September 2001 Progress Report

METEOROLOGICAL DEVELOPMENT LABORATORY

MONTHLY PROGRESS REPORT

September 2001

Statistical Forecast Development (P. Dallavalle): Development of cool season MOS equations to predict ceiling height, total sky cover, and precipitation type from the 0600 and 1800 UTC forecast cycles of the AVN model has been completed. Ceiling height and sky cover forecasts generated from these equations will be available for over 1400 sites in the contiguous U.S., Alaska, Hawaii, and Puerto Rico. Precipitation type forecasts will be available for sites in the contiguous U.S. and Alaska.

Development of Eta-based MOS guidance is underway for stations in the contiguous U.S. Equations to predict the probability of 0.01 inches or more of liquid-equivalent precipitation (PoP) have been developed for the cool season. Test equations to predict wind speed and direction have also been developed. In tests on independent data, we found that the mean absolute errors of the Eta-based wind speed guidance were approximately the same as those of the NGM-based MOS guidance and several tenths of a knot higher than those of the AVN-based MOS guidance. For wind speeds of 22 knots or greater, the AVN-based wind speed guidance had higher threat scores than either the NGM- or Eta-based MOS guidance.

Five Technical Procedures Bulletins were completed and turned over to OCWWS. These bulletins describe various aspects of the AVN and MRF MOS systems. The following documents are now avail able from OCWWS or MDL: "AVN-based MOS Guidance - The 0000/1200 UTC Alphanumeric Message" by P. Dallavalle and M. Erickson; "AVN- based MOS Guidance - The 0600/1800 UTC Alphanumeric Message" by P. Dallavalle and M. Erickson; "MRF-based MOS Guidance - The Alphanumeric Message by M. Erickson and P. Dallavalle; "AVN-based MOS Total Sky Cover and Ceiling Height Guidance for the Contiguous U.S., Alaska, Hawaii, and Puerto Rico" by M. Weiss; and "MRF- based Precipitation Type Guidance for the United States" by R. Allen.

Operations and Software Support (M. Erickson): AVN-based MOS guidance for the 0600/1800 UTC forecast cycles was implemented in the NCEP operational jobstream. We will begin disseminating the new 0600/1800 UTC alphanumeric messages in October. In addition, we implemented new MRF MOS temperature, dew point, and thunder storm forecast equations for the cool season; new AVN MOS PoP and precipitation amount equations for the cool season; and adjusted sky cover relative frequencies required in the AVN and MRF MOS sky cover forecast equations.

New alphanumeric bulletins containing AVN and MRF MOS guidance for 273 stations selected by the Air Force Weather Agency (AFWA) were implemented in late September. The bulletins are available from both the 0000 and 1200 UTC AVN cycles. In October, bulletins containing the 0600 and 1800 UTC AVN MOS guidance will also be produced.

Forecast Verification Analysis (V. Dagostaro): We began investigating existing techniques to vertically adjust temperatures from grids to station elevations, such as FSL's algorithm used in IFPS. This is being done in anticipation of gridded forecast verification.

We assisted OCWWS in error-checking their statistics-on-demand system to display local and AVN MOS forecasts. We also provided August verification scores to them.

To bring our seasonal verification office note series up to date, we computed the necessary scores for the 1997 warm season through the 1998-99 cool season using our new, automatic procedure to produce summary tables. We are examining the verification of snowfall amounts, but are seeing data inconsistencies between our sources.

IFP Product Development and Evolution (M. Peroutka): MDL developers began installing an Alpha Test version of the Interactive Forecast Preparation System. The software will be delivered to a group of 18 WFOs for testing and evaluation, and it will eventually be delivered to all sites as part of AWIPS Release 5.1.2 or 5.2.1. This version of IFPS is the first to use Pentium-based workstations to enhance performance of gridded applications. One of the activities that the WFOs will pursue with the new software is to generate gridded forecasts and transmit them to a central server for mosaicking.

WFO Application Development and Support (E. Mandel): Early in the deployment of AWIPS Release 5.1.1, a few operationally critical applications (e.g., XNOW, Aviation Workstation, CAF) were found to be incompatible with the new versions of COTS packages (e.g., Tcl/Tk, Perl, Python) included with Release 5.1.1. The Local Applications Working Group (LAWG) worked closely with the regions and local application developers to quickly identify and correct the integration problems. New versions of the local applications were then posted to the Local Applications Database (LAD) for sites to download and re-install on their AWIPS platforms.

To minimize the impact of future AWIPS releases on local applications, the LAWG is developing a methodology that will allow local application developers to test operationally critical local applications prior to the release of upgraded versions of AWIPS COTS packages. The group will also look at operationally critical applications and feasibility of including them into the AWIPS baseline software so that they are tested as part of the AWIPS testing phases.

Nowcast Guidance Development (D. Kitzmiller): Operational SBN dissemination of gridded, 0-3 hour quantitative precipitation and lightning forecasts was implemented this month on schedule. The automated forecasts are based on a combination of remote sensor observations (radar, infrared satellite, and lightning strikes) and numerical weather prediction model output.