The 13km RUC Nearing Implementation at NCEP Changes, testing, plan

1
The 13km RUC - Nearing Implementation at
NCEPChanges, testing, plan
Stan Benjamin John Brown Kevin Brundage Dezso
Devenyi Georg Grell Bill Moninger Steven Peckham
Barry Schwartz Tanya Smirnova Tracy Lorraine
Smith Steve Weygandt Geoff Manikin NCEP/EMC
RUC web site - http//ruc.fsl.noaa.gov

• Aviation Weather Center Monday 16 May 2005

2

• - Implementation of 13km RUC in operations at
  NCEP
• Assimilation of new observations
• - GPS-precipitable water ? improved moisture
  forecasts
• - METAR cloud/vis/current weather ?
  improved ceiling and vis fcsts
• - Mesonet
• - 915 MHz boundary-layer profilers, RASS
  temperatures
• - Soil moisture/temp nudging
• Model changes New versions of
• - mixed-phase cloud microphysics (NCAR-FSL)
• - Grell-Devenyi convective parameterization
• - Revised radiation cloud effects
• - Corrected treatment of frost formation
• ? improved icing and convection
  forecasts, cloud/sfc temp, vis forecasts
• Improved post-processing visibility, precip
  type, 20km/40km look-alike
• Hourly forecasts to be extended to 9h from 3h
  duration
• (at 01z, 02z, 04z, 05z, )

3
AREA FORECAST DISCUSSION...UPDATE NATIONAL
WEATHER SERVICE GOODLAND KS 1155 AM MDT SUN MAY
8 2005 .UPDATE... A SHORTWAVE TROF WAS EVIDENT
THIS MORNING AT BOTH 700 AND 500 MB OVER
SOUTHEAST WYOMING...SPREADING TOWARD THE TRI
STATE AREA IN NORTHWESTERLY FLOW ALOFT. THE
ETA/NAM WAS HANDLING THIS FEATURE WELL. THE RUC
IS A BIT TOO DRY.

• What is different qualitatively in precip/surface
  behavior with the RUC13?
• Definitely a wetter model than the previous
  RUCs
• - Surface dewpoint, moisture aloft
• - CAPE
• - Precipitation
• But drier over warm oceans

4
2005 - 13km RUC implementation plan February-May
2005 - Real-time parallel testing EMC -
Intercomparison RUC13 vs. RUC20 by EMC, FSL -
daily inspection w/ graphics, statistics (raob,
surface) - Transfer afterward to
NCEP/NCO May-June 2005 - Real-time parallel
testing NCO - 4-week field test evaluation
NWS regions, AWC, SPC STARTING NEXT
WEEK - Retrospective testing (at NCEP) for cold
season - Report on testing to EMC, NCEP
directors June-July 2005 - Operational
implementation
5
13km RUC
20km RUC
Terrain elevation - 200 m interval

• Improvements expected from 13km RUC
• Improved near-surface forecasts
• Improved precipitation forecasts
• Better cloud/icing depiction
• Improved frontal/turbulence forecasts

NCEP computer upgrade allows RUC13 to run in same
time as current RUC20
6

• RUC History NCEP (NMC) implementations
• - First operational implementation of RUC
• - 60km resolution, 3-h cycle
• 1998 40km resolution, 1-h cycle,
• - cloud physics, land-sfc model
• 2002 20km resolution
• - addition of GOES cloud data in assimilation
• 2003 Change to 3dVAR analysis from previous OI
• (April)
• 2005 13km resolution, new obs, new model
  physics
• (estimated June-July)
• 2007 WRF-based Rapid Refresh to replace RUC

7
13km RUC
20km RUC
Soil moisture 22z - 21 Feb 2005 Dark blue
water
More detailed coastline with 13km resolution
8
RUC 3DVAR development/testing
RUC Analysis Goals

