GFS maps: Central Italy, CAPE e Lifted Index
CAPE e Lifted Index: analysis and forecast
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| Geop.+Temp. 500 hPa | 2 m Temperature | 500 hPa Temp. Anomalies | Rain & Snow + 0 C Level | 10 m Wind | Cloud Cover |
| Geop. + Temp. 500 hPa (GIF) | Minimum Temperature | 2 m Temp. Anomalies | 1 Day Total Precipitation | 500 hPa Wind | CAPE & Lifted Index |
| Geop.+Temp. 850 hPa | Maximum Temperature | Daily 2 m Average Temp. | Precipitable Water | 200 hPa Jet Stream | CIN |
| Geop. + Temp. 850 hPa (GIF) | 2 m Temp. trend | Daily 2 m Temp. Anomalies | RH + Vertical Vel. 850 hPa | 300 hPa Jet Stream | 500 hPa Forecast Stability |
| Geop.+Temp. 925 hPa | 850 hPa Temp. trend | Daily 850 hPa Average Temp. | RH + Vel. Verticale 700 hPa | 850 hPa Forecast Stability | |
| 500 hPa Geop. + Temp. trend | 850 hPa Temp. Anomalies | Daily 850 hPa Temp. Anomalies | RH + Vel. Verticale 500 hPa | Last 4 GFS run comparison |
GFS Central Italy: CAPE [J/kg] e Lifted Index [°C]
These maps show the CAPE (Convective Available Potential Energy, in J/Kg) and the Lifted Index (in °C).
The CAPE is an atmospheric instability index that measures the amount of energy available for convection. The higher this value, the more energy
a particle of air has to rise along the vertical. For example, a CAPE of 1000 J/kg means that each kg of air receives a total energy
of 1000 Joules during a free ascent. The following table shows the relationship between CAPE values and the storms:
| CAPE [J/Kg] | Risk of Thunderstorms |
|---|---|
| <500 | No thunderstorms |
| 500÷1000 | Risk of isolated thunderstorms |
| 1000÷2000 | Fairly probable thunderstorms |
| >2000 | Strong thunderstorms quite likely (risk of tornadoes) |
The Lifted Index is an atmospheric instability index obtained by computing the temperature that air near the ground would have if it were lifted to 500 hPa and comparing that computed temperature to the actual temperature at that level. When the value is positive, the atmosphere (at the respective height) is stable and when the value is negative, the atmosphere is unstable. The following table shows the relationship between Lifted Index values and the storms:
| LIFTED INDEX [°C] | Risk of Thunderstorms |
|---|---|
| >2 | No thunderstorms |
| 0÷2 | Risk of isolated thunderstorms |
| -2÷0 | Fairly probable thunderstorms |
| -4÷-2 | Risk of severe thunderstorms |
| <-6 | Strong thunderstorms quite likely (risk of tornadoes) |
On the top left is shown the UTC initialization time. UTC time is indicated with Z letter (Zulu Time).
On the top right is shown the UTC forecast time.
The maps at 00Z, 06Z, 12Z and 18Z are updated respectively starting from 04.30 AM, 10:30 AM, 4:30 PM, 10.30 PM (CEST TIime).
Forecast model: Global Forecast System (GFS) with 0.25°x0.25° (lat x lon) spatial resolution.
These maps show the CAPE (Convective Available Potential Energy, in J/Kg) and the Lifted Index (in °C).
The CAPE is an atmospheric instability index that measures the amount of energy available for convection. The higher this value, the more energy
a particle of air has to rise along the vertical. For example, a CAPE of 1000 J/kg means that each kg of air receives a total energy
of 1000 Joules during a free ascent. The following table shows the relationship between CAPE values and the storms:
On the top left is shown the UTC initialization time. UTC time is indicated with Z letter (Zulu Time).
On the top right is shown the UTC forecast time.
The maps at 00Z, 06Z, 12Z and 18Z are updated respectively starting from 04.30 AM, 10:30 AM, 4:30 PM, 10.30 PM (CEST TIime).
Forecast model: Global Forecast System (GFS) with 0.25°x0.25° (lat x lon) spatial resolution.
NOTE: in central European countries, when solar time is in effect, the CET time is used, which is equal to UTC +1 hour, while when daylight saving time is in effect, the CEST time is used, which is equal to UTC +2 hours. Right now it is 21:15 UTC.
Notes on GFS forecast maps
The Global Forecast System (GFS) is a National Centers for Environmental Prediction (NCEP)
weather forecast model that generates data for dozens of atmospheric and land-soil variables,
including temperatures, winds, precipitation, soil moisture, and atmospheric ozone concentration.
The system couples four separate models (atmosphere, ocean model, land/soil model, and sea ice) that work
together to accurately depict weather conditions.
GFS is a global model with a base horizontal resolution of 0.25° (28 kilometers) between grid points.
The GFS is run 4 times a day, the temporal resolution covers analysis and forecasts out to 16 days.
See the GFS analysis maps archive from 2013 to today
To see the GFS ANALYSIS MAP ARCHIVE from 2013 to today click on the red link.