Fallen Dewpoints Right on Schedule - But Tropics Might Heat Up !

TODAY: First frontal boundary of the Fall Calendar Season (which began only but yesterday) is in full swing even this morning with northerly winds and lows in the mid-upper 50Fs this morning in the western Florida Panhandle Region with those northerly winds having worked into Central Florida. The air mass, particularly south of I-4 won't be 'greatly' affected during this first 'full frontal assault' though. The main impacts once the boundary clears Central Florida (which will not be fully under Sunday) will be lower Dew point Temperatures. You might recall earlier this year a post proclaiming the onset of 'Summer' in which it was suggested the 'summer is truly here when the dew points never fall below 70F. Such has been the case the past couple of months (may it be known) but come Sunday into Monday for the first half of next week the forecast calls for falling dew point temperatures and a slight cooling otherwise as well. The main impact being it won't be as humid and 'heat indices' likewise will be lower. Highs will be mainly in the mid-upper 80Fs inland and lower to mid-80Fs along the coast especially as we get toward Monday - Wednesday of next week with dew points in the mid-lower 60Fs. The weekend itself appears will be all but dry with dew points in the mid-upper 60Fs to near 70F right at the beach itself. Otherwise, the only contender for rain chances north of a Melbourne to Tampa line and south of I4 will be today and perhaps on Friday. But come Saturday onward and especially Sunday through Tuesday there is about a zero chance of rain. Lows in the mornings won't be but a few degrees cooler but it will be noticeably drier giving a cooler 'feels like'. With these things said, the next subject at hand and probably hasty with it, is to watch the tropics or other odd 'anomalies' to occur in the upcoming 3-4 weeks. The time period of mainly ' from the last week of September through to the first week of November is notorious for atypical weather events such as 'no name storms', 'strong nor-easter' type weather', small scale heavy rain/large rainfall total events and last but not least - tropical systems.

 It is the 'Tropical Systems' realm we're investigating (for now) in this write up , and we'll keep it very brief. The GFS in the past two runs now (going out just beyond the unreasonable 10-day forecast time frame but very close to it) has shown two runs in a row  a tropical system to form between the eastern tip of Cuba and/or just east of the Bahamas and then moved westward to the Florida peninsula. At the same time a large and likely Strong Hurricane could be threatening Bermuda. This would all be toward NEXT weekend.

Below is the latter GFS Model run. Here it shows a landfall 'tropical system' centered near

just north of West Palm Beach' to move west across the state, enter the Tampa Region, then curve back eastward to exit the state off Central Brevard County. Does that sound reasonable to you? Not on my end it doesn't. The previous run was even 'spookier'. Tis the season I guess, but as we've noted earlier, we are coming to 'that time of year for anomalies'  .
 

As you can see, this is still well out in time and could easily change.

 The GFS has handled what 'might evolve' as being from latent energy associated with the front's passing through our areas in the next few days as they then nestle down in the frontal grave yard of the Florida Straits. 

But they might not be all dead just yet (!) is the point. It does appear that the GFS is trying to bring one 'back to life' as a cyclonically rotating system to cross Florida.

 The first option the model showed was not one but two (!) systems around the state all embedded within a large low pressure system. 

The latter run closed it up to one more organized system as seen above. 

No matter, could be interesting so just a heads up for now. Maybe by this time tomorrow the whole idea might have been completed abandoned. In the mean time, Fall has made a  very 'Timely' showing  this year , right to the calendar date.

Man Your Life Boats! Large Rainfall Totals Possible The Next 10 Days

 

Purple colors means very high 'precipitable' water values
through the depth of the atmosphere

TODAY: If there were a Noah today, he'd be calling all to Get Onboard and Get with The Program because rains are a-comin' (!) but who would believe His Report? After all, it looks nice enough out there now, and 'I've got better things to do than be concerned about some mamby - pamby report about something I see no evidence of with my bare eyes.'

However, things are 'setting up' in some form and fashion for not only some large rainfall totals (esp. just inland from the east coast toward I95) today, but also tomorrow. And, for that matter, for several days to come for varying reasons. 

This is not a 'sure thing' however, especially the further out in time we go, but  the 'trends' have been that in some form or fashion there will be good rain chances persisting for at least at an intermittent fashion (with a few breaks in the cycles) for the next 6-10 days (at least).

Firstly, moisture advecting in from the west from nearly stationary remnant 'Nicholas' will be combining with a more SW-W (toward the east) steering flow, and that with the east coast sea breeze will result in a moisture convergence most prominent along the east side of the state later in the day along the west coast - east coast sea breeze merger and outflow boundary collisions of earlier shower activities. 

The large rainfall totals will not only be from all the available moisture (precipitable water) but due to the slow forward motions of the storm activity itself. Steering, though toward the east, is rather weak so storms themselves will be in no hurry to pull out once one unloads over a location.

The same situation will occur tomorrow in must of the same areas, with the north half of the state most favored.

Now, as one may realize another tropical system is currently in the process of evolving well east of Florida. This system which will likely be named is not expected to make landfall anywhere along the U.S. East Coast as it lifts northward and eventually curves to the NNE off the Carolinas. However, as it moves out, a trailing low level 'trough axis' - a bit like a cold front - will translate south and westward from it as it merges with a larger continental trough moving off the NE - and Mid-Atlantic States. 

That 'trough axis' will trail back south and west toward/across Florida where the remaining pooling of moisture from Nicholas will again come into play. So now we will have that moisture COUPLED with convergence along this newly formed trough axis from the departing tropical system, which if named, would be 'Odette'.

Between today and tomorrow, we could see rainfall totals between 3-4" in isolated cases (most likely along to just west of I95) but other areas could well see 2" inches plus, with wide spread 1/2 - 1" totals possible. That is only for the next two days from "Nicolas" more or less, alone; now, to consider what occurs when 'Odette' (if so named, but makes no difference one way or the other) is included, which will affect the state for another 2 days or so due to that 'trailing trough axis arching back across Florida', we can double that total. 

But hold on, as the GFS is showing a potentially potent tropical wave to be approaching from the east by the time these first two scenarios have been exasperated, which would only then prove to be another 'nail in the coffin' of moisture laden atmospheric mayhem.

'Sum Total" for Today through the middle of next week (at least) is to expect rainfall (not all day long, mostly in the late mornings through mid-evening) today through Tuesday. THEN, when the pattern changes but we still have moisture all about, another pattern of nocturnal and early day rains might set up for the east coast primarily for several days to come. So far, severe weather is not expected, but dangerous lightning strikes will be at stake as the primary hazard (as well as localized short-term flooding).

This post is considering a 'worst potential outcome' though. Chances are we will end up in the middle-ground realm - but still - rains are on the way to begin later today - for any one location though -such as your own - there is no saying if you will see such high totals or not - one place only 5 miles away from any other location can manage as much as 4 inches more than another location not far away.