diff --git a/CHANGES.md b/CHANGES.md
index 1ed8b8576067..e52ca3f0ec38 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -46,6 +46,7 @@ Change Log
 * Fixed an issue causing the Bing Maps key to be sent unnecessarily with every tile request. [#6250](https://github.com/AnalyticalGraphicsInc/cesium/pull/6250)
 * Fixed bug with zooming to dynamic geometry. [#6269](https://github.com/AnalyticalGraphicsInc/cesium/issues/6269)
 * Fixed documentation issue for the `Cesium.Math` class. [#6233](https://github.com/AnalyticalGraphicsInc/cesium/issues/6233)
+* Fix Firefox WebGL console warnings. [#5912](https://github.com/AnalyticalGraphicsInc/cesium/issues/5912)
 
 ### 1.42.1 - 2018-02-01
 _This is an npm-only release to fix an issue with using Cesium in Node.js.__
diff --git a/Source/Core/PixelFormat.js b/Source/Core/PixelFormat.js
index 5c01b6999909..6654608f5b21 100644
--- a/Source/Core/PixelFormat.js
+++ b/Source/Core/PixelFormat.js
@@ -281,6 +281,26 @@ define([
                 componentsLength = 1;
             }
             return componentsLength * PixelDatatype.sizeInBytes(pixelDatatype) * width * height;
+        },
+
+        /**
+         * @private
+         */
+        createTypedArray : function(pixelFormat, pixelDatatype, width, height) {
+            var constructor;
+            var sizeInBytes = PixelDatatype.sizeInBytes(pixelDatatype);
+            if (sizeInBytes === Uint8Array.BYTES_PER_ELEMENT) {
+                constructor = Uint8Array;
+            } else if (sizeInBytes === Uint16Array.BYTES_PER_ELEMENT) {
+                constructor = Uint16Array;
+            } else if (sizeInBytes === Float32Array.BYTES_PER_ELEMENT && pixelDatatype === PixelDatatype.FLOAT) {
+                constructor = Float32Array;
+            } else {
+                constructor = Uint32Array;
+            }
+
+            var size = PixelFormat.componentsLength(pixelFormat) * width * height;
+            return new constructor(size);
         }
     };
 
diff --git a/Source/Renderer/CubeMap.js b/Source/Renderer/CubeMap.js
index e08eccd1c718..00a3fe450861 100644
--- a/Source/Renderer/CubeMap.js
+++ b/Source/Renderer/CubeMap.js
@@ -33,7 +33,6 @@ define([
     'use strict';
 
     function CubeMap(options) {
-
         options = defaultValue(options, defaultValue.EMPTY_OBJECT);
 
         //>>includeStart('debug', pragmas.debug);
@@ -121,25 +120,29 @@ define([
         gl.activeTexture(gl.TEXTURE0);
         gl.bindTexture(textureTarget, texture);
 
-        function createFace(target, sourceFace) {
+        function createFace(target, sourceFace, preMultiplyAlpha, flipY) {
+            // TODO: gl.pixelStorei(gl._UNPACK_ALIGNMENT, 4);
             if (sourceFace.arrayBufferView) {
+                gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, false);
+                gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, false);
                 gl.texImage2D(target, 0, pixelFormat, size, size, 0, pixelFormat, pixelDatatype, sourceFace.arrayBufferView);
             } else {
+                // Only valid for DOM-Element uploads
+                gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, preMultiplyAlpha);
+                gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, flipY);
+
+                // Source: ImageData, HTMLImageElement, HTMLCanvasElement, or HTMLVideoElement
                 gl.texImage2D(target, 0, pixelFormat, pixelFormat, pixelDatatype, sourceFace);
             }
         }
 
