"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".

Thursday, January 19, 2017

Severe Weather Threat Increased for Sunday/Sunday Night

Sunrise Wednesday Morning - (Sunset Image at End of Post For Same Day)
TODAY-SATURDAY: Continued above normal temperatures with light wind today through Friday.

By Friday wind becomes a bit more Southerly, continued warm

By Saturday afternoon things now become sketchy . Chances of shower/storms (if possible) appears would be restricted to north of I-4. Elsewhere, increasing high clouds.

SUNDAY: Big Day of Questions: Latest GFS model overnight run (and continuity from previous post) continues to advertise the risk of a squall line moving across the state.

The  factors most contributing to the risk would be strong mid-upper level winds of 90Kts (mainly north half of state), with a 500mb 'jet' of near 90knts  with up to 30kts of bulk shear contribuiting even in the lowest 2000 ft from surface to 925mb, with higher amounts of shear up through the column. 

Consider, that when we have thunderstorms, sometimes strong in the summer, there is normal NO shear at all.

Additionally, at least early on, there would be Convective Available Potential Energy between 800-1200 J/kg2 (though the GFS might be underscoring this value). Helicity values in the 200m2/s2 don't hurt, but are not particularly of great concern , but could contribute to brief tornadic spin ups (that rather weak as far as tornadoes are concerned)

Factors that would prevent this 'possible event' from reaching a solid MDT RISK DAY is poor mid-level lapse rates and directional wind shear values mostly having passed east of the state before other factors that do contribute come together, mainly after dark Sunday evening.

As a result, and given that there is still a few more days to monitor and many more model runs to monitor as Sunday draws closer, this situation does bear close, scrutinous monitoring.

As seen below, for purposes only, the highest risk for the strongest Category of severe levels in the winds mostly appears would be All of North Central to northern parts of South Central Florida.

Further south , however, has some other factors which 'could have' brought that region into greater threat but will leave well enough alone. The Storm Prediction Center has already placed all of North Central in a 'Substantial Severe" watching mode. 

Thus, Sunday might evolve into being a MODERATE RISK DAY. Rare for Florida.
Greatest threat appears to be high end severe straight line winds, quick and difficult to warn for tornado spin ups , especially if this ends up being a QLCS SQUALL LINE, with broken line segments.

Expect that if nothing else changes, this will be one of those weather events where TV CHANNELS will be doing continuous LIVE COVERAGE. 

BEYOND: Breezy on Monday and cloudy. Cooler but not cold, possible light rain though clouds seem to be prevalent mode. Temperatures running near normal.

EVEN YET: As noted in previous post, if conditions line up this time for one SEVERE EVENT, the chance that more could follow is always a potential. 

The Latest GFS does show not only one but TWO possible events up to the first week of February. The latest of all might be a humdinger but given how far out in time that is, and that it was only of the latest run - there is no continuity so would discard ..and revisit in about a week.

YET EVEN STILL: GFS continues to show a big but short lived 'COLD EVENT" - though the model does seem to over exaggerate cold events beyond Day 7, so will disregard. Point being, not time to put away the mitts, scarves, and snow shovels.

Sunset Wednesday Evening

No comments: