Florida Weather

[TheStormExpert]

The teleconnections today look slightly more favorable for any cold arctic air to penetrate down towards the Deep South and maybe possibly Florida at some point in the long range. With today's update now keeping the PNA fully positive in the next two weeks, and the NAO/AO now forecasted (for now) to go more negative during the next two weeks.

Do these changes in the teleconnections forecasts each day affect what each model shows day by day?

[gatorcane]

NWS Miami taking note of the models:

.LONG TERM (SATURDAY-TUESDAY)...

THE AFOREMENTIONED COLD FRONT WILL MOVE INTO NORTH FLORIDA SATURDAY
NIGHT/EARLY SUNDAY AND THEN STALL. THE MODELS BEGIN TO DIFFER AT
THIS POINT WITH THE GFS SAGGING THE FRONT SOUTH INTO SOUTH FLORIDA
BY EARLY TUESDAY ALTHOUGH AT A WEAKENING STATE. THE ECMWF HOWEVER
SHOWS WHAT EARLIER RUNS OF THE GFS HAD SHOWN WITH A STRONG SURFACE
WAVE DEVELOPING ALONG THE FRONT AS A STRONG UPPER TROUGH BEGINS TO
DEVELOP OVER THE EAST CENTRAL PART OF THE COUNTRY. AT ANY RATE,
UNTIL THE MODELS ARE MORE CONSISTENT FROM RUN TO RUN DO NOT PLAN TO
MAKE ANY SIGNIFICANT CHANGES TO CURRENT FORECAST AT THIS TIME.

http://forecast.weather.gov/product.php ... glossary=1

NWS Tampa has a much more detailed discussion:

DURING MONDAY NIGHT AN UPPER LEVEL TROUGH OVER THE SOUTHERN PLAINS
WILL AMPLIFY SIGNIFICANTLY BECOMING A FULL-LATITUDE UPPER TROUGH BY
EARLY TUESDAY. THIS UPPER TROUGH WILL SWING EAST ACROSS THE LOWER MS
VALLEY AND NORTHERN GULF COAST...BECOMING NEGATIVELY TILTED AS IT
DOES SO BY EARLY WEDNESDAY. AS THIS TROUGH MOVES EAST IT WILL INDUCE
YET ANOTHER SURFACE LOW OVER THE MS/TN VALLEYS ON TUESDAY WITH THIS
LOW THEN DEEPENING AND LIFTING RAPIDLY NORTHEAST TO THE EASTERN
GREAT LAKES REGION ON WEDNESDAY...WITH ITS TRAILING COLD FRONT
MOVING ACROSS THE FORECAST AREA TUESDAY NIGHT AND EARLY ON WEDNESDAY.
SUFFICIENT MOISTURE COMBINED WITH GOOD UPPER LEVEL SUPPORT FROM THIS
SYSTEM WILL SUPPORT SCATTERED TO NUMEROUS SHOWERS MOVING ACROSS THE
REGION ALONG AND AHEAD OF THE COLD FRONT WITH COLD TEMPS ALOFT (-12
TO -13C) SUPPORTING STEEP ENOUGH LAPSE RATES TO SUPPORT ISOLATED
STORMS AS WELL. BOTH THE ECMWF AND GFS ALSO SHOW A LOW LEVEL JET
(40-50 KNOT RANGE) MOVING ACROSS THE NORTH CENTRAL PENINSULA. THIS
JET COMBINED WITH THE ADEQUATE INSTABILITY AND INCREASING BULK SHEAR
(SHERB VALUES APPROACHING 1.0) AND STRONG LOW LEVEL CONVERGENCE
ALONG AND AHEAD OF THE FRONT MAY INCREASE THE POTENTIAL FOR SOME
ORGANIZED CONVECTION WITH A FEW STRONG TO SEVERE STORMS POSSIBLE
FROM THE BAY AREA NORTH INTO THE NATURE COAST TUESDAY NIGHT WHERE
THE BEST DYNAMIC SUPPORT WILL RESIDE.

ONGOING CONVECTION WILL QUICKLY END FROM NORTH TO SOUTH EARLY
WEDNESDAY MORNING AS THE COLD FRONT AND DEEP MOISTURE AXIS EXITS
RAPIDLY EAST SOUTHEAST OF THE REGION WITH DRIER AND COOLER AIR
ADVECTING INTO THE AREA ON A BREEZY NORTHWEST WIND FLOW WITH A GOOD
DEAL OF SUNSHINE EXPECTED BY WEDNESDAY AFTERNOON AS THE DRIER
AIR OVERSPREADS THE REGION. SLIGHTLY ABOVE NORMAL TEMPERATURES
OVER THE WEEKEND WILL FALL BACK TO BELOW SEASONAL NORMS EARLY NEXT
WEEK AS COOLER DRIER AIR MOVES IN IN THE WAKE OF THE COLD FRONT.

http://forecast.weather.gov/product.php ... glossary=1

[NDG]

The teleconnections today look slightly more favorable for any cold arctic air to penetrate down towards the Deep South and maybe possibly Florida at some point in the long range. With today's update now keeping the PNA fully positive in the next two weeks, and the NAO/AO now forecasted (for now) to go more negative during the next two weeks.

