The 13km RUC - Pre-implementation briefing

onChanges, testing, plan

NCEP – Friday 24 June 2005

NOAA-FSLStan BenjaminJohn BrownKevin BrundageDezso DevenyiGeorg GrellBill MoningerSteven PeckhamBarry SchwartzTanya SmirnovaTracy Lorraine SmithSteve Weygandt…

NCEP-EMCGeoff Manikin Dennis KeyserGeoff DiMego…

NCEP-NCODave MichaudLuke LinJulia Zhu…

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2005- Implementation of 13km RUC in operations at NCEP

• Assimilation of new observations - GPS-precipitable water - METAR cloud/vis/current weather - Mesonet temp/dewpoint

- 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 post-processing – visibility, precip type, add sfc-based CAPE/CIN (previously only Best CAPE)

• 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 – NCEP Centers, NWS CR- Retrospective testing (at NCEP) for cold season- Report on testing to NCEP directors

Tuesday 28 June 2005- Planned 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

Terrain elevation - 100 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)

2004 – Vertical advection, land use (April)PBL-depth for surface assimilation

(September)

2005 – 13km resolution, new obs, new model physics(June)

2007 – WRF-based Rapid Refresh w/ GSI 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

4 aspects of RUC13 3DVAR analysis:

1. New observations assimilated

2. Cloud analysis (GOES, adding METAR ceiling/vis/curr-wx)

3. Revised control variable for moisture (pseudo-RH)

4. 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 / 1hMETAR-cloud-vis-wx ~1500 / 1h--------------------------------------------------

NC

EP

R

UC

20

op

era

tion

al

RUC13

(at NCEP June 2005)

Cloudanalysisvariables

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

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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12Z Cloud Analysis 5-19-05

RUC20

RUC13

Improved ceiling/cloudWith RUC13

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

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3h forecast fit to GPS precipitable water obs over CONUS

RUC20

RUC13

RMS difference

Bias

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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 recalculation of obs 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 analysis soundings – 12z 18 April 2005

obs

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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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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 – due to conv scheme change – more later)

CAPE

0-12h prec

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Oper RUC20

Para RUC13

2m Td – 9h fcstsValid 0z – 20 Jun

Typical improvement in 2m Td forecasts from RUC13 …

2m Td – obsValid 0z – 20 Jun

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Oper RUC20

Para RUC13

2m Td – obsValid 0z – 20 Jun

CAPE – 9h fcstsValid 0z – 20 Jun

… resulting in improved sfc-based CAPE forecasts

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

Sfc wind, 3-h pcpnPrecipitation type, 3-h pcpn

Rain

X-sec

Snow

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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)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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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- NCEP pre-implementation testing started – Jan 05

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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

Para RUC13

Improved moisture analysis in RUC13

– pseudo-RH instead of ln-qv

- use of GPS PW

21 April 2005 – 12z

+

+

ICT

35ICT sounding comparison – 21 Apr 05 – 12z

RUC13-exp

RUC20-ops

ICT - analysis soundings – 12z – 21 Apr 05

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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

- Improved initial conditions- Improved precip physics- Higher horizontal resolution

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RUC20 vs. RUC13 precipitation forecast (12h) verificationSpring/sum – Mar-Jun 05 (verif w/ NCEP 24h precip analysis)

RUC13-Slightly higher equitable threat score- bias closer to 1

- Improved initial conditions- Improved precip physics- Higher horizontal resolution

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RUC13 vs. RUC20Analysis fit - raobs

RH

RUC13 – dashedRUC20 - solid

wind

temp

38-day – 14 May – 21 Jun 05

height

Upper-level stats - Better fit to obs w/ RUC13- Equal or slightly worse fcsts- Better surface forecasts

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RUC13 vs. RUC203h/12h fcst - raobs

wind

temp

3h

3h

12h

12h

38-day – 14 May – 21 Jun 05

RUC13 – dashedRUC20 - solid

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RUC13 vs. RUC203h/12h fcst - raobs

RH

height

3h

3h

12h12h

38-day – 14 May – 21 Jun 05

RUC13 – dashedRUC20 - solid

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RUC13 vs. RUC200h/12h fcst - raobs

height

temp

0h

0h

12h

12h

Winter-retro-15-day – 15-30 Nov 04

RUC13 – dashedRUC20 - solid

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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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12-h surface

forecasts verified

vs. METAR

obs20 May– 24 Jun05

(valid 12z)

RUC13

vs. RUC20 (oper)

RMS

RMS

bias

bias

2m temp

2m RH

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Participants in RUC13 evaluation• AWC – Steve Silberberg• SPC – Steve Weiss• OPC – Joe Sienkiewicz• HPC – Pete Manousos• NWS Central Region – Tom Hultquist

AWC summary• Looked at wind speed, icing diagnostics, stability/moisture, cloud base• Improved in all categories, also enthusiastic on addition to 9h hourly forecast• Strongly supports RUC13 implementation, would also like 24h forecasts every 3h.

OPC summary• Concentrated on visibility over ocean• ParaRUC slightly better but needs further improvement

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SPC summary

• Improved 2m Td, CAPE, moisture structure in RUC13• RUC13 precip often better but more false alarms• Very enthusiastic about hourly 9h forecasts• Supports implementation

HPC summary• Improved height, surface fields, • Extremely useful w/ higher resolution, hourly output• Supports implementation

NWS Central Region

• Much better 2m T/Td in Great Lakes region, supportive

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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

~ 28 June 2005- Planned operational implementation

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5 km NDFD AnalysesRUC13 post-outputs on NDFD 5kmGrids- 10 fields

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RUC13 output grids• ~Same products/fields as for RUC20 and RUC40

– Add sfc-based CAPE/CIN to best-300mb CAPE/CIN, T-skin

• NDFD 5km background field output for RTMA

• 20km and 40km look-alike grids – Native, isobaric, surface files (as before)

• Continuing RUC web forum for questions (under RUC web site)

• Continuing RUC hot backup at FSL –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 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, sfc-based CAPE/CIN

• 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)