California fires fueled by record drought

By: Dr. Jeff Masters , 1:40 PM GMT on October 23, 2007

An area of disturbed weather has developed near the northern Lesser Antilles Islands, due to a westward-moving tropical wave interacting with an upper-level low. Wind shear is currently too high (30 knots) to allow development of this disturbance. However, the past two runs of the NOGAPS model have predicted that wind shear will fall enough by Friday to allow a tropical depression to form near the western Bahamas. This storm is predicted to move westward across eastern Cuba and into the Western Caribbean. The GFS model does not go along with this scenario, but hints at a weak system developing and moving northeast out sea over the middle Atlantic. The UKMET and ECMWF models do not develop a Bahamas storm, either, but do show a large region of low pressure with low wind shear developing over the Western Caribbean later this week. It would not be a surprise to see a tropical depression develop in the Western Caribbean late this week or early next week.

Southern California's fire storm
Surface maps show a strong high pressure system centered over Nevada and Utah. The clockwise flow of air around this high is driving strong northeasterly winds over Southern California. As the air spills down the mountain passes into coastal San Diego and Los Angeles, gravity helps accelerate the winds. The air compresses and warms as it descends, due to the higher pressures found at sea level. This creates a very hot, low-humidity wind--the dangerous Santa Ana wind. At 1:37 pm PDT yesterday, the humidity in downtown Los Angeles was 8%. Some wind reports Monday afternoon in Southern California, showing the strength of the Santa Ana winds:

Los Angeles County peak wind gusts
------------------------------------------------- --
Leo Carrillo Beach... ... ... ... ... ... ... Northeast 44 mph.
Van Nuys... ... ... ... ... ... ... ... ..... North 39 mph.
Tonner Canyon... ... ... ... ... ... ... .... Northeast 46 mph.
Malibu Canyon... ... ... ... ... ... ... .... Northeast 41 mph.
Malibu Hills... ... ... ... ... ... ... ..... North 54 mph.
Newhall... ... ... ... ... ... ... ... ... .. Northeast 38 mph.
Newhall Pass... ... ... ... ... ... ... ..... North 72 mph.
Saugus... ... ... ... ... ... ... ... ... ... North 60 mph.
Del Valle... ... ... ... ... ... ... ... .... Northeast 50 mph.
Acton... ... ... ... ... ... ... ... ... .... Northeast 45 mph.
Camp Nine... ... ... ... ... ... ... ... .... North 71 mph.
Chilao... ... ... ... ... ... ... ... ... ... Northeast 55 mph.
Mill Creek... ... ... ... ... ... ... ... ... North 41 mph.
Sandberg... ... ... ... ... ... ... ... ..... East 40 mph.
Warm Springs... ... ... ... ... ... ... ..... East 62 mph.
Whitaker Peak... ... ... ... ... ... ... .... North 48 mph.
Lake Palmdale... ... ... ... ... ... ... .... Northeast 46 mph.
Poppy Park... ... ... ... ... ... ... ... ... East 43 mph.
Saddleback Butte... ... ... ... ... ... ..... East 33 mph.
Lancaster... ... ... ... ... ... ... ... .... East 31 mph.

Ventura County peak wind gusts
--------------------------------------------
Oxnard... ... ... ... ... ... ... ... ... ... East 41 mph.
Camarillo... ... ... ... ... ... ... ... .... Northeast 51 mph.
Point Mugu... ... ... ... ... ... ... ... ... Northeast 43 mph.
Piru... ... ... ... ... ... ... ... ... ..... North 49 mph.
Simi Valley... ... ... ... ... ... ... ... .. Northeast 41 mph.
Thousand Oaks... ... ... ... ... ... ... .... North 42 mph.
Laguna Peak... ... ... ... ... ... ... ... .. Northwest 62 mph.

Fourteen large wildfires have developed spanning seven counties in California since Saturday, thanks to the Santa Ana winds, and the prevailing extreme drought conditions. Rainfall in San Diego has been a mere 2.6 inches thus far in 2007, 32% of normal. The July 1, 2006 through June 30, 2007 period was the 4th driest on record in San Diego. In Los Angeles, it was the driest year since record keeping began 130 years ago. Downtown Los Angeles has recorded just 3.37" of rain thus far in 2007--only 28% of normal.

