Cirrus Causes Much Warmer than Expected Temps for FL

[gatorcane]

I'm watching the latest vis loops this afternoon and can makes these inferences:

1) Low stratocumulous clouds are starting to edge closer to the East Coast of Florida indicating the mid-level (and perhaps low-level) wind flow is showing signs of coming in more from the NE -- this would mean a warmer night than expected for the East and Southeast coasts of Florida. These signs could be ephemeral, however, so we will have to monitor this situation...

2) A deck of cirrus clouds from the Western GOM is racing ENE towards South Florida -- that could also hold up temps if this cloudcover remains in tact and is over Florida during the late night hours....

Any thoughts?

Latest vis:

[NDG]

There are going to be many nervous farmers in interior parts of Cent & southern FL tonight when they see those temps go down after sunset, but the cirrus clouds should be moving in around midnight and that should at least tap the temps from falling off that much or begin to rise towards sunset.

[gatorcane]

update:

looks like the cirrus canopy coverage is on the increase and it continues to race towards peninsula Florida....I expect the lows to be about 5 degrees warmer than expected tonight......

this should be good news to farmers if this cirrus canopy can hold together....

[gatorcane]

update:

looks like the cirrus canopy coverage is on the increase and it continues to race towards peninsula Florida....I expect the lows to be about 5 degrees warmer than expected tonight......

this should be good news to farmers if this cirrus canopy can hold together....

[gatorcane]

000
FXUS62 KMFL 292051
AFDMFL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
351 PM EST MON JAN 29 2007

.DISCUSSION...

LATEST SUITE OF COMPUTER MODEL GUIDANCE CONTINUES TO SUGGEST THAT
NEAR FREEZING TEMPERATURES ARE POSSIBLE DURING THE EARLY MORNING
HOURS ON TUESDAY. THEREFORE...THE FREEZE WARNING CONTINUES TO BE
IN EFFECT FOR GLADES...HENDRY...WESTERN PALM BEACH AND WESTERN
BROWARD AND EASTERN COLLIER COUNTIES. IN EASTERN COLLIER AND
WESTERN BROWARD COUNTIES...THE WARNING IS MAINLY FOR AREAS NORTH
OF ALLIGATOR ALLEY.

IN ADDITION...AREAS OF PATCHY FROST ARE POSSIBLE ACROSS THE INLAND
PORTIONS OF SOUTH FLORIDA. ITS IMPORTANT TO NOTE THAT FROST CAN
OCCUR WITH TEMPERATURES UP TO NEAR 36 DEGREES...SO A LARGER AREA
THAN THE FREEZE WARNING CAN BE AFFECTED

HAVING STATED THE NEED FOR THE FREEZE WARNING...OVER THE LAST
SEVERAL DAYS THE GUIDANCE HAS SUGGESTED THAT HIGH LEVEL CIRRUS MAY
APPROACH SOUTH FLORIDA TONIGHT. LATEST GUIDANCE CONTINUES TO
SUGGEST THE APPROACH OF THE CIRRUS AND LATEST SATELLITE IMAGERY
INDICATES THAT PATCHES OF CIRRUS HAVE CROSSED EASTWARD OF 90 WEST
LONGITUDE WITH PATCHES OF CIRRUS ENTERING THE CENTRAL GULF. SO
EVEN AT THIS STAGE...ITS DIFFICULT TO ASCERTAIN JUST HOW MUCH
EFFECT THE INCOMING UPPER LEVEL MOISTURE AND/OR CIRRUS MIGHT
AFFECT THE TEMPERATURES EARLY TUESDAY. GIVEN THE
UNCERTAINTY...AREAS INCLUDED IN THE FREEZE WARNING MAY REACH NEAR
OR JUST BELOW FREEZING TEMPERATURES.

[gatorcane]

and here you have it folks -- what I called earlier today is now being reflected in the forecast:

I am updating the title of this thread accordingly...

000
FXUS62 KMFL 300310
AFDMFL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
1010 PM EST MON JAN 29 2007

.UPDATE...
A SCATTERED TO BROKEN DECK OF CIRRUS IS CURRENTLY APPROACHING THE
SOUTH FLORIDA PENINSULA FROM THE WEST...AND WILL LIKELY CONTINUE
TO THICKEN AS IT MOVES EASTWARD OVERNIGHT. THIS WILL UNDOUBTEDLY
HAVE A TREMENDOUS IMPACT ON THE MINIMUM TEMPERATURES ACROSS THE
AREA...BUT WITH SEVERAL OF OUR NORTHWESTERN COOP SITES ALREADY
REPORTING TEMPERATURES IN THE LOWER 40S...DEW POINTS AROUND
30 F...AND LIGHT WINDS...WILL LEAVE CURRENT FREEZE WARNING INTACT
AS SEVERAL LOCATIONS MAY REACH OR DIP BELOW 32 F. HOWEVER...WILL
ADJUST CLOUD COVER GRIDS TO REFLECT INCREASING CIRROFORM CLOUD
COVER THROUGH THE NIGHT...AND WILL ALSO ADJUST DEW POINTS TO BETTER
MATCH CURRENT VALUES. NO MAJOR CHANGES WILL BE MADE TO THE MARINE
FORECAST...WITH GULF STREAM SEAS EXPECTED TO SUBSIDE THROUGH THE
NIGHT. UPDATED PRODUCTS WILL BE ISSUED SHORTLY.

70/DD

&&

[gatorcane]

this is just what the farmers across inland South Florida needed...

