TODAY: Interesting day today that could amount to a whole lot of nothing. Model guidance continues to be very inconsistent in the precipitation fields. Then again, I used to NEVER use them, other than to see if they broke any out. Sometimes they are almost right on the mark, whereas other times you wonder if the model has the right day. Today, none of the models agree much on where or even IF rain will fall today. And when it does, it is at different times. Per once model, it should be raining right on my roof as I type. Not even remotely close.
This forecast discussion addresses the best case scenario for rain over much of the areas that really need it due to on going drought. However, if this does occur after 4-5pm, the storms could be very strong with 1/4-3/4" inch hail in the very strongest of storms (1 or 2 storms some where), with 'hefty, 'hefty' gusty winds. I would not expect storms before 4pm to be very strong. Storms are not expected to be officially bonafide severe though due to lack of instability and stronger winds in the mid-levels even though higher up they are about as stronng as we ever see here, even in the winter! .NOW: What I'm calling 850mb trough number 1 moved in on the west coast during the early morning ..and is now starting to lift off to the NNE. In its wake of showers and a decaying thunderstorm over South Tampa Bay.. is a lot of anvil debris which is being caught up in the strong jet stream winds overhead and spreading to the east coast.
However, these should thin out during the next few hours heading toward latter portions of the afternoon. Additionally, toward the west side of the state clearing is already in progress, and as such, so is increasing instability. Meanwhile, on the east side of the state near the coast is where coastal helicities will continue until late afternoon as long as the wind remains from the SE-SSE. These winds penetrate about as far inland as I-95 (at most) with any strength.
IN TROUGH ONE THUNDER STORMS HAVE OCCURRED. ONE IS NEAR TAMPA BAY. THIS TROUGH IS FORECAST TO LIFT NNE QUICKLY AND BEGIN TO BE REPLACED BY TROUGH 2.
MEANWHILE, EAST OF THE TROUGH THE ENVIRONMENT IS CAPPED AT 700MB. THIS IS FOR NOON TIME. AS YOU CAN SEE, NO RAIN ON THE EAST SIDE OF THE STATE. See the placement of TROUGH 2 in the second image after 6pm. TROUGH 2 is way up there in Virgina, and will generate some strong storms there.
Here on the left is 6pm. Trough 1 is well to the north and Trough 2 has moved in. In thinking of the best chance for rain or storms, by this time the high clouds will be cleared, and more important, height falls at the 850 and 700mb levels will break the cap which would permit storms to form rapidly toward 5pm on the east half of the state where the clouds might have begun to clear. At this time is when winds aloft will be the strongest as it so happens..up to nearly 120 kts at 200 mb.
Additionally, temperatures will begin to fall to meet the dew points and precipitable water values will rise and lift north a bit in response to height falls. Temperatures aloft are quite cold at 700mb and 500mb...cold enough to support hail and strong wind gusts of 40-50mph. If the mid level winds were any stronger we would be dealing with big time severe storms today.
Strongest storms, if they form will be within 6 miles of the East Coast where the strongest onshore component wind is found and as such, low level coastal helicities that feed into the storm along the storm relative wind fields . Any storm that does form ,and strongly, is likely to move right on offshore to the east and into the Atlantic.
NOW FOR THE CAVEAT: The high clouds have to clear for the atmosphere to destabilize. At least on the west half of the state. And that is just the beginning. All in all, confidence is low today of anything to materialize of note worthy record keeping, but the above is something to keep in mind. Wouldn't hurt to watch the 3pm onward time frame...just to see what might be brewing in your neck of the woods. Could be that activity will start before that time if it does. Also expecting some frequent lightning with any strong storm.
BEYOND: Weekend is looking nice, with only a marginal chance of thunderstorms sometime well into next week. Become warm by Sunday or Monday.