270 likes | 391 Views
NOAA’s National Weather Service. NWS RAH Aviation Initiatives. Jason Beaman National Weather Service Raleigh, NC March 4, 2008. NOAA’s National Weather Service. Initiatives Overview . The utilization of AMDAR data in various weather events Reducing thunderstorm FAR
E N D
NOAA’s National Weather Service NWS RAH Aviation Initiatives Jason Beaman National Weather Service Raleigh, NC March 4, 2008 NOAA’s National Weather Service
Initiatives Overview • The utilization of AMDAR data in various weather events • Reducing thunderstorm FAR • Highlighting crosswind impacts • Developing a conditional climatology database
Aircraft Soundings RDU GSO Average around 90 per week Average around 30 per week
Aircraft Soundings RDU GSO Average around 90 per week Average around 30 per week
Aircraft Soundings Use for short term forecasting in winter weather
Aircraft Soundings – January 18, 2007 Case .THURSDAY...A MIXTURE OF LIGHT SNOW AND SLEET CHANGING TO LIGHT FREEZING RAIN BY MID MORNING... THEN RAIN BY NOON. LITTLE IF ANY SNOW ACCUMULATION. ICE ACCUMULATION OF LESS THAN ONE TENTH OF AN INCH. HIGHS IN THE MID 30S. NORTH WINDS AROUND 10 MPH WITH GUSTS UP TO 20 MPH. CHANCE OF PRECIPITATION 80 PERCENT.
Aircraft Soundings – January 18, 2007 Case • Broad SW Flow • Strong Isentropic Lift • Cold to start due to high off of NE. Warm • advection aloft expected to quickly • change any wintry • precip to rain after • sunrise. • Only minor accumulations were anticipated
Aircraft Soundings – 10Z 2007/01/18 Precip began sooner than forecast. AMDAR sounding and dev2 RUC sounding indicated a small warm nose. Precip started as a wintry mix at RDU.
Aircraft Soundings– 12Z 2007/01/18 • AMDAR sounding at 1120Z showed the warm nose had cooled and the layer from 875-900mb was isothermal and near freezing. RDU began reporting snow shortly after 11z. • Some media and school partners become concerned about significant accumulation. • Upstream AMDAR sounding from CLT showed rapid mid level warming • Confidence remained high of a rapid changeover after sunrise.
Aircraft Soundings– 14Z 2007/01/18 • AMDAR and RUC now show the anticipated warming • A rapid changeover to rain occurred around 14z and all accumulated snow melted before noon. • This displays the value of AMDAR data and its incorporation into RUC forecasts
Aircraft Soundings Used for fire weather forecasting (Mixing Heights and Transport Winds) and synoptic scale wind events February 10, 2008
Aircraft Soundings – February 10, 2008 Case 850 mb 700 mb
Aircraft Soundings – February 10, 2008 Case Both the 12z GSO RAOB and 1242Z RDU AMDAR sounding show a deep mixed layer after the inversion breaks with westerly winds of 50+ kt at the top of the layer.
Aircraft Soundings – February 10, 2008 Case Both the 00z 2/11 GSO RAOB and RDU AMDAR sounding show a deep mixed layer up to 750 mb with westerly winds of near 75 kt at the top of the layer.
Aircraft Soundings Used for aviation forecasts (LLWS potential)
Aircraft Soundings Used for model verification and evaluation (grid point and BUFR soundings) During a potential winter storm on January 19th, 2008, AMDAR soundings helped to show that forecast BUFR soundings verified much too cold. What was thought to be a possible 2-4” snow turned into a minor event with many areas receiving less than 1 inch.
Reducing Thunderstorm FAR • Stay away from multiple hour TEMPOs or prevailing groups, especially 12+ hrs. • Utilize CB and VCTS to convey the risk to the aviation community. • Wait until you can “see the whites of its eyes”
Reducing Thunderstorm FAR 0-6 hr FAR 6-12 hr FAR 2006: 0.58 2006: 0.96 2007: 0.49 2007: 0.83 Thunderstorm Hours 2006: 1108 hours 2007: 919 hours
Reducing Thunderstorm FAR Thunderstorm Hours 2006: 1108 hours 2007: 919 hours
Reducing Thunderstorm FAR • There are a few caveats when forecasting for thunder… • For manned sites, it can be difficult for the observer to judge how close a thunderstorm is to the airport, especially at night. This can make the difference between TSRA vs. VCTS. • Automated ASOS sites can and do erroneously report TSRA when in fact it is a distant storm
Crosswinds • In strong downslope wind events in the RAH CWA (i.e. 2/10/08), crosswinds have led to significant delays at area terminals • Utilizing Aviation AFD to relay risk for high impact events • Several tools available through CWSU Fort Worth http://www.srh.noaa.gov/zfw/
Crosswind diagrams • available for hub airports • Can help to relay critical information through forecast discussion
Conditional Climatology • New conditional climatology tools in AvnFPS make it easy to create a conditional climatology database for TAF locations.
RWI July Conditional Climatology IFR fog diurnal in nature in July. However, the percent of occurrence climbs well above 20% from 09-11z with near a 30% occurrence at 10z. Over a 60% chance of MVFR ceilings during the early morning. July very similar to June with most IFR conditions occurring in predawn hours (what one expects during the summer). The IFR occurrence climbs to nearly 20% by 12z.