"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, January 7, 2011

This Weekend At a Glance

Images: 1st image shows the forecast for 12pm (noon) today. Second image is a forecast for 7pm, Sunday night. The expanse of the weekend.

NOW: Nice weather statewide through the' majority' of the weekend. Currently at noon time, there is an amazingly very small temperature gradient (difference) over the entire state from extreme North to the Keys, with temperatures varying from high-end upper 50s at and north of SR520 to lower and some mid-60s to the south with mostly clear skies with the exception of a few stratocumulus advecting toward the West Coast near Sarasota off of what appears to be a thermally induced Loop Current trough. But everywhere I'm finding low 60s. So in essence, everyone is within about 5 degrees of one another.

We see in the first image high pressure over the Southwest Gulf of Mexico that will be moving east (and mainly south of the state) in tangent with a weak trough (the dashed blue line) today and into tonight. The only affect these two items of interest will have is to keep winds elevated from the WNW to W due to the air pressure gradient between them...with perhaps a brief backing to the WSW in the wind direction as the trough passes. No big 'cloud or temperature' event is foreseen. In essence, unless one is closely monitoring the weather this will occur unnoticed unless engaging in activities dictated by wind strength (such as kite boarding or kite flying). Good day for both.

TONIGHT-SATURDAY: Winds remain elevated primarily from the west at 10-20mph (strongest during the afternoon as mixing with daytime heating occurs), but little worth mentioning other than perhaps some passing bands of high cirrus clouds ahead of the next 'dry front' late Saturday. This front is shown in the first image to be roughly located across the South Central Plains states. Although this front will have minimal impact here, it is setting up for some hellacious forecast problems in other parts of the Southeast as the next system (yet to form) approaches. One way to look at it would be to say that it will lay the foundation (in the form of cold air near the ground) that will making for a complex meteorological scenario by the end of the weekend up there. But that's their problem. Closer to home (Central and South Florida)....Saturday will be perhaps 5 degrees warmer across the boards than today, if not by more than that of this afternoon. A few high clouds, but no biggy.

OVERNIGHT SATURDAY-SUNDAY: This is when the first crux of weather changes in store for all of Florida during the period of Sunday morning to Tuesday morning will begin. The front will cross late Saturday (more likely Saturday night) with the first big change. Namely, a wind shift to the NW-NNW-N over the period of a few hours if not less. This is different from the westerly direction we've experienced since yesterday. This veering of the wind direction will continue throughout the day on Sunday, becoming easterly by afternoon. Temperature forecast is a bit tricky for those along A1A from Daytona and points south with morning low temperatures dependant on how quickly the wind gains a semblance of an onshore component.

But when everything comes out of the wash, believe the end result will be that this area (A1A corridor) will end up with a low temperature similar to what was felt this Friday morning, which varied depending on one's location. For instance, I saw Patrick AFB was reading 48F this morning while my porch in Cape Canaveral was 43F (close to if not cooler than the Melbourne area and Orlando). But hey, that's 5F degrees. Believe Sunday morning will be similar along the coast, but folks from US1 and west will be in the low 40s to start the day, Sunday. (side note: will watch for cloud potential right at the coast at sunrise, Sunday)

The remainder of Sunday. Interesting day from a meteorological perspective, considering we could start the day very cool to cold and clear, and end the day nearly cloudy and almost 'warm'.
We see in the second image included in this post that a low pressure system will have formed off the Texas Coast, as a warm front begins to form along the receding air mass (from the south)... that which passed through yesterday. This boundary will assert itself with a vengeance as it gets fully developed along or just north of I-10 (near the Florida/Georgia border) and conflicts with much colder air already residing to the north.

Remember now that front that I mentioned earlier leaving cold air in its tracks up there? Now's the time to retroflect. I circled that area in black just to depict a very generalized zone of potential future weather impacts in that area which will consist of freezing rain, sleet, and/or snow. Must say, the folks in the Tallahassee NWS office will have their hands full in dealing with lots of "whens, wheres, ifs, ands, or buts" as the zone will be close to if not within part of their area of responsibility. But getting ahead of myself.

SUNDAY NIGHT-MONDAY: Modifications continue Sunday night through Monday. Surface winds overnight shift to the southeast, ushering in warmer air behind (south) of the northward moving warm front over night. But the front won't get too far beyond I-10. As such, in the temperature department it will be a "Mild Monday", with lots of clouds at various levels. Winds ESE to start the day, Monday, and becoming southerly by day's end. Lows in the mid-upper 60s at the coast with high temperatures in the low 70s state wide and some mid 70s with everyone being in 'the warm sector' now (south of the warm front). The surface low will traverse a path similar to that of the previous system, namely close to I-10, although it is beginning to look like it will track a bit further south from near Inverness or Crystal River on the west coast near the Big Bend and across North Central Florida somewhere between Ocala and Gainesville, with the cold front trailing off to the SW-WSW.

The low will track across the state all day Monday with the trailing front then finally passing through Central Florida across all zones nearly simultaneously after sunrise Tuesday through noon time, accompanied by clouds-a-plenty. This system will be different from the last one though. As hypothesized yesterday, our atmosphere will have had little time to become fully entrenched in deep moisture throughout, additionally, the majority if not all of the upper level dynamics will be stretched horizontally and along the warm front before the cold front gets here. End result, little to no rain. I see The Weather Channel as I type showing "thunderstorms' for Monday. So, some rethinking in those regards and continued close observation of future model runs will be maintained with any changes (or none) to my current line of thinking being made known in future posts.

POST COLD FRONT (NEXT WEEK): Subject to change (wink)... Looks like the majority of next week, from Tuesday afternoon to week's end will consist of morning temperatures below normal, but nothing extreme or comparable to what occurred last month. Obviously when it comes to nailing down temperatures to the "Nth" degree it's too soon to say. But the general impression going into mid-late week next week is that the coldest location in the state will be along and north of I-4, or roughly from just south of Daytona Beach, to just north and west of downtown Orlando (by a smidge)on through to South Tampa Bay. I've seen entire winters hold this general temperature regime so it's not abnormal. Could see lots of mornings where the Tampa area is a good 10F degrees colder than the Space Coast (in general). This results from surface winds being from more directly from the North rather than the WNW-NW as now appears will be the case. The warmest, but still somewhat cool zone, will run east of a line from Port Canaveral SSW through Lake Okeechobee toward Naples.

Morning temperatures west of the line could be in the 30s (with some freezing possible, particularly further north), with mainly morning lows in the mid 40s east of the line (warmer along A1A). Warmer south of Vero/Ft Pierce of course along the East Coast 'round the clock.

BEYOND: Perhaps I should include a 'Future-cast" every other post or so, if only to point out how varied the models are when it comes to the long range. For instance, no longer seeing "snow" for Central Florida, but the trend continues for a cold spell heading into the 2nd and 3rd week of January. On the flip side, look at it this way - - get through the last week of January and its all uphill from there (not to say there won't be some bumps or even ditches in the road ahead). What we need is some good rain in here...the drought continues, worsens, and spreads.

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