Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

 

Today:

Labrador: risk of a thunderstorm north of Labrador City/Wabush to Esker to Schefferville

 

Monday: None

 

Convective Discussion

An upper trough over Hudson’s Bay and an associated active cold front will move across northern Quebec today. A strong southwesterly low-level-jet is feeding moisture ahead of the surface feature. Precipitable water levels are currently between 30-35 mm. The cold front will reach western Labrador this evening. However, with the loss of daytime heating, forecast guidance is suggesting a weakening area of instability over the fp17hx area.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

 

Thunderstorm Outlook for Tomorrow

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

None

 

Convective Discussion

The base of a cold upper trough in conjunction with the warm waters off western NL produced a few strikes and convective showers earlier this morning. However the upper trough is expected to continue progressing eastward with heights rising in its wake yielding stable conditions across all of Atlantic Canada. As such no thunderstorms are anticipated for the next 2 days.

 

Thunderstorm Outlook for Today

 

 

Thunderstorm Outlook for Tonight

 

 

Thunderstorm Outlook for Tomorrow

 

 

Allen

Convective Outlook Valid for Today , Tonight and Tomorrow

Regional Impacts

 

Today

NL/NS/NB/PEI/LAB: None

Southeastern Marine waters: Lightning and reduced visibility in heavy downpours.

 

Tonight

NL/NS/NB/PEI/LAB: None

Southeastern Marine waters: Lightning and reduced visibility in heavy downpours.

 

Friday

None

 

Convective Discussion

 

The UA at YYT this morning revealed the same tropical air mass that was in place across the Maritimes yesterday, with PWATs near 50mm. Instability exists aloft at ~850 mb but MUCAPE is limited (~150 J/Kg or less) due to some thermal ridging at the 500mb pressure level. This is also noted through the limited delta T between the 700 and 500mb levels of ~11-12 C, indicative of very little mid level instability. For this reason the no lightning is expected of land areas of eastern NL, however across the marine areas to the south and east of the Avalon higher MUCAPEs upwards of 500 J/Kg exist, and this should allow sufficient buoyancy and charge separation to produce isolated to scattered lightning today and tonight. Primary hazard for these mariners will be sharply reduced visibility in downpours.

 

By Friday this air mass is expected to move well to the east of the region and associated marine waters, with a much drier and stable air mass in its wake.  Stable conditions across Atlantic Canada are expected to last through Saturday at this time with no thunderstorms activity.

 

Thunderstorm outlook for today:

 

 

Thunderstorm outlook for tonight:

 

 

Thunderstorm outlook for Friday:

 

 

Allen

Convective Outlook Valid for Today, Tonight and Tomorrow

Today:

NS/NB/ PEI/NL: Embedded thunderstorms giving lighting and heavy downpours with rates of 50 mm per hour possible.

 

Tonight:

NS/PEI/NL&LAB: Embedded thunderstorms giving lighting and heavy downpours with rates of 50 mm per hour possible.

 

Thursday:

NS/NB/PEI/NL&LAB: None

 

Convective Discussion

 

A an area of low pressure is developing over New England and is expected to intensify as it tracks northeast across New Brunswick  and into the Gulf of St. Lawrence tonight and into the Labrador Sea by tomorrow night. Moisture has increased in the southerlies over Nova Scotia (50 to 60 mm precipitable water, Yarmouth’s 12Z has 57mm) which will push north and eastward over southern Newfoundland today. Embedded convection has already been occurring in the valley of Nova Scotia with observations near 40 mm per hour with continuing high rates of rain coming in from the Atlantic coast of Nova Scotia. Thunderstorms are also possible from the cold front which will track through Maine and towards western New Brunswick this afternoon and evening.  The threat of convection increases tonight and overnight as well for eastern Nova Scotia and southern Newfoundland as the cold front continues.  It does not appear that Hurricane Franklin, which is well south of the marine district, will interact much with this upper trough as it pulls further east. Regardless, there is still a chance that some added moisture from Franklin could get brought into the trough, enhancing rainfall amounts tonight into Thursday morning over southern Newfoundland.

 

There is a cool and dryer air mass behind this low for Thursday as a ridge of high pressure sets up over the Great Lakes and extends over the Maritimes for the end of the week and into the weekend.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Thursday

 

Forecaster: McArthur

Convective Outlook Valid for Today, Tonight and Tomorrow

Regional Impacts

 

Today:

NB/ NS / PEI / NL&LAB: None

Southern Maritime waters: Embedded thunderstorms with heavy downpours over the southern marine waters

 

Tonight:

NS/NB: Embedded thunderstorms giving lightning and heavy downpours

 

Wednesday:

NB/NS/PEI/NL: Embedded thunderstorms giving lighting and heavy downpours

 

Convective Discussion

 

A ridge of high pressure over Newfoundland will push east today as an upper trough of low pressure builds in from the west.  A trough extending from the Great Lakes towards Labrador will combine with a developing area of low pressure off Long Island today and tomorrow. There is also a weak frontal boundary today extending from central New York northeast into northwestern New Brunswick ,which is expected to give some TCUs or an isolated CB this afternoon and evening. With increasing 500mb temperatures moving into Maine, convection may be capped over northwestern New Brunswick, but some heavy downpours are still possible this evening. There will be an increase in moisture south of Nova Scotia (50 to 60 mm precipitable water) which will push northward tonight and Wednesday into Nova Scotia and eastward southern Newfoundland into Thursday. Embedded convection is likely with this system but there is uncertainty in how mid-level convection will materialize with the warm nose near 850mb and moisture profile between 700 and 500mb.  Meanwhile, Hurricane Franklin, which is well south of the marine district, may interact with this upper trough as it pulls further east, but there remains high uncertainty as well in whether the storm centre itself will be captured and quickly pulled east or will remain too slow and get left behind south of the marine district. Regardless, there is still a chance that some added moisture from Franklin could get brought into the trough, enhancing rainfall amounts tomorrow night.

 

Thunderstorm Outlook for Today

 

Thunderstorm Outlook for Tonight

 

Thunderstorm Outlook for Wednesday

 

Forecaster: McArthur