Air quality
Not surprisingly, air quality due to particulate matter has been awful in Southern California (Figure 1). Exceedances of the Federal air quality standards by more than a factor of two have occurred the past three days in both Los Angeles and San Diego. Hightened particulate pollution is strongly correlated with increased death rates, particulary in vulnerable populations, such as those with heart conditions, athsma, or other lung diseases. Everyone should avoid any outdoor exertion; people with respiratory or heart disease, the elderly, and children should remain indoors. Keep your windows and doors closed unless it is extremely hot inside. In these cases, seek alternate shelter. Run your air conditioner if you have one. Keep the fresh air intake closed and the filter clean to prevent bringing additional smoke inside. EPA's Airnow website has more information.


Figure 1. Visible satellite images taken midday on Saturday, Sunday, and Monday. Overlaid on the images is the peak daily particle pollution Air Quality Index (AQI) levels due to smoke. Poor air quality became more widespread across the region as the number and size of the fires increased from day to day. Smoke is visible as white or bluish-white streaks. Blowing dust (brown streaks), reducing visibility under three miles, is also apparent on the images. Image credit: NASA and EPA.

The forecast
The warm, dry, and windy weather will continue today, bringing a repeat of yesterday's extremely dangerous fire situation. A trough of low pressure is expected to move into northern California Wednesday morning, weakening the high pressure system driving the Santa Ana winds. By Thursday, the Santa Ana winds will be gone, and fire fighters will be able to gain the upper hand.

This may only be the first of several serious fire situations in Southern California in the coming months. Santa Ana winds conditions commonly develop during the October through March period, and the extreme drought conditions in Southern California are not going to improve until at least December, when the winter rainy season typically starts. The 3-month precipitation forecast from NOAA's Climate Prediction Center calls for a 33% chance of below-average rainfall over Southern California for the coming winter.

The University of Wisconsin's CIMSS group has a more detailed blog with many weather maps and satellite animations of the Southern California fires.

San Francisco's Climate Challenge
San Francisco residents have a different and more positive kind of challenge this week. An innovative contest designed to encourage residents to reduce energy usage is being launched, with a sign-up deadline of Wednesday. The content offers prizes up to $5000 for those residents able to reduce their energy consumption the most over the coming month. For more information, see the new Weather Underground climate page: at http://www.wunderground.com/climate/. The new page will track current climate trends each month, and feature stories on new research and programs in the climate change field every few weeks. We'll also add a full set of information on the science of climate change over the coming months. The goal is to have a web site that keeps track of the most important issues in climate change.

Jeff Masters

Effect the winds in this truck! (chentetij)
Volcadura de un trailer por los vientos de Santana
Effect the winds in this truck!
Smoke over Woodbridge (wheels)
A fire east of Irvine produced major air polution
Smoke over Woodbridge

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208. Patrap
4:53 PM CDT on October 23, 2007
GOES WV Loop of Tropical Basin


Link
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207. Ivansvrivr
9:46 PM GMT on October 23, 2007
I would expect the folks in charge to be slow to react to eastern storm because of climatology. As if telling folks in Nashville to get out the snow shovel in May. It doesn't snow in Nashville in May and Canes don't form and move westward underneath a strenghthening High in that area in November.
206. extreme236
9:53 PM GMT on October 23, 2007
BBL
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205. extreme236
9:52 PM GMT on October 23, 2007
98A invest on navy site for the north indian ocean
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204. extreme236
9:52 PM GMT on October 23, 2007
Well with shear decreasing over the low pressure with the twave near the antilles, we could see an invest soon and I wouldnt be surprised to see any development
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203. cantoriesnumber1fan
9:49 PM GMT on October 23, 2007
.
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202. Weather456
5:47 PM AST on October 23, 2007
GULF OF MEXICO/ATLANTIC OCEAN WEST OF 60W....

The first strong cold front of the season is pushing across the Gulf Region this afternoon extending from a 1006 mb low over Tennessee at 36N/85W across the Gulf to the Tehuantepec Peninsula between Mainland Mexico and the Yucatan Peninsula. Satellite imagery showed well define frontal rope structures at the leading edge of a 300 nm wide swath of clouds and showers. This swath is largest south of 23N. The associated 1030 mb high pressure is building behind the front across Central Mexico producing very strong Northwest-West-Southwest winds over the region west of 90W. QuikSCAT showed near 50 knots winds over the Bay of Campeche and buoy 42055 last report was 30 knots sustain. These winds are producing near 20 ft seas over the Western Gulf of Mexico. All this activity is due to the pressure gradient between this rather strong high pressure system and the front.

Visible satellite imagery showed an anticyclonic return flow and fair weather dominates the remainder of the Gulf. This is due to a large 1024 mb high out in the open Western Atlantic.

