The 13km RUC - Nearing Implementation at

NCEPChanges, testing, plan

Aviation Weather Center – Monday 16 May 2005

Stan BenjaminJohn BrownKevin BrundageDezso DevenyiGeorg GrellBill MoningerSteven Peckham

Barry SchwartzTanya SmirnovaTracy Lorraine SmithSteve Weygandt

Geoff Manikin – NCEP/EMC

RUC web site - http://ruc.fsl.noaa.gov

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2005- 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 profilers915 MHz boundary-layer profilers, RASS

temperatures- Soil moisture/temp nudging

2005Model 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, …)

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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

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.

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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

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13km RUC

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

20km RUC

Terrain elevation - 200 m interval

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

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RUC History – NCEP (NMC) implementations

1994 - 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

7More detailed coastline with 13km resolution

13km RUC 20km RUC

Soil moisture – 22z - 21 Feb 2005Dark blue = water

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

• 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

Observations used in RUCData Type ~Number Freq.--------------------------------------------------Rawinsonde 80 /12hNOAA profilers 30 / 1hVAD winds 110-130 / 1h Aircraft (V,temp) 1400-4500 / 1hSurface/METAR 1500-1700 / 1hSurface/METAR 1500-1700 / 1hBuoy/ship 100-150 / 1hGOES precip water 1500-3000 / 1hGOES cloud winds 1000-2500 / 1hGOES cloud-top pres 10 km res / 1hSSM/I precip water 1000-4000 / 6h--------------------------------------------------GPS precip water ~300 / 1hMesonet ~5000 / 1hPBL – prof/RASS ~25 / 1hMETAR-cloud-vis-wx ~1500 / 1h--------------------------------------------------

NC

EP

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UC

20

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RUC13

(at NCEP June 2005)

Cloudanalysisvariables

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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

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)

RUC Cloud Analysis

-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 layersClear - Up to cloud base (if needed) - to 12,000 feet for CLR report

Assimilation of METAR cloud/wx/visBetter analysis, prediction of ceiling and visibility

analysis – withMETAR cloud/visibility obs

Cloud water mixing ratio

Sample modificationof cloud water from METAR cloud/weather/visibility observations

Cloud water mixing ratio

400Pres(mb)

-500-

-600-

-700-

-800-

-900-

1000

1700 UTC 27 Jan 2004

Background(previous1h fcst)

RelativeHumidity

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IFRLIFR VFR CLR MVFR

Sample ceiling analysis impact

Ceiling from RUC hydrometeors

AnalysisWITH

cld/wx/vis obs

AnalysisNO

cld/wx/vis obs

Aviation Flight Rules

cloud ceiling height (meters)

1800 UTC 17 Nov 2003

Observations

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GPS precipitable water observations~200-300/h - All-weather obs

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Analysis fit to GPS precipitable water obs over CONUS

RUC20

RUC13RMS difference

Bias

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3h forecast fit to GPS precipitable water obs over CONUS

RUC20

RUC13

RMS difference

Bias

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RUC enhancements:

1. Use of METAR obs throughboundary-layer depth (Sept 04)

2. Assimilation of GPS precipitable

water observations (RUC13 - ~Jun05)

CAPE impact from two RUC enhancements

3h fcst WITHenhancements

3h fcstOPERATIONAL

0000 UTC 21 Apr 2004

Severe reports

NWS SPCNorman, OK

Tornadoes

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• September 2004 – Change to oper RUC20 analysis

– use boundary-layer depth in assimilation of surface/METAR obs better temp/dewpoint/CAPE/convection forecasts

Spring 2005 – Will be first convective season to see effect of PBL-based assimilation. Also will be evident in RUC13 results.

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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 surfacebased on estimated boundary-layer depth

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PBL-based METAR assimilationProblem: Representativeness of sfc data in PBL not usedDesign: Use METAR data through PBL depth from 1h fcst Create extra pseudo-residuals (obs-bkg) in PBL

RUC oper analysis18z 3 Apr 02IAD

Original slides from April 2004

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PBL-based METAR assimilation

Use METAR data through PBL depth from 1h fcstRUC oper analysis

18z 3 Apr 02IAD

x xxx

Effect of PBL-basedMETAR assimilation

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EMC/Geoff Manikin RUC20/13 comparison web pagehttp://www.emc.noaa.gov/mmb/ruc2/para

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EMC/Geoff Manikin RUC20/13 comparison web pagehttp://www.emc.noaa.gov/mmb/ruc2/para

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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

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RUC13-exp

RUC20-ops

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.

