Great Lakes Severe Weather May 20-22

Convective initiation looks likely this evening along the warm front that will be moving through southern ontario. Dew points will be in the mid to upper 60's this afternoon with LI values well below zero. CAPE values will get as high as 3000j/kg across extreme Sw ontario.
 hires_cape_ne_17.png ( 306.19K ) Number of downloads: 0


The greatest risk of T-storms will be late this evening into the overnight across SW ontario (london, windsor and sarnia). The GTA and ottawa could see some action as well with strong winds as the main threat.

London sounding for this afternoon looks pretty impressive with your classic hydrolapse signature between 900 and 700mb. The CAP looks fairly week with a nice unstable layer in the mid levels. Shear is also present with parameters that support small hail and gusty winds.
 130520135046.gif ( 25.32K ) Number of downloads: 0


The t-storm risk continues into tuesday:
 day2otlk_0600.gif ( 28.99K ) Number of downloads: 0


Wednesday:
 day3otlk_0730.gif ( 28.11K ) Number of downloads: 0

Eastern Canada Warm Spell May 1-12

The european continues to advertise a significant heat ridge becoming established NE of an upstream cut off low. This will help pump heat and dryness throughout eastern canada as a strong area of low pressure stalls over the american midwest. This upper high will allow for twenties to build through ontario and quebec with even a shot at 25-30C in the montreal and toronto areas later in the period.

Euro 7 day maximum temperatures:
 t2max_ecmwf_ne_1.png ( 596.62K ) Number of downloads: 7

6-10 day height anomalies:
 ecm_z500a_5d_east_11.png ( 220.35K ) Number of downloads: 0

April 24-26 Eastern Canada Snowfall

The GFS and the euro have been showing this feature diving in from the prairies for several runs now. 850mb temperatures are well below freezing although surface temperatures hover just above the freezing mark.

GFS Skew T for Toronto:
 GFS_3_2013042106_F120_43.5000N_79.5000W.png ( 56.31K ) Number of downloads: 2


Ottawa:
 GFS_3_2013042106_F126_45.5000N_75.5000W.png ( 55.25K ) Number of downloads: 2


GFS precipitation and 850's:
 gfs_pr3_slp_t850_east_39.png ( 480.58K ) Number of downloads: 1


 gfs_pr3_slp_t850_east_43.png ( 464.39K ) Number of downloads: 1

ON/QC Thunderstorm Risk April 15-16

A potent cold front will move through the region on monday with a surge of heat out ahead of it. We could see some small hail, strong winds and heavy rainfall monday evening and night with the most intense cells firing up from windsor to barrie and east to toronto, kingston and perhaps montreal.

Total totals:
 hires_totals_ne_13.png ( 215.27K ) Number of downloads: 2

NAM 4km Sim Radar:
 hires_ref_ne_40.png ( 228.87K ) Number of downloads: 4


 hires_ref_ne_46.png ( 240.16K ) Number of downloads: 0


PWAT:
 hires_pwat_ne_46.png ( 224.95K ) Number of downloads: 0

April 11-12 Spring Snow/Ice Storm

Looks like parts of ontario and quebec may have another chance at some wintry weather next week. The european has been suggesting that a swath of snow works its way through ontario and quebec with a stubborn cold air mass keeping mid and upper level temperatures cold. In this situation the GTA and surrounding areas would start off as snow before switching over to heavy sleet and then eventually rain. Could be a messy system if the cold air mass stay in place.
Heres the european snowfall map in inches:

 ecmwfued_hgtprs__great_lakes_174_C_snowtot.png ( 29.15K ) Number of downloads: 4