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Rainshadow

New Nam Arrived On First Full Day Of Spring

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Tony, they might be different' Look at the difference from pivotal 3km nam, which I thought was suppose to be the new nam

qpf_acc.us_ne.png

then 12km nam

f45.gif

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2 hours ago, tombo82685 said:

Really? I know pivotal lost the 12km one and now just has the 3km

I think tropical tidbits got rid of the 4km? 

3km looks upgraded on tropical. The hourly temp maps are sharp and awesome. 

They really detail the microclimates well, like across MontCo when we had great radiational up north a few days ago. 

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4 hours ago, tombo82685 said:

Tony, they might be different' Look at the difference from pivotal 3km nam, which I thought was suppose to be the new nam

qpf_acc.us_ne.png

then 12km nam

f45.gif

Those differences existed even before the upgrade, I am at a lost to explain the qpf differences other than they existed before March 21st. 

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5 hours ago, tombo82685 said:

Tony, they might be different' Look at the difference from pivotal 3km nam, which I thought was suppose to be the new nam

qpf_acc.us_ne.png

then 12km nam

f45.gif

I know this explanation is dated, but the differences have always been there:

WHY IS THE QPF DIFFERENT BETWEEN THE 12-KM NAM PARENT DOMAIN AND THE 4-KM NAM CONUS NEST? (4 Nov 11)

The NAM 12km parent uses (as it always has) the Betts-Miller-Janjic (BMJ) parameterized convection scheme (Janjic, 1990 MWR, 1994 MWR). 
The NAM nests use a highly modified version of the BMJ scheme ("BMJ_DEV") which has moister profiles and is set to have reduced 
convective triggering, which leaves majority of the precipitation 'work' to the grid-scale microphysics (Ferrier). These settings for the
nests in the BMJ_DEV scheme gave better QPF bias than running with explicit convection, and better forecast scores against 
upper-air and surface observations. So you should expect to see different QPF fields between the 12km NAM parent and the nests.

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so is the 12km nam on psu e wall the new nam or the old nam? Cause the 12km is only used for the zoomed in regions. When you go for the US map it's not the nam 12km

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Just now, tombo82685 said:

so is the 12km nam on psu e wall the new nam or the old nam?

Has to be the new nam, ncep doesnt have the computer capacity to be running the older version.

 

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Just now, Rainshadow said:

Has to be the new nam, ncep doesnt have the computer capacity to be running the older version.

 

When you go to the US map version, it's not the 12km nam it's something else. 

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16 minutes ago, tombo82685 said:

When you go to the US map version, it's not the 12km nam it's something else. 

I dont know about the labeling, but its not the old nam. 

 

 

From EMC site, I think its still whether they are using the 12km parent or 3km nest (that used to be 4 km).

Changes to the NCEP North American Mesoscale (NAM) Forecast System

  1. Forecast model changes
    1. Horizontal grid resolution changes:
      1. CONUS nest from 4 km to 3 km
      2. Alaska nest from 6 km to 3 km
      3. CONUS fire weather nest from 1.333 km to 1.5 km
    2. More frequent calls of physics (now every 2nd time step for all domains); change frequency of radiation updates for the NAM 12 km parent domain from hourly to every 20 minutes
    3. Advect specific humidity every dynamics time step Mix out superadibatic layers
    4. Changes to Betts-Miller-Janjic convective scheme to improve 12 km parent QPF bias, especially during the cool season
    5. Updated Ferrier-Aligo microphysics to improve stratiform precipitation, better anvil reflectivity, reduce areas of light/noisy reflectivity over oceans
    6. Improved effect of frozen soil on transpiration and soil evaporation, leads to reduced cold/moist bias during cool season
    7. Radiation changes to reduce incoming surface shortwave radiation under liuqud clouds; reduces warm-season 2-m temperature bias
  2. Data Assimilation / Analysis Changes
    1. Replace 12-h NAM Data Assimilation System (NDAS, 3-h analysis updates for the 12 km parent domain) with a 6-h data assimilation cycle with hourly analysis updates for the 12 km parent and the 3 km CONUS/Alaska nests. The Hawaii/Puerto Rico/Fire weather nests will be initialized from the 12-km first guess at the end of 6-h assimilation cycle.
    2. Use of lightning data (from NLDN and ENL networks) and radar reflectivity-derived temperature tendencies in the diabatic digital filter initialization.
    3. Add execution of the diabatic digital filter initialization prior to the NAM free forecast (was only run during NDAS in previous ops NAM version 3).
    4. Assimilate new observation types:
      1. Aircraft data: Aeromexico, ADS-C, Air-Wisconsin
      2. New satellite radiance data: NOAA NPP (ATMS, CRIS), METEOSAT-10 SEVIRI, DMSP-F17 SSMIS; METOP-B AMSUA, MHS, IASI
      3. New GPS Radio Occultation data: METOP-B 3 (subtype)
      4. New satellite winds: Himawari-B, METEOSAT-7, 10 Imager WV AMV, NOAA-15, 18, 19 AVHRR IR AMV, METOP-A, B AVHRR AMV

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48 minutes ago, tombo82685 said:

im lost

Just as long as you are on the first tee at Kresson at 10 am on October 30th, all is good.

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57 minutes ago, Rainshadow said:

Just as long as you are on the first tee at Kresson at 10 am on October 30th, all is good.

I may get lost to bgm. 

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