Using GFE for Tropical Operations
Last Updated 04/01/2018
National Weather Service
Forecast Decision Training Division
a New TCV
Adding Inland and/or Marine Zones to a Tropical Watch or Warning
Creating a Tropical Hazard Without a TCV
Storm Surge Collaboration
Creating Wind and HTI Elements
Creating the TCV, HLS, and MWW
Troubleshooting the TCV and HLS
Upgrading the Tropical Hazards
Finding and Resolving Hazard Conflicts
Removing Areas from Inland or Marine Tropical Hazards
Canceling/Ending Tropical Hazards
There are numerous grids, products, and services generated during a tropical event. From just a WFO perspective, the advisory cycle is incredibly busy, especially the hour prior to the advisory being issued by NHC. The general timeline to complete each of the various steps is below. For a larger image, click the timeline image below.
A GFE perspective must be running on your workstation.
1. An AlertViz banner will display notifying you a
pre-TCV has arrived. The banner will instruct you to run the PlotTPCEvents
from the Hazards menu.
4. Under the Hazards drop down menu,
click PlotTPCEvents. This will
plot the NHC-issued tropical hazards into the Hazards grid. Click on the
Hazards grid to view the NHC hazards.
Since the PlotTPCEvents operates directly on the Hazard grid, if other NHC hazards were in effect for part of the new area, the tool will take care of the needed replacements (i.e. HU.A becoming a HU.W).
5. Click on the blue disk to Save the Hazards grid. Ensure Hazard is selected and click Save Weather Elements.
Each WFO is responsible for issuing tropical
storm and hurricane hazards for marine and inland zones. These hazards should
closely match any NHC-issued coastal hazards in both area and threat. If
a cyclone is expected to only affect marine zones or for inland sites who
do not receive TCVs, follow these instructions.
1.Click on the Hazards grid to display the current hazards on the screen.
2. Click SeparateHazards
from the Hazard drop down menu.
3. Pre-select the desired NHC-issued hazard and Click MakeHazard so it will populate the ETN box with the correct ETN.
4. Add zones as needed to the selected hazard. Be very careful not to remove or change any of the NHC-issued zones.
5. Adjust the beginning and end times accordingly. The valid time in GHG should cover the expected time of the hazard. Remember that tropical hazards always receive an end time of 000000T0000Z (until further notice) in the TCV. The grid times are needed for the ZFP and CWF for expressions of uncertainty.
a. If you need to further segment your marine zones for meteorological reasons, see the MWW section.
6. Click Run/Dismiss.
7. Repeat process for any other center-issued hazard to which you need to add zones.
a. If you are upgrading any hazards, make sure to delete the watch grids before proceeding.
8. In the Hazards drop down menu, click MergeHazards. If you have a Merge Conflict, resolve that before proceeding.
9. Click on the blue disk to Save the Hazards grid. Click Save Weather Elements.
10. If needed, add the storm surge hazards.
Creating a Tropical Hazard with No TCV
As long as an advisory package is being issued for a storm, you can create tropical hazards and any needed products. These hazards should match the wind threat as indicated after running the TCWindThreat as well as hazards from neighboring offices.
1. Click on the Hazards grid to display the current hazards on the screen.
2. Click MakeHazard from the Hazard drop down menu.
3. Select Tropical Cyclone from the categories of hazards and choose the type of hazard you wish to create.
4. Using the slider bars on the right, choose the time frame for which you are forecasting the conditions to occur.
5. Left click and drag any inland or marine zone(s) you wish to add. They will become red when added.
6. Choose the advisory package from which to pull the ETN.
to choose a TCM will result in one of 2 errors alerting you to a
missing ETN. If these are received, click Acknowledge, follow the
message and restore the MakeHazard window (do not open a new one) and
fix the ETN selection.
7. Click Run if other hazards need to be created or Run/Dismiss if this is your final hazard to be created.
8. Repeat process for any other hazard you wish to create. If you are upgrading any hazards, make sure to delete the watch grids before proceeding.
a. If you need to further segment your marine zones for meteorological reasons, see the MWW section.
9. In the Hazards drop down menu, click MergeHazards. If you have a Merge Conflict, resolve that before proceeding.
10. Click on the blue disk to Save the Hazards grid. Click Save Weather Elements.
3. Click within the hazard (red) area, then click the right mouse button and choose Select Homogeneous Area. This creates and edit area where that hazard exists.
4. Switch to the other grid in question. The edit area likely overlaps with at least one zone of this hazard. Make sure None is highlighted on the color bar, then click the right mouse button and choose Assign Value. This removes the overlapping zone(s) from the conflicting hazard.
