"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".

Wednesday, March 30, 2011

Severe Storms Likely North Central/North Today, Significant Severe Storms Tomorrow

Current Satellite Image with a few highlights annotated for later today.
See text below for details.

RECAP: A few strong, severe storms occurred yesterday over South Florida where a 1" hail report was made. The strongest storm was located over uninhabited terrain, so no official report could be obtained regarding the suspected size of the hail in which the storm appeared to contain from radar imagery. Wind reports that came in were below severe criteria. Otherwise, weather was quite pleasant state wide.

TODAY: The pseudo-warm front that lingered over South Florida yesterday afternoon moved north to South Brevard during the early evening. A 'cold pool' from the NNE filtered down the east coast to Brevard County. Warm air over-running the cold pool with winds at the surface off cool waters created a period of low clouds and coastal fog.  

Between 4-6AM the warm front surged northward to the Florida /Georgia border where it has remained as of this writing. SSE-S winds from South Florida (where it will be quite warm today) will ride northward across Central Florida as a developing Mesoscale Convective Complex runs from West to East as noted in the image above by the arrow drawn in.  A tornado watch will likely be issued shortly for the I-4 corridor, but do not know if the Beachline or 520 area will be included in this watch. Believe it might not be, but might be included in a watch during the early afternoon sometime where I've drawn in the box.

Currently, the atmosphere over Central Florida is already becoming primed for severe weather after investigation of a wide variety of parameters used to make this determination. However, the Storm Prediction Center, last I saw, was not really looking at Central Florida as much as North Central. So we'll will have to 'watch and see what they decide". Meanwhile...other than what will be an active afternoon from Volusia County and north...the region from Pineda Cswy and north to Titusville along the east coast needs to be watched VERY closely.

REASON  TO WATCH CENTRAL BREVARD/SOUTHERN VOLUSIA: Believe that warm air feeding from the south (South Florida could reach 90F today) over this region will lead to strong surface based instability this afternoon due to cold air aloft. Dewpoints will be high, in the low 70Fs. That is moist! Additionally, the near coast surface winds should remain nearly perpendicular to the the prevailing westerlies located just over head (which increase with height), or from the SSE-S as drawn in the image in this post. 

 Any storm that goes up in this environment could rotate. Therefore, the area from North Osceola Couny east to (particularly) Patrick Air Force Base to the Cape needs to be watched for storm rotation as well. Expect the storms will intiate just to the south and rapidly grow as they feed northward into the MCS as it passes just to the north along to just south of I-4. These storms will be isolated, but fairly intense. Additionally, IF they do form, they will do so very - VERY rapidly. On the other hand, they might not consider this a significant "Heads Up!".

Storm motion: Although the complex of storms will be moving from west to east, with embedded cells moving around 30-40mph from west to east, storms the might form in the secondary zone near the Beachline will initally form up from the SSW before merging into the complex. So, expecting to see some odd storm motions. Additionally, some storms along the leading, southern edge of the complex might acquire their own, discrete environment and 'break lose' from the complex and drop toward the south suddenly. This would happen near to just north of the Beach line.

Monitor your TV today, especially after 2-3pm, since it is likely that live, continuous coverage will be in high gear by the Orlando stations since portions of their viewing area will be impacted.

Activity all areas will end from west to east by 7-8pm at the latest. Last along the east coast. 

DISCLAIMER: These thoughts/ideas are of my own, and have not been alluded to in any official forecast discussions from formal channels, so take them with a grain of salt. But do be aware that these possibilities regarding the Beach Line region have a chance of occurring (at least, in my mind). Otherwise, the entire day could pass by with little more than a rain shower South of the Beach Line should the above said not materialize.

THURSDAY: Another active day as a secondary system rapidly develops over the Gulf of Mexico during the wee hours and explodes while heading east as another upper level system now located in the far Northern Plains phases with a system approaching in the sub-tropical jet from the west. The two will phase over the Gulf Of Mexico overnight tonight and should erupt fairly rapidly. This system will probably take the form of a Quasi-Linear Convective System (QLCS) with embedded bow echoes and rotating cells along its leading edge.

Currently, all of North Central - parts of South Florida are being outlooked officially in a HATCHED SLIGHT RISK, meaning storms could be SIGNIFICANTLY SEVERE. The main threat with tomorrow's system appears will be very strong winds, gusting to 70-75mph, although hail and a tornado cannot be ruled out. Wind speeds in storms tomorrow have not be formally announced yet, so that number just noted is of my own best estimate. They could end up being even higher. Additionally, they will be moving very fast! Faster than today.

It appears that tomorrow's activity, associated with a strong jet stream aloft and cold front at the surface, will enter the area about the same time as today's will, perhaps a bit sooner. Either way, it should clear North Central through South Central from 2-8pm...but there are some indications that rain could continue until almost midnight over South Central (near the Beach line and south).  

SOUTH FLORIDA: Very tricky. Forecast guidance is showing almost no rain down in South Florida for either system, which does not seem feasible. Therefore, expect a chance of severe weather as far south as at least Ft. Lauderdale in the form of winds and a tornado chance.  

At time, and this will change, the risk for the strongest of activity will be from near SR 520 South toward Martin County. That southern most area needs to be watched even more, since thermal instability appears will be stronger. Antecedent cloud cover over North Central/Central MIGHT tone down the overall intensity of the storms/rain, but that determination is a bit too early to be made with good confidence early this morning.

BEYOND: Another front could clears the state on Saturday/Sunday, but should go through dry. No big temperature falls thank goodness. The next system of contention comes into the picture around April 5th or 6th. It COULD be another severe weather maker, but it's way to early to say with any confidence due to huge disparities between the various models.

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