TUS soundings – 12z 18 April 2005

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RUC13-exp

RUC20-ops

RUC13 forecast soundings at TUS also better than RUC20 - Reasons• Assimilation of GPS PW• Improved soil moisture in RUC13

• Better physics/assimilation, soil nudging

TUS soundings – 12z 18 April 2005

RUC 6h forecasts valid 12z

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36h afterrestoration of oper RUC20 soil moisture

Oper RUC20

Para RUC13

6h fcst valid 00z Analysis valid 00z

2m dewpoint- 00z 22 Apr 05 - excessivedryness in RUC20

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RUC13 analysis – includes nudging of soil moisture and temperature

Dependent on:• 2m T/Td 1h forecast errors• Only in daytime (zen angle > 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

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Oper RUC20

Para RUC13

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Typical CAPE effect from improved soil moisture and moisture analysis in RUC13

12h forecastsValid Thur evening00z- 5 May 05

Oper RUC20

Para RUC13

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Typical CAPE effect from improved soil moisture and moisture analysis in RUC13

Para RUC13

Oper RUC20

More convective precip inRUC13 over land, less over ocean

CAPE

0-12h prec

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Typical CAPE effect from improved soil moisture and moisture analysis in RUC13

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MODEL PHYSICS CHANGES FOR RUC13

-Land-surface model: When ground temp < 0°C, 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.

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Test of Ice Saturation for Surface Latent-heat Flux

13 Apr 2004 - 18h fcst valid 06z

Oper RUC20 Revised RUC20

Cloud-water mixing ratio at lowest model level

Reduction in fog, especially over snow.Much improved visibility forecasts, avoids high bias

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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

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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

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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

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EAST COAST BOMB 22-23 JAN 2005RUC13 9h Forecast for 0900 UTC 23 Jan

Sfc wind, temp, 3-h pcpnPrecipitation type

Snow

Rain

X-sec

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HYDROMETEOR CROSS SECTIONS

RUC13 RUC20 - OPER

CLOUD-WATER MIXING RATIO (qc)

Atlantic MA ME

RUC 9h Forecasts for 0900 UTC 23 Jan

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Hydrometeor Mixing Ratios (Cont)RAIN WATER (qr)

RUC13

Atlantic MA ME

Oper - RUC20

More rain in RUC13 – different rain processes

RUC 9h Forecasts for 0900 UTC 23 Jan

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Hydrometeor Mixing Ratios (Cont)CLOUD ICE (qi)

RUC13 Oper RUC20

Atlantic MA ME

Less ice in RUC13 – modified ice-particle accretion

RUC 9h Forecasts for 0900 UTC 23 Jan

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Hydrometeor Mixing Ratios (Cont)SNOW (qs)

RUC13 Oper RUC20

Atlantic MA ME

More snow in RUC13 – modified ice-particle accretion

RUC 9h Forecasts for 0900 UTC 23 Jan

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Hydrometeor Mixing Ratios (Cont)GRAUPEL (qg)

RUC13 Oper RUC20

Atlantic MA ME

Less graupel in RUC13 More supercooled liquid water (important for icing/aviation)

RUC 9h Forecasts for 0900 UTC 23 Jan

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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

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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

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RUC20

RUC13

6h precipitation forecastValid 18z Thurs 30 Sept 2004RUC20 (oper) vs. RUC13

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Obs radar - 0235z - 31 Mar 05

RUC13 9h fcst - valid 03z- 31Mar05

RUC20 9h fcst - valid 03z - 31 Mar 05

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Obs radar - 0115z - 12 May 05

RUC13 12h fcst - valid 03z- 12May05

RUC20 12h fcst - valid 03z- 12May05

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CAPE

Oper RUC20

Exp RUC13

Improved moisture analysis in RUC13 – pseudo-RH instead of ln-qv- use of GPS PW

Thursday 21 April 2005 – 12z

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Thursday 21 April 2005 – 12z

Oper RUC20

Exp RUC13

Improved moisture analysis in RUC13 – pseudo-RH, GPS PW

Radar summary – 1400z

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RUC20 vs. RUC13 precipitation forecast (12h) verificationWinter –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

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RUC20 vs. RUC13 precip forecast – 24h period ending 12z - 12 Feb 2005 (verified w/ NCEP 24h precip analysis)

RUC20

RUC13

obs

(inches)

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Ceiling analysis: comparison of Operational RUC (top) with the NCEP RUC13 (bottom)

Scale (AGL): x 1000 ft

Analyses at 1800 UTC on 9 May

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Observations: cigs <= 5000 ft only

Observations: cigs <= 500 ft onlyPoint 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.

Observations: cigs <= 3000 ft only

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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

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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

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Focus on the Midwest and Northern Plains. Quite a few obs have cigs < 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.

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Focus on eastern Texas. Cigs < 3000 ft are relatively widespread.

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Variable RUC20 RUC13

Temp –s.d. East domain 2.8 2.6

Temp – s.d. West domain 3.6 3.3

Dewpoint – s.d. East domain 2.9 2.7

Dewpoint – s.d. West domain 3.5 3.2

12-h surface forecasts verified vs. METAR obs25 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

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Rawinsonde verification - wind - RUC13 vs. RUC20

-RUC13 provides improvement in 150-300 mb winds

20km 13km

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Rawinsonde verification - RH - RUC13 vs. RUC20

-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.

20km 13km

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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

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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

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2005- 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 temperatures2005Soil moisture/temp nudging2006Improved moisture analysis – pseudo-RH instead of

log q2007Model 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)