"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".

Friday, March 25, 2011

Very Warm Sunday, Chance of Showers/Storms Monday - Thursday

General Current Location of Surface Boundary Expected to make further southward progress into mid evening

TODAY: Image shows the current location of a surface front, apparently having just cleared Southern Brevard County past hour. About the only indication of this feature is drier air (lower dew points) and slightly cooler temperatures, but not by too much. Temperatures into the upper 70Fs/low 80Fs are still reaching well into far north Florida this hour (not pictured).  Temperatures today a good 5-8 degrees cooler than yesterday most areas, little in clouds and lower dew points combined with lighter wind makes for a nice day to wrap up the week.

SATURDAY/SUNDAY: No rain for starters. Pleasant again on Saturday, similar to today but a bit warmer with an afternoon sea breeze both coasts. On Sunday a storm system which will have impacted much of the Deep South on Saturday (tornado watch(s) expected there) will be approaching North Florida. Surface high pressure over the state will be forced to the east and south of the state, inducing conditions similar to those we had yesterday. That's is, a WSW wind, warm, with increasing moisture (higher dewpoints).  Very warm with highs near 90F plus/minus a degree or two.  Strong to severe thunderstorms will likely occur on Sunday close to I-10 all across far North Florida, and possibly a strong storm near far Northern Volusia County into Flagler County Sunday evening.

MONDAY: "Weather" finally begins for the state for the week (off and on). A chance of much needed rain to douse the ever increasing drought conditions; most notably Central/North Central Florida for starters, but no one will be immune to the chance of rains/storms. 

Surface front will move in toward Central Florida during the day. Although wind profiles will be mainly unidirectional with height (not turning), a sea breeze is expected this day to aid inland low level wind convergence, much like would be expected on a summer day. Additionally, the NAM has been forecasting a slug of mid-level moisture to cross the Keys courtesy of Cuba  over night Sunday night and to be fully in place all across Central Florida by shortly after daybreak, Monday.  This moisture will be what separates Monday from Sunday for the most part.

The thing that  further separates Monday from  say, a summer day, will be the mid-upper level temperatures. 700mb temp. is forecast to be only about 2-3C (last summer it ran around 10F), and 500mb temperatures are forecast to be around -12C (last summer they were around -5C). So you see, they will (or are forecast to be) quite cold in comparison to a summer day. Conversely,  the surface temperatures will be in the mid-80Fs, assuming there is not too much mid-level cloud cover accompanying the arrival of the moisture pool from the south during this day.  With this said, believe the SPC (Storm Predicition Center) will have Central and North Florida in a "See Text" on their website over Florida for marginally severe sized hail and/or strong downburst winds. Most likely the strongest of storms, if they materialize, will be restricted to west of I-95, namely in Orange/Seminole/Volusia/N. Osceola Counties. Steering will be toward the East Coast, but at this time believe that the still cool ocean temperatures (low level subsidence behind the sea breeze boundary) will sap storm strength east of I-95. Something to watch. Otherwise, a generic forecast of a 30-40% chance of showers/thunderstorms is expected to be made widely known over the media prior to this day, with little to no mention of a strong storm unless the National Weather Service sees things the same way as I just wrote. Too early in time to make the proclamation for a strong storm just now anyway.

TUESDAY/FRIDAY: Surface boundary might make it further south after Monday night toward Lake Okeechobee, but appears will rebound back to the north on Tuesday afternoon with day time heating. Once again, another day of showers/thunderstorms is possible, but will not divulge in trying to get down to specifics (storm strength possibilities) until we see what transpires on Monday unless something new stands out in model guidance prior. 

Same holds true for Wednesday, but at current time it looks like either Tuesday or Wednesday we'll see a significant break in the rain chances as the atmosphere 'reloads'.  For now, expect that this differentiation in elements will not go out to the general public considering that lack of confidence in the models is already becoming increasingly uncertain after Monday.

Thursday, March 31st, is where things get very interesting at least by the GFS model. Strong surface low is forecast to form close to the Florida Panhandle with all fields in place to provide for a severe weather event...possibly as soon as the 31st during the afternoon, with a replay event in the form of a Quasi-Linear convective system (QLCS) type squall line composed of small bowing segments and discrete cells  going into April Fool's Day at some point in time on this day. 

There is not model consensus on this eventual outcome, so just something to watch for most definitely.  If the GFS model does materialize, we could end up seeing a portion of the peninsula in a severe thunderstorm watch Thursday afternoon, with a tornado watch far North Florida/Panhandle (portions).  Severe Thunderstorm watch replaced by Tornado Watch or another Severe Watch for the remainder of the  entire state going into either the overnight hours of the 31st or by mid-morning on April Fool's.  Still a lot of time to watch what develops regarding this storm system potentially developing...worst case scenario would be if the storm holds off until the afternoon hours of Fool's Friday when thermal instability would be maximized, recalling that last time a similar scenario developed earlier this year when we had that tornado watch was purely a low CAPE/high shear event. This go around, we'd have CAPE (instability) thrown into the mix; however, wind fields will not be as strong.

Enjoy the very pleasant weekend Central and South Florida. Far north, not so nice on Sunday due to potentially strong storms.

No comments: