"But seeing they could not See; hearing they could not Hear"
“The views expressed herein are those of the author and do not necessarily represent those of the National Weather Service or affiliate/related organizations. Please consult .gov sites for official information”

"From its chamber comes the whirlwind, and cold from the scattering winds." - Job 37:9.

"The wind blows to the south and turns to the north; round and round it goes, ever returning on its course".

Monday, November 7, 2011

Will Gale Have a "Sex" Change to "Sean"? More of the Same Locally

Sunrise temperature plots show winds again decoupled overnight with drainage flow ensuing along the Suwanee River Valley Basin and South along I-95 to SE Florida. The only locations that did not decouple overnight were extreme coastal NE Florida and along the immediate coast from Cocoa Beach to Pompano Beach. At Cape Canaveral the temperature varied from 68F - 73F degrees pre-dawn at my place over the course of a few hours proving that this area was trying to make the break, but PAFB never experienced these variations. DAB's winds went NW and cool once again as did MIA and Kendall area. 

TODAY: Very similar to yesterday with weaker on shore winds today. Morning RUC forecast soundings are indicating that unlike yesterday the inversion around 5000 ft might never lift, thus inland winds across the interior should not be as strong today as well as those along the immediate east coast which should be in the 10-20mph with some stronger gusts almost anywhere, but most likely far NE Florida and SE Florida and areas toward the West side of the state.

Model guidance is useless once again for a rain forecast since none of the driving principals for convective or stratiform type rain really rules either of those roosts, so went with visible satellite imagery , morning trends, and the forecast available moisture in the lowest 5000 ft of the atmosphere. With that, the best chance of measurable rain today  from a purely visceral perspective appears to be from the FL/GA border to Ormond Beach or just north of there. Admittedly, not very 'scientific'.

From another perspective, my other gut instinct is to label this overall weather period of today through Tuesday as being a purely nocturnal type setup. In that sense, the better chance of showers from DAB to MIA will be after 6pm through 9AM Tuesday morning. Noting that none of the models are showing rain anywhere even now as they are coming in steadily toward and over NE Florida into Flagler County. The only reason I'm not fully buying into this idea is because the latest RUC is not showing the 5000 ft inversion  to lift today as it normally would during the afternoon. If so, the better moisture will remain locked in place below that level and allow for a continuation of showers all day almost anywhere underneath the inversion...sneaky devils. 

This would also mean, however, that inland winds will not be nearly as strong as yesterday with showers making it well into the interior under the inversion. It also means afternoon highs will remain in the lower-mid 70Fs...since the cooler night time air and that being advected off the cooling Atlantic waters would remain trapped under the inversion. Best thing to observe casually, if the temperature starts to climb into the upper 70Fs to near 80F, the rain chance goes least until just after or near sunset. In short, any rains to reach the state south of the JAX area is merely 'atmospheric spittle' ejecting from the low well offshore just under 1000 miles away.

Visible satellite image with daybreak indicates some brighter cloud tops as opposed to yesterday's 'field of cotton' type image indicating that showers might very well extend out through the great beyond into the Atlantic from east of Jupiter Inlet and North. Thus, chance of showers with big periods of sunshine as well. Shower tops are very low, so they can sneak in pretty quickly since they will not be visible from far away except to the prudent observer.

Much of what will occur today also depends on what happens with the Gale (low) offshore. Morning  RUC and NAM trends for it to become better organized throughout the day, and per those runs this low in my mind could become a named subtropical low ("Sean") by tonight (per the RUC) or by Tuesday night (per the NAM) models...given that the system is ingesting warm air and lifting it to the upper levels slowly but surely. The RUC has the system warm core through the bottom 5-7000ft by 6pm tonight, whereas the NAM is slower. The GFS never makes the system subtropical at all. For now, would ride with that model, but morning visible satellite imagery has been trending stronger/better . The storm is twice that of yesterday if not more in terms of compactness. The bigger (or other) conundrum in terms of naming the system is that is ingesting dry air throughout the mid-upper levels of the atmosphere, so that factor alone might preclude a "Sean" Storm despite the surface forecast winds that would befit such nomenclature. 

Clearly a low circulation in the low levels at sunrise, with a broader expanse of circulation extending to the SW by 240NM (nautical miles). Note how the cloud 'types' change in between the Green Arrows where the small low topped showers are contained off the Florida East Coast. Those combined with the patches of paper thin, pancake stratocumulus clouds indicate subsidence above the 5-60000ft inversion (sinking air) as well as it being BONE DRY aloft.

Meanwhile, a front is nearly stationary today across the Plains states, but will be on the move tonight as a large and deep upper level low presses in closer to the area from Arizona / New Mexico. All modes of severe weather are possible in parts of Texas, Oklahoma and South Central Kansas, with hail seeming to be the most likely distraction (up to 2" or more sized) as well as some tornadoes, although the set up is not screaming "Tornado" in my mind, it is close to it though, and therefore the area is already being closely monitored with a least one Tornado Watch possible after 1pm CST.

TUESDAY: Either way, it looks like the 'low' offshore will remain nearly stationary today generally 850-950 miles east of St. Augustine but begin a general drift toward the W-WSW through  Wednesday.
The more well developed the system becomes, the lower the rain chances and wind strength will be on Tuesday, namely since the state will not only be under subsidence from sinking air due to the wedge of High Pressure extending from Virginia to the Central Gulf, but also due to sinking air on the west side of the low as it backs closer to the east coast of Florida.

WEDNESDAY: So far guidance continues to indicate the low will be on its closest approach to East Central Florida. The NAM and GFS are indicating a sliver of moisture convergence to work down the coast from  DAB to MIA through the course of the day (from Just west of I-95 and east). This will be a different type of set up if it does occur than what has been happening the past few days, and would not spread further inland.

THURSDAY/FRIDAY: Cold front to approach the Panhandle. Temperatures will fall before and after this so called 'boundary'   due to the winds  being NW. least in the morning, but warmer Thursday afternoon. In truth, it looks like a "Faux Pas Front"...with cooler temperatures due solely to a function of prolonged NW winds pulling drier land-based air across the state as opposed to marine air. Net result is lower morning low temperatures (lower dew points) on Friday with low 60Fs at the coast cooling to the mid-upper 50Fs along and west of US1 / I95 with upper 40Fs down the spine of the state toward NW Osceola County and lower 40Fs Panhandle toward interior NE Florida. Warm Thursday afternoon but a few degrees cooler Friday afternoon and night.

DRY except perhaps some sprinkles working just offshore and down the coast and perhaps coming onto land in Southern Palm Beach through Dade Counties and the upper Keys.

SATURDAY: Stellar weekend. By this time the low offshore is lifted well to the north, and a bit ironically has a cold front extending from it well out at sea as it becomes fully extra-tropical...After a cool start to the day, temperatures from then on out are similar to what we have experienced the past few days, if not a few degrees warmer, with the only rain chances around the Keys and far SE Florida (meager). Winds swing to NE late Saturday with slow air mass modification commencing.

Next front on the schedule per this time of year should be approaching 6-7 days later, and sure enough the GFS follows that line of climatological reasoning.

Still looks like the period between November 16 - 22 time frame could have something 'active' in terms of either wet , wind, or both...but not of severe convective (thunderstorms) type. 

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