Operational Use of LAPS

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Operational Use of LAPS
Ed Szoke and Steve Albers NOAA Forecast
Systems Laboratory Forecast Research
Division LAPS Group Boulder, Colorado
Joint collaboration
with the Cooperative Institute for Research in
the Atmosphere, Colorado State University, Fort
Collins, CO
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Outline

• What is LAPS?
• What goes into LAPS
• Some examples of using LAPS
• Examples of LAPS on AWIPS

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Local Analysis and Prediction System (LAPS)

• A system designed to
• Exploit all available data sources
• Create analyzed and forecast grids
• Build products for specific forecast applications
• Use advanced display technology
• All within the local weather office

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AWIPS LAPS Grid

• LAPS Analysis Grid
• Hourly Time Cycle
• Horizontal Resolution 10 km
• Is adjustable to other resolutions
• Vertical Resolution 50 mb

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LAPS Data Sources
The blue colored data are currently used in AWIPS
LAPS. The other data are used in the "full-blown"
LAPS and can potentially be added to AWIPS/LAPS
if the data becomes available.
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LAPS Surface Analysis
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Products Derived from Wind Analysis
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Standard Deviation Check

• Compute Standard Deviation of observations-backgro
  und
• Remove outliers
• Now adjustable via namelist

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Multi-layered Quality Control

• Gross Error Checks
• Rough Climatological Estimates
• Station Blacklist
• Dynamical Models
• Use of meso-beta models
• Standard Deviation Check
• Statistical Models (Kalman Filter)
• Buddy Checking

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3-D Temperature

• First guess from background model
• Insert RAOB, RASS, and ACARS if available
• 3-Dimensional weighting used
• Insert surface temperature and blend upward
• depending on stability and elevation
• Surface temperature analysis depends on
• METARS, Buoys, and Mesonets (LDAD)

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LAPS Wind Analysis
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Using multiple radars in LAPS (reflectivity)

• Nearest radar with valid data used
• /- 10 minute time window
• Final 3D reflectivity field produced within cloud
  analysis
• Wideband is combined with Level-III
  (NOWRAD/NEXRAD)
• Non-radar data contributes vertical info with
  narrowband
• QC checks including satellite
• Help reduce AP and ground clutter

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CloudSchematic
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Cloud Isosurfaces
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Surface Precipitation Accumulation

• Algorithm similar to NEXRAD PPS, but runs
• in Cartesian space
• Rain / Liquid Equivalent
• Z 200 R 1.6
• Snow case use rain/snow ratio dependent on
  column maximum temperature
• Reflectivity limit helps reduce bright band
  effect

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Case Study Example

• An example of the use of LAPS in convective event
• 14 May 1999
• Location DEN-BOU WFO

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Case Study Example

• On 14 May, moisture is in place. A line of storms
  develops along the foothills around noon LT (1800
  UTC) and moves east. LAPS used to diagnose
  potential for severe development. A Tornado Watch
  issued by 1900 UTC for portions of eastern CO
  and nearby areas.
• A brief tornado did form in far eastern CO west
  of GLD around 0000 UTC the 15th. Other tornadoes
  occurred later near GLD.

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NOWRAD and METARS with LAPS surface CAPE 2100 UTC
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NOWRAD and METARS with LAPS surface CIN 2100 UTC
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Soundings near CAPE max at B, E and F 2100 UTC
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CAPE Maximum persists in same area 2200 UTC
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CIN minimum in area of CAPE max 2200 UTC
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Point E, CAPE has increased to 2674 J/kg 2200 UTC
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Convergence and Equivalent Potential Temperature
are co-located 2100 UTC
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Why Run Models in the Weather Office?

• Diagnose local weather features having mesoscale
  forcing
• sea/mountain breezes
• modulation of synoptic scale features
• Take advantage of high resolution terrain data to
  downscale national model forecasts
• orography is a data source!

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Why Run Models in the Weather Office? (cont.)

• Take advantage of unique local data
• radar
• surface mesonets
• Have an NWP tool under local control for
  scheduled and special support
• Take advantage of powerful/cheap computers

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LAPS Modeling System

• LAPS analyses are ideal for initializing a local
  model
• Since they use all available data
• A unique aspect of LAPS initialization is a
  method known as the Hot Start
• The Hot Start method uses the 3D cloud analysis
  from LAPS to initialize an updraft where active
  convection is underway

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Method of assigning a vertical velocity based on
3D cloud analysis.
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Status of LAPS LAPS models

• LAPS analyses are part of AWIPS (and at every
  WFO)
• Local model (currently MM5) has been run here at
  FSL with output to Boulder WFO since the mid
  1990's
• LAPS group is involved with other modeling at
• U.S. Space Centers (at 10, 3 and 1 km resolution)
• Experimental Highways program
• Hourly runs of MM5 and WRF at 12 km
• U.S. Forest Service (12 and 4 km resolution)
• Taiwan (MM5 at 9 and 3 km resolution)

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Example of a forecast for heavy rains on the
backside of Super Typhoon Mindulle. (24h
forecast of total precipitation in inches from
the 9 km run).
More forecasts can be found at http//laps.fsl.noa
a.gov/forecasts/laps_products.cgi and real-time
Taiwan 9 km forecasts at http//mscweb.cwb.gov.tw/
mm5/
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Radar mosaic at 1000 LT (0200 UTC) on 25 Oct 2004
Radar mosaic at 0800 LT (0000 UTC) on 25 Oct 2004
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LAPS 3 km analysis at 0000 UTC on 25 Oct 04 of
radar reflectivity (some blocking evident),
surface wind, and sea-level pressure.
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Closeup of the LAPS 3 km analysis, with
observations.
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LAPS 9 km analysis for 0300 UTC on 25 Oct 2004.
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LAPS 22 h storm total precipitation (scale in
mm), ending at 1200 UTC on 25 Oct 04.
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Closeup of the previous image.
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Observed precipitation matching the LAPS time
period for Typhoon Nock.
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Other LAPS fields can be displayed... here is one
for Precipitable Water (PW), ending 0200 UTC on
25 Oct 04.
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LAPS development in Korea

• Some initial LAPS was done a few years ago
• A web site with some examples is at
  http//iris.metri.re.kr/laps/