# Presentation: 529544

## NCEP HPC Winter Weather Desk 2005 - 2006

***Peter C. Manousos***
***NCEP HPC Science & Operations Officer***
***(peter.manousos@noaa.gov)***

***PART 2 ***
***WWD MECHANICS***

## Goals of Presentation

**Review WWD Strategy **
**List deadlines**
**Show mechanical process required to meet WWD deadlines**

## WWD STRATEGY

**WWD provide WFOs prelim (internal) guidance**
**WWD collaborate with WFOs as necessary**
**WWD issues final (public) product suite **

## Mechanical Shift Instructions

**4 scripts needed to meet deadlines**
**WWD, wwdifin, lowtrack (make and send), sendww**
**Detailed instructions found in the Winter Weather Desk Binder**
**Including how long it takes to run each script**
**READ IT !!!**

## Specific Deadlines (9/15-5/15)

**0400/1600Z *****(wwd)***
**00/12Z NAM, GFS in through f84**
**09/21Z SREF in through f84**
***IF NO CONTOURS EXPECTED OVER ENTIRE CONUS– RUN  wwdnogo (but lowtracks and disco still needed)***
**0500/1700Z *****(wwdifin d1)***
**WW Model diagnostic web page fully populated**
**Day 1 Prelim products available**
**Notification of Day 1 Prelim graphics availability sent via 12 Planet**
**Collaboration window open**
**0545/1745Z *****(wwdifin d2)***
**Day 2 prelim products available (notification sent via 12 Planet)**
**0615/1815Z *****(wwdifin d3)***
**Day 3 prelim products available (notification sent via 12 Planet)**
**0815/2015Z**
**Collaboration Window closed**
**0930/2130Z *****(sendww)***
**Public Products available (notification sent via 12 Planet)**

## WWD SCRIPT

**Produces vgf file containing accumulation contours**
**24 hour accums of ZR and combined S/IP**
**Converts a QPF source into accumulations of ZR and combined S/IP**
**QPF source can be a blend**
**Precip type is obtained from a single model or a blend of models **
*If a blend, most probable ptype is calculated *
**2:1 ratio for Sleet, Climatological Ratio for Snow**
**Requires human intervention to decide the best blend of QPF and PTYPE source**

## Why not just edit the previous shift’s forecast

**Accums and probs are 24hrly, but products are issued every 12h**
**Day shift products valid 00z-00z**
**Night shift 12z-12z**
**Your shift’s product valid times are offset 12h from the previous shifts products **
**Therefore you cant use the previous shifts forecast as a starting point**

## WWDIFIN

**Posts internal accumulations to password protected web page (not AWIPS)**
**Also generates the probability contours for the external products**

**SENDWW**

** ****Posts probabilistic (external) products to web and AWIPS**

## Low Tracks Script

**“****make” option**
**Plots model forecast of low position as a symbol in 12h increments**
*Symbols color coded by lead time*
**HPC adds BAWX low position and central pressure **
*60 and 72 position determined by WWD forecaster in coordination with MDD *
**HPC lows are connected with a “track” arrow**
*Spread of symbols provides user sense of uncertainty *
**“****send” option**
**Posts image to web and to AWIPS**
**Creates pretty version that is posted to web **
**IMPORTANT**
**HPC Lows must be grouped with central pressure for pretty version to be created AND for verification to be compiled**

## HPC WWD Public Product Verification

**Verification of probability forecasts not available until mid summer **
**Low Track RMS (in nm)**
**A blend of the GFS/NAM still offering an overall best starting point for forecasters – although SREF mean has caught up since last year**

## DON’T FORGET !

**Group your Lows with Central Pressure**
**Send blurb on 12 Planet (both internal and external products)**
**Verify products went out to WEB (and AWIPS for external products)**
**Send the Discussion**
**File a log !**
**Hang up your charts **

## “wwdnogo”

**Special script when no snow/ice is expected**
**Automatically post internal and external graphics to web and AWIPS **
**Automatically posts the low tracks graphic to the web and AWIPS**
**You do not need to send a message out on 12 planet**
**You still need to **
**Send the discussion**
**File a log**