'Gulf Effect Snow'

[AggieSpirit]

I have a pretty good understanding of the Lake Effect snow process in North America.

What I am curious of is if there are any instances, or is it possible, to have that same effect cause snow along the US Gulf coast? Obviously it would be quite rare, but would it be possible.

I figure you would have to have a really cold and atmosphere deep high pressure system make it far enough south, and then as the high moved east, the return flow on the backside of the high would pick up moisture off the warm water (gulf is around 60 I think in the winter). As that moisture climbs through the atmosphere, it would form snow. Of course, the southern return on the backside of the high would have to be still cold or sealed off from warm air by another front I think.

Is this possible? Or am I imagining things?

[Valkhorn]

Nah it is possible but that isn't what drives heavy gulf coast snowstorms.

The two significant gulf coast snowstorms in the last 100 years or so have been the New Years storm of 1963-64 and the one in 1895 (February I think) were pretty much similar.

What causes great gulf coast snowstorms is usually a great southern push of arctic air. Sometimes a good blue norther can get it started or just a really strong Arctic outbreak in the southeast. Then as a front drives down, a low develops off of the Gulf Coast and explodes rapidly, driving a lot of precipitation over the southeast.

The 1895 storm produced up to 2 feet in Houston and Galveston, and 8"+ in parts of New Orleans. That is water equivalent to a normal winter type low pressure system which might in warmer weather dump 4 or 5 inches of rain across parts of the Gulf Coast.

All the records of the 1895 storm that I can find are of observations near and around the coast from Brownsville to New Orleans. Inland there weren't many reports I could find, so I suspect it bombed out off the coast of Texas, headed East or ENE and eventually hit NW FL as a mostly rain event. There could have been snow there but NW FL was not very populated then like the western gulf coast was.

Note: Few records show the year of this event as 1899, since there was a major arctic outbreak then, but since most records point to 1895 as the year, and since two separate events of this magnitude 4 years apart are too rare, 1895 is the generally accepted year.

The 1963-4 New Years event was a classic gulf low that bombed out right when there was plenty of cold air to be sucked in. A northeasterly swath of heavy snow developed around the afternoon of Dec. 31st and tracked northeastward producing snowsqualls across southeast MS into central and North Alabama into TN. Snowfall amounts to note were of a half foot in New Orleans, almost a foot in Hattiesburg, 16" in parts of Meridian, MS, and 15" in Birmingham, Alabama.

[chadtm80]

AggieSpirit we had "Ocean effect snow" here in East central florida last year believe it or not.. Well if you realy want to call it snow.. Was very minute and very quick.. But Ocean effect snow none the less.. So it does happen

[KatDaddy]

Truley an amazing event. BLizzard conditions in Tallahassee, Florida may have occurred. Here is a summary I found

February 13, 1899 -

it was the coldest morning ever along the Gulf Coast, with temperatures of 6.8 degrees at New Orleans, Louisiana, 7 degrees at Pensacola, Florida and 1 degree below zero at Mobile, Alabama. The record low temperature for the state of Florida was set at Tallahassee when the mercury tumbled to 2 degrees below zero. The record low temperature for the state of Louisiana was set at Minden, when the thermometer fell to 16 degrees below zero. A trace of snow fell at Fort Myers, Florida. This was the farthest south snow has ever been observed in the US until 1977.

Here is the Feb 14th 1895 Snowstorm summary

February 15, 1895 -

a big Gulf snowstorm dumped 6 inches of snow at Brownsville, Texas, 15 inches at Galveston, Texas, and 24 inches at Rayne, Louisiana in 24 hours. Snow fell at the very mouth of the Mississippi River. Houston, Texas recorded 22 inches of snow and 9 inches blanketed New Orleans, Louisiana.

[AggieSpirit]

Thanks for the responses so far!

Here is something I was thinking of too --- the geography of Lake Ponchatrain..... is that lake big enough to cause 'Lake Effect Snow' over New Orleans with a very cold high in place, and a north wind?

Ponchatrain usually is warm in teh winter too, like the Gulf.

Wonder if that has ever happened!

The Florida 'ocean' effect snow last year - I remember seeing a bit about it I think --- during that cold snap where it was freezing pretty close to Miami.

[Valkhorn]

Well let's see, you'd need very cold air over a warm lake and due northerly winds. They would also have to be very strong.

I don't know if it's occurred in recorded history. Since the lake is very shallow it doesn't produce a lot of heat. The oceans and great lakes are very deep, so if they are warm they produce a lot more heat per se.

Now there are reports of ice jams in and around New Orleans... once in the late 1700's, and once in 1899 too I think.

The temperature would have to be just right too. If it was too cold then you wouldn't get any moisture because the air would be too dry.

