Important -

• The image content is not EXACTLY identical to what is viewed internally at HPC due to software limitations to produced the images. In most cases, they are a very close proxy (95%).

• Although additional models are available internally at HPC, only data from the NAM, GFS, and SREF (mean) are displayed on this page (so far).

• Images are generated as soon as model data is available on the NWS super computer in GEMPAK gridded format (after grib and prior to transmission on the SBN)

• Images provided on this page are two panel in nature - the model diagnostic field is displayed in the left panel, and for reference the PMSL, 1000-500mb Thickness, and 6h QPF is displayed in the right panel

• Images can be zoomed by clicking the ZOOM button, and then left mouse clicking on the image.  While in ZOOM mode you can roam or pan around the image by dragging the left mouse button.  Revert back to the original image by clicking RESET.

• If images are looping, you can use the additional Start/Stop and frame advance buttons to control the loop.

AREA: Geographic area images are centered upon

MODEL:  To date the only models that diagnostics are posted on this page are the NAM, GFS, and SREF (mean).    The COMP selection represents images showing comparisons of the NAM, GFS, and SREF.  COMP does not represent an actual model.

DISPLAY TYPE: The manner to display the image as follows -

• Single - displays the selected field for a selected model only for the selected forecast hour (no loop).
• Loop - displays a loop of a selected field over all forecast hours from the most recent run of selected model.  Selecting a FHR has no effect on the display when in loop mode.
• Trend - (dprog/dt) displays a loop of the selected model field from the most four recent runs of the selected model - all valid at the selected forecast hour.

FIELD: The model diagnostic to display as follows** -

    Standard Diagnostics

• 250 - 250 mb Heights/Isotachs and Divergence. Heights are in white, isotachs are shaded in kts, and divergence are tan contours
• 500 - 500 mb Heights and absolute vorticity.  Heights are in white and absolute vorticity is contoured in purple - values greater than 16 units are shaded.
• 700 - 700 mb Heights, temperatures, and wind.  Heights are in white, temperatures (C) are color contoured, and winds (kts) are brown barbs.
• 750 - 750 mb Heights, temperatures, and wind.  Heights are in white, temperatures (C) are color contoured, and winds (kts) are brown barbs.
• 850 - 700 mb Heights, temperatures, and wind.  Heights are in white, temperatures (C) are color contoured, and winds (kts) are brown barbs.

    Mositure/Lift/Instability Diagnostics

• QG(w) - Primary QG components, 1000-500mb Mean RH, and 500-700mb layer omega. Mean RH shaded, upward omega in tan contours, Differential Geostrophic Vorticity (1000-300mb) in blue contours, and low level warm air advection (750mb) in red.
• QG(e) - Primary QG components, 1000-500mb Mean RH, and 500-700mb layer omega. Mean RH shaded, upward omega in tan contours, Differential Geostrophic Vorticity (1000-300mb) in blue contours, and low level warm air advection (850mb) in red.
• 750 ThetaE - Precipitable Water with 750mb Winds, ThetaE, and wind convergence.  Precipitable Water shaded, 750mb winds in brown (kts), ThetaE in white, and wind convergence in blue contours.
• 850 ThetaE - Precipitable Water with 850mb Winds, ThetaE, and wind convergence.  Precipitable Water shaded, 850mb winds in brown (kts), ThetaE in white, and wind convergence in blue contours.
• BL - Boundary layer moisture convergence, wind, and PMSL.   BL moisture convergence is shaded, winds are brown barbs (kts), and PMSL is tan contours.

    Winter Weather Related Diagnostics

• Ptype - Precip type (NCEP Baldwin/Schichtel algorithm), PMSL, and 500-700mb layer omega.  Precip type is shaded (green = rain, blue = snow, purple = sleet, red = freezing rain).  PMSL is contoured in white and upward omega is contoured in tan.
• ZLvls - Mean 1000-500mb RH, 500-700mb layer omega, 0C isotherms at specific levels.  Mean RH shaded, upward omega tan contours, and 0C isotherm for the Boundary Layer (purple), 900mb (red), 850mb (green), 800mb (blue), 750mb (yellow), 700mb (white).
• MidLvlAdv - Mean 1000-500mb RH, 700mb wind, temps, and Warm Air Advection, 500mb Cold Air Advection, and Boundary Layer 0 C isotherm.  Mean RH shaded, 700 mb wind tan barbs (kts), temps in yellow contours, 700 mb warm air advection in red contours, 500mb cold air advection in blue contours, and BL 0 temp purple contour.
• Fgen650 - Frontogenesis in the 650mb layer with RH, stability, and EPV* above the layer, and 300-500mb QVector Divergence.  Frontogenesis contoured in orange, RH contoured in green, Stability Zero Line in black, EPV* shaded, and QVector Divergence in white.
• Fgen750 - Frontogenesis in the 750mb layer with RH, stability, and EPV* above the layer, and 300-500mb QVector Divergence.  Frontogenesis contoured in orange, RH contoured in green, Stability Zero Line in black, EPV* shaded, and QVector Divergence in white.
• Fgen850 - Frontogenesis in the 850mb layer with RH, stability, and EPV* above the layer, and 300-500mb QVector Divergence.  Frontogenesis contoured in orange, RH contoured in green, Stability Zero Line in black, EPV* shaded, and QVector Divergence in white.
• FgenSlope - Mean 1000-500mb RH, Layer Fgen at 850, 750, 650, and 550mb with Boundary Layer 0 C and 700 mb -15C isotherm.  Mean RH shaded, 700 mb -15 C dashed, BL 0 C isotherm purple, Layer Fgen 850 (red ), 750 (yellow), 650 (blue), 550 (white).

    Winter Weather Related Criteria Diagnostics (Composites)

• FrozQPF -  Where QPF will be in frozen form and where blizzard criteria met.  Where 6h QPF > .01 and BL temp close to freezing. Yellow shade indicates criteria met using BL temp < 3C, red indicates using BL temp < 0. Purple shade indicates where blizzard criteria nearly met and cyan indicates where it is met (< 30kts sfc wind, visibility less than 1/4 mile, and and BL temp near or below zero C
• Fgen/Banding -  Heavy snow possible due to banding and dendritic growth detected.  ANYTHING red represents 850mb layer, yellow for 750mb, and blue for 650mb. Heavy contours represent where significant FGEN and RH >= 80% in that layer detected. Circles represent where saturated EPV (EPV*) is =< 0 just above the FGEN layer. Dashed lines are -15C isotherms through that layer. BL 0C isotherm is provided for reference. Circles bounded by like color heavy contours indicate banding possible...if like colored -15C isotherm runs through that same area - dendritic snow growth likely also.
• LES-  Criteria conducive for LES detected.  White contour represents where CAA>=0 and 1000-850mb shear <= 30deg and dela T (skin temp minus 850mb temp) >= 10 C. Shaded area is 1000-850mb RH. Tan contours show mean omega in the 500-700mb layer. The 1000-850mb 1300m thickness line is dashed.. BL zero line is in purple.. 850 mb -10 and -15 C isotherms in yellow.