offices to assist in the initialization of the ICWF at those sites. An intercomparison of storm surge forecasts from four different models, including SLOSH, has begun. Considerable new and modified software to support METAR on AFOS was written and tested. Build 1 hydrometeorological software is complete and nearly integrated into the AWIPS infrastructure for providing to PRC. Build 8 of the ICWF was delivered to Charleston, West Virginia, for beta testing, developers worked with the staff at the Boise Forecast Office to design an approach to generating fire weather forecasts, and a customized version of the zone forecast program was developed to support the XXVI Olympiad.

Short-Range Weather Forecasting Task (P. Dallavalle): On February 28, all remaining MOS guidance products available from the Limited-area Fine-mesh Model (LFM) were eliminated. These products included the LFM-based MOS forecast package for Alaska, various graphics and text products for the National Centers for Environmental Prediction (NCEP), very short-range (2 to 6 hours) thunderstorm and severe storm probabilities, 12-36 hour thunder- storm and severe thunderstorm outlooks, very short-range quantitative precipitation amount probabilities, and some specialized thunderstorm probability products.

Efforts to convert our operational and developmental systems from the HDS mainframe to the CRAY platform continue. Nearly all of the operational codes that produce the centralized MOS guidance from the Nested Grid Model (NGM) have been converted. The MOS forecast program, pre-processor, post-processor, and most codes generating the alphanumeric and BUFR messages have been modified and are scheduled for implementation on April 10. We are currently modifying the software modules that create the NGM-based MOS graphics products. At the same time that we are converting our processing to the CRAY, we are establishing new archives for the NGM, Eta, and Aviation (AVN) models. The next major MOS development for the 6- through 72-h projections will be AVN-based; some MOS products will also be available from the Eta model.

Medium-Range Weather Forecasting Task (M. Erickson): NCEP has requested TDL support for temperature and precipitation forecasting for days 3 through 7 and for the week two period. NCEP specifically requested ensemble-based statistical products. Part of our plan for statistical development from the Medium-Range Forecast (MRF) model ensembles includes generation of guidance for NCEP's Hydrometeorological Prediction Center (HPC). We are currently coordinating with HPC to determine the forecast format. Since MRF forecasts of precipitation amount are now available from the ensembles, we've begun work to generate ensemble-based MOS PoP forecasts. Work to convert the existing MRF-based MOS system from the HDS mainframe to the CRAY is also underway. As part of this effort, we are planning to modify the MRF archives, initiate an archive of ensemble model output that can be used to support the week two guidance, and generate a set of ensemble-based MOS forecasts by using the current MRF-based MOS equations on each of 14 MRF runs.

National Verification Processing Task (V. Dagostaro): In support of the AFOS-Era Verification (AEV) program, we developed a plan to convert and enhance the central data processing software which is currently executed on the HDS mainframe to run on a UNIX-based platform. Work has begun on implementing the first phase of the plan, namely, coordinating with NCEP to collect AEV data on the CRAY. We are also developing the software to process and store the data. The verification processing will be moved from the HDS computer to a local workstation.

Quality control of the AEV data for the October 1995 - February - 1996 period has been completed. The quality control/inventory summaries will be distributed to the Regional Scientific Services Division Chiefs after the end of the 1995-96 cool season in March.

Severe Weather Prediction Task (R. Reap): We are currently converting the operational NGM-based three-dimensional trajectory model to run on the CRAY mainframe under the UNIX operating system. Source code to handle input of NGM forecast fields in GRIB format has been successfully written and tested. Parcel trajectories computed from the new code are identical to those generated by the HDS-based operational trajectory model. The program to analyze the initial temperature and mixing ratio at trajectory origin points has been converted to handle radiosonde data and surface land and ship synoptic data in BUFR format. Tests are underway to complete checkout of the analysis program and subsequent model routines that generate 24-, 36-, and 48-h forecasts of temperature and dew point.

New NGM-based MOS probability equations to identify regions favorable to aircraft icing over the contiguous U.S. were developed for the October 1 - March 14 cool season period. The equations were developed from NGM forecast variables, national lightning location data, and pilot reports (PIREPS) from the NCEP Aviation Weather Center's (AWC's) data archives. The method used is similar to the approach for developing the warm season icing equations described in the previous quarterly progress report. Details of the development and verification statistics will be presented later this year to the Committee for Analysis and Forecast Techniques Implementation (CAFTI) for approval of operational implementation in early fall. The probability forecasts will be used as guidance by AWC forecasters in issuing operational icing notices for use by the aviation community. The forecasts will be displayed in graphical form on AWC's N-AWIPS system.