• Initial fields that yield very accurate
• short-range forecasts (down to 1-h)
• - upper-level wind forecasts
• - aviation hazards (turbulence, icing,
  ceiling/visibility)
• - surface sensible weather forecasts
• Hourly assimilation of all conventional
  observations, including surface observations
• Close analysis fit to all observations,
  especially METAR and rawinsonde

9

• 13-km 3DVAR running at FSL since summer 2004,
• NCEP testing in progress
• 5 aspects of RUC13 3DVAR analysis
• 1. New observations assimilated
• 2. Cloud analysis (GOES, METAR
  ceiling/vis/curr-wx)
• 3. Use of surface obs throughout PBL (NCEP Fall
  2004)
• 4. Revised control variable for moisture
  (pseudo-RH)
• 5. Soil moisture/temp nudging

10
Observations used in RUC Data Type
Number Freq. ------------------------------
-------------------- Rawinsonde 80
/12h NOAA profilers 30 /
1h VAD winds 110-130 / 1h
Aircraft (V,temp) 1400-4500 /
1h Surface/METAR 1500-1700 /
1h Buoy/ship 100-150 / 1h GOES
precip water 1500-3000 / 1h GOES cloud
winds 1000-2500 / 1h GOES cloud-top pres
10 km res / 1h SSM/I precip water
1000-4000 / 6h --------------------------------
------------------ GPS precip water 300
/ 1h Mesonet 5000 / 1h PBL
prof/RASS 25 / 1h METAR-cloud-vis-w
x 1500 / 1h ------------------------------
--------------------
Cloud analysis variables
NCEP RUC20 operational
RUC13 (at NCEP June 2005)
11

• Obs quality issues with RUC13
• Mesonet data
• Winds of questionable quality widespread
  siting, anemometer height problems
• Will be later added from approved mesonet
  providers (e.g. OK Mesonet)
• Assigned larger obs errors
• Boundary-layer profilers
• Implementation deferred (decision 6 May 05)
• Quality appears to be poorer than NOAA-network
  profilers better monitoring needed
• Rawinsonde moisture profiles
• Intermittently shows incorrect saturation in
  lowest 200 mb
• Detected in RUC13 processing using GPS PW
  neighbors

12

RUC Cloud Analysis

• Use multiple data types to modify cloud,
• hydrometeor, and moisture fields
• -- GOES cloud-top pressure/temp
• (implemented in 2002 w/ RUC20)
• -- Surface METAR (clouds, weather, visibility)
• (2005 w/ RUC13)
• Construct 3-d logical arrays (YES/NO/UNKNOWN)
• for clouds and precipitation from all info
• Clear/build moisture, cloud, precipitation
  fields
• Safeguards for known problems (marine stratus,
• convective clouds, snow, nocturnal inversion)

13
Assimilation of METAR cloud/wx/vis Better
analysis, prediction of ceiling and visibility

• Nearest station up to 100 km distance
• Assigned in ASL, includes terrain intersection
  for low clouds
• - Maps info to 3-d cloud, precip. Y/N/U arrays
• - Change cloud water, cloud ice, water vapor
  fields as follows
• Build for BKN / OVC / Vertical Visibility
• - 40 mb thick layer (2 model levels)
• - 150 mb thick for precip. GOES clouds
• - Can build multiple broken layers
• Clear
• - Up to cloud base (if needed)
• - to 12,000 feet for CLR report

14
Background (previous 1h fcst)
Cloud water mixing ratio
Sample modification of cloud water from METAR
cloud/weather/ visibility observations
1700 UTC 27 Jan 2004
400 Pres (mb) -500- -600- -700- -800- -900-
1000
analysis with METAR cloud/ visibility obs
Cloud water mixing ratio
Relative Humidity
15
Sample ceiling analysis impact
Analysis WITH cld/wx/ vis obs
Ceiling from RUC hydrometeors
Observations
1800 UTC 17 Nov 2003
Aviation Flight Rules
Analysis NO cld/wx/ vis obs
cloud ceiling height (meters)
16
GPS precipitable water observations 200-300/h -
All-weather obs
17
Bias
RUC20 RUC13
RMS difference
Analysis fit to GPS precipitable water obs over
CONUS
18
3h forecast fit to GPS precipitable water obs
over CONUS
Bias
RMS difference
RUC20 RUC13
19
CAPE impact from two RUC enhancements
0000 UTC 21 Apr 2004
3h fcst WITH enhancements
3h fcst OPERATIONAL