A 1024 mb ridge centered near 33N/62W is the dominate weather feature over the Western Atlantic. Fair weather and anticyclonic flow dominates the area from 60W to the East Coast north of 20N, with the exception of the southeast portion where a tropical wave is producing cloudiness and showers northeast of the Islands.

by W456
Member Since: July 24, 2005 Posts: 407 Comments: 19076
201. UYA
9:48 PM GMT on October 23, 2007
OK Drak.
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200. Drakoen
9:40 PM GMT on October 23, 2007
198. UYA 9:40 PM GMT on October 23, 2007
now that an area of low pressure has developed we could see an invest soon.

How soon would that be?
Just curious.


could be anytime within the next 24-48 hours.
Member Since: October 28, 2006 Posts: 57 Comments: 32600
199. Patrap
4:39 PM CDT on October 23, 2007

Photograph by Damian Dovarganes/AP

Stoked by fierce winds in Malibu, California, on October 22, 2007, hot embers from a wildfire glow and float, leaving bright streaks in this long-exposure photograph. (Watch a video report.)

As of today, October 23, more than a dozen wildfires across southern California have destroyed some 1,300 homes; forced approximately 300,000 residents to evacuate; and charred 400 square miles, according to state and local officials.

The destruction has led President George W. Bush to proclaim the region, which includes Los Angeles and San Diego, a disaster area. The declaration clears the way for federal troops to aid Californians.

National Geographic News Link
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198. UYA
9:38 PM GMT on October 23, 2007
now that an area of low pressure has developed we could see an invest soon.

How soon would that be?
Just curious.
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197. Drakoen
9:37 PM GMT on October 23, 2007
now that an area of low pressure has developed we could see an invest soon.
Member Since: October 28, 2006 Posts: 57 Comments: 32600
196. UYA
9:35 PM GMT on October 23, 2007
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
530 PM EDT TUE OCT 23 2007

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A WEAK AREA OF LOW PRESSURE HAS DEVELOPED IN ASSOCIATION WITH THE
AREA OF DISTURBED WEATHER AND TROPICAL WAVE LOCATED NORTHEAST OF
THE LESSER ANTILLES. UPPER-LEVEL WINDS ARE NOT CONDUCIVE FOR
SIGNIFICANT DEVELOPMENT OF THIS SYSTEM. THE LOW IS EXPECTED
TO MOVE VERY LITTLE DURING THE NEXT COUPLE OF DAYS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
Member Since: Posts: Comments:
195. Ivansvrivr
9:32 PM GMT on October 23, 2007
Texan, check out Drak's blog. HUGE what if.....
194. Drakoen
9:31 PM GMT on October 23, 2007
close up.
Member Since: October 28, 2006 Posts: 57 Comments: 32600
193. Soloco2
9:22 PM GMT on October 23, 2007
Nice job, Drak........thanks
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192. ryang
5:30 PM AST on October 23, 2007
My Tropical update...
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191. SomeRandomTexan
4:26 PM CDT on October 23, 2007
ivan---
lol...lol...

Now there will be no bed-wetting in here... I don't feel like changing the linens right now.
Member Since: August 30, 2007 Posts: 0 Comments: 1863
190. lightning10
9:25 PM GMT on October 23, 2007
In Whittier, CA there is an Orange sky and is raining ash very slightly.
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189. Bobbyweather
5:27 PM EDT on October 23, 2007
.48 HOUR FORECAST NEW LOW 28N41W 1010 MB. N OF 27N BETWEEN 44W
AND 52W N TO NE WINDS 20 TO 25 KT SEAS 8 TO 11 FT.

From the NHC's High Seas Forecast
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188. UYA
9:26 PM GMT on October 23, 2007
I'm not expecting anything to be whatever for the remainder of the season....but I'm an optimist.
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187. SomeRandomTexan
4:22 PM CDT on October 23, 2007
Ivan---
I really agree with you on where the potential hazard lies. I don't see anything threatening from the ATL. WCARIB and GOM will be the places for the storms to form if the want to hit CONUS....imo
Member Since: August 30, 2007 Posts: 0 Comments: 1863
186. Ivansvrivr
9:21 PM GMT on October 23, 2007
UYA I'm definetly not expecting anything to be named by morning. Late season systems are slow to form. Then don't move much until front comes along to pull entity northor northeast. Maybe this weekend or so. Nothing to wet the bed over yet.
185. Drakoen
9:22 PM GMT on October 23, 2007
If you have any questions you can ask me in my blog.
Member Since: October 28, 2006 Posts: 57 Comments: 32600
184. Bobbyweather
5:18 PM EDT on October 23, 2007
Good afternoon! I saw Melissa's TCR, and I saw that Melissa only reached 40 mph. However, I disagree. Even though they are in a 6-hour basis, the TCR has it from 00 UTC, and NHC issues advisories from 03 UTC.
(P.S. Even though NHC are experts, everyone makes mistakes.)

