# Presentation: 449850

## MMB Briefing on Clouds etc.19 May 2005 Brad Ferrier

**Status on WRF codes for clouds & radiation**
**Version 1.3 (V1.3) for ARW in NCO prod runs **
**V2 for NMM & ARW**
**Miscellaneous physics issues**
**Summary of 1 March 2005 NE snowstorm reruns**
**Frequency of physics calls => RH vs. precip fields**
**Preliminary feedback from ’05 SPC Spring Program**
**Brief summary of JCSDA Workshop on Satellite Assimilation of Clouds & Precipitation**
**Mesoscale dynamics issue**
**Cloud verification issue**

## WRF V1.3 code for clouds & radiation

**Recent change to WRF “nest” runs for June**
**DX ~ 5 – 6 km for NMM, ARW – w/o convection**
**6-member WRF ensemble in SREF later in year**
**Timing tests by Matt**
**Original plan to run Lin or NCEP5 microphysics in ARW**
**Took too much CPU time ... go with “Ferrier”**
**Bug in running “Ferrier” in ARW, providing total condensate as input into Dudhia radiation, YSU PBL rather than cloud water, ice, & rain**
** ****Working on fix thanks to help from Dudhia**

## WRF V2 code for clouds & radiation

**Bug fix for SW****↓ rather than SW****net**** into LSM made in versions 1,2**
**Dan’s making progress in putting GFS radiation into WRF**
**Status on NAMX changes **
**Gave updated Ferrier microphysics to Tom ****(T_ice=-30C)**
**Cloud-radiation changes have been coded and it runs, but need to make changes to the WRF post to preview impacts on 3D cloud fractions, Cu precip rate, & visibility**
**Ferrier is the only microphysics scheme that works in NMM, while all other schemes but Ferrier work in ARW => V1.3 solution from Jimy will help here**
**Propose a flag for advecting total condensate vs. individual hydrometeor species, independent of core & microphysics**

## Summary of 28 Feb/1 Mar snowstorm reruns

**Many WRF NMM V2 eastern nest runs using 2005022712 initial conditions (NAM ICs+LBCs)**
**NAM fcst Low too close to coast, high QPF**
**WRF NMM slightly better, but still bad**
**WRF NMM runs had better L track off coast with **
**SAS Cu + YSU PBL**
**KF Cu**
**YSU PBL**
**Much better forecast with GFS ICs+LBCs**
**Thanks to Matt, was able to run with mixed ICs & LBCs  => GFS ICs most important**

## 24-h WRF NMM runs valid 2005022812

**NAM IC+LBC**

**GFS IC+LBC**

**GFS IC**
**NAM LBC**

**GFS IC**
**NAM LBC**

## 36-h WRF NMM runs valid 2005030100

**NAM IC+LBC**

**GFS IC+LBC**

**NAM IC**
**GFS LBC**

**GFS IC**
**NAM LBC**

## 48-h WRF NMM runs valid 2005030112

**NAM IC+LBC**

**GFS IC+LBC**

**GFS IC**
**NAM LBC**

**GFS IC**
**NAM LBC**

## Initial Surface Pressure at 2005022712

**NAM**

**GFS**

-  **Much lower surface pressure over Gulf of Mexico in GFS; **** ****	****time series of HPC analyses suggests intensifying storm**

## Frequency of physics calls => RH vs. precip fields

**Several WRF “blogs” => **_**[20050420](http://www.emc.ncep.noaa.gov/mmb/bf/wrf_blog/20050420)**_
**More frequent physics calls will reduce supersaturations, but ...**
**Could also increase high bias in QPF  (Dan’s runs)**
**May need to revisit downward flux of precipitation ... storage vs. fall out through bottom of grid cell**
**If this is the problem, then may require more CPU resources to resolve**
**Evaluation using other microphysical schemes will be helpful**
**Slow down hydrologic cycle by delaying or turning off accretion of cloud water by rain & precip ice (thx Dan)**
**Zavisa’s latest changes to convection strongly impact triggering of deep, shallow Cu**

## Preliminary Feedback from SPC

**Focusing on 4-5 km ARW & NMM runs w/o convection, 2-km ARW/CAPS runs, though they also look at 8-km ARW, NMM, NMMGFS**
**Excellent web page for **_**[2005 Spring Program](http://www.spc.noaa.gov/exper/Spring_2005)**_
**From **_**[sounding diagnostics page](http://www.spc.noaa.gov/exper/Spring_2005/sndgcomp)**_**, the NMM is to be too moist at lower levels (sfc, PBL)**
**From **_**[model verification page](http://www.spc.noaa.gov/exper/Spring_2005/archive/calendar.html)**_**, radar reflectivities from the NMM never exceed 50 dBZ while they frequently exceed 50 dBZ from ARW (examples to follow)**
**Can explain this if dBZ is due to rain, where a fixed mean D****r**** is assumed for rain contents >1 g m****-3**** from tropical oceanic rain DSD studies**
**May not apply over continents in warm season, especially if rain is formed from melting of large graupel and hail**

## 24-h fcst of 1-km dBZ at 2005051800

**(base reflectivity)**

## 24-h fcst of Composite (column-maximum) dBZ at 2005051800

## Base reflectivity at 2005051800

**(base dBZ)**

**(1-h max base dBZ****2300 – 0000)**

**Large ice**

## JCSDA Workshop on Satellite Assimilation of Clouds & Precipitation (May 2-4)

_**[Program with links to talks](http://www.jcsda.noaa.gov/CloudPrecipWkShop/program.html)**_
**Links to **_**[modeling group report](http://www.emc.ncep.noaa.gov/mmb/bf/presentations/JCSDA Modeling Group Final Report.ppt)**_**, draft talk by Ohring presented at last week’s **_**[GMoB](http://www.emc.ncep.noaa.gov/mmb/bf/presentations/Ferrier_GMoB_5-12-05.ppt)**__**[ ](http://www.emc.ncep.noaa.gov/mmb/bf/presentations/Ferrier_GMoB_5-12-05.ppt)**__**[mtg](http://www.emc.ncep.noaa.gov/mmb/bf/presentations/Ferrier_GMoB_5-12-05.ppt)**_
**Improved draft will be presented by Ohring at ITOVS mtg in China**
**Benefits:**
**Issues with ISCCP clds exposed by new algorithm using MODIS, also seen from CLAVR**
**Viewing clouds from bottom (sfc) vs. top (sats)**
**Collaboration between Chang & Li (UMD) w/ Heidinger (UW) for joint JCSDA work**

## JCSDA Workshop (2 of 3)

**Salient modeling issues for MMB**
**Higher resolutions will not solve our problems**
**Convection ... a big headache .. treat as nonlocal mixing+ transport w/o making sfc precip?**
**What % of compensating subsidence from gravity waves in grid?; downdrafts?**
**Tripoli: most important impact of convection is transport of momentum “after dust settles”**
**Me: what about heating/cooling ala Pandya & Durran?**
**Get views from Dave Raymond (next month), Greg, others?**

## JCSDA Workshop (3 of 3)

**Recommendations for future work**
**Compare 4D statistical properties of T, Q, & cloud+precip fields in time, space **
**Onset of “A-train” & GPM will provide great opportunities for cld+precip satellite obs**
**Ensembles of CRMs from GCSS WGs?**
**Include radiances from single-column modeling using ARM data, other “supersites”?**
**Linearize, simplify physics for assimilation?**
**High quality, independent cloud & precip data sets for verification (sats + rads + gauges)**
**Work on convection, more resources for some NWP centers *****(hint hint)***

## Global Cloud Climatologies

**(PATMOS is Heidinger’s successor to CLAVR)**