Do these changes in the teleconnections forecasts each day affect what each model shows day by day?

Yes, especially the GFS.

As far as the AO going negative I wouldn't doubt it, pretty good agreement between the ensembles members but with the NAO going way negative there is a lot of disagreement among them.

[TheStormExpert]

One of the many positive things about this prolonged cool period we've been experiencing here in Florida is not having to use the A/C for over a week!

Hoping it doesn't warmup too much anytime soon, but I see a brief warmup this weekend into early next week before our next cold front comes through Christmas Eve.

Models have been trending warmer somewhat (especially the Euro) in the past 24hrs. with the Christmas cold front.

IMO this front will act as a pattern transitioning front (similar to the Halloween front). After the Christmas cold front it should start getting gradually colder across the country as we progress closer to New Year's. The question is just how cold, for how long, and will this cold make it's way down into Florida?

I guess we will just have to wait and see for now. The NAO, AO, and PNA will tell the whole story!

[gatorcane]

It does appear Florida will see below normal temperatures around Christmas based on what I am seeing from the global models. Doesn't look like anything record-breaking but enough to put us all in the holiday spirit here! Beyond that, the globals are in good agreement on the pattern changing across North America which would allow cold air from Canada to push into the lower 48 from the NW. Whether it can impact Florida or not is still TBD but I am leaning towards there being some impacts with even colder weather arriving around New Year's or a little after.

[Bocadude85]

I am tired of all the cold weather, bring back the warmth!

[TheStormExpert]

It does appear Florida will see below normal temperatures around Christmas based on what I am seeing from the global models. Doesn't look like anything record-breaking but enough to put us all in the holiday spirit here! Beyond that, the globals are in good agreement on the pattern changing across North America which would allow cold air from Canada to push into the lower 48 from the NW. Whether it can impact Florida or not is still TBD but I am leaning towards there being some impacts with even colder weather arriving around New Year's or a little after.

Agree about the Christmas cold front, but it's just a wait and see situation after that right now. Though it does seem that are coldest air of the winter season tends to come just after Christmas/New Year's, or during the first half of January.

[TheStormExpert]

I am tired of all the cold weather, bring back the warmth!

Your wish should be granted this weekend!

[NDG]

Good morning, looking forward to 4 days of above average temps for my area
A brief cool down just in time for Christmas Eve and Christmas day, which I don't mind, but there is a difference in the 7-10 day range between the GFS and Euro. With the GFS keeping the FL Peninsula near to below average while the Euro has another big warm up in that range before cooling us down again closer to the 10 day range.
Looking at the rest of the country there is a big pattern change, the above average mid level heights across the northern US/southern Canada is going away with a big cool down for that area with pieces of that Arctic Air mass visiting the Deep South from time to time. Question is if the NAO is going to be at least neutral enough for the core of the Arctic air mass not to penetrate the FL Peninsula.
Looking back at the NAO index through the last 50 years, months that the NAO has averaged big time positive during November and December, the following month in January has also averaged positive, 12 out of 15 times, so the odds are that the NAO will stay most likely to average out positive next month.

[psyclone]

So far so good as we tip toe into the most dangerous time of the year for big freeze events. it's been a long time since we've had to deal with significant cold. here's hoping our good luck continues.

[gatorcane]

18Z GFS keeps the artic blast to the north of South Florida on this run through 384 hours, with 80s in South Florida, for example temps at noon for New Year's Day, maybe I should head to the beach to start 2015

[northjaxpro]

Have to wait and see gatorcane as we get closer to the event. The peninsula has been so extremely fortunate regarding the NAO not going negative for these arctic outbreak events the past few years. Looking at the latest long range runs, colder temps return but as always, we will have ti see if the cold can penetrate into the peninsula enough to have significant impacts especially areas along and all points south of the I-4 corridor.

[TheStormExpert]

It seems like the only way to get cold arctic air to dive deep down into Florida is for it to come straight south out of Eastern Canada, not Central/Western Canada. I'm pretty sure this was the case during the winter months of 2010 where it came out of Eastern Canada due to a very negative NAO.