Anyway, when do you guys think Dean's TCR will come out? I'm really excited to see the pressure. If the pressure goes down 2 mb, he will beat the tie 905 mb set by Camille and Mitch.
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183. Drakoen
9:21 PM GMT on October 23, 2007
I just updated my blog on the current conditions.
Link
Member Since: October 28, 2006 Posts: 57 Comments: 32600
182. Ivansvrivr
9:14 PM GMT on October 23, 2007
E.Carrib us ULL bigtime shear. W.carrib/Gom has better UL environment, more triggers and Climatology all in it's favor. IF(stressed) something pops look south not east. Note all the late season storms mentioned in last hour LILI,Irene,Wilma,Thhanksgiving84 were all W.carrib and Gom. None from east. I'm not ruling anything out, but those who have watched storms the longest are looking south and west.
181. UYA
9:19 PM GMT on October 23, 2007
Yep Ivan....I saw that.....I just don't think much will become of that Gust-frontal situation....at least in the next 54 hours.
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180. SomeRandomTexan
4:16 PM CDT on October 23, 2007
Ivan---
so you think in a couple of days the front will separate and form two systems? Do you think such a strong system would do that? Thanks
Member Since: August 30, 2007 Posts: 0 Comments: 1863
179. extreme236
9:20 PM GMT on October 23, 2007
BBL
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178. extreme236
9:16 PM GMT on October 23, 2007
174. SomeRandomTexan 9:14 PM GMT on October 23, 2007
extreme---
I dont see how anything forms there with the presence of the strong frontal boundary.... maybe a day or two down the road anything could happen... what do you think?


I agree
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177. JLPR
9:13 PM GMT on October 23, 2007
so i see nice vorticity with the on east of the Antilles
interesting
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176. extreme236
9:15 PM GMT on October 23, 2007
Upper level winds may not be conducive now, but shear is continuing to decrease
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175. extreme236
9:14 PM GMT on October 23, 2007
000
ABNT20 KNHC 232113
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
530 PM EDT TUE OCT 23 2007

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A WEAK AREA OF LOW PRESSURE HAS DEVELOPED IN ASSOCIATION WITH THE
AREA OF DISTURBED WEATHER AND TROPICAL WAVE LOCATED NORTHEAST OF
THE LESSER ANTILLES. UPPER-LEVEL WINDS ARE NOT CONDUCIVE FOR
SIGNIFICANT DEVELOPMENT OF THIS SYSTEM. THE LOW IS EXPECTED
TO MOVE VERY LITTLE DURING THE NEXT COUPLE OF DAYS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$

FORECASTER BROWN
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174. SomeRandomTexan
4:13 PM CDT on October 23, 2007
extreme---
I dont see how anything forms there with the presence of the strong frontal boundary.... maybe a day or two down the road anything could happen... what do you think?
Member Since: August 30, 2007 Posts: 0 Comments: 1863
173. Ivansvrivr
9:11 PM GMT on October 23, 2007
UYA notice in that statement that southern half of front/convectiion sounds like it may separate from the northern end. Opal formed same way. Next front moved Opal N.E.
172. HurricaneGeek
5:12 PM EDT on October 23, 2007
How about E ast of the Islands? when will that be an invest

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171. NRAamy
2:12 PM PDT on October 23, 2007
it's 95 degrees here!! What the hell is going on?! This is the most bizarre weather I have ever seen....Southern Calif is gonna fry tonite...between the heat, the winds, and the fires....

( frantically calling PriceLine, to get in touch with William Shatner, for a great deal on a flight to Miami...)
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170. extreme236
9:12 PM GMT on October 23, 2007
the main systems to watch right now IMO is the disturbance in the central caribbean and the disturbance east of the antilles
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169. UYA
9:12 PM GMT on October 23, 2007
Take your pick....nothing is set regarding this front yet.
I suspect it will be the usual October wash-out.
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168. TheCaneWhisperer
9:10 PM GMT on October 23, 2007
The front is going to be a tease for the SEFL Coast :-(
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167. extreme236
9:12 PM GMT on October 23, 2007
Nothing in the BoC will become an invest IMO right now as that convection is well involved and associated with a strong cold front
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166. SomeRandomTexan
4:11 PM CDT on October 23, 2007
Ivan---

so is the BOC and the WCARIB the same thing or is it to separate systems.....
Member Since: August 30, 2007 Posts: 0 Comments: 1863
165. UYA
9:09 PM GMT on October 23, 2007
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL3
400 PM EDT TUE OCT 23 2007