         if (defined(source)) {
-            // TODO: _gl.pixelStorei(_gl._UNPACK_ALIGNMENT, 4);
-            gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, preMultiplyAlpha);
-            gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, flipY);
-
-            createFace(gl.TEXTURE_CUBE_MAP_POSITIVE_X, source.positiveX);
-            createFace(gl.TEXTURE_CUBE_MAP_NEGATIVE_X, source.negativeX);
-            createFace(gl.TEXTURE_CUBE_MAP_POSITIVE_Y, source.positiveY);
-            createFace(gl.TEXTURE_CUBE_MAP_NEGATIVE_Y, source.negativeY);
-            createFace(gl.TEXTURE_CUBE_MAP_POSITIVE_Z, source.positiveZ);
-            createFace(gl.TEXTURE_CUBE_MAP_NEGATIVE_Z, source.negativeZ);
+            createFace(gl.TEXTURE_CUBE_MAP_POSITIVE_X, source.positiveX, preMultiplyAlpha, flipY);
+            createFace(gl.TEXTURE_CUBE_MAP_NEGATIVE_X, source.negativeX, preMultiplyAlpha, flipY);
+            createFace(gl.TEXTURE_CUBE_MAP_POSITIVE_Y, source.positiveY, preMultiplyAlpha, flipY);
+            createFace(gl.TEXTURE_CUBE_MAP_NEGATIVE_Y, source.negativeY, preMultiplyAlpha, flipY);
+            createFace(gl.TEXTURE_CUBE_MAP_POSITIVE_Z, source.positiveZ, preMultiplyAlpha, flipY);
+            createFace(gl.TEXTURE_CUBE_MAP_NEGATIVE_Z, source.negativeZ, preMultiplyAlpha, flipY);
         } else {
             gl.texImage2D(gl.TEXTURE_CUBE_MAP_POSITIVE_X, 0, pixelFormat, size, size, 0, pixelFormat, pixelDatatype, null);
             gl.texImage2D(gl.TEXTURE_CUBE_MAP_NEGATIVE_X, 0, pixelFormat, size, size, 0, pixelFormat, pixelDatatype, null);
@@ -163,12 +166,13 @@ define([
         this._flipY = flipY;
         this._sampler = undefined;
 
-        this._positiveX = new CubeMapFace(gl, texture, textureTarget, gl.TEXTURE_CUBE_MAP_POSITIVE_X, pixelFormat, pixelDatatype, size, preMultiplyAlpha, flipY);
-        this._negativeX = new CubeMapFace(gl, texture, textureTarget, gl.TEXTURE_CUBE_MAP_NEGATIVE_X, pixelFormat, pixelDatatype, size, preMultiplyAlpha, flipY);
-        this._positiveY = new CubeMapFace(gl, texture, textureTarget, gl.TEXTURE_CUBE_MAP_POSITIVE_Y, pixelFormat, pixelDatatype, size, preMultiplyAlpha, flipY);
-        this._negativeY = new CubeMapFace(gl, texture, textureTarget, gl.TEXTURE_CUBE_MAP_NEGATIVE_Y, pixelFormat, pixelDatatype, size, preMultiplyAlpha, flipY);
-        this._positiveZ = new CubeMapFace(gl, texture, textureTarget, gl.TEXTURE_CUBE_MAP_POSITIVE_Z, pixelFormat, pixelDatatype, size, preMultiplyAlpha, flipY);
-        this._negativeZ = new CubeMapFace(gl, texture, textureTarget, gl.TEXTURE_CUBE_MAP_NEGATIVE_Z, pixelFormat, pixelDatatype, size, preMultiplyAlpha, flipY);
+        var initialized = defined(source);
+        this._positiveX = new CubeMapFace(gl, texture, textureTarget, gl.TEXTURE_CUBE_MAP_POSITIVE_X, pixelFormat, pixelDatatype, size, preMultiplyAlpha, flipY, initialized);
+        this._negativeX = new CubeMapFace(gl, texture, textureTarget, gl.TEXTURE_CUBE_MAP_NEGATIVE_X, pixelFormat, pixelDatatype, size, preMultiplyAlpha, flipY, initialized);
+        this._positiveY = new CubeMapFace(gl, texture, textureTarget, gl.TEXTURE_CUBE_MAP_POSITIVE_Y, pixelFormat, pixelDatatype, size, preMultiplyAlpha, flipY, initialized);
+        this._negativeY = new CubeMapFace(gl, texture, textureTarget, gl.TEXTURE_CUBE_MAP_NEGATIVE_Y, pixelFormat, pixelDatatype, size, preMultiplyAlpha, flipY, initialized);
+        this._positiveZ = new CubeMapFace(gl, texture, textureTarget, gl.TEXTURE_CUBE_MAP_POSITIVE_Z, pixelFormat, pixelDatatype, size, preMultiplyAlpha, flipY, initialized);
+        this._negativeZ = new CubeMapFace(gl, texture, textureTarget, gl.TEXTURE_CUBE_MAP_NEGATIVE_Z, pixelFormat, pixelDatatype, size, preMultiplyAlpha, flipY, initialized);
 
         this.sampler = defined(options.sampler) ? options.sampler : new Sampler();
     }
diff --git a/Source/Renderer/CubeMapFace.js b/Source/Renderer/CubeMapFace.js
index 83e9a165cd73..152cb59c9dfa 100644
--- a/Source/Renderer/CubeMapFace.js
+++ b/Source/Renderer/CubeMapFace.js
@@ -1,21 +1,25 @@
 define([
         '../Core/Check',
         '../Core/defaultValue',
+        '../Core/defined',
         '../Core/defineProperties',
         '../Core/DeveloperError',
+        '../Core/PixelFormat',
         './PixelDatatype'
     ], function(
         Check,
         defaultValue,
+        defined,
         defineProperties,
         DeveloperError,
+        PixelFormat,
         PixelDatatype) {
     'use strict';
 
