Major upgrade next year to the Global Forecast System (GFS)

NOAA/NWS selected the Geophysical Fluid Dynamics Laboratory (GFDL) finite­ volume cubed-sphere (FV3) dynamical core as the NWS Next Generation Global Prediction System (NGGPS).  The current operational GFS, which has a spectral dynamical core, will be replaced by the proposed GFS with FV3 dynamical core and improved physics parameterizations in the second quarter of Fiscal Year 2019.

The proposed GFS version maintains a horizontal resolution of 13 km and has 64 levels in the vertical extending up to 0.2 mb.  It uses the same physics package as the current operational GFS except for:

-Replacing Zhao-Carr microphysics with the more advanced GFDL microphysics

-Updating parameterization of ozone photochemistry with additional production and loss terms

-Introducing parameterization of middle atmospheric water vapor photochemistry

-Revising bare soil evaporation scheme

The data assimilation system will be updated to include:

  • Infrared Atmospheric Sounding Interferometer (IASI) moisture channels

  • Advanced Technology Microwave Sounder (ATMS) all-sky radiances

  • Fix for an issue with the Near Sea Surface Temperature (NSST) in the Florida Strait

  • Upgrade to the use of Cross-track Infrared Sounder (CrIS) radiances

  • NOAA-20 CrIS and ATMS data

  • Megha-Tropiques SAPHIR data

  • Advanced Scatterometer (ASCAT) data from MetOp-B


Release notes for WeatherSpork version 4.3.10

  • Fixed an issue that some users experienced with trouble logging in after a password change which now will require that users enter a PIN.
  • Fixed a flight category inconsistency in the Meteogram when displaying the 3 day vs 1 day view.
  • Removed confusing scroll bars in Airports view when displaying the Skew-T log (p) diagram.
  • Rounded probabilities in freezing precipitation forecasts to nearest 10 percent.
  • Fixed a bug that caused the 7-day forecast to be rendered improperly.

Release notes for WeatherSpork version 4.3.8

  • Round ceiling height to reportable whole values using NWS standards.
  • Round up probabilities in precipitation forecasts to nearest 10 percent.
  • Show “None” for thunderstorm and precipitation forecasts when probabilities are less than 15% so it will match NWS standards.
  • Fixed a visual glitch in 7-day Forecast view.
  • Provide better guidance to users to handle orphaned favorites after an Imagery view update.
  • Usability improvements.

Introducing our WeatherSpork member referral program

Are you a fan of WeatherSpork?  If so, we have a way for you to earn our gratitude!  With each new member you refer, we will extend your annual member by one month.  Twelve referrals means you’ll get an entire year free.  It’s that simple.  You could become a Sporkie for life if you referred at least one new member each and every month.  So what are you waiting for…let’s get Sporking!

To receive credit be sure that when your friend joins by visiting they include your first and last name in the “How did you hear about WeatherSpork and/or” field during the registration process.  Then within the next 5-7 business days (or less) you will see your expiration date pushed into the future by a month.  If you’ve already referred a friend or two since we released the app on March 1, then your membership has already been adjusted.  Thanks for your contribution!

We know that WeatherSpork can’t grow unless our customers stand behind the product.  We hope that you can help us grow to remain the gold standard for aviation weather in the coming months and years.

“Most pilots are weatherwise, but some are otherwise.”

Scott Dennstaedt
Weather Systems Engineer
Co-founder, WeatherSpork

Spork meets Droid, Android, that is!

We are excited to let you know that we’ve just released our new app to Google Play for those that use an Android device.  With very few exceptions, the WeatherSpork app will have the same look and feel and has all the same features as our popular iOS and web-based versions of WeatherSpork.  So when you are an “exSporkt” on one device, you are an exSporkt on all WeatherSpork platforms.  U.S. Droid users, don’t delay, go right now and visit Google Play. You won’t be disappointed.

At this time, WeatherSpork is only available to U.S. customers for Google Play.



“Most pilots are weatherwise, but some are otherwise.”

Scott Dennstaedt
Weather Systems Engineer
Co-founder, WeatherSpork

Rain showers should get your attention

Too many pilots see the word “showers” and think it’s just some harmless light rain event.  When, in fact, a forecast for showery precipitation should get your attention since rain showers are a result of a convective process.  In many cases, forecasters often use showery precipitation (SHRA or VCSH) when they have a fair amount of uncertainly about a future convective event.  Forecasters won’t include TSRA or VCTS in a TAF unless they feel certain thunderstorms will impact the airport’s terminal area.