FOR WEDNESDAY WILL SEE THE COLD FRONT STALL TO THE EAST OF OUR AREA
WITH THE BEST CONVECTIVE POTENTIAL ALSO TO OUR EAST. THE LATEST 12Z
GFS SHOWS THE UPPER LOW DROPPING SOUTHEAST INTO SOUTHERN AL AND THE
WESTERN FLORIDA PANHANDLE DURING THE DAY. THIS IS NOW THE CLOSEST
APPROACH OF THE UPPER LOW THAT THE GLOBAL MODELS HAVE SHOWN.
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164. Ivansvrivr
9:09 PM GMT on October 23, 2007
"So any ideas on when the disturbance E of the Islands will become a invest?"

W.Carrib/Bay of Campeche will be invest
163. HurricaneGeek
5:08 PM EDT on October 23, 2007
So any ideas on when the disturbance E of the Islands will become a invest?
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162. UYA
9:05 PM GMT on October 23, 2007
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
143 PM EDT TUE OCT 23 2007

..A POSSIBLE HEAVY RAIN EVENT SHAPING UP FOR WEST CENTRAL FLORIDA...

.SHORT TERM (TONIGHT - THURSDAY)...ANY DIURNAL SHOWERS OR STORMS ACROSS
THE FORECAST AREA EARLY THIS EVENING WILL WIND DOWN AFTER SUNSET WITH
LOSS OF DAYTIME HEATING. THEREAFTER EXPECT TO SEE AN SLOW INCREASE IN
CLOUDS AND RAIN CHANCES...ESPECIALLY ACROSS THE NATURE COAST AFTER
MIDNIGHT AS A COLD FRONT/TROUGH AXIS ASSOCIATED WITH THE DEEP CUTOFF
LOW OVER THE LOWER MS VALLEY DRIFTS SLOWLY EASTWARD. MODELS THIS AFTERNOON
CONTINUE TO DIVERGE WITH RESPECT TO THE STRONG CLOSED LOWS EVOLUTION
AND MOVEMENT DURING THE SHORT TERM PERIOD..
.WITH THE GFS/ECMWF NOW
MOVING THIS FEATURE AS FAR EAST AS ALABAMA THROUGH THURSDAY...BEFORE
RETROGRADING IT BACK TO THE WEST AND NORTHWEST ON FRIDAY...WHILE THE
NAM STOPS ITS EASTWARD MOVEMENT OVER MISSISSIPPI. GIVEN THE GFS SOLUTION
THE ATTENDANT NORTH TO SOUTH COLD FRONT/TROUGH AXIS NOW ACROSS THE WEST
CENTRAL GULF WILL MOVE EAST TONIGHT MOVING INTO WEST CENTRAL FLORIDA ON
WEDNESDAY...THEN SHIFTING SOUTH AND EAST ON THURSDAY AS SOME DRIER AIR
WRAPS INTO MY NORTHERN ZONES ON THURSDAY...WITH BEST RAIN CHANCES SHIFTING
SOUTHWARD. ON THE OTHER HAND THE NAM IS NOT AS AGGRESSIVE IN MOVING THE
CLOSED LOW EAST AND RETROGRADES IT BACK TO THE WEST FASTER THAN THE GFS
SO ITS ATTENDANT COLD FRONT/TROUGH AXIS HANGS OUT OVER WEST CENTRAL
FLORIDA THROUGH THURSDAY WITH MUCH HIGHER RAIN CHANCES AS SEEN ON THE
LATEST MET POP GUIDANCE.

GIVEN THE DIFFERENCES IN THE MODELS CONFIDENCE IN ANY ONE SOLUTION
REMAINS RATHER LOW RIGHT NOW...
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161. Ivansvrivr
9:06 PM GMT on October 23, 2007
Floodman-Cat says "hello"
160. Ivansvrivr
9:03 PM GMT on October 23, 2007
BigberthabremudaHigh has alerady stopped front in it's tracks. Front moved High just enough to open up W.carrib.
159. homegirl
9:04 PM GMT on October 23, 2007
Some interesting buoy info:Link
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158. HurrMichaelOrl
8:58 PM GMT on October 23, 2007
Based on the ridiculously warm temperatures forcast they must not be predicting that front to get to central/south Florida. Looking at it on satellite how could it not get here, what's going to stop it?
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Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather

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