# Presentation: 690592

## NCEP SREF Bundle  Jeff McQueen, Jun Du, B. Zhou, G. Manikin, E. Rogers and Geoff DiMego September 2, 2003

**where the nation’s climate and weather services begin**

##  Short Range  Ensemble Forecast 

** ****Short Range  Ensemble Forecast **
**(SREF) System**
_***Current  Configuration***_

** ****Current resolution: 48 km**** **
** ****10 members: 5 Eta ****using BMJ**** plus 5 RSM ****using SAS**
**5 = 1 control + 2 breeding pairs (p1,n1,p2,n2)**
**Full North American Domain**
**Eta from June 2002, RSM from 2001**
** ****09 and 21 Z runs to 63 hours**
**GFS Ensemble boundary conditions**
** ****Products: ****AWIPS 212 CONUS grids available ****on NCEP ftp **
**Thinned Content for Each Member [standard GRIB]**
**Mean, spreads, probabilities [n**_**on-standard**_** GRIB]**

##  SREF 

** ****SREF **
_***Proposed Upgrades***_

** ****Late Summer: 48 km **
**Go from 10 to 15 members:**
**Add 5 Eta ****using Kain-Fritsch**** members**** **
**5 = 1 control + 2 breeding pairs (p1,n1,p2,n2)**
**NCO running in parallel since **_**September 2002**_
** ****Output format changes:**** **
** ****Use Ensemble GRIB Extension Standards**** for mean, spread and probabilistic products on AWIPS CONUS grid #212**
** ****All probabilistic products in one file (rather than 5)**

##  SREF 

** ****SREF **
_***Proposed Upgrades***_

** ****Additional GRIB output:**
**Requested by Service Centers**
**Eta: Additional cloud and convective products (13)**
**RSM: Additional convective fields and vertical levels (40)**
**Additional fields can be used to generate future ensemble products**
** ****Create BUFR Sounding File**
**BUFR Soundings for all 10 Eta ensemble members**
**Requested and used by SPC, HPC and AWC**
**Working on plans to ship to NCEP Service Centers**

##  SREF 

** ****SREF **
_***Example of Eta BUFR Sounding***_

## SREF

**SREF**
_***Eta Members Ensemble Meteogram***_

##  SREF 

**Grid #212: Lambert Conformal 40 km, 185x129**
_***Probabilistic Parameters***__***	***__***	***__***	***__***      Units***__***	***__***	***__***           Threshold____________***_
**Convective Avail. Pot. Energy ****	****	****  [J/kg]****	****      ****≥****  500, 1000, 2000, 3000, 4000****	**
**Convective Inhibition (CIN) ****	****	****	****  [J/kg]****	****      ****≤****  -50, -100, -200, -300, -400****	**
**Storm Relative Helicity (SREH)         [m2/s2]****	****      ****≥****  100, 150, 200, 250, 300**
**Lifted Index****	****	****	****	****	****	****    [K]           ****≤****  0, -2, -4, -6, -8 ****	**
**Precipitation (3, 6, 12, 24 hr)****	****	****       [Inches]****	****       ****≥****  0.1, 0.25,0.5, 1.0, 2.0            12hrly Accumulated Snow Fall****	****       [Inches]****	****       ****≥****  1, 2.5, 5, 10, 20 **
**Prob precip type is rain****	****	****                  [%]**
**Prob precip type is freezing rain            [%]**
**Prob precip type is snow or sleet            [%]**

** ****SREF **
_***GRIB formatting being fixed for these***_
_***probabilistic products***_

## SREF Proposed UpgradesJuly 2003 Correlation Coefficients

- 850 mb Temperature

- 850 mb U-wind

## SREF Proposed UpgradesJuly 2003 RMSE

- 850 mb Temperature

- 850 mb U-wind

## SREF Proposed UpgradesJuly 2003 Spread (Std. Deviation)

- 850 mb U-wind

**SREF Proposed Upgrades**_***July 2003 Spread (Std. Deviation)***_

## SREF Proposed UpgradesEnsemble Forecasts vs Analysis

- % Occurrence

- % Occurrence

**SREF Proposed Upgrades**_***Ensemble Forecasts vs Analysis***_

## SREF Proposed UpgradesEnsemble Members vs Analysis

- % Occurrence

**SREF Proposed Upgrades**_***Ensemble Members vs Analysis***_

## SREF Proposed UpgradesIndividual Member SLP Contours

## SREF Proposed UpgradesCold Season Application and Evaluation

## SREF Applications

_***Spring Season Applications (SPC)***_

**Advanced SREF Products w/ proposed 15 member upgrades**
*** *****SPC probability of occurrence calculations for key Severe Wx parameters:**
**Wind Shear > 40 kts in column**
**CAPE > 1000 Joules/kg **
**Convective rain > 0.01 inch**
**Multiply probabilities to form a Joint Probability Product**
**Bias corrected gridded outputs**

## SREF 

**SREF***** ***
_***Wind Shear  Prob > 40 kt***_

- June 06 2003

## SREF 

_***CAPE > 1000***_

- June 06 2003

## SREF 

_***Convective Precip Probability***_

- June 06 2003

## SREF 

_***Combined Severe Weather Probability***_

- June 06 2003

## SREF

_***All Centers Give Thumbs Up plus Comments***_

- AWC:  *Wants the KF members for convective forecasts *
*NGM's Kuo convective parameterization should be added to the ensemble for forecasting afternoon convection*
- SPC:   *Found SREF very useful during Spring Program *
*Probabilistic products helped quantify factors influencing severe weather occurrences*
- TPC:   *Will begin looking at 10 m Gale wind and **precip threshold **probability *
- HPC:*   **Will use BUFR sounding output from SREF members to develop guidance for forecasting precip type during Winter Weather Experiment*
- OPC:*   **Interested in **displays of convective precip probability and 10 m Gale wind probability*

