Thunderstorm Outlook for Day 1
Regional Impacts
Slight risk of a non-severe thunderstorm over eastern NS this afternoon, and western NF.
Convective Discussion
This morning upper air patterns shows an upper low over Labrador giving extensive cloud cover, also
An upper ridge extends north-south through Ontario to the southeastern US. The airmass between these two features is somewhat unstable, and this instability is found in the mid-levels. Large bands of alto-cumulus extend from southern NF to NS to PEI and then NB, and are producing scattered showers. Clear air prevails over western NS as the 500mb heights increase ahead of the upper ridge.
Forecast guidance is suggesting limited instability this afternoon over eastern NS and western NF, but the limiting factor will be the lack of bright sunshine over NS, and the relatively cool temperatures and dry air over NF. For this reason towering cumulus is mostly expected and the likelihood of deeper convection and the chance of any lightning is rather small.
Thunderstorm Outlook for Tuesday
No thunderstorms expected.
=======================================================================================
Information on Threat Relationships
| Threat | Rainfall Amount | Wind Gusts | Hail Diameter | Tornado Probability |
| Minor | < 25 mm | < 70 km/h | < 2 cm | Unlikely |
| Moderate | 25 – 50 mm | 70 –89 km/h | 2 – 4 cm | Low |
| Severe | 50– 100 mm | 90– 119 km/h | 4 – 6 cm | Moderate |
| Extreme | 100 mm or more | 120 km/h or greater | 6.0 cm or greater | High |
| Risk of Thunderstorms: Thunderstorms that develop in this area will be less organized and will not likely meet warning criteria. Severe Thunderstorm Watches will not likely be required. | ||||
| Slight Risk of Severe Thunderstorms: There is a low probability that weakly organized thunderstorms will develop, these thunderstorms may reach warning criteria. Severe Thunderstorm Watches may be required | ||||
| Moderate Risk of Severe Thunderstorms: There is a moderate probability that organized thunderstorms will develop, thunderstorms are likely to reach warning criteria. Severe Thunderstorm Watches will likely be issued. | ||||
| High Risk of Severe Thunderstorms: There is a high probability that well organized thunderstorms will develop, these thunderstorms are likely to meet or exceed warning criteria. Severe Thunderstorms Watches will be issued. | ||||