[northjaxpro]

Yes, a delivery of arctic air from Eastern Canada has occured to bring Florida impressive cold. January 1985 is the best analog to use in this case. However, it is not the only sure set-up needed to bring arctic air to the Florida peninsula. Just look at two of the most impressive arctic outbreaks of the 20th century. The historic deep freezes of December 1983 and December 1989 all bought down arctic air down from Siberia across Western Canada and south and east into the United States. Both events had massive High Pressures so strong that it forced the arctic air to filter all the way down into Florida with record cold.

[cycloneye]

HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE TALLAHASSEE FL
430 AM EST SUN DEC 21 2014 /330 AM CST SUN DEC 21 2014/

...HEAVY RAINFALL EXPECTED TUESDAY THROUGH WEDNESDAY WITH AN
INCREASING POTENTIAL FOR AREAL AND RIVER FLOODING...

THE COMBINATION OF A VERY MOIST AIRMASS LIFTING NORTHWARD ACROSS
THE REGION INTERACTING WITH A STRONG WINTER TIME STORM MOVING INTO
THE MID SOUTH WILL CREATE WIDESPREAD MODERATE TO HEAVY RAINFALL
ACROSS THE TRI-STATE AREA ON TUESDAY INTO WEDNESDAY.

WHILE THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO THE EXACT
PLACEMENT OF HEAVIEST RAINFALL WITH THE STORM SYSTEM ON TUESDAY AND
WEDNESDAY...CONFIDENCE IS INCREASING IN A PERIOD OF SIGNIFICANT
RAINFALL OCCURRING ACROSS THE REGION DURING THIS TIME FRAME. STORM
TOTAL ACCUMULATIONS OF 3 TO 5 INCHES WITH ISOLATED HEAVIER
AMOUNTS ARE POSSIBLE WITH THIS SYSTEM.

RAINFALL TOTALS OF THIS MAGNITUDE WILL INCREASE THE POTENTIAL FOR
LOCALIZED FLOODING ACROSS THE REGION...PARTICULARLY DURING THE
TIME OF HEAVIEST RAINFALL ON TUESDAY NIGHT INTO WEDNESDAY
MORNING.

WITH AREA RIVERS AND ASSOCIATED TRIBUTARIES AT OR BELOW NORMAL FLOWS
FOR DECEMBER...THE CURRENTLY PREDICTED RAINFALL AMOUNTS ARE
GENERALLY EXPECTED TO PRODUCE ONLY RISES TO ACTION STAGE AT MOST
OF THE RIVER FORECAST POINTS. THE NOTABLE EXCEPTIONS TO THIS WILL
BE WITHIN THE OCHLOCKONEE AND WITHLACOOCHEE RIVER BASINS WHERE
THERE IS AN INCREASED POTENTIAL TO REACH MINOR FLOOD STAGE LATER
THIS WEEK. SHOULD MORE RAIN OCCUR THAN CURRENTLY FORECAST...THE
CORRESPONDING RIVER FLOOD RISK WOULD INCREASE AND INCLUDE
ADDITIONAL RIVER BASINS REACHING AT LEAST MINOR FLOOD STAGE.

FOR THE LATEST RIVER STAGE INFORMATION...VISIT OUR AHPS PAGE AT
THE FOLLOWING LINK (ALL LOWERCASE):

HTTP://WATER.WEATHER.GOV/AHPS2/INDEX.PHP?WFO=TAE

$$

GODSEY

[northjaxpro]

Yeah, it will be good to get some much needed rain the next couple of days. It has been extremely dry with no appreciable rain seen here since the day before Thanksgiving. Wednesday could be an interesting day as we will be solidly in the warm sector and a few strong storms could develop across the area in advance of the cold front which will move through Christmas Eve evening.

[TheStormExpert]

Yeah and the latest model runs are starting to back off on the intensity of this front and pushing it back even further again so it'll now come through early Christmas morning.

[northjaxpro]

Yeah, the front probably will clear off the SE Florida coast sometime on early Christmas morning. It will move through Jax early Christmas Eve evening.

[NDG]

Good to see this morning that both the GFS and Euro have backed away from their earlier forecast of a strong cold front. I was worried about the idea of me roasting a pig in my back yard (Cuban Christmas Tradition) Christmas morning with the forecasted lows by the GFS of low to mid 40s. Nice to see that with the delay of the cold front temps will not get that low Christmas morning across central FL.

BTW, ensembles are starting to back away from their earlier forecast that the NAO will be dipping big time negative for the end of the month into early next year, not surprising as I mentioned earlier.

[gatorcane]

06Z GFS does a complete flip-flop and shows frigid weather for Florida for New Years, 1AM EST temps below