A solid thread of some scattered thunderstorms during the evening through southern NB, then a more widespread threat tomorrow as a slow moving front, along with high CAPE values, high temperatures/dewpoint may bring an interesting end to Sunday.
A couple of isolated fast moving heavy showers just north of Saint John at this hour, no sferics are being detected at the moment.
http://laity.ca/StormVue.php
Ron (relliot), looks like you may get a few heavy sprinkles or even a thundershower in the next little while. That band of showers that crossed south western NB is headed your way. A few brighter echoes showing up on radar (thunderstorm perhaps).
Some of the storms tomorrow in NB could be nasty. Models prog CAPE to be near 1500 j/kg across southern NB by 21z, and the shear will be impressive as well, and moisture will be plentiful. So some of the storms could certainly be strong to severe as the front sags south across NB throughout the day.
Lightning is really starting to pop-up this morning in Quebec in the Saguenay region. Models have upped the instability slightly for this afternoon to near 2000 j/kg of CAPE and LIs near -6. The severity of the storms will depend on the amount of heating that occurs. Right now, there is milky cirrus spreading across NB. Hopefully this dissipates as the ridge builds in or we wont reach the temps that were forecast, though models don't show the real heat reaching here until late this afternoon. Dewpoints could approach 20C later today as well. Looks like some warm frontal showers are spreading southeast from northern NB as well. I would expect a complex and/or line of storms, some of which could be strong/severe to move south across NB this afternoon and move around the periphery of the ridge. With the strongest dynamics/moisture/shear in eastern NB this afternoon, the strongest storms should be in this area.
Here are the temps across the region as of 13z with the fronts drawn by me in GEMPAK:
Lightning is really starting to pop-up this morning in Quebec in the Saguenay region. Models have upped the instability slightly for this afternoon to near 2000 j/kg of CAPE and LIs near -6. The severity of the storms will depend on the amount of heating that occurs. Right now, there is milky cirrus spreading across NB. Hopefully this dissipates as the ridge builds in or we wont reach the temps that were forecast, though models don't show the real heat reaching here until late this afternoon. Dewpoints could approach 20C later today as well. Looks like some warm frontal showers are spreading southeast from northern NB as well. I would expect a complex and/or line of storms, some of which could be strong/severe to move south across NB this afternoon and move around the periphery of the ridge. With the strongest dynamics/moisture/shear in eastern NB this afternoon, the strongest storms should be in this area.
Dewpoints have already reached 20C here in Quebec City as well as in Montreal.
Severe thunderstorm watches have been issued for areas in nw NB.
Grand Falls and Victoria County
12:30 PM ADT Sunday 8 June 2008
Severe thunderstorm watch for
Grand Falls and Victoria County issued
This is an alert to the potential development of severe thunderstorms with heavy downpours large hail and damaging winds.
Monitor weather conditions..Listen for updated statements. If threatening weather approaches take immediate safety precautions.
Conditions are favourable for the development of thunderstorms over the above mentioned regions this afternoon. Thunderstorm activity is expected to persist into this evening. A cold front will cross the district later this evening ushering in a more stable airmass.
Watches
Québec
11:04 AM EDT Sunday 8 June 2008
Severe thunderstorm watch for
Québec issued
Weather conditions for these regions are favourable to the
development of severe thunderstorms. Some of them could produce large
hailstones - high winds - heavy rain and intense lightning.
Public in these regions should be on the lookout for weather
conditions and listen for subsequent watches and especially a warning
which could be issued if severe weather threatens.
This severe watch is in effect from 11:05 AM to 07:00 PM EDT.
Storm prediction center has issued a mesoscale discussion for northern Maine wrt to the severe potential:
MESOSCALE DISCUSSION 1277
NWS STORM PREDICTION CENTER NORMAN OK
1126 AM CDT SUN JUN 08 2008
AREAS AFFECTED...NRN ME
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 081626Z - 081800Z
TRENDS ARE BEING MONITORED FOR THE POSSIBILITY OF AN INCREASING
SEVERE THREAT THAT COULD NECESSITATE A WW LATER THIS AFTERNOON.
UPPER SUPPORT FOR CONVECTIVE DEVELOPMENT IS A BIT UNCERTAIN. BUT
...A MOISTENING BOUNDARY LAYER IS BECOMING INCREASINGLY UNSTABLE
ALONG AND SOUTH OF A WARM FRONTAL ZONE EXTENDING DOWNSTREAM OF A
WEAK FRONTAL WAVE OVER SOUTHEAST QUEBEC. AND...MODEL GUIDANCE IS
SUGGESTIVE THAT A SUBTLE WAVE WILL PROGRESS THROUGH BROADER SCALE
ANTICYCLONIC FLOW ACROSS NORTHERN MAINE BETWEEN NOW AND THE 18-20Z
TIME FRAME. THIS PROBABLY WILL BE SUFFICIENT TO SUPPORT
INCREASING/DEEPENING CONVECTIVE DEVELOPMENT. IT APPEARS THAT MIXED
LAYER CAPE WILL EXCEED 1000 J/KG. AND...IN THE PRESENCE OF STRONG
DEEP LAYER SHEAR BENEATH 50 KT NORTHWESTERLY 500 MB FLOW...ON THE
SOUTHERN FRINGE OF THE STRONGER WESTERLIES...A FEW FAST MOVING
STORMS CAPABLE OF PRODUCING SOME WIND DAMAGE AND HAIL ARE POSSIBLE.
..KERR.. 06/08/2008
ATTN...WFO...CAR...GYX...
47327116 47347079 47226987 47296889 46886778 46246761
45786812 45917079 46477231 46957204
http://www.spc.noaa.gov/products/md/md1277.html
There are some severe storms firing in northern Maine right now with severe thunderstorm warnings for them. There is one lone cell near Caribou that looks like it may have some weak rotation!
Edit: The storm near Grand Falls looks to be a weak supercell - that region is now under a severe thunderstorm watch. Winds have veered to be more southeasterly out ahead of this storm dramatically increasing the wind shear. SPC's tornado index is rather high for this region as well... People in the path of this storm, look out!