Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

 

Labrador… Isolated thunderstorms giving 15-20mm of rain today and tomorrow.

New Brunswick.. Isolated thunderstorms giving 15-20mm of rain today and tomorrow.

Nova Scotia… A chance of thunderstorms over western areas this tonight and tomorrow, possibly giving 30mm/hr rainfall rates.

 

Convective Discussion

 

A slow moving area of low pressure will move eastward very slowly over the next few days, while a tough of low pressure develops southwest of the Maritimes. With the upper low(s) over Ontario and Newfoundland remaining virtually stationary as well no significant dynamics will come into play for the Atlantic Region. Moisture is modest at best with precipatable water values generally around 20mm with some pockets of higher amounts. However there is some decent instability and airmass thunderstorms could develop for a lot of areas, it is possible that significant downdrafts near 70 km/hr could occur with some thunderstorms .

Overnight and early tomorrow there is a slight chance that an organised area of convection will set up over southwest Nova Scotia giving potentially heavier rainfall mounts possibly up to 30mm, however this band could also remain just offshore. We will revaluate during the remainder of the day as new guidance becomes available.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

 

Thunderstorm Outlook for Tomorrow

 

 

Mel Lemmon

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

Slight risk of an afternoon thunderstorm over parts of Labrador: northwest of Wabush-Churchill Falls today; and then over western and central regions Tuesday.

 

Convective Discussion

Another round of thunderstorm activity is expected today in a warm and somewhat unstable airmass supported by a light to moderate southerly flow over northern Quebec. An upper trough over Hudson’s Bay extending SEward and a 60kt southerly upper-level jet will serve as the main trigger mechanism. Forecast guidance is suggesting surface-based CAPE values between 200-500 J/kg in an elongated area from Ungava to near Schefferville, lifted indices 0 to -2.

There has NOT been any lightning detected since Sunday evening near the upper low centre currently located over Laurentian Fan. That system produced a large rain band which affected most of the Maritimes yesterday and last night as it travelled westward, it now extends from northern NB to Lurcher and is weakening.

 

Thunderstorm Outlook for Today

 

 

 

Thunderstorm Outlook for Tonight

 

 

 

Thunderstorm Outlook for Tomorrow

 

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

Just a slight risk of a thunderstorm this afternoon (and Monday afternoon) north of the YWK area.

 

Convective Discussion

A short wave will move across northern QC today giving some scattered thunderstorms, which will likely drift into western LAB this afternoon and evening…but should remain north of the YWK and Lab City area. Looks like the possibility of another isolated TSRA again Monday afternoon, though the support is much less for that to happen. OTWZ nil sig wx to talk about due in part to that retrograding low south of NF.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Tomorrow

 

Jeremy

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

Slight risk of a TSRA Sunday afternoon and evening north of the Wabush/Lab City area.

 

Convective Discussion

Quiet weekend in store across the region today as we deal with a developing cut off low that will lurk south of NF likely for the next 5 to 7 days or so. A plume of moisture currently streaming northward into NF today and tonight could produce a very isolated embedded flash or 2 but that would be about it. Aside from that there will be a short wave trough pushing across northern QC on Sunday that could lead to an isolated TS drifting into western LAB, but that would be north of the Wabush/Lab City area.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

 

Thunderstorm Outlook for Tomorrow

 

Jeremy

Convective Outlook Valid for Today, Tonight and Tomorrow

Regional Impacts

 

NS/NB/PEI/NL… None

 

Convective Discussion

 

As an upper trough stalls over the Maritimes today, cold dry air will usher in from northern Quebec dropping dewpoints to the low to mid single digits. Dry low levels in conjunction with minimal wind shear will likely inhibit any thunderstorm development today across the Maritimes. A warm nose above 600 mb will inhibit much vertical development over central NS, however some isolated TCU are still possible. Extreme western New Brunswick may also see some isolated TCU this afternoon, but extremely dry low levels will likely prevent any development. The only area that is likely to see any lightning will be well offshore, closer to the 500 mb jet southeast of Nova Scotia.

 

Similar dry conditions are expected again tomorrow under the stalled upper low, with no thunderstorm development expected.

 

Thunderstorm Outlook for Today

 

 

Thunderstorm Outlook for Tomorrow

 

 

Copp