"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".

Tuesday, March 20, 2018

"Risk" of All Modes of Severe Weather Being Possible Today

The "Good Friday" Severe Storm - 2016
TODAY: Very little change in thinking from previous post the other day. 

A prefrontal boundary across North Florida will start to become 'active' come late morning toward the Big Bend area south and eastward toward the Gainesville  - St Augustine line (mainly) and south.

As stronger wind aloft in the mid-levels begins to coincide with the leading edge of a jet stream speed max now entering the north Gulf and poised to approach the area mainly from I-4 and north heading to mid -afternoon activity should increase in coverage and intensity due to the resultant bulk-shear up through the atmosphere  coupled with daytime heating.

Mid level lapse rates in this area accompanied by bulk-shear (mainly speed shear with some directional shear as well) in between the 5000-20,000 foot levels and ample low level instability with very cold air aloft could produce storms with 'damaging hail' and/or straight line winds. A tornado cannot be completely ruled out.

The time frame for the areas of North Florida southward through Volusia County is from  around 1pm - 4pm.

Further south, daytime heating will have had more time to work over parts of North Central - Central Florida (assuming this timing is correct) and that there is good insolation ( not too many high clouds spreading over this area), which will result in  'better' low level lapse rates as well. 

This 'window of opportunity' of better low level lapse rates will coincide with the 'increasing winds aloft through the mid-levels' over-spreading the area south of I-4 as the jet speed max approaches the state (as noted above) enhancing upper level divergence producing greater lift in the atmosphere.

Thus, as of this time ( 5:00AM) the 'line of activity' and possible random storm cells out ahead of the main-thrust of activity could see an up-tick in the hours between 3-6PM as the pre-frontal trough pushes East to East South East across the state. 

The time frame currently anticipated for the Southern Volusia -Orange-Seminole - North to Central Osceola - and most of Brevard Counties of the 'highest risk' of 'potentially severe storms' is between 3pm - 7pm as activity presses east and south across the peninsula as day-time heating will be reaching it's peak and resultant surface based CAPE (convective available potential energy) increases.

Note that time frames noted above are subject to change, as are conditions, once later model runs are released and made available during the late morning hours (generally after 10:30AM - noon time).  'Potentially' a region in the Enhanced Risk area (see below) might be upgraded to Moderate Risk, and if so suspect it would be for the region generally 30 miles north and south of the Daytona Beach area. But , again, that is nothing but surmising.

BLOG "Forecast" From Previous Post

Above was the 'forecast' (blog only) for today from the other day, and below is the latest SPC outlook. 

SPC OUTLOOKS are available 'HERE"

It is 'highly recommended' that access to media outlets , whether by weather radio or even one's trusted television station be at hand to monitor potential threats in one's specific location going into early-mid afternoon.

Again, above is the 'best guess' risk area from a few days ago in the previous post, and the latest advisory issued by the Storm Prediction Center (SPC) located in Norman, Oklahoma . As can be seen, the forecasters at The SPC have determined there is an Enhanced Risk (which is greater than a Slight Risk) for parts of mainly North - North Central Florida. A later update will be released around 8AM EDT with another to follow around 12:30PM EDT.

Side note: "Celestial" Spring begins at 12:15PM EDT, today as the sun will be passing over the the equator heading toward the Tropic of Cancer at which point is the first day of 'Summer' (in late June).

Activity should quickly weaken, assuming the current timing of activity being depicted by the 4KM NAME and High Resolution  Rapid Refresh (HRRR) models coincident with sunset, as the central low level axis (pre-frontal trough) progresses further south toward Ft Pierce - West Palm Beach areas and stronger wind in the mid-levels shifts off the east coast of Central -South Central Florida.

WEDNESDAY: Breezy NW wind all day and dry. Colder air is on the way for Thursday- Saturday morning, but Wednesday will still see the 70Fs despite the wind.

THURSDAY-FRIDAY: Cooler again with lows ranging in the mid-40Fs to lower 50Fs and highs in the mid-upper 60FS most areas but touching the lower 70Fs Friday. Thursday will be quite breezy going into Friday , but the wind will quickly diminish going through Friday and into the weekend.

FRIDAY-AFTERNOON and BEYOND: Warming to normal to even above normal temperatures this weekend , and dry with light wind. Cooler sea-side with the sea breezes in place, with highs at the beaches more than likely in the 70Fs.

The next chance of rain is currently being shown (easily subject to change) in the period from near Good Friday - Easter Sunday or a day or two either side of that period. No cold air influx , at least as cool as it will be Thursday - Saturday morning, is being shown to arrive at all at this point, but rather a frontal boundary is to press into the Southeast States and eventually Central Florida and wash out. This could change, however.

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