• RUC enhancements
• Use of METAR obs through
• boundary-layer depth (Sept 04)
• Assimilation of GPS precipitable
• water observations (RUC13 - Jun05)

Tornadoes
Severe reports
NWS SPC Norman, OK
20

• September 2004 Change to oper RUC20 analysis
• use boundary-layer depth in assimilation of
  surface/METAR obs ? better temp/dewpoint/CAPE/conv
  ection forecasts
• Spring 2005 Will be first convective season to
  see effect of PBL-based assimilation. Also will
  be evident in RUC13 results.

21
Problems with model PBL structure in RUC
analysis Sounding structure is sometimes not
realistic and does not account for boundary-layer
depth No accounting in current RUC analysis for
vertical correlation of forecast error near
surface based on estimated boundary-layer depth
22
Original slides from April 2004
PBL-based METAR assimilation Problem
Representativeness of sfc data in PBL not
used Design Use METAR data through PBL
depth from 1h fcst Create extra
pseudo-residuals (obs-bkg) in PBL
RUC oper analysis 18z 3 Apr 02 IAD
23
PBL-based METAR assimilation Use METAR data
through PBL depth from 1h fcst
RUC oper analysis 18z 3 Apr 02 IAD
Effect of PBL-based METAR assimilation
x
x
x
x
24
EMC/Geoff Manikin RUC20/13 comparison web
page http//www.emc.noaa.gov/mmb/ruc2/para
25
EMC/Geoff Manikin RUC20/13 comparison web
page http//www.emc.noaa.gov/mmb/ruc2/para
26

• Revised moisture analysis design in RUC13
  pseudo-RH
• Current RUC20
• Separate analyses of in-situ moisture
  observations and precipitable water obs with
  intervening recalculation of observation
  innovations
• Use of log (water vapor mixing ratio-qv) as
  analysis control variable for moisture.
• Some good characteristics (continuous in 3-d
  space, will not go negative) but not responsive
  to increase RH (e.g., from 10 to 50)
• Related to summer 2004 RUC analysis fixes to
  avoid CAPE noise problems
• Revised RUC13
• Fully integrated moisture analysis with both
  in-situ and precipitable water obs treated
  together
• Uses pseudo-RH (RH relative to background sat
  qv) as analysis control variable

27

• RUC13 matches moisture profiles much better than
  OperRUC20
• Use of pseudo-RH moisture control variable
  instead of
• Log (water vapor mixing ratio) used in RUC20.

RUC13-exp
RUC20-ops
TUS soundings 12z 18 April 2005
28

• RUC13 forecast soundings at TUS also better than
  RUC20
• - Reasons
• Assimilation of GPS PW
• Improved soil moisture in RUC13
• Better physics/assimilation, soil nudging

RUC 6h forecasts valid 12z
RUC13-exp
RUC20-ops
TUS soundings 12z 18 April 2005
29
Oper RUC20
2m dewpoint - 00z 22 Apr 05 - excessive dryness
in RUC20
6h fcst valid 00z
Analysis valid 00z
36h after restoration of oper RUC20 soil moisture
Para RUC13
30

• RUC13 analysis includes nudging of soil
  moisture and temperature
• Dependent on
• 2m T/Td 1h forecast errors
• Only in daytime (zen angle gt 0.3) with no
  clouds or precipitation (defined after METAR/GOES
  cloud assimilation)
• Developed as part of NOAA New England
  High-Resolution Temperature (NEHRT) Program
• - FSL, ETL, NSSL, NCEP/EMC