Technical Procedures Bulletin No. 430 entitled "Probability Forecasts of Clear-Air Turbulence for the Contiguous U.S." was completed and distributed. R. Reap presented a paper by the same title at the 13th Conference on Probability and Statistics held in San Francisco in February. Both documents describe the NGM-based MOS system currently used to produce turbulence proba- bility forecasts for the AWC. This system has been detailed in previous progress reports.

LOCAL TECHNIQUES DEVELOPMENT PROJECT (W. Seguin)

0-3 Hour QPF and Severe Weather Task (D. Kitzmiller): As part of the 0-3 h QPF development, we continued to archive GOES-8 imager data for channels 2, 3 and 4, Eta model forecasts, and surface observational data over areas of the United States where Radar Stage III analyses are prepared and archived and where disturbed weather was observed. We also implemented an automated system for ingesting, decoding, and placing GOES channel four data on the HRAP polar sterographic grid. This procedure will supply real-time experimental forecast applications with satellite data.

Software and documentation for dumping and inventorying WSR-88D Archive II tapes was provided to the Science and Operations Officer at the St. Louis forecast office. In addition, a joint paper with a St. Louis forecaster was submitted for the upcoming AMS Weather Analysis and Forecasting Conference.

Thunderstorm Identification and Forecasting Task (S. Smith): A number of enhancements were made to the thunderstorm identification algorithm initially developed by the Sterling forecast office and since ported to the AWIPS Government Development Platform by TDL. Code to properly identify, tag, and track cells was completed. To minimize the effects of spurious 6-min cell motions, the code was altered to provide time-averaged (up to 30-min) cell motion vectors. The algorithm logic was enhanced to allow the thunderstorm threat warning to be activated when a cell is within a prespecified distance of an airport, even if no lightning is detected. Previously, cloud-to-ground lightning had to be present for a warning to be activated. In addition, if high reflectivity values are observed near an airport with only weak VIL values and no lightning, a warning will also be activated.

Algorithms to estimate the probability of hail and severe weather were added to the technique. The user now has the option to have these results displayed along side the cell they represent and also be part of the text product. For the graphic display, warning circles around thunderstorms are now color-coded based on their proximity to the nearest airport.

The software is now being installed on the AWIPS Pathfinder system. We plan to conduct an evaluation of the technique during the spring-summer convective season.

A paper was presented at the 18th AMS Conference on Severe Local Storms held in San Francisco entitled "How Soon Can a ThunderStorm be Identified? A Comparison of Satellite-Observed Cloud-top Cooling and the Onset of Cloud-to-Ground Lightning."

Work is continuing on the development of a technique for determining the minimum satellite cloud-top temperature for radar identified thunderstorms. A satellite parallax correction is being added to set a physical limit to the separation distance between a radar cell and its corresponding satellite cloud top.

Local AWIPS MOS Program (LAMP) Task (W. Seguin): An analysis of the LAMP ceiling height forecasts for 1100 and 1400 UTC cool season was completed this quarter. A careful examination was made of the forecast bias and other skill scores. The results for both dependent and independent data were encouraging, and verified that the adaptive thresholding technique used in the scaling of the ceiling forecasts was performing as expected.

Work continued on wrapping up the equation and threshold development. In some instances, particularly for some of the start times first developed, selected equations or thresholds were either not developed or were developed differently than those developed last. For example, backup equations and threshold for "Obstructions to Vision" were rederived this quarter as were thresholds for 0500 UTC warm one hour PoPs and thresholds for 0800 UTC warm season and 1400 UTC cool season "Sky." Furthermore, an error was found and corrected involving the development of all eight cool season start times for precipitation type.

LAMP forecasts are being generated and shipped to four forecast sites (WSFO's Charleston, Norman, Atlanta, and Boise) every 3 hours for operational use in generating forecasts and initial- izing the Interactive Computer Worded Forecast. In addition, LAMP display software was loaded onto a workstation and demonstrated at the annual AMS meeting held in Atlanta. This display software was also shipped to WSFO Charleston for their use and evaluation.