5. Proceed with merging your hazards.
3. Click on the tropical hazard grid you wish to edit, then click MakeHazard from the Hazard drop down menu.
4. Left click once on each red inland or marine zone you wish to remove. They will change to the default black background of the tool. See either Adding Local Zones to a Tropical Watch or Warning. Be careful to not remove any NHC-issued zone.
5. Click Run or Run/Dismiss at the bottom of the tool.
6. Repeat process for any other tropical hazard from which you wish to clear an area.
7. In the Hazards drop down menu, click MergeHazards. If you have a Merge Conflict, resolve that before proceeding.
8. Click on the blue disk to Save the Hazards grid. Click Save Weather Elements.
1. If coastal zones are part of the hazard, you MUST wait for the NHC TCV to be received, then run the PlotTPCEvents tool. Otherwise, proceed to step 2.
2. In the Hazards drop down menu, click SeparateHazards. A temporary hazard grid will be created for each hazard in effect.
3. Click on the hazard you wish to cancel, then right click and hold for menu.
4. Drag down to Delete Grid and release mouse button.
5. Repeat process for any other hazard you wish to end.
6. In the Hazards drop down menu, click MergeHazards.
7. Click on the blue disk to Save the Hazards grid. Click Save Weather Elements.
All Atlantic basin WFOs and HFO must create the Hurricane Threats and Impacts elements as they are required elements for running the TCV and HLS. The elements are WindThreat, FloodingRainThreat, TornadoThreat, and, if a coastal site, StormSurgeThreat. More information can be found via the HTI User Guide.
The Wind and WindGust grids also need to match the NHC forecast and be collaborated with your neighboring offices. This is accomplished through the use of the GTCM procedure.
Some keys for effectively creating Wind grids with the NHC-forecast cyclone are:
1. Prior to the gridded TCM arrival (around conference call time), prepare your background wind field using the model which is closest to the NHC forecast. Include all local effects, as needed.
a. If the event is ongoing, your Wind grids should already be fairly close.
2. When the gridded TCM arrives, check the data by viewing in D2D to verify it is the latest information. Then run the GTCM procedure with capping and smoothing values that match your neighboring WFOs.
a. If gradient winds of greater than 34 kts need to be maintained, the procedure can be run over just the edit area where the cyclone will track or just over a selected time range. For multiple cyclones (TAFB or OPC), run over the area/time range with storm 1, then repeat with a different edit and/or time range for storm 2.
3. Tweaks to the resulting output can be made, but should be very carefully coordinated and should not change the cyclone forecast.
4. Create WindGust grids using the preferred method/procedure that results in consistent values across CWAs.
5. All offices should strive to complete Wind and subsequent WindGust editing around the same time so the NDFD is updated uniformly. The NDFD only updates twice an hour.
The TCWindThreat procedure takes the Wind Speed Probability grids along with the Wind and WindGust grids that result from running the GTCM and local WindGust procedures and generates a WindThreat grid that can be used to guide planning and preparation for the event. The result is not a forecast but what people should reasonably prepare for. Based on the settings chosen, different wind speed probability thresholds are chosen for each of the four possible threat levels. The procedure also takes into account the deterministic wind values in your GFE domain (not just area of responsibility) to account for values that could potentially affect your area.
Most often, you will now run with Preliminary PWS so you can run this procedure sooner than past seasons. The default/typical setting uses the lowest exceedance probability thresholds from the PWS guidance for each threat level. The thresholds move to higher exceedance levels as you move to High and then Higher. Highest uses purely the Wind grids to determine the threat.
The resulting threat is outlined as shown.
Again, this is to guide planning since it has a safety margin factored in. It is not a forecast, but compliments the forecast.
Run the procedure with values that match your neighbors and make sure to collaborate the output. These grids are mosaicked and used by regional and national customers to assess their risk.
This procedure must be run every advisory regardless of surge threat. The grids the procedure creates are required for all zones deemed by your site to be coastal.
The 2018 version of TCStormSurgeThreat adds P-ETSS as a data source. The rest of the options remain unchanged from last season.
The procedure always creates InundationMax,
InundationTiming, and StormSurgeThreat. For PHISH and PETSS, the various datum grids (SurgeHtPlusTide) will
also be created. NHC SSU will strive to provide guidance during an event,
so ISC should be the most common source. But resources may preclude that
from occurring each advisory.
