HPC Forecast Operations Branch

1
HPC Forecast Operations Branch
Michael Musher Meteorologist (General
Forecaster) NCEP/Hydrometeorological Prediction
Center Camp Springs, MD (Michael.Musher_at_noaa.gov)
2
Goals of the Presentation

• Pass along feedback from HPC forecast staff
  concerning the NCEP guidance.
• Present new HPC forecast tools, products and ways
  of incorporating the NCEP product suite.
• Any questions?

3
General Model Concerns

• The NAM is much better on the handling of
  Monsoonal moisture surging into the SW and
  resultant convection/QPF than the operational
  GFS during the summer months.
• The GFS grid scale feedback due to convection in
  the warm season appears to have gotten worse
  this year.
• This fall/early winter season, the NAM is
  consistently too fast with Pacific systems
  arriving into the Pacific NW.
• The GEFS ensemble members, continue a trend, of
  clustering around the deterministic GFS solution
  for the large scale pattern.

4
Model Concerns w/ Tropical Systems

• The GFS occasionally depicts hurricanes as
  shallow systems, which during GUSTAV/IKE, led to
  some runs being too slow and far left in the Gulf
  of Mexico and southern Plains.
• The NAM can show skill for track and intensity
  forecasting, if a tropical cyclone forms within
  its domain.
• GEFS ensemble members show a left bias in
  forecasting tropical cyclones.

5
Model Concerns Southern Hemisphere

• GFS - Cycle to cycle continuity is
  very bad beyond 48 to 60 hrs. -
  Has a tendency to make radical rather than
  gradual corrections and as a result, it tends to
  over correct.
• GFS Ensembles - They are too heavily
  biased in support of the operational model and
  as a result, the mean tends to mimic the GFS.

6
Positive Feedback

• The models (NAM and GFS) mass fields including
  moisture gradients appear to initialize better
  than previous years.
• The SREF mean is a great option for the alignment
  and axis of qpf, when model guidance indicates
  large spread and uncertainty.

7
One more item plus graphics

• The GFS convective feedback/qpf maxima, breaking
  out early in an event, can excessively block low
  level moisture return into favorable large scale
  vertical lift thus the action occurring out
  ahead or well downstream from a large scale
  system/upper trough can corrupt the overall mass
  field output.

8
(No Transcript)
9
(No Transcript)
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
HPC Programs and Desks
Forecast Verification
QPF
Winter Weather
Basic Weather
Medium Range
Model Diagnostics
Surface Analysis
Tropical
International Desk, Alaska, Development
Training and the Daily Weather Map
14
HPC Staff
42 Meteorologists

• Three Branches
• ADMINISTRATION
• 1 Director and 1 Deputy Director
• FOB (Forecast Operations Branch)
• 1 Chief
• 29 Forecasters (5 Senior Branch Forecasters)
• 2 Meteorological Technicians
• DTB (Development Training Branch)
• 1 Chief
• 1 SOO
• 5 Research Mets
• 1 International Forecaster

15
HPC Masterblender
Forecast Shift
Forecast Hour
Available Model Guidance
16
(No Transcript)
17
Winter Weather Blender
12z or 00z to 1815z or 0615z
Forecast Hour

• Review previous models/forecast, analyze new
  model guidance and begin in-house collaboration.
• After collaboration between MD and QPF, a
  consensus model solution is chosen through 84
  hrs.
• The Winter Weather Forecaster then uses the model
  choice to generate internal accumulation graphics
  after 16z/04z.
• Forecaster then manually adjusts blender output.
• Day 1 due at 17z or 05z
• Day 2 due at 1745z or 0545z
• Day 3 due at 1815z or 0615z

Model Precip Type
Model QPF Options
18
Internal Accumulation Graphics
Provides a starting point or first guess for the
WFOs
19
Winter Weather Low Track Graphic
20
Model Diagnostics Desk

• Issues the Model Diagnostic
• Discussion (PMDHMD) in four parts/segments.
  -1115/2315 The 1st PMDHMD issuance
  incorporating the NAM evaluation.
  -1230/0030 2nd PMDHMD issuance
  incorporating the GFS evaluation.
  -1330/0130 The 3rd PMDHMD issuance
  incorporating the NAM/GFS/SREF Mean and
  UKMET/Canadian.                   
  -1400/0200 Prepare and send the 500 mb
  graphics. -1445/0245 The
  final PMDHMD issuance incorporating the new
  ECMWF run.

21
HPC Verification vs. NCEP Guidance
22
Michael Musher NCEP/Hydrometeorological
Prediction Center Camp Springs,
MD (Michael.Musher_at_noaa.gov)
Any Questions?