"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".

Saturday, April 21, 2012

Two "Potential" Shots At Severe Weather Central

BOTH ZONES ARE CONDITIONAL ON MITIGATING FACTORS: Best that can be determined at this time , and is not entirely in agreement with official forecasts (Namely, the afternoon red zone) for some afternoon storms which could be severe with tornadoes possible (few if any), Gusty winds, and some hail...(possibly). The Red Zone is for this afternoon with a pre-frontal system;  then again toward or after dark toward midnight in the Purple area. Note that Central encompasses both realms of possibility; however, there is low certainty which, if either, will manifest to live up to its potential. Some guidance actually shows NO rain or very little in many areas. Wind fields are simply too tempting  (as well as threatening to ignore, especially tonight.
TODAY: Will not write an in-depth analysis or forecast post, since the upcoming day (being today) has already been looked at in previous posts, and the media is covering the situation. All in all, what is shown above is a bit not in sync with official forecasts I saw, namely for the area toward the Big Bend and east toward JAX.

Pre-system  ejection of vorticity is forecast this afternoon across the North Half. Latest RUC and actuals match up closely in regard to instability. The question becomes, how unstable can it actually become with high clouds over the questionanable area in Red? If this instability can manifest (which may or may not be in progress as I type), severe storms are entirely possible. There is cloud cover out there after all, and If not, there is a chance that only isolated activity will manifest. This forecast post is based mainly on 06z runs, and a bit of the 12Z NAM (and recent RUC). Will say that the RUC and overnight GFS and NAM seem to all hedge in on East Central toward the Brevard area during daylight today... bears keeping in mind. 

All factors of severe possible, although with such a saturated air mass hail is a bit questionable . It might be that the over-saturated air mass will be the saving grace in regard to any severe weather, or even much weather at all. Below is for this afternoon. Note the heavy cloud cover over the South. In the red is where the best wind fields are forecast as well as instability by mid afternoon. If this instability does not manifest, there is a chance it will be generic thunder and rain. Far South though, although not shown toward the Keys..could be another story.

TONIGHT: A second impulse to ride in across the South Half of the state, making an entrance toward Naples and Punta Gorda. Wind fields will enter SW Florida toward sunset and rapidly spread NE  toward Brevard on the east side and all locations South as well. The north seems to be out of the picture over night. At this time, the GFS is showing instability over South Florida and storms by mid-afternoon; however, 'actuals' are not supporting model output in this regard. Note though, that the wind fields will possibly work into that area first!..Thus, might be unwise to discard that area completely today. Basically, 2 out of 3 major models at this time of day say 'no go' for the south until at least late afternoon ...Otherwise, tonight the models all agree the better wind fields with much greater shear and helicity will be over the south half anywhere from Sunset toward 3AM time frame. There is one issue I have. That being, the best bulk shear lags other words, factors MIGHT not sync up. On the otherwise, if they do or come close to doing so, it could be a no holds barred severe weather situation. It is tonight the better Theta E air is drawn nortward and south of a secondary boundary, in which case lack of instability might not be a mitigating factor. Thus, The Storm Prediction Center's outlook closely matches up with the night time scenario drawn in for the south noted by the purple lines in the first image.

All will not be said and done until Sunday late afternoon or a bit earlier. Yet another questionable time frame and again, for North Central. The entire system should clear the state by sunset in the rain chances, and from that time forward cooler and drier air moves in for Monday-Wednesday mornings.

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