Thunderstorms this Afternoon and into the Weekend

Atlantic Wide View courtesy of NOAA

Good afternoon everyone.  If you've been outside today you'll know that it is warm and humid.  Isolated to scattered thunderstorms will begin to fire between 2-4 PM, moving into our region by the 5 PM rush.  Forecasting the strength of these storms is tricky.  On one hand, the available energy is substantial.  On the other hand, the wind shear is minimal.  What that means is the wind is basically blowing in the same direction at all levels.  Therefore any thunderstorms that form will need to tap into other factors to become severe which is less likely.  However, Western areas and even the Worcester Hills may have enough elevation to "force" the thunderstorms to become severe.

So in English, thunderstorms will be scattered across Southern New England this afternoon and evening.  They will be hit or miss and one or two may be severe.  The threat from the severe storms will be damaging winds and small hail.  There is also not much to drive these storms, so locally heavy rainfall and street flooding is also possible.

Weekend Forecast
Saturday will start off with fog.  By mid morning this will be burning off and the sun will come out.  While there is a threat for an isolated thunderstorm tomorrow afternoon, the set up is nowhere near as favorable as today.  Highs will reach into the mid 80's (cooler at the coast).  Sunday is a different story.  A vigorous system not seen too often in August will approach.  It looks like another chance for a rainy Sunday except this time it will not be a steady downpour all day.  On Sunday a powerful line of severe thunderstorms may develop and push through the area with heavy rains and damaging winds.

Tropics Discussion

Soon to be Tropical Storm Harvey- courtesy of NOAA/NHC

Tropical Depression 8 has formed north of the Honduras border.  The storm is small and compact and heading towards Belize.  I think it has a chance to be over open water long enough to become a strong Tropical Storm or a Category 1 Hurricane before it makes landfall.  The name will be Harvey.  This is a heavy rainfall threat for Central America.

There are also two large tropical waves in the Atlantic Ocean; the one I've been talking about for a few days and another just off the African coast.  The one that is off of Africa may actually develop before the one heading towards the islands of the Caribbean.  The next two names on the list are Irene and Jose.  At this point I've already laid out the scenario's for the two waves.  Yesterday the major medium range weather models threw a bit of a wrench into the forecast and sent the system towards the Northern Gulf of Mexico coast.  Then last night the European model (superior physics because they spent more money) brought the storm back towards the east coast.  Its quite a few days away anyway so we remain in the wait and see mode.  Check out the line of tropical waves about to exit Africa over the next few days

http://tropic.ssec.wisc.edu/real-time/europe/images/irnm7.GIF


Happy Friday everyone