Because the HDS mainframe computers will be removed this year, all important LAMP development code and JCL were copied to permanent files on the workstations in SSMC2. In addition, equations and thresholds datasets stored on magnetic tape were copied to optical disks on these workstations.

Heavy Precipitation Forecasting Task (J. Charba): Most of the development effort concentrated on the preparation of implementation software for LAMP QPF. Efforts are being made to make the QPF implementation software as similar as possible to the existing LAMP implementation software.

In addition to this activity, Dr. Charba participated in and is supporting the NWS disaster survey being conducted on the severe flooding which occurred in the northwestern United States this quarter.

MARINE ENVIRONMENTAL PREDICTION PROJECT (W. Shaffer)

Hurricane Storm Surge Forecasting Task (W. Shaffer): A model intercomparison is underway, comparing results from SLOSH, the Meteo France model of Pierre Daniel, and a model named "The Arbitor Of Storms" (TAOS) tailored for the Organization of American States by Charles Watson. The Hawaiian island of Kauai was chosen for the intercomparison since the island was recently hit by hurricane Iniki and because the island is similar to many of the Caribbean islands. In addition, the NWS already had a SLOSH model developed for Kauai. Topographic and bathymetric maps were provided to Meteo France; Watson chose to run his model from a preexisting database of terrain and bathymetry. A series of 9 hypothetical hurricanes was chosen, giving a variety of storm landfall directions, forward speeds, and categories.

Dr. C. S. Wu has been added to our staff to work on the problem of modeling waves generated by hurricanes as they propogate toward the coastline. The importance of this work was highlighted by hurricane Opal (October 1995). Opal generated surges of 8-10 feet, as measured by tide gages and still high water marks. However, waves caused runup and setup that extended to about 24 feet along portions of the Gulf coast.

Extratropical Storm Surge Forecasting Task (W. Shaffer): We have turned over to NMC the code to implement our extratropical surge model for the Gulf of Mexico and for Norton Sound, Alaska. In the meantime, an interesting case of an extratropical storm forming off the Florida/Georgia coastline in early March is being investigated.

LOCAL TECHNIQUES DEVELOPMENT PROJECT (D. Ruth)

Field Applications Assistance Task (R. Beasley): Work continued in preparation for the implementation of the METAR and TAF codes on July 1, 1996. Local testing of the SAODECII program to decode METAR observations, including concurrent testing with the Hourly Weather Roundup Program, was completed and plans are being made to begin a field test. Revisions to the aviation forecast monitoring program, MONITR, to allow it to swap to the terminal forecast message decoder were completed, and the program was mailed to two forecast offices for field testing. An initial version of the new aviation forecast decoder, TAFDEC, was completed and local testing has begun. This program will be field tested with the MONITR program and the national verification program, VERIFY, during the third fiscal quarter.

SAODECII was also updated this quarter to allow it to process more than 200 ASOS sites. This was necessary because the number of commissioned ASOS stations exceeded 200 on March 1.

A new program, WRTSAODATA, was completed that outputs four AFOS products containing decoded surface data in ASCII format. This program was requested by the Mid-Atlantic River Forecast Center for their operations. The program will also be used during the End-to-End METAR/TAF Communications test being conducted by the National Weather Service as a way of confirming the receipt of surface observations.

The program which retrieves individual observations from collectives, MOBSEP, was updated to allow it to properly retrieve Mexican METAR observations. This was a more difficult problem than normal because these observations do not have a record separator or the phrase METAR/SPECI.

The verification program, VERIFY, was updated to allow the number of verification stations transmitted to the central computer facility to be any number from one to 12. Previously, only two sites could be communicated to the central facility.

CHKSFCOBS, a new program prepared last quarter to detect missing aeronautically required elements in commissioned ASOS observations, continued to undergo field testing this quarter. Modifications were made to the code to allow the program to be run on all desired stations during a single execution. This greatly reduced the amount of CPU time required as compared to the original version which processed stations individually open receipt.