     /**
      * @private
      */
-    function CubeMapFace(gl, texture, textureTarget, targetFace, pixelFormat, pixelDatatype, size, preMultiplyAlpha, flipY) {
+    function CubeMapFace(gl, texture, textureTarget, targetFace, pixelFormat, pixelDatatype, size, preMultiplyAlpha, flipY, initialized) {
         this._gl = gl;
         this._texture = texture;
         this._textureTarget = textureTarget;
@@ -25,6 +29,7 @@ define([
         this._size = size;
         this._preMultiplyAlpha = preMultiplyAlpha;
         this._flipY = flipY;
+        this._initialized = initialized;
     }
 
     defineProperties(CubeMapFace.prototype, {
@@ -91,15 +96,52 @@ define([
         var target = this._textureTarget;
 
         // TODO: gl.pixelStorei(gl._UNPACK_ALIGNMENT, 4);
-        gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, this._preMultiplyAlpha);
-        gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, this._flipY);
+
         gl.activeTexture(gl.TEXTURE0);
         gl.bindTexture(target, this._texture);
 
-        if (source.arrayBufferView) {
-            gl.texSubImage2D(this._targetFace, 0, xOffset, yOffset, source.width, source.height, this._pixelFormat, this._pixelDatatype, source.arrayBufferView);
-        } else {
-            gl.texSubImage2D(this._targetFace, 0, xOffset, yOffset, this._pixelFormat, this._pixelDatatype, source);
+        var uploaded = false;
+        if (!this._initialized) {
+            if (xOffset === 0 && yOffset === 0 && source.width === this._size && source.height === this._size) {
+                // initialize the entire texture
+                if (defined(source.arrayBufferView)) {
+                    gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, false);
+                    gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, false);
+
+                    gl.texImage2D(this._targetFace, 0, this._pixelFormat, this._size, this._size, 0, this._pixelFormat, this._pixelDatatype, source.arrayBufferView);
+                } else {
+                    // Only valid for DOM-Element uploads
+                    gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, this._preMultiplyAlpha);
+                    gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, this._flipY);
+
+                    gl.texImage2D(this._targetFace, 0, this._pixelFormat, this._pixelFormat, this._pixelDatatype, source);
+                }
+                uploaded = true;
+            } else {
+                gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, false);
+                gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, false);
+
+                // initialize the entire texture to zero
+                var bufferView = PixelFormat.createTypedArray(this._pixelFormat, this._pixelDatatype, this._size, this._size);
+                gl.texImage2D(this._targetFace, 0, this._pixelFormat, this._size, this._size, 0, this._pixelFormat, this._pixelDatatype, bufferView);
+            }
+            this._initialized = true;
+        }
+
+        if (!uploaded) {
+            if (source.arrayBufferView) {
+                gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, false);
+                gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, false);
+
+                gl.texSubImage2D(this._targetFace, 0, xOffset, yOffset, source.width, source.height, this._pixelFormat, this._pixelDatatype, source.arrayBufferView);
+            } else {
+                // Only valid for DOM-Element uploads
+                gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, this._preMultiplyAlpha);
+                gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, this._flipY);
+
+                // Source: ImageData, HTMLImageElement, HTMLCanvasElement, or HTMLVideoElement
+                gl.texSubImage2D(this._targetFace, 0, xOffset, yOffset, this._pixelFormat, this._pixelDatatype, source);
+            }
         }
 
         gl.bindTexture(target, null);
@@ -160,6 +202,7 @@ define([
         gl.bindTexture(target, this._texture);
         gl.copyTexSubImage2D(this._targetFace, 0, xOffset, yOffset, framebufferXOffset, framebufferYOffset, width, height);
         gl.bindTexture(target, null);
+        this._initialized = true;
     };
 
     return CubeMapFace;
diff --git a/Source/Renderer/Texture.js b/Source/Renderer/Texture.js
index 2ba7284e05c7..9d7387962a41 100644
--- a/Source/Renderer/Texture.js
+++ b/Source/Renderer/Texture.js
@@ -164,19 +164,22 @@ define([
         var preMultiplyAlpha = options.preMultiplyAlpha || pixelFormat === PixelFormat.RGB || pixelFormat === PixelFormat.LUMINANCE;
         var flipY = defaultValue(options.flipY, true);
 
+        var initialized = true;
+
         var gl = context._gl;
         var textureTarget = gl.TEXTURE_2D;
         var texture = gl.createTexture();
 