[Valkhorn]

Come to think of it the 1977 snow event in Florida could have been partially ocean effect. It was a light band of snow that moved from around Orlando and Tampa down to Miami and Homestead. In fact, a day after snow was reported in part of the Bahamas.

I would love to see satellite shots of that event to double check.

[chadtm80]

Snow flurries report from last Winter here in central Florida

Snow Flurries Seen At Florida Beaches
Flurries Will Continue Into Early Afternoon

POSTED: 11:22 a.m. EST January 24, 2003
UPDATED: 11:45 a.m. EST January 24, 2003

A combination of very cold temperatures and strong north-to-northeast winds are producing ocean-effect snow flurries offshore and along the coast of east Central Florida, especially near Cape Canaveral, according to the National Weather Service.




WINTER WEATHER
How Does Snow Form?


The flurries will continue into the early afternoon hours before temperatures modify, causing the light snow and flurries to change over to very light rain or drizzle.

No accumulation of snow is expected. The last time flurries were recorded across east Central Florida was in December 1989.
Copyright 2003 by WFTV.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

[AggieSpirit]

This is all good stuff.

So you have to have a deep ocean/lake body for 'effect' snows to occur -- forgive my dumbness, but is that because there is less evaporation per cubic inch/foot (whatever) from shallower bodies of water than deeper bodies?

I suppose if Ponchatrain were 500 feet deep, or something like that, this would be more likely to occur?

[Stormsfury]

Truley an amazing event. BLizzard conditions in Tallahassee, Florida may have occurred. Here is a summary I found

February 13, 1899 -

it was the coldest morning ever along the Gulf Coast, with temperatures of 6.8 degrees at New Orleans, Louisiana, 7 degrees at Pensacola, Florida and 1 degree below zero at Mobile, Alabama. The record low temperature for the state of Florida was set at Tallahassee when the mercury tumbled to 2 degrees below zero. The record low temperature for the state of Louisiana was set at Minden, when the thermometer fell to 16 degrees below zero. A trace of snow fell at Fort Myers, Florida. This was the farthest south snow has ever been observed in the US until 1977.

Here is the Feb 14th 1895 Snowstorm summary

February 15, 1895 -

a big Gulf snowstorm dumped 6 inches of snow at Brownsville, Texas, 15 inches at Galveston, Texas, and 24 inches at Rayne, Louisiana in 24 hours. Snow fell at the very mouth of the Mississippi River. Houston, Texas recorded 22 inches of snow and 9 inches blanketed New Orleans, Louisiana.

The February 14th-15th, 1895 storm was a PURE but relatively weak storm system deep in the GOM ... and covered a LARGE expanse of real estate across the Gulf States and that storm ... there was a VERY STRONG arctic high (around 31.00" of mercury centered over Eastern Colorado) which channeled extremely cold air across the Entire Eastern 2/3 thirds of the nation ... and that SFC low developed in the Eastern GOM west of Tampa and moved Northeast to off the Carolina Coast on the 16th ...

The February 1899 blizzard was quite a special storm indeed ... and I have a writeup column with maps regarding this and more information from the National Climatic Data Center about the Gulf Effect Snows in Tampa, FL ...

Go to this page and use the Archived Winter Weather Toolbar Menu ... it has the links for the Blizzard of 1899 plus 4 maps ...

Here's one of those maps showing the GOM effect snows and the -2º in Tallahassee, FL - the only recorded time in FL history that the temperature fell below zero in the Sunshine State.

http://www.stormsfury1.com/Weather/WinterWeather.html



SF

[QCWx]

I've even seen Albemarle Sound effect snow here in the carolinas. It is very rare though.

[Stormsfury]

Come to think of it the 1977 snow event in Florida could have been partially ocean effect. It was a light band of snow that moved from around Orlando and Tampa down to Miami and Homestead. In fact, a day after snow was reported in part of the Bahamas.

I would love to see satellite shots of that event to double check.

And yes, that was ... take a look here ...

http://www.islandnet.com/~see/weather/a ... m02jan.htm

[Valkhorn]

Where did you get the info from the 1895 system?

From the observations I saw and timeframes to me it looked like it developed off of the Texas coast and moved Eastward and weakened drastically after bombing west of New Orleans.

From the information I found I don't consider it a weak system. It did dump 2 feet of snow in Houston. If the maximum snowfalls and precipitated water amounts were under an inch either way, it would be weak. However two feet of snow can equate to two inches of rain, and for temperatures below 32 degrees that is a lot of precip no matter how you slice it. No weak system causes 2 feet of snow, not even Lake Effect.