WFO Application Development Task (D. Ruth): Design, Development, and Testing teams continue to develop hydrometeorological (HM) applications for the early builds of AWIPS. This work is being carried out in part by TDL and its application support contractor, GSC, and in part by the AWIPS Prime Contractor, PRC. Efforts have became more focused this quarter as the deadline for the delivery of the Build 1 HM software approaches. HM Build 1 software to be delivered in late April include GRIB Decoder, NEXRAD Image and Graphic Overlay Display Generation, Contouring, Parameter Derivation of Grids, and stand alone portions of the WFO Hydrologic Forecast System (WHFS). TDL and PRC are working closely on integrating the HM applications into the evolving PRC AWIPS Build 1 software. This includes extensive work in the areas of accessing and storing grid and NEXRAD image data ob jects, rendering HM data on the screen, and handling log and error messages. Formal HM testing and extensive user testing of the Build 1 HM software integrated into PRC AWIPS Build 1 software is planned for the NMT system in early May.

DDT guidelines have been finalized for the usage of FORTRAN extensions and naming conventions. TDL, OH, and GSC personnel are working on implementing configuration management software (PCMS) purchased for the headquarters GDP to support HM applica- tions development for AWIPS.

Software design reviews were conducted this quarter for the NEXRAD Graphic Overlay Display and Derived Parameter on Grids applications. Code Walkthroughs were conducted for GRIB Decoder, Contouring, NEXRAD Image Display and Derived parameter on Grids applications.

Product Generation Task (M. Peroutka): Build 8.0 of the Inter active Computer Worded Forecast (ICWF) was developed and delivered to the Forecast Office in Charleston, West Virginia, (CRW) for beta testing this quarter. This build allows forecasters to use ICWF to issue updated forecasts. The program which generates updated Zone Forecasts is careful to preserve any hand-edited changes which the forecaster may have made to the original product. Build 8.0 also includes an improved version of the formatter for long-fused Watch/Warning/Advisory (WWA) products. The programs which generate two tabular products (CCF and RDF) have been enhanced to support days 3 through 5.

A customized version of the Zone Forecast program was developed to support the XXVI Olympiad. This software was tested in Peachtree City at the Olympic Weather Support Office (OWSO) in March. TDL developers worked closely with the OWSO staff to hand off code for the WWA program. This portion of the ICWF forms the basis for the Olympic WWA program.

TDL developers worked closely with the staff at the Boise Fore cast Office (BOI) to design an approach to generating Fire Weather Forecasts. These techniques are being developed jointly by TDL and BOI.

TDL and FSL developers continued to work closely to build the AWIPS Forecast Preparation System (AFPS). Efforts this quarter focused on integrating TDL's MOS ingest and product formatting code into the AFPS development system. Almost all of the source code has been checked in. Several programs have been built successfully.

Several members of the ICWF team attended the 76th annual meetingof the American Meteorological Society in Atlanta. Mark Oberfield presented a paper entitled "Creation of Aviation Forecasts from a Digital Database." Matt Peroutka contributed to another paper named "Weather Information Display, Analysis and Product Generation Tools Used for Support of the 1996 Summer Olympic Games: Daily Forecasts." TDL developers also provided demonstrations of the ICWF and LAMP using workstations located in the PRC booth.

Interactive Techniques Development Task (D. Ruth): Two new graphical user interfaces were developed for ICWF Build 8.0. The first interface enables forecasters to select those zones for which an updated forecast will be issued. Selections are ini tialized according to changes made in the digital database. The second interface allows offices to create gridpoint to zone set-up files. This is one of several interactive programs which are being developed to facilitate the creation of site-specific ICWF configurations by local offices with AWIPS.

The WWA interface has seen several improvements for Build 8.0, and the link between it and the statement service has stabilized considerably. An enhancement was made to the ICWF matrix editor to facilitate simultaneous editing of early and extended periods. Flexible time period boundaries may be set by the forecasters.

A spectrum of dark colors specific to forecast elements were developed for ICWF image displays. Dark images contrast well with lighter graphic and text objects. ICWF colors were provided to PRC for use by hydrometeorological applications in AWIPS.

A prototype of a slider bar interface which enables forecasters interactively to adjust thresholds for the initialization of categorical forecasts was distributed in Build 8.0. This technique can be used to tailor MOS or ETA forecast guidance. Resulting thresholds are interpolated in time and can be applied to intermediate high-resolution gridfields without disrupting the time and space continuum of the model guidance. A fully functional capability is planned for Build 9.0.

TDL staffers attended the Northeast Storm Conference in Saratoga Springs, New York, in March. Todd Patstone and David Manning demonstrated the ICWF and presented a poster session.

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