Here’s an example.  Consider you are making a short flight from Cedar Rapids (KCID) in Iowa to Chicago Executive (KPWK) around 12Z on the morning of May 11th.  The previous evening you fire up WeatherSpork and go to the Imagery view and take a look at the new HREF Model graphics.  You notice an area of convection with echo top heights greater than 30,000 feet is forecast to be poised just to the west and northwest of your route by 08Z as shown below. With such a high probability of tops above 30,000 feet MSL, this area of weather is likely to contain dangerous convective turbulence at 08Z.

However, as you forward the loop to 12Z (below) you notice that the high probability of 30,000 ft echo top heights has diminished, indicating this area of convective weather is expected to weaken with time.  Therefore, forecasters also will likely treat this weather system as a weakening area of weather.

So the next morning you take a look at the radar depiction and notice that at 11Z, the pattern to the weather looks remarkably like the echo tops height forecast from the HREF Model you saw the previous evening.

You go to the WeatherSpork Airports view and find the latest TAF issued for Cedar Rapids.  The TAF doesn’t mention any possibility thunderstorms during the morning.  However, you do notice that there’s a forecast for light rain showers (-SHRA) beginning at 15Z.  So what’s that all about?

KCID 111120Z 1112/1212 08015G21KT P6SM OVC050
FM111500 08017G25KT P6SM -SHRA OVC035
FM111800 09017G25KT P6SM OVC020
FM120000 09014G21KT 6SM BR VCSH OVC015
FM120500 05013KT 5SM -SHRA BR OVC012

You then take a peek at the Area Forecast Discussion (AFD) out of the Quad Cities NWS weather forecast office. The aviation section explains the forecaster’s thinking.  The forecaster also believes this was a weakening area of showers and isolated storms. Then, the last sentence of this section goes on to say that thunderstorms were not included in the TAF for KCID because of the limited predictability due to the weakening system.

.AVIATION…(For the 12Z TAFS through 12Z Saturday Morning)
ISSUED AT 525 AM CDT Fri May 11 2018

A weakening area of showers and isolated storms will move through
the area late this morning into early this afternoon and have
timed a 2-3 hour window of rain at each site. Later this afternoon
and tonight, scattered showers and isolated storms will be most
favored at KDBQ, with lesser coverage expected to the south.
KDBQ/KCID/KMLI can expect periods of MVFR ceilings and/or
visibilities beginning as early as late morning. With limited
predictability, have not include mention of thunder in TAFs.

Nevertheless, the showery precipitation forecast is a placeholder for an uncertain thunderstorm event.  If the weather doesn’t dissipate as expected, the forecaster will amend the TAF once the event becomes more certain.  Even if this area of convection doesn’t meet the thunderstorm criteria to make it into the TAF, showery precipitation implies vertically-developed clouds from convective debris of this weakening system and may still contain dangerous convective turbulence.

“Most pilots are weatherwise, but some are otherwise.”

Scott Dennstaedt
Weather Systems Engineer
Co-founder, WeatherSpork

Release notes for WeatherSpork version 4.3.6

  • Fixed a bug to provide better results when doing a search in the Imagery view.
  • Use abbreviation of sm (statute mile) instead of mi (miles) when showing visibility.
  • Use > 6 sm for MOS forecast of unlimited visibility.
  • Use < 200 feet or < 1/2 sm for MOS forecast of very low IFR ceiling and/or visibility, respectively.
  • Other bug fixes and usability enhancements.

Crosswind & prevailing wind color depiction on Meteogram view

There’s no doubt that wind is the leading cause of weather-related aircraft accidents.  Even so, strong crosswinds can make for a challenging landing even for the most seasoned pilot. So to help alert you to nasty wind conditions expected at an airport over the next three days, WeatherSpork version 4.3.5 has enhanced the wind Meteogram by adding “traffic light” colors (red, yellow and green) to the time-series wind graph depicted on the Meteogram view.

For an airport, the observed or expected prevailing wind (shown above) is plotted as a continuous line and color coded by wind speed using the following colors:

  • Green – 0 to 10 knots.
  • Yellow – 11 to 20 knots.
  • Red – greater than 21 knots.

The crosswind component is depicted as a color-filled graph overlaid on the same time-series depiction. Crosswinds are evaluated by determining the best opportunity runway based on the observed or forecast winds at the surface using the following colors:

  • Green – 0 to 10 knots.
  • Yellow – 11 to 15 knots.
  • Red – greater than 16 knots.

So the next time you go flying be sure to check the WeatherSpork Meteogram to determine if a challenging takeoff or landing are in your future.

“Most pilots are weatherwise, but some are otherwise.”

Scott Dennstaedt
Weather Systems Engineer
Co-founder, WeatherSpork


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