"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".

Saturday, January 16, 2016

"Risk" of Severe CAT Winds / Quick Tornadic Spin Ups Before Daybreak Sunday

"A Very Cool Sunrise from Mid-Week" - Cape Canaveral, Florida
TODAY: Seeming benign weather during daylight hours, deceivingly so, will quickly transform as the atmospheric landscape undergoes rapid changes after sunset.

NOTE: *RISK   does not mean WILL OCCUR - Risk means 'risk'. Chances are some areas will experience severe weather however, overnight tonight.

Upper level disturbance passing across North Central Mexico will phase with the Northern Branch Jet dropping South roughly along the Rockies from Canada to Southern Texas to  develop a weak but rapidly strengthening surface low first just off the Texas SE Coast to traverse the Northern Gulf toward roughly the Cedar Key area of the Florida West Coast before day break Sunday.

Warmer waters of the Loop Current could play into some forecast glitches so have gone in favor of leaning more in going with model guidance and then adding a presumption for a bit stronger potential beyond what guidance and THE OFFICIAL Severe Weather Outlook by the Storm Prediction Center (SPC) is advertising as a safety precaution. 

Currently, the SPC has a Slight Risk for parts of the West Side and across South Florida, but for blogger purposes only -  will include all of the state generally south of a line running from near Brooksville to the Brevard/Volusia County line. 

Early Saturday Morning OUTLOOK from SPC (Storm Prediction Center)
 Blog purposes only outline a slightly larger area to include all areas in the
 Marginal SPC risk as Slight Risk . Areas south of the 'Green Line" below, could experience strong straight line winds, possibly some near severe as well, but the 'signals' were not convincing enough to included in a large 'severe' threat at this stage and early hour Saturday morning.

BLOG OUTLOOK with concern of a stronger Surface Low or perhaps one a bit further south
and/or higher DEWPOINT AIR reaching as far north
as the 'Mims area" toward the County Line of Brevard

Factors at play are more favorable for Severe Weather (in the wind category especially for a few reasons than for Friday's event ) when most reports came in with winds ranging through the 40s (mph) ..isolated stronger.

 Bulk shear to the lowest 5000 ft will be stronger, the Jet aloft will be even stronger as will all winds across other standard levels used for guidance. 

Lastly, during our previous event (yesterday) the state was under the left entrance region of the Jet (which is where sinking motions can occur aloft) but in the situation over-night  tonight the state will be under the Left Exit region of an up to a 160kt jet stream which maximizes divergence aloft producing a lifting mechanism necessary for upward vertical motions and storm growth/maintenance .  See below.

 That's right,  winds of up to 175 mph will be passing WELL overhead early tomorrow morning across North Florida which leaves Central in the Left Exit Region or 'Right Rear Quadrant"  of the departing Jet Max as a strengthening surface gale is taking shape in the eastern Gulf.

GFS forecast image for SURFACE WIND (in knots) as Low approaches. Realizing
this low will be NONEXISTENT only about 18 hours earlier (or nearly so)

Wind  well aloft at 200MB

As was the case with the previous event, the vastly limiting factor to a much larger threat will be lack of atmospheric instability in regard to  "Convective Available Potential Energy" (CAPE). Wind energy is already more than sufficient for a big severe weather event, but without the CAPE chances of severe storm coverage is greatly reduced.

Rainfall totals south of I-4 are not expected to be very high though a brief heavy downpour is still possible. Storm forward motion  will quickly go from near 20 mph to nearly 45-50mph forward motion between the hours of 3AM -5:30AM. The biggest 'tornado threat' might well be ahead of what could be a developing QLCS squall line or  squall line as was inferred in the previous post would be the case a few days ago.  Again, this will be a high shear, low Cape event. Brief tornadoes can occur along QLCS squall lines that can be nearly impossible to foresee in advance by radar as being 'likely to occur'.

TIME FRAME: The Time Frame for 'Potential Risks" will begin around 3AM West Coast but quickly spread to East coast regions by 4:15AM. If there is a squall line type feature, there is still a risk of a quick tornado spin up well ahead of 'supposed squall line' mainly along the east coast south of Cape Canaveral toward Central Palm Beach County and along the West coast. 

Almost all 'significant weather that will or even won't occur' will have cleared the area by 7:30-8:00 AM Central and a bit later South Florida. Clearing skies to follow especially by mid-afternoon.

ALSO: A period of stronger, gusty surface wind with gusts over 32 mph  maybe even near 40 mph possible for a time late morning into Sunday afternoon as the low moves away and becomes a full blow gale passing near to just west of Bermuda.

OVERNIGHT SUNDAY NIGHT: Cooler air will follow this system but nothing much cooler that it is this morning. The colder air is to follow on the heals of a secondary trough to pass to the north of Florida unbeknownst to the 
'earth-bounders' . 

Monday will be cool with still some wind with highs in the lower-mid 60Fs, a bit like it was on Wednesday and Thursday earlier this week. That is, a bit below normal for this time of year.

TUESDAY: Colder air advection coupled with much drier air might well set the stage for the coldest 24 hour period this season for TUESDAY with highs struggling to reach mid-50Fs north of line from North Tampa Bay to Cape Canaveral. Areas closer to and north of I4 might never see 55F degrees on Tuesday.   Freezing temperatures though are not expected but perhaps North Florida and interior parts of far North Central and northern West Central. Lows closer to base-camp (Cape Canaveral) might reach below the allusive 46F threshold which has yet to occur this season.

WEDNESDAY MORNING is when coolest temperatures will be just in from the immediate coast from the Cape and South but colder north. Wednesday morning might be even a bit warmer for Brevard and South than Tuesday but inland a different story where it will be 'about the same'..though a few degrees warmer might make the difference between frost and no frost for agricultural interests though . Wind will be light this day though and air mass recovery to warmer will commence after dark Wednesday evening.

THURSDAY: Warmer for a good 48 hours before next front approaches. The next two systems will pass north of Florida meaning the severe weather threat will not exist again for quite a while. 

Though there is a chance of showers perhaps later in the week for parts of the east coast suspect that chance might 'go away'... the better chances do not arrive (so far as shown) until sometime  around the 26th of the month. 

All in all then, after tomorrow morning this active weather phase we've been in will be over for a while. 

"February" might be a different story, however.

Relatively Rare Non-crested Kelvin-Helmholtz wave clouds near Cape Canaveral

No comments: