GeoMan's Southern California Weekend Storm Forecast

[Geomagnetic Man]

The following is not a NWS or SPC forecast, as is the forecast of me, GeoMan James. Official forecasts from the NWS or SPC can be visited at http://www.nws.noaa.gov, or http://www.spc.noaa.gov



WINTER STORM ANDREW FINAL FORECAST ITS OVER SOON

ANDREW CATEGORY 4

Winter Storm Andrew will make landfall as a Category 4 storm with Major Flooding, Rain and Thunderstorms, Numerous lightning strikes tonight, into tomorrow.

AREA FORECAST DISCUSSION
ONTARIO CA
Monday, October 17, 2005 2:30 PM

DISCUSSION ... FOR ALL OF SOUTHWESTERN CALIFORNIA INCLUDING ALL OF ORANGE COUNTY ... SOUTHERN LOS ANGELES COUNTY ... WESTERN RIVERSIDE COUNTY ... AND SOUTHWESTERN SAN BERNARDINO COUNTY ...

SYNOPSIS....Winter Storm Andrew has lived up to it's name, causing flooding, wind damage, and even tornadic signatures.

PRE-STORM FACTS: We use this section to tell you the conditions before the storm. If we tell you a condition and it comes true when we say it, expect the storm to be on track! The condition will be nothing, the Storm is here.

...SHORT RANGE DISCUSSION...

MODEL ANALYSIS...Winter Storm Andrew will move inland tomorrow morning, but not before bringing in a heavy band of rain and thunderstorms tonight, and a chance of Thunderstorms Tomorrow evening.

THE RAIN CHANCES...Winter Storm Andrew has given us impressive amounts of rain in the storm total period with areas in Los Angeles County reaching 3 and a half inches of rain. More is expected tonight. A rain shield will cover the area with rain and thunderstorms much like it did last night. More rain is expected out of this than last night. A flood watch is issued. We thought the rain might clear out tomorrow, but a northern flow around the low pressure center might give us rain off the local Northern Mountains as the flow will take anything to the South. Storm Movement Tonight will be to the West, and Tomorrow to the South.

THE THUNDERSTORM CHANCES... Thunderstorms will be very numerous tonight in the rain shield. Like last night, however a bit more intense we think, due to a cold air pocket aloft at -18 degrees Celsius. This combined warmer low level temps will provide the gradient needed for intense thunderstorms. A Severe Thunderstorm Watch will be issued tonight, and lasting into tomorrow. A Tornado Watch will also be posted.

WIND CHANCES... Winter Storm Andrew will not be a hurricane like Hurricane Andrew, not even winds that close will be recorded from this. The dynamics needed for the bow echo type systems, the frontal winds will not hit the forecast area this time as far as current trends look. So winds do not look like a problem, and no wind watch will be needed at this time.


MEDIUM RANGE DISCUSSION...After Andrew, all looks calm again, however another storm might be on the Horizon. Could this be Bart? Find out soon.

...WATCHES / WARNINGS / ADVISORIES...SEVERE THUNDERSTORM WATCH, TORNADO WATCH, FLOOD WATCH.

Severe Thunderstorm Watch- Issued a Severe Thunderstorm Watch for the entire forecast area from 11pm tonight till 6pm Tuesday Evening. Large Hail, Heavy Downpours, strong winds, and even the isolated tornado could accompany these storms.

Tornado Watch- Issued a Tornado Watch for the entire forecast area from 11pm tonight till 6pm Tuesday Evening. A Tornado watch means that conditions will become favorable for an isolated tornado or 2 with the strongest severe cells.

Flood Watch- Issued a Flood Watch in response to this massive rain shield that will form tonight. This watch will go from 6pm to 6am, and end. Accumulations up to 3 inches could be recorded.


GeoMan James

[wxmann_91]

Serious situation along the Grapevine right now:

CAC029-180330-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY CA
533 PM PDT MON OCT 17 2005

THE NATIONAL WEATHER SERVICE IN HANFORD CA HAS ISSUED A

* FLASH FLOOD WARNING FOR..
SOUTH CENTRAL KERN COUNTY IN CENTRAL CALIFORNIA

* UNTIL 830 PM PDT

* AT 524 PM PDT...TRAINED WEATHER SPOTTERS REPORTED FLASH FLOODING
IN THE FRAZIER PARK AREA AS WELL AS THE GRAPEVINE.

