"But seeing they could not See; hearing they could not Hear"
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"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".

Friday, March 9, 2012

Strong Storms "Possible" Today - Wretchedly Windy Coastal Weekend

Note Captions. Factors pro/con for any storms today in the body of this post. Any storms that can manifest today , especially after 3PM have the potential for hail and/or strong wind
TODAY: The boundary/front noted yesterday continues Southward as forecast now across the Deep South, although the timing of its approach and passage on Saturday is a bit sketchy now per the morning North American Model (NAM). This post is based mainly on the current trends locally though, the RUC, and the GFS model, and an earlier run of the HRRR model (which I have not viewed again during the past 2 hours, so things could have changed). It is worth noting that should the NAM verify, conditions will not be quite as 'wet' which is feasible given the current situation atmospherically across East Central Florida, with better conditions for a storm or two <not shown here> toward Martin County , St. Lucie, or even Northern Palm Beach Counties. Otherwise:

Cloudy conditions over East Central this morning should break up a bit by noon time. Light sea breeze Central and North Eastern Coasts likely after 12-1pm, but should not make much   inland penetration beyond I-95 or 'so'. Temperatures aloft are quite cold today, with 500mb running around -12C per the KSC morning sounding (in the summer with our storms they were a much warmer, 8-10 +C ; this makes for a good 15-20C difference in how cold aloft the air temperature is today as opposed to during the summer. Cold air aloft makes for strong storms. 

The atmosphere is much drier today than in summer, but drier air can equate to more isolated activity allowing for storms (if they manifest) to not compete for the Convective Available Potential Energy (CAPE) that will be available, which is less than in the summer. It also allows for decent of cold air thru the drier layers, making for strong wind gusts at ground level. 

In short, we have competing factors pro/con for storms today. A 20,000 ft (500mb) wind increase is expected to surge across the north half of the state toward early-mid afternoon which should add additional lift to the mid-levels of the atmosphere. A con for storms would be the poor lapse rates showing up on the NASA/MLB LDIS graphic,  but those seem to be becoming more supportive during the past three hours as time goes by.

Steering today from Central to North Central will be from the west to east around 10 mph; however, the very cool sea-breeze will likely prevent any storms from penetrating much further east beyond the east coast sea breeze boundary, sapping them of strength due as they 'ingest' this cool air at ground and low levels of the atmosphere which causes activity to 'erode' along the forward moving flanks of the storms as they enter this relatively 'cold' sea breeze.

As such, storms (if they do occur) 'could' appear to move very little due the persistent 'progressive erosion from the east coast sea breeze. With this in mind, it is possible that some areas if storms manifest could see up to 1.00" of rain west of I95 toward Orlando, Osceola , Seminole Counties for starters, but any such manifestation will be very isolated. With the cold air aloft in place any stronger updraft in a generated storm (again - the pre-requisite for any storms in the first place is an updraft of significant strength which is a bit in question) could produce hail and frequent lightning . 

The NWS (National Weather Service) alludes to a potential of small hail. Whether or not it reaches severe size (1.00" in diameter) is definitely debatable considering the other factors that are either lacking or those that are too weak to support severe sized hail today. I suspect storm motion will be rather slow either way, but considerable cloudiness at least will over spread much of the entire Eastern Central State by later today due to shower or storm cloud debris moving from east to west above the depth of the sea breeze boundary. 

As noted in the above image caption, activity could be very isolated due to persistent East Central Cloudiness early today. If those do not break up, all bets are off for strong storms, with possible storms (or one) further south toward the NE-E shores of Lake Okeechobee.

Any rains, wherever they may (or may not be), should cease shortly after sunset with lose of daytime heating.

SATURDAY:  As noted a few posts ago, it looked like a repeat of the previous windy front (although at that time this was a questionable presumption, admittedly).  Meanwhile, the cold front will mainly be sliding off shore the U.S. East Coast to the North of Florida with the tail end skimming past Central anywhere between 7AM Saturday morning to mid-afternoon. For this post, I'm siding with the GFS consistency over the NAM's; this too, bears watching though. Either way, this 'backdoor' type front will be accompanied after passage by increasing NE-ENE winds of 20-23mph with gusts possible of 36mph near the east coast, as well as some showers from near Volusia County to coastal Brevard from the time of its immediate passage and up to 12 hours afterward. Very breezy, especially near the beaches overnight Saturday night.

SUNDAY: The wind surge due to high pressure building rapidly eastward beyond the front will force the moisture convergence band (remnant front) southward and down the east coast overnight Saturday and into Sunday as rain chances go to zero for Central. Wind will continue breezy, although not quite as strong as what potentially lies ahead for late Saturday and  Saturday night.

Rip currents will be a 'big deal' this weekend, considering the insurgence of  inexperienced guests from the northern climes who may not be as fretful of entering iceberg temperature water.

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