The different procedure choices are summarized below:
If pSurge is available for this storm, and SSU is not providing grids, use that. Recall that the guidance is based on the previous advisory's information. If storm is transitioning to post-tropical or is subtropical, PETSS may be the best data source. For both options, use the exceedance level recommended by SSU. If no model is available, use the Manual modes and input values up to 3 feet over pre-selected areas. As noted previously, a 2017 best practice was to have SSU provide the grids to use but resources may preclude that from happening every advisory.
For Manual modes, ETSS or ESTOFS can be used to determine what values to use in the Inundation Height slider bar. Just make sure to properly account for datum differences when determining those values. For the first time running during an event, choose Manual Replace so all grids get created. Otherwise Manual Add can be used to modify the existing grids. For all Manual modes, an edit area over which the values will be assigned must be loaded first. Then choose the Inundation Height (0-3 ft.) and the hours over which that value will be experienced. Once grids have been created via Replace, different values can be created over different areas using Manual Add. See the training video for actual examples.
The resulting threat grid is based on the InundationMax value at each grid cell.
Run the procedure with values that match SSU recommendations and your neighbors and make sure to collaborate along the way. If edits are needed to InundationTiming to zero-out tidal-only time steps, make sure to re-run with the UpdateInunMax option to bring the InundationMax and StormSurgeThreat in line with those edits. The StormSurgeThreat grid should never be post-edited directly as it will result in the various surge elements being inconsistent.
The 2018 version of the TCFloodingRainThreat procedure is shown below.
The blending option allows the text FFG to be used where there is no gridded FFG or the resolution is coarser than GFE, like around lakes and along the coastline. If No is selected, no output will be produced where gridded FFG is not available.
It is important to note for 2018 that the ERPs are neighborhood, instead of point-based, probabilities. This should make the procedure more sensitive to high rain threat scenarios.
Collaborate your QPF forecast with WPC and your neighboring WFOs and RFCs and then coordinate the procedure settings used before running. If needed, collaborate any post-editing that may be needed. These grids are mosaicked and used by regional and national customers to assess their risk. Consider the message you wish to communicate considering the various levels correspond as shown.
The TornadoThreat procedure uses various SPC guidance grids to generate a threat grid. The final grid is the highest threat at each gridpoint after interrogating each probability grid shown.
First the Day 1 ptor is used to generate an initial grid
Then if the pxtor (prob of sig tor) for Day 1 is greater than 10% it bumps up any non-None areas by one category. For context, a ptor > 30% would be exceedingly rare for a tropical event.
Then Day 2 ptotsvr is used to determine threat
Then if the Day 2 prob of significant total severe weather is greater than 10% it bumps up any non-None areas by one category. For context, a Day 2 ptotsvr > 60% would be exceedingly rare for a tropical event.
Finally Day 3 is taken into account If Day 3 prob of significant total severe weather > 10% for any points, the Elevated would become Mod.
The TornadoThreat grid is one that will likely need post-editing as the SPC probabilities are not well-calibrated for tropical events. Collectively decide what message you wish to convey and adjust the procedure output to match that according to the threat levels, as shown.
If the threat for life-threatening inundation exists, the NHC SSU will initiate the collaborative process that results in the storm surge watch/warning. The upcoming collaboration will be discussed on the hotline call so offices affected can expect the banner below to join the tropical_collaboration1 chatroom in NWSChat and to run CopyNHCProposed to generate an editable grid. If there are multiple storms requiring collaboration, tropical_collaboration2 may be the room for your storm. NHC will announce that on the Hotline call for each storm.
This procedure also creates a difference grid that shows where areas are recommended to be added or removed when compared to the last advisory. Recall that the guidance being used is from the previous advisory. If this is your first advisory with a SS W/W, the procedure will let you know no difference grid could be created.
Decide which areas to leave in the W/W and which areas may need to be removed. Ensure the W/W ends or begins on a zone boundary. Zones which have at least 3% coverage in the SS W/W will automatically be included in your WFO TCV. Also collaborate with your neighboring WFOs on areas being modified. This can be accomplished both via chat and ISC.
Once your edits are complete, save your ProposedSS grid which shares your grid with both SSU and your neighboring WFOs. If SSU has any issues with your edits, that will be noted via chat or possibly a phone call.
Once SSU has approved of all edits, they will finalize the process and notify all WFOs collaboration is complete. You will receive another banner at this point prompting you to run MergeProposedSS to add the finalized SS W/W to your Hazards grid. If you attempt to run MergeProposedSS with unsaved, separated, or locked Hazards, you will be forced to rectify that before running again.
1. If hazards are currently separated into temporary hazard grids, finish your edits then click MergeHazards from the Hazards drop down menu. If you have a Merge Conflict, resolve that before proceeding.