* WEATHER SPOTTERS REPORT WATER NEARLY 4 FEET DEEP ALONG FRAZIER
PARK ROAD. CALTRAN OFFICIALS INDICATE THAT NORTHBOUND LANES OF
INTERSTATE 5 IN THE VICINITY OF THE GRAPEVINE ARE CLOSED DUE TO
MUDSLIDES.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY.
MOVE TO HIGHER GROUND.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE. REMEMBER THE NATIONAL WEATHER SERVICE SLOGAN.."TURN
AROUND...DON'T DROWN". IT COULD SAVE YOUR LIFE!

LAT...LON 3482 11903 3481 11882 3499 11884 3498 11904

$$

!KD!

[wxmann_91]

Well, I guess it's time for another update (sure fun talking to myself ).

I should've included these warnings also:

CAC037-180215-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE OXNARD CA
513 PM PDT MON OCT 17 2005

THE NATIONAL WEATHER SERVICE IN OXNARD HAS EXTENDED THE

* FLASH FLOOD WARNING FOR THE HARVARD BURN AREA NEAR BURBANK...
CENTRAL LOS ANGELES COUNTY IN SOUTHWEST CALIFORNIA

* UNTIL 715 PM PDT

* AT 510 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
ADDITIONAL SHOWERS AND THUNDERSTORMS MOVING NORTHWEST AT 35
MPH ACROSS CENTRAL LOS ANGELES COUNTY...TOWARD THE HARVARD BURN
AREA. MUD HAS ALREADY BEEN REPORTED FLOWING OUT OF THE HARVARD
BURN AREA...ACROSS COUNTRY CLUB DRIVE. ADDITIONAL RAINFALL OF UP
TO ONE QUARTER INCH PER HOUR IS LIKELY THROUGH 715 PM AND A
THREAT OF MUD AND DEBRIS FLOWS IN AND BELOW THE HARVARD BURN AREA
NEAR BURBANK WILL CONTINUE.

IN ADDITION TO FLASH FLOODING...RAINFALL IS EXPECTED TO CAUSE DEBRIS
FLOWS IN THE HARVARD BURN AREA...ACCORDING TO THRESHOLDS PROVIDED BY
THE USGS. AREAS AFFECTED INCLUDE ROADS AND RESIDENCES IN AND BELOW
THE BURN AREA.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

LAT...LON 3418 11826 3423 11825 3425 11831 3419 11833

$$

MOYER/JACOBSON

CAC037-180245-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE OXNARD CA
558 PM PDT MON OCT 17 2005

THE NATIONAL WEATHER SERVICE IN OXNARD HAS EXTENDED THE

* FLASH FLOOD WARNING FOR..
NORTHWESTERN LOS ANGELES COUNTY IN SOUTHWEST CALIFORNIA
INCLUDING THE GORMAN BURN AREA

* UNTIL 745 PM PDT

* AT 550 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED
TO SHOW SHOWERS AND THUNDERSTORMS MOVING NORTHWEST ACROSS THE
MOUNTAINS OF LOS ANGELES COUNTY. CLOSE TO ONE INCH OF RAIN HAS
FALLEN SINCE 400 PM OVER THE GORMAN BURN AREA. THE CALIFORNIA
HIGHWAY PATROL REPORTED THAT MUD AND DEBRIS WAS FLOWING OUT OF THE
BURN AREA AND BLOCKING PARTS OF INTERSTATE 5 NEAR GORMAN...AND THE
INTERSTATE HAS BEEN CLOSED TO TRAFFIC IN BOTH DIRECTIONS.
ADDITIONAL RAINFALL OF NEAR ONE THIRD INCH PER HOUR WILL CONTINUE
TO CAUSE FLASH FLOODING AND MUD AND DEBRIS FLOWS BELOW THE GORMAN
BURN AREA. FLOODING IS ALSO LIKELY TO CONTINUE ALONG HIGHWAY 138
WEST OF LANCASTER.