+        // TODO: gl.pixelStorei(gl._UNPACK_ALIGNMENT, 4);
+
         gl.activeTexture(gl.TEXTURE0);
         gl.bindTexture(textureTarget, texture);
 
         if (defined(source)) {
-            // TODO: _gl.pixelStorei(_gl._UNPACK_ALIGNMENT, 4);
-            gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, preMultiplyAlpha);
-            gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, flipY);
-
             if (defined(source.arrayBufferView)) {
+                gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, false);
+                gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, false);
+
                 // Source: typed array
                 if (isCompressed) {
                     gl.compressedTexImage2D(textureTarget, 0, internalFormat, width, height, 0, source.arrayBufferView);
@@ -184,6 +187,9 @@ define([
                     gl.texImage2D(textureTarget, 0, internalFormat, width, height, 0, pixelFormat, pixelDatatype, source.arrayBufferView);
                 }
             } else if (defined(source.framebuffer)) {
+                gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, false);
+                gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, false);
+
                 // Source: framebuffer
                 if (source.framebuffer !== context.defaultFramebuffer) {
                     source.framebuffer._bind();
@@ -195,11 +201,16 @@ define([
                     source.framebuffer._unBind();
                 }
             } else {
+                // Only valid for DOM-Element uploads
+                gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, preMultiplyAlpha);
+                gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, flipY);
+
                 // Source: ImageData, HTMLImageElement, HTMLCanvasElement, or HTMLVideoElement
                 gl.texImage2D(textureTarget, 0, internalFormat, pixelFormat, pixelDatatype, source);
             }
         } else {
             gl.texImage2D(textureTarget, 0, internalFormat, width, height, 0, pixelFormat, pixelDatatype, null);
+            initialized = false;
         }
         gl.bindTexture(textureTarget, null);
 
@@ -224,6 +235,7 @@ define([
         this._sizeInBytes = sizeInBytes;
         this._preMultiplyAlpha = preMultiplyAlpha;
         this._flipY = flipY;
+        this._initialized = initialized;
         this._sampler = undefined;
 
         this.sampler = defined(options.sampler) ? options.sampler : new Sampler();
@@ -469,15 +481,50 @@ define([
         var target = this._textureTarget;
 
         // TODO: gl.pixelStorei(gl._UNPACK_ALIGNMENT, 4);
-        gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, this._preMultiplyAlpha);
-        gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, this._flipY);
+
         gl.activeTexture(gl.TEXTURE0);
         gl.bindTexture(target, this._texture);
 
-        if (source.arrayBufferView) {
-            gl.texSubImage2D(target, 0, xOffset, yOffset, source.width, source.height, this._pixelFormat, this._pixelDatatype, source.arrayBufferView);
-        } else {
-            gl.texSubImage2D(target, 0, xOffset, yOffset, this._pixelFormat, this._pixelDatatype, source);
+        var uploaded = false;
+        if (!this._initialized) {
+            if (xOffset === 0 && yOffset === 0 && source.width === this._width && source.height === this._height) {
+                // initialize the entire texture
+                if (defined(source.arrayBufferView)) {
+                    gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, false);
+                    gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, false);
+                    gl.texImage2D(target, 0, this._pixelFormat, this._width, this._height, 0, this._pixelFormat, this._pixelDatatype, source.arrayBufferView);
+                } else {
+                    // Only valid for DOM-Element uploads
+                    gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, this._preMultiplyAlpha);
+                    gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, this._flipY);
+
+                    gl.texImage2D(target, 0, this._pixelFormat, this._pixelFormat, this._pixelDatatype, source);
+                }
+                uploaded = true;
+            } else {
+                gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, false);
+                gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, false);
+
+                // initialize the entire texture to zero
+                var bufferView = PixelFormat.createTypedArray(this._pixelFormat, this._pixelDatatype, this._width, this._height);
+                gl.texImage2D(target, 0, this._pixelFormat, this._width, this._height, 0, this._pixelFormat, this._pixelDatatype, bufferView);
+            }
+            this._initialized = true;
+        }
+
+        if (!uploaded) {
+            if (source.arrayBufferView) {
+                gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, false);
+                gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, false);
+
+                gl.texSubImage2D(target, 0, xOffset, yOffset, source.width, source.height, this._pixelFormat, this._pixelDatatype, source.arrayBufferView);
+            } else {
+                // Only valid for DOM-Element uploads
+                gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, this._preMultiplyAlpha);
+                gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, this._flipY);
+
+                gl.texSubImage2D(target, 0, xOffset, yOffset, this._pixelFormat, this._pixelDatatype, source);
+            }
         }
 
         gl.bindTexture(target, null);
@@ -536,6 +583,7 @@ define([
         gl.bindTexture(target, this._texture);
         gl.copyTexSubImage2D(target, 0, xOffset, yOffset, framebufferXOffset, framebufferYOffset, width, height);
         gl.bindTexture(target, null);
+        this._initialized = true;
     };
 
     /**