2. Ensure you have the following grids complete:
3. Click on the blue disk to Save your grids. Click Save Weather Elements.
4. On the Products drop down menu, click Publish to Official. Make sure to publish all grids and all times!
5. Under the Products drop down menu, click Formatter Launcher.
6. In the Formatter Launcher window, click Products, then choose Hazard --> Hazard_TCV.
7. Choose the appropriate TCP for your storm. It is
critical to choose the correct TCP as it affects the MND header and the
ability to run the HLS.
a. With early WSP and NHC SSU trying to provide the surge grids, there should no longer be a reason to change the default options for Populate Surge Section and Are WSP grids available?.
8. Click Run. 9. Make sure the output looks correct. If anything looks out of order, correct the necessary grids and re-run the TCV. Do not edit the output. 10. When you are ready, click Transmit to send the product.
Click Transmit again on the transmit window which comes up to actually issue
the product. 12. In the Formatter Launcher window, click Products, then
choose HLS (Hurricane Local Statement). a. Ensure the Situation Overview has
already been created by entering WRKHLS in the
AFOS Cmd window (the one on the right side of the Text Window) and
including the overview of the event for this advisory. Save that file so it
will be imported when the HLS is run. Do not use
any other editor than the text workstation as invisible characters
can be introduced which cause the HLS to fail.
11. Check the GHG Hazards Monitor to ensure your hazards are there which verifies the transmit was successful. This transmit also saves off information which is required to run HLS.
8. Click Run.
9. Make sure the output looks correct. If anything looks out of order, correct the necessary grids and re-run the TCV. Do not edit the output.
10. When you are ready, click Transmit to send the product.
Click Transmit again on the transmit window which comes up to actually issue
12. In the Formatter Launcher window, click Products, then choose HLS (Hurricane Local Statement).
a. Ensure the Situation Overview has already been created by entering WRKHLS in the AFOS Cmd window (the one on the right side of the Text Window) and including the overview of the event for this advisory. Save that file so it will be imported when the HLS is run. Do not use any other editor than the text workstation as invisible characters can be introduced which cause the HLS to fail.
Make the appropriate selections on the interface. For Step 3, select
only the hazards which present a real threat to the CWA and order them
according to the impact they will have. You do not have to choose
all of the hazards, but at least one needs to be chosen. For Step 5,
Conditions/Ongoing is to be chosen when the CWA is about 6 hours
either side of 34 kt winds affecting your CWA.
14. Click Run.
15. Edit all framing code as appropriate and ensure WRKHLS was properly
imported as the Situation Overview. In the Precautionary/Preparedness
Actions section, make sure to not only trim down the list but to remove
the phase wording intended to help you decide which information to
As edits are made, make sure to leave the general format (e.g. ** around Main Headline, bullet format) as the formatter produced it.
16. Run Spell Check, correct any valid issues discovered, and click Transmit. Click Transmit again on the transmit window which comes up to actually issue
If you need to segment the MWW for meteorological reasons (e.g. some zones
in TR.A will have 10 ft. seas while others will have 3-5 ft.), you can use
the end time
to force that separation since the ETN replaces the segmentation ability. When creating Hazards, make one set of zones end one hour before the rest, as shown.
b. Only make this change to the
end time of the hazard. The end time is
always UFN in the VTEC for tropical hazards and one hour difference should
impact the Expressions of Uncertainty in the CWF.
The new TCV and HLS are very complex formatters which rely on a variety of grids, guidance, and other internal files. Feedback messages are provided to help guide you in case of issues.
1. The most common reason for a TCV formatter failure is one or more of the required grids was not generated. If this is the case, a list of missing weather elements, as shown.
If you have the listed element in your grid manager, then make sure to go back and publish ALL grids and ALL times. It is best to use a weather element group that contains all of the required grids such as the baseline HTI weather element group.
2. A storm-based HLS cannot be generated unless a TCV has first been issued for that advisory. Only a Dispel Rumors HLS can be created without first issuing a TCV. If you attempt to create an HLS without first issuing a TCV for the given advisory, you will receive the message below in your formatter launcher window.
a. If a TCV was issued and a different forecaster is running the HLS and receives this message, then there are likely permission issues with the tcvAdvisories directory. This will need to be addressed by your ITO or the NCF.
3. At least one impact section must be chosen when running the HLS, even for the last HLS. If no impact sections are chosen, you will receive the following error in the formatter launcher window.
4. For any other TCV or HLS failure, call the NCF and open a CRITICAL trouble ticket.