## SREF

_***Other Comments***_

- Western Region:
*K-F tends to do quite a bit better here in the Southwest where our summer boundary layer is much deeper and drier *
*Should examine SREF performance in forecasts of the upper low (off the Pacific NW coast during August)** *
- Eastern Region:* *
*WFO Tauton Eta10 with K-F will often more correctly initiate convection earlier than ops runs:  K-F SREF will benefit field *
*Concerns about how to display member soundings on BUFKIT and AWIPS*
*K-F ensemble will improve QPF predictions over the Northeast in concert with other operational ensembles such as MM5 ** *

## SREF Proposed Upgrade

_***Summary***_

**All upgrade package components have been JIFed and are being tested on production machine**
**Improvements seen in accuracy and spread**
**15-member ensemble and products actively used and desired by AWC, HPC and SPC**

## BACKUP SLIDES

##  SREF 

** ****SREF **
_***Grib Mean/Spread Products***_

**Grid 212: Lambert Conformal 40 km, 185x129**
_***Mean and spread Parameters***__***	***__***	***__***Units***__***	***__***	***__***Level***__***	***__***               ***_***(*= not in Spread files)***
**2m Temperature****	****	****	****	****[K]****	****	****	****Sfc****	****	****	**
**10m U, Vwind****	****	****	****	****	****[m/s]****	****	****	****10 m****	**
**Total precipitation(3,6,12,24hr)****	****[kg/m2]****	****	****Sfc****	****	****	**
**Convective Avail. Pot. Energy ****	****	****[J/kg]****	****	****	**
**Convective inhibition (CIN) ****	****	****[J/kg]****	****	****	****	**
**Storm RElative Helicity (SREH)****	****[m2/s2]****	****	****0-3000 m****	****	**
**Lifted Index****	****	****	****	****	****[K]****	****	****	****0-30 mb abv grnd****	**
**Sea Level Pressure****	****	****	****	****[Pa]****	****	****	****Sfc****	****	**
**Pressure****	****	****	****	****	****	****[Pa]****	****	****	****1000-50 mb (every 50 mb) ?****	****	****	**
***Categorical rain *******	******	******	******	******[y/n]******	******	******	******Sfc******	******	******	***
***Dominant precip type (over 3hr)* ******	******[1-7]******	******	******	******Sfc                                  ***
***12hrly Large scale Snow Fall*******	******	******[kg/m2]******	******	******Sfc******	******	***
***12hrly Snow Depth* ******	******	******	******	******[kg/m2] ******	******	******Sfc***
**12hrly Accumulated Snow Fall****	****	****[kg/m2]****	****	****Sfc****	*****	******	***
***Absolute vorticity*******	******	******	******	******[/s]******	******	******	******1000-50 mb (every 50 mb)?*****	**
**Geopotential height****	****	****	****	****[gpm]****	****	****1000-50 mb (every 50 mb)?****	**** **
**Relative humidity****	****	****	****	****[%]****	****	****	****1000-50 mb (every 50mb)?**
**U, V- wind ****	****	****	****	****	****[m/s]****	****	****	****1000-50 mb (every 50 mb)**
**Temperature****	****	****	****	****	****[K]****	****	****	****1000-50 mb (every 50 mb)?****	**
**Thickness ****	****	****	****	****	****[gpm]****	****	****1000-850, 1000-500, 850-700mb**

##  SREF 

** ****SREF **
_***Additional Fields in Post***_

_***Eta Fields***__***	***__***	***__***	***__***	***__***	***__***	***__***	***__***RSM Fields__________________________***_
**best CAPE****	****	****	****	****	****	****	****best CAPE **
**convective cloud cover****	****	****	****	****	****20 new pressure levels (40 total) **
**non-convective cloud****	****	****	****	****	****dewpoint temperature all pressure levels **
**cloud bottom height (ceiling)****	****	****	****2m dewpoint temperature **
**cloud bottom pressure (ceiling)****	****	****	****storm relative helicity **
**cloud top height ****	****	****	****	****	****	****storm motion **
**cloud top pressure****	****	****	****	****	****storm motion U component **
**cloud top temperature****	****	****	****	****	****storm motion V component ****	****	****	**** **
**maximum wind level height **
**maximum wind level pressure **
**maximum wind level U component **
**maximum wind level V component **
**tropopause height***** ******     ***

##  SREF 

** ****SREF **
_***Recent Changes***_

- _Date__	__	__	__	__	__	__	__Change (Jif #)__________________________________
- 01/22/02	 Eta Members: Implement new Ferrier Cloud physics (33)
- 08/06/02	 Eta Members:  Update land-sfc model heat flux routines to prevent negative fluxes (651)
- 04/14/03	 RSM Members: Modify Grib post to produce extra output levels (40)
- 07/08/03	 Eta members: Corrected truncation program to read from new format Eta restart files (264)

##   SREF 

**  ****SREF **
_***Late Summer Impact Results***_

- Forecast Hour

## SREF 

**http://wwwt.emc.ncep.noaa.gov/mmb/SREF/SREF.html**

**SREF **
_***Probabilistic Cloud Cover***_