Oper RUC20
Para RUC13
31
Oper RUC20
Para RUC13
32
Oper RUC20
Typical CAPE effect from improved soil moisture
and moisture analysis in RUC13 12h
forecasts Valid Thur evening 00z- 5 May 05
Para RUC13
33
Oper RUC20
0-12h prec
CAPE
Para RUC13
More convective precip in RUC13 over land, less
over ocean
Typical CAPE effect from improved soil moisture
and moisture analysis in RUC13
34
Typical CAPE effect from improved soil moisture
and moisture analysis in RUC13
35
MODEL PHYSICS CHANGES FOR RUC13

• Land-surface model When ground temp lt 0C, vapor
  
• deposition on ground now based on ice
  saturation, not water
• Diminishes unrealistic widespread nighttime
  fog formation,
• especially over snow cover
• Evident in real-time comparisons between RUC13
  and oper RUC20 for visibility forecasts,
  especially at night.

36
Test of Ice Saturation for Surface
Latent-heat Flux
13 Apr 2004 - 18h fcst valid 06z
Cloud-water mixing ratio at lowest model level
Oper RUC20
Revised RUC20
Reduction in fog, especially over snow. Much
improved visibility forecasts, avoids high bias
37
RUC13 Model Physics Changes (cont)

• -Convection (Grell-Devenyi scheme)
• Empirically estimated ensemble weights to
  improve
• quantitative precipitation forecasts
• RUC20 - dCAPE/dt
• - Kain-Fritsch CAPE relaxation
• - low-level vertical velocity
• - moisture convergence
• RUC13 - adds Arak-Schu scheme for cloud work fn
• - no KF over ocean, reweighted all closures
• Addition of convection-inhibition ensemble
  members
• CAPE dp 25, 75, 125 mb fn ( TKE)
• Does not produce significant outflows (slightly
  more in RUC13)
• Still no shallow convection in RUC13 Grell-Dev
  scheme
• Still much less sounding modification than
  NAM/BMJ
• Eliminated extreme surface drying showing up in
  certain
• situations

38
RUC13 Model Physics Changes (cont)

• Microphysics NCAR and FSL
• Overall goal To incorporate best
  understanding of
• warm-rain and mixed-phase processes
  important
• for cold-season aviation operations
  (inflight icing, pre-takeoff
• deicing requirements, low ceiling,
  visibility) into operational
• NWP models.
• Major changes for RUC13
• Dropsize distribution now transitions
• between drizzle and rain
• Replace Kessler with Barry-Reinhardt
  autoconversion
• (collision-coalescence cloud droplets to
  rain)
• ? Correct ice-particle accretion (ice ?
  snow more readily)
• ? Ice particle fall speed no longer set to
  1 m/s

39
RUC13 Model Physics Changes (cont)
- Snow - Diagnosis of snow-particle size
distribution - Operational RUC20 -
Depends on snow mixing ratio - RUC13
- Depends on temperature ? - Graupel
- Growth/depletion via deposition/sublimation
Change size distribution from gamma to
inverse exponential - Results in less graupel
40
EAST COAST BOMB 22-23 JAN 2005
RUC13 9h Forecast for 0900 UTC 23 Jan
Sfc wind, temp, 3-h pcpn
Precipitation type
X-sec
Snow
Rain
41
HYDROMETEOR CROSS SECTIONS
RUC 9h Forecasts for 0900 UTC 23 Jan
CLOUD-WATER MIXING RATIO (qc)
RUC13
RUC20 - OPER
Atlantic MA ME
42
Hydrometeor Mixing Ratios (Cont)
RUC 9h Forecasts for 0900 UTC 23 Jan
RAIN WATER (qr)
RUC13
Oper - RUC20
Atlantic MA ME
More rain in RUC13 different rain processes
43
Hydrometeor Mixing Ratios (Cont)
RUC 9h Forecasts for 0900 UTC 23 Jan
CLOUD ICE (qi)
RUC13
Oper RUC20
Atlantic MA ME
Less ice in RUC13 modified ice-particle
accretion
44
Hydrometeor Mixing Ratios (Cont)
RUC 9h Forecasts for 0900 UTC 23 Jan
SNOW (qs)
Oper RUC20
RUC13
Atlantic MA ME
More snow in RUC13 modified ice-particle
accretion
45
Hydrometeor Mixing Ratios (Cont)
RUC 9h Forecasts for 0900 UTC 23 Jan
GRAUPEL (qg)
Oper RUC20
RUC13
Atlantic MA ME
Less graupel in RUC13 More supercooled liquid
water (important for icing/aviation)
46
RUC13 Model Physics Changes (cont)