The 1899 blizzard was quite different however it did produce a good deal of snow in Tallahassee. Blizzard reports are VERY skeptical since there wasn't as clear of a definition then as it is now. Also, a Blizzard in 1899 terms is very relative. Most people of that day never ventured out of their own state and just about any major snow (especially in Florida) would have been labelled in the papers as a 'blizzard' or 'severe snow storm.' The winds would not have maxed out during the height of the snow, and seeing as how the winds died down enough to allow for a low of -2 in that area, there is no way the winds would have maxed out that much I think. We are talking drastic changes there for there to be 30mph winds sustained half a day before a calm winds (and clear skies) low of -2.

Even in 1977, the papers in south florida when it snowed put that news in the headlines of the Miami Herald, and in a font size normally reserved for declarations of War or something.

No matter what year, reports of snow are going to be more and more exaggerated the further south in Latitude you go

Now the 1963 system was even stronger in terms of southern snow. Bay St. Louis, MS reported 16" of snow from that system.

[Valkhorn]

Correction: I'm not sure the -2 was that drastically close to the Blizzard report, but again I am highly skeptical it was a true Blizzard in Tallahassee.

Again, then in that city even the National Weather Service officials probably had never truly seen serious snow, much less a Blizzard.

Unless there were observations to prove it (which I have a hard time tracking down) it wasn't a Blizzard. If you do have obs to prove it for that far south I'd sure like to see them.

[PTrackerLA]

If only we cold go back in time and see witness this amazing event, I couldn't even imagine what 2 feet of snow would do to southern Louisiana in 2003. Here's hoping for a repeat in Jan 2004

[Valkhorn]

Oh yes, and I can't see the 1895 low pressure system developing near Tampa when parts of Brownsville actually reported 7 to 10" of snow. If it was a low pressure, it would have had to have been one of the strongest in reported history to produce that much precip almost 1000 miles away from cyclogenesis.

In addition, there would have been different obs than what was along the gulf coast then. For all reasons I can find the heavy snowfall accumulation stopped around the central Gulf coast.

Also a system deep in the Gulf of Mexico wouldn't develop near Tampa That is not deep in the Gulf of Mexico.

[Stormsfury]

Where did you get the info from the 1895 system?

From the observations I saw and timeframes to me it looked like it developed off of the Texas coast and moved Eastward and weakened drastically after bombing west of New Orleans.

From the information I found I don't consider it a weak system. It did dump 2 feet of snow in Houston. If the maximum snowfalls and precipitated water amounts were under an inch either way, it would be weak. However two feet of snow can equate to two inches of rain, and for temperatures below 32 degrees that is a lot of precip no matter how you slice it. No weak system causes 2 feet of snow, not even Lake Effect.

The 1899 blizzard was quite different however it did produce a good deal of snow in Tallahassee. Blizzard reports are VERY skeptical since there wasn't as clear of a definition then as it is now. Also, a Blizzard in 1899 terms is very relative. Most people of that day never ventured out of their own state and just about any major snow (especially in Florida) would have been labelled in the papers as a 'blizzard' or 'severe snow storm.' The winds would not have maxed out during the height of the snow, and seeing as how the winds died down enough to allow for a low of -2 in that area, there is no way the winds would have maxed out that much I think. We are talking drastic changes there for there to be 30mph winds sustained half a day before a calm winds (and clear skies) low of -2.

Even in 1977, the papers in south florida when it snowed put that news in the headlines of the Miami Herald, and in a font size normally reserved for declarations of War or something.

No matter what year, reports of snow are going to be more and more exaggerated the further south in Latitude you go

Now the 1963 system was even stronger in terms of southern snow. Bay St. Louis, MS reported 16" of snow from that system.

You'll need to install a PDF-like component before you can view the US daily maps ... but there you go ... (but I misworded my development near Tampa ... I meant, located west of Tampa) ...

http://docs.lib.noaa.gov/rescue/dwm/dat ... _maps.html

[Valkhorn]

They're not there in that link you provided. It's a 404 no matter what...

[Valkhorn]

Crap, even if you save target as those files and you save them, how in the heck do you open them?

I always get unexpected end of file errors...

[Valkhorn]

Nevermind... I'm looking at them now... man I hate IE...

According to the 1895 maps with the Precip there was a Low that formed in the Gulf, deeeep in the Gulf, else there wouldn't have been precip there with that kind of signature.

Also remember the following, even in 1900, five years later, they had no idea there was a true hurricane sitting out in the gulf until it got very close to land. Look at the maps

They didn't have electronic Bouys then and the only time they knew a Low pressure had formed out in the sea were from ship reports.

Remember, that map has not been updated in 100 years, so it has to be taken with a grain of salt, and you have to read between the lines and do a little Forensic Meteorology...