Varied Amounts Of Soaking

Rainfall today varied widely around the region -- from next to nothing in Reading to three inches of rain in parts of Chester County, as well as in Central Delaware, to about an inch along I-95.

Scattered, slow-moving thunderstorms did a number on portions of the region during the midday and early afternoon hours.  If it wasn't heavy rain, the isolated severe weather that knocked down some wires and brought gusty winds was an added insult to injury for parts of South Jersey and Southeast Pennsylvania.

The culprit yesterday was a slow moving cold front  drifting down through the region, working through a tropical airmass and helping fire up showers and storms that not only produced a lot of rainfall but also moved very little.

What's left out there this evening will diminish as the night progresses...and tomorrow, thankfully, will be much less humid by the time you head home from work.

Reviewing First Half Of June

The first half of June has been a relatively warm one -- thanks in large part to our very warm start to June (93 on the 1st, 88 on the 2nd).  Take those out of the equation and we're essentially "normal" on temperatures for the balance of the month.  Our average of 72.6, including the 1st and 2nd, is 1.5 degrees above.

What isn't normal is our rainfall -- 7.33" through Saturday, which is five plus inches above average.  Some spots have seen close to if not more than nine inches of rain this month and among the climate sites in the region, Georgetown, DE has 9.34" of rain so far this month, over seven inches of rain above average.

And we still have half of the month to go.  Probably won't see as much rain in the second half as we have in the first but we need a bit less than three inches of rain to set a record for rainiest June since 1872 in the city.

June 19th, 2013 Forecast

Look for scattered showers and thunderstorms tonight, most numerous during the evening.  There could still be some storms around after midnight, but they will eventually taper off late tonight.  Humidity will be lowering throughout the night, so it will feel much more comfortable outside as you step out the door in the morning.  Lows will range from 58 north and west to 65 in the city.  Winds will become northerly at 5 to 15 mph.

Wednesday may start off with leftover cloud cover, but skies will become mostly sunny by midday or so.  It will be a fantastic afternoon with low humidity and highs in the mid to upper 70s. There will be a refreshing breeze out of the north at 5 to 15 mph.

High pressure will set up for Thursday through Saturday with temperatures warming back into the 80s, so as the calendar switches to summer on Friday the weather will also slowly transition to summer.  A warm front will move through on Sunday and bring heat, humidity, and possible thunderstorms with it right through Tuesday.  Our second heat wave of the year is possible Sunday through Tuesday (possibly beyond) with temperatures flirting with 90.

Wednesday Planner

7 AM 65 degrees, Less Humid

Noon 73 degrees, Becoming Mostly Sunny

5 PM high 79 degrees, Pleasant

Sunrise 5:32 AM
Sunset 8:32 PM

Heavy Rains In Spots Could Cause Localized Flooding Issues Today

While we're not forecasting widespread or epic soakings throughout the Delaware Valley today, any scattered thunderstorms that do develop won't be in any hurry to move as steering in the low and mid levels is pretty weak. Knowing that there's not a lot of directional kick today, storms that fire up later on today will have the tendency to produce heavy rainfall in some locations.

The potential does exist for some localized flooding in parts of the region later today.  Flash flood guidance for one hour rainfall is rather low -- around 1.2" across the northern and western suburban counties, even less than that over Central and North Jersey, according to the National Weather Service.  The only places that have "respectable" flood thresholds are the Shore counties to our east and southeast, plus Camden and Gloucester Counties over the river in New Jersey.

While thunderstorm development over the region today should be scattered or in scattered lines, not everyone gets wet. Modeling varies still on placement as the NAM keeps the bulk of thunder threat north of the city while the GFS places more thunder activity south.  The Euro gives everyone scattered storms in being fair and balanced to the whole of the region.  With the weak front the only real focal point and the atmosphere relatively rich in moisture, storms may be more apt to fire near the front later on today...which would be to our north.

Regardless, the threat for scattered thunder through the region does exist and any storms that do fire have the threat to produce some heavy rainfall and perhaps gusty winds. Odds don't favor much severe weather but a rogue severe storm or two is possible later on.

Some Scattered Thunder Again Today

A cool front will drift south into the region today, bringing another chance of showers and storms to the region.  Like yesterday, storms will be scattered around and not everyone will get in on them.  Modeling suggests the chances are highest in the afternoon (not surprising) but models do vary on placement of storm activity.  Any thunderstorm that develops could be locally severe with gusty winds and hail but odds favor few severe storms overall  and most storms to generally be on the scattered side.

Like yesterday, any storm that does develop will be slow moving and locally drenching.  Some spots could pick up a couple of inches of rain in a short amount of time. Other spots will end up dry through the whole of the day as thunder will be of the scattered, hit or miss variety.

Highs this afternoon get into the lower 80's in most locations, with the Shore the notable exception as highs top out in the upper 70's by day's end.  There will probably be more clouds around than yesterday, which will result in temperatures being a few degrees cooler than yesterday's high of 88 in the city.