[NDG]

Good job gator, the mid to upper level cloud deck has moved in a good hour and a half to two hours earlier than I thought here in central FL, my temperature has come up a couple of degrees in the last 1/2 hour, after dropping down to 41.5, so that might had been my low of the night, if the cloud deck continues and winds just about the ground become more easterly during the night I am going to be a good 6-8 degrees warmer than forecasted by the NWS.

[gatorcane]

Good job gator, the mid to upper level cloud deck has moved in a good hour and a half to two hours earlier than I thought here in central FL, my temperature has come up a couple of degrees in the last 1/2 hour, after dropping down to 41.5, so that might had been my low of the night, if the cloud deck continues and winds just about the ground become more easterly during the night I am going to be a good 6-8 degrees warmer than forecasted by the NWS.

You are correct, I was looking at observations in the Tampa Bay area as I know some people are wondering if they should cover their plants --

temps have also risen in the past hour as the dew points have increased with the cloud deck.....

a good sign.....

[jdray]

Already 29F here at my house @ 11:30pm

but I dont have many clouds overhead right now

[NDG]

Gatorcane, you wouldn't believe it, 3 out of 4 local TV mets here in Orlando are still calling for low temps in the upper 20s to low 30s in this area, low 20s in Ocala One met, the one that had called for a hard freeze in Orlando north of I-4, said that this was just a temp passing cloud deck that made the temps go up by a couple of degrees, that the skies were going to clear out for the rest of the night in a little while, thus freezing temps by AM tomorrow

[gatorcane]

Gatorcane, you wouldn't believe it, 3 out of 4 local TV mets here in Orlando are still calling for low temps in the upper 20s to low 30s in this area, low 20s in Ocala One met, the one that had called for a hard freeze in Orlando north of I-4, said that this was just a temp passing cloud deck that made the temps go up by a couple of degrees, that the skies were going to clear out for the rest of the night in a little while, thus freezing temps by AM tomorrow

But if you look at the AVN loops there is another, even thicker cloud deck racing in from the Eastern GOM. If this cloud cover lingers, it will stay several degrees above freezing for much of the Orlando area ---

But it all depends on that cloud deck...

[NDG]

I know that gatorcane, I myself highly doubt that we will get below the mid 30s, I was just pointing out that the local tv mets are still calling for subfreezing temps for most of the Orlando area even though atmospheric soundings and sat pics indicate otherwise, warmth advection seems to be taking place, I guess they still need a news headline for tomorrow: "Cloud Deck unexpectedly saved orange groves in central FL", for their ratings.

[jdray]

Well,

I made it to 28F before rebounding to 30F overnight with the cloud cover.


Have been under 32F since 10PM last night.

10 hours of freeze between 28F and 31F.


Thanks clouds, my heat pump thanks you.

[NDG]

Thanks to the clouds and rising heights the 20s didn't made to areas of central FL as predicted.

Forecasted lows:



Actual temps at 12z (purple shading is area below 32F)

[NDG]

I know that gatorcane, I myself highly doubt that we will get below the mid 30s, I was just pointing out that the local tv mets are still calling for subfreezing temps for most of the Orlando area even though atmospheric soundings and sat pics indicate otherwise, warmth advection seems to be taking place, I guess they still need a news headline for tomorrow: "Cloud Deck unexpectedly saved orange groves in central FL", for their ratings.

I knew it! They needed a headline this morning in case residents were wondering "OMG, what happened to the hard freeze last night?":lol:

Headline from the same TV station this morning:
[url=http://www.local6.com/weather/10876118/detail.html]"Cloud Cover Prevents Significant Temp Drop In Central Fla." Click to story
[/url]

[gatorcane]

I know that gatorcane, I myself highly doubt that we will get below the mid 30s, I was just pointing out that the local tv mets are still calling for subfreezing temps for most of the Orlando area even though atmospheric soundings and sat pics indicate otherwise, warmth advection seems to be taking place, I guess they still need a news headline for tomorrow: "Cloud Deck unexpectedly saved orange groves in central FL", for their ratings.

I knew it! They needed a headline this morning in case residents were wondering "OMG, what happened to the hard freeze last night?":lol:

Headline from the same TV station this morning:
[url=http://www.local6.com/weather/10876118/detail.html]"Cloud Cover Prevents Significant Temp Drop In Central Fla." Click to story
[/url]

I've lived in Florida for over 21 years and typically these arctic blasts are overexaggerated. Usually low temps end up much warmer than expected..

Look at Southeast FL -- headlines were everywhere about a temps that were going to dip into the upper 30s and low 40s inthe metro areas....temps ended up about 5-10 degrees warmer.....

It takes the perfect setup to see 20s and 30s across south florida. Usually something saves us at the last minute --

- winds blow in off the water
- clouds move in from the West and Southwest off the Gulf

[NDG]

I guess you can call me naive because of the way local news media handles & advertises freeze warnings. I've only been living here in Cent FL a little bit over a year now. I just find it amusing the way they exaggerate it.

[gatorcane]

I guess you can call me naive because of the way local news media handles & advertises freeze warnings. I've only been living here in Cent FL a little bit over a year now. I just find it amusing the way they exaggerate it.

thanks for the maps by the way, where did you move from?

[NDG]

I guess you can call me naive because of the way local news media handles & advertises freeze warnings. I've only been living here in Cent FL a little bit over a year now. I just find it amusing the way they exaggerate it.

thanks for the maps by the way, where did you move from?

New Orleans, right after Katrina.