• Coupling between physics processes
• Reduction of cloud attenuation coefficients
  for shortwave and longwave transmission to
  match WRF/MM5
• Effects of microphysics changes (more ice
  fallout - results in less Cirrus, Cirrostratus)
  on radiation budget and surface temperature
  forecasts
• Detrainment of hydrometeors from convection
  to the grid
• scale More latent heating due to freezing
  on explicit scale in convection

47

• 2004/05 - 13km RUC testing
• Fall 2003 - 13km RUC model real-time testing
  started
• - Initialized from 20km analysis, run 4x daily
• May 2004 Full 1-h cycle testing started
• Evaluation
• - FSL verification against raobs, sfc,
  precipitation obs
• - 13km RUC vs. backup RUC raob
• - NOAA New England High-Resolution Temp Project
• - ETL, NSSL evaluation
• - June-Sept 2004
• - Experimental use in NWS Central and Eastern
  Region WFOs
• - July 2004 current
• - Available via LDM from FSL (contact Tracy
  Smith)
• - NCEP pre-implementation testing started Jan
  05

48
RUC20
6h precipitation forecast Valid 18z Thurs 30 Sept
2004 RUC20 (oper) vs. RUC13
RUC13
49
RUC13 9h fcst - valid 03z- 31Mar05
RUC20 9h fcst - valid 03z - 31 Mar 05
Obs radar - 0235z - 31 Mar 05
50
RUC20 12h fcst - valid 03z- 12May05
Obs radar - 0115z - 12 May 05
RUC13 12h fcst - valid 03z- 12May05
51
Oper RUC20
CAPE
Exp RUC13
Thursday 21 April 2005 12z
Improved moisture analysis in RUC13 pseudo-RH
instead of ln-qv - use of GPS PW
52
Oper RUC20
Radar summary 1400z
Exp RUC13
Thursday 21 April 2005 12z
Improved moisture analysis in RUC13 pseudo-RH,
GPS PW
53
RUC20 vs. RUC13 precipitation forecast (12h)
verification Winter Jan-Feb 05 (verified w/ NCEP
24h precip analysis)

• RUC13
• higher equitable threat score
• bias closer to 1
• Why?
• Improved initial conditions
• Improved precip physics
• Higher horizontal resolution

