Severe Thunderstorm Risk Late Today Very Cool Start to New Week
Today brings a strong sharp cold front which is now on the scene and heading eastward across Pennsylvania. The streak of clouds to the west shows up rather obviously on the satellite picture today. Partially clear skies ahead of it set us up for some daytime heating. While it is not all that humid this Sunday dew points will be on the rise. Throw a strong upper trough in the mix and you have the set up for severe thunderstorms. The Storm Prediction Center continues to indicate a slight risk (15% chance) of severe weather from Northeastern Virginia to Northwestern New England.
We are already seeing a line of thunderstorms on the radar this morning moving across Central Pennsylvania. Short range models weaken the first line and form a second line later this afternoon putting the threat time in Eastern Pennsylvania to Southern New England betwee 3pm and 7pm. The problem is these short term models have not been handling the development of severe weather well at all so we will instead focus on what the radar is telling us rather than what the models are proposing. Recognize the risk and keep an eye to the sky.
Once these thunderstorms play out we will see improving weather conditions tonight but what follows is a sharp upper trough for Monday bringing with it gusty winds, clouds and some sunshine. Temperatures Monday morning will bottom out in the upper 40s and lower 50s area wide.
Monday is likely to be a reminder of a day back a month or so ago or perhaps since we are always going forward & not backward, a day to look forward to in late September. The air is cold and a bit unstable aloft so look for some fair weather clouds to develop to mix in with the sun. Notice Monday’s highs will not get out of the 60s in many locations and in elevate areas north and west of the coast even 60 degrees will be tough to accomplish. At least it will be dry and free of any severe weather threats which have been so regular around here lately.
Tuesday will be mostly sunny with highs reaching back at least into the lower 70s. Then Wednesday the high moves offshore and we start a west southwest flow which should warm us to the upper 70s and lower 80s with some sunshine. However we will see a cold front moving approaching and that could set off some thunderstorms Wednesday night.
The puzzle for later next week will be like the one we had last week. A stalling frontal boundary to the south and waves moving along it. Cooler air and higher pressures to the north and the battleground zone that will lie in between. We will address the longer term later today.
MANY THANKS TO TROPICAL TIDBITS FOR THE USE OF MAPS
Please note that with regards to any tropical storms or hurricanes, should a storm be threatening, please consult your local National Weather Service office or your local government officials about what action you should be taking to protect life and property.