54
RUC20 vs. RUC13 precip forecast 24h period
ending 12z - 12 Feb 2005 (verified w/ NCEP 24h
precip analysis)
obs
RUC20
RUC13
(inches)
55
Ceiling analysis comparison of Operational RUC
(top) with the NCEP RUC13 (bottom)
Scale (AGL) x 1000 ft
Analyses at 1800 UTC on 9 May
56
Observations cigs lt 5000 ft only
Observations cigs lt 3000 ft only
Observations cigs lt 500 ft only
Point observations at 1800 UTC 9 May, for
different ceiling heights, to compare to previous
figure. 4 areas of lower cigs are apparent.
-New England Better coverage of lower cigs by
RUC13 looks good. -Northern Plains/Midwest more
coverage of lower cigs in RUC13, tho similar
coverage for very lowest categories. Again, obs
for aob 5000 ft cigs support RUC13. -West
Coast both have lower cigs in LA area. More
coverage on RUC13 in intermountain west, not sure
if this is overdone or not. -Northeast TX RUC13
looks better here.
57
Ceiling 1h forecasts comparison of Operational
RUC (top) with the NCEP RUC13 (bottom)
Scale (AGL) x 1000 ft
Forecasts at 1900 UTC on 9 May
58
Ceiling 3h forecasts comparison of Operational
RUC (top) with the NCEP RUC13 (bottom)
Scale (AGL) x 1000 ft
Forecasts at 2100 UTC on 9 May
59
Focus on the Midwest and Northern Plains. Quite
a few obs have cigs lt 3000 ft, but only a few
lower vis reports. It does appear that low
clouds lurk JUST east of the eastern WI
shoreline, like what was found in the RUC
Operational run.
60
Focus on eastern Texas. Cigs lt 3000 ft are
relatively widespread.
61
12-h surface forecasts verified vs. METAR obs 25
Nov 2004 18 Jan 2005 - every 3 h
(00z,03z,21z) 20-km RUC (oper) vs. 13-km RUC

• METARs in RUC domain (East/West of 100 W)
• RUC13 uses 13km mini topography field derived
  from 3.3km topo

62
Rawinsonde verification - wind - RUC13 vs. RUC20
20km 13km

• RUC13 provides improvement in
• 150-300 mb winds

63
Rawinsonde verification - RH - RUC13 vs. RUC20
20km 13km

• RUC13 provides much better RH forecasts
• With RUC13, 3h RH forecasts are more accurate
  than 12h RH forecasts (unlike RUC20)
• ? GOES and GPS used (more) effectively, physics
  improved also.

64
2005 - 13km RUC implementation plan February-May
2005 - Real-time parallel testing EMC -
Intercomparison RUC13 vs. RUC20 by EMC, FSL -
daily inspection w/ graphics, statistics (raob,
surface) - Transfer afterward to
NCEP/NCO May-June 2005 - Real-time parallel
testing NCO - 4-week field test evaluation
NWS regions, AWC, SPC - Retrospective testing
(at NCEP) for cold season - Report on testing to
EMC and NCEP directors June/July 2005 -
Operational implementation
65
RUC13 output grids

• Same products/fields as for RUC20 and RUC40
• Add sfc-based CAPE to best-300mb CAPE
• 20km and 40km look-alike grids
• Native (Note 50 levels instead of 40)
• 25-mb isobaric and 88 2-d grids
• 25 2-d variables
• BUFR station time series output
• nearly identical to Eta (Exception 5 soil levels
  with RUC (out of actual 6) compared to 4 with
  Eta/NAM model)
• RUC13 station files with all output time (as
  with RUC20)
• RUC13 improved land/water matching (important
  for coastal stations)
• Continue RUC web forum for questions (under RUC
  web site)
• Continue RUC hot backup transition to 13km

66

• - Implementation of 13km RUC in operations at
  NCEP
• Assimilation of new observations
• - GPS-precipitable water ? improved moisture
  forecasts
• - METAR cloud/vis/current weather ?
  improved ceiling and vis fcsts
• - Mesonet, RASS temperatures
• Soil moisture/temp nudging
• Improved moisture analysis pseudo-RH instead of
  log q
• Model changes New versions of
• - mixed-phase cloud microphysics (NCAR-FSL)
• - Grell-Devenyi convective parameterization
• - Revised radiation cloud effects
• - Corrected treatment of frost formation
• ? improved icing and convection
  forecasts, cloud/sfc temp, vis forecasts
• Improved post-processing visibility, precip
  type, 20km/40km look-alike
• Hourly forecasts to be extended to 9h from 3h
  duration
• (at 01z, 02z, 04z, 05z, )
• (12h forecasts to be continued at 00z, 03, 06
  init times)