IN ADDITION TO FLASH FLOODING...RAINFALL IS EXPECTED TO CAUSE DEBRIS
FLOWS IN THE GORMAN BURN AREA...ACCORDING TO THRESHOLDS PROVIDED BY
THE USGS. AREAS AFFECTED INCLUDE INTERSTATE 5 NEAR THE SUMMIT OF
TEJON PASS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

LAT...LON 3440 11803 3483 11810 3494 11896 3447 11871

$$

MOYER/JACOBSON

Statement for the warning posted in my last post:

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY CA
635 PM PDT MON OCT 17 2005

CAC029-180330-
KERN CA-
635 PM PDT MON OCT 17 2005

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 PM PDT FOR SOUTH
CENTRAL KERN COUNTY...AND INCLUDES THE FRAZIER PARK AREA AS WELL AS
THE GRAPEVINE NEAR LEBEC.

AT 617 PM PDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED DEBRIS FLOWS
ALONG INTERSTATE 5 NEAR LEBEC. EVACUATIONS ARE UNDERWAY IN FRAZIER
PARK WHERE WATER IS NEARLY 4 FEET DEEP IN PLACES. SEVERAL ROADS ARE
FLOODED AND IMPASSABLE. ALL NORTHBOUND LANES OF INTERSTATE 5 REMAIN
CLOSED THROUGH THE GRAPEVINE.

ADDITIONAL RAINFALL AMOUNTS OF A QUARTER TO A HALF INCH ARE
POSSIBLE IN THE WARNED AREA THIS EVENING WITH ADDITIONAL RISES LIKELY
ALONG AREA STREAMS AND CREEKS THROUGH 800 PM THIS EVENING.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

LAT...LON 3482 11903 3481 11882 3499 11884 3498 11904

$$

!KD!

TWC has shown video of a massive mudflow in the Burbank area. Don't know how serious the situation is, but the news so far isn't good. The burn areas got it pretty hard and numerous mudslides and debris flows have been the result.

Another aspect with this dynamic storm has been severe weather - ping-pong ball size hail reported in Los Angeles County today, and due to the storms dropping extensive amount of rain in a short time, downtown LA has recieved over 2 inches today I think.

Meanwhile over here, for me today was a bust, only a half hour of rain, and since 5 PM (two hours ago), the conditions would make you think that there was never a storm - sunny with just a few cumulus clouds for sunset, the dry slot has really set in.

[weatherlover427]

I had about 1/2" of rain from this system so far; with some really (and I mean REALLLLLLLY) huge drops around 11pm to midnight last night). There were also some loud thunderclaps and vivid lightning bolts accompanying the cells last night. This afternoon, we had gusty winds from the south at 20-25mph for a short time, but nothing too bad. That's about it to report from me in Costa Mesa so far.

[wxmann_91]

I had about 1/2" of rain from this system so far; with some really (and I mean REALLLLLLLY) huge drops around 11pm to midnight last night). There were also some loud thunderclaps and vivid lightning bolts accompanying the cells last night. This afternoon, we had gusty winds from the south at 20-25mph for a short time, but nothing too bad. That's about it to report from me in Costa Mesa so far.

Yeah, I saw the radar images, and you were experiencing dark yellows and oranges at that time. Unfortunately, yesterday when I got the bulk of my rains it I thought this system was weak, the rains didn't pack a lot of Ummph, were pretty much light - moderate. I hope tomorrow's rains will have a lot more, TWC is actually forecasting hail tomorrow, this is the first time I've seen that.

[Geomagnetic Man]

Winter Storm Andrew Post Storm Discussion

Winter Storm Andrew showed up on models 6 days before it hit. It was
undetermined what kind of storm it would be at that time. As the 3rd
day of forecasting came through we got an understanding at what we were
dealing with. Winter Storm Andrew was going to be a storm to remember.
On Sunday October 16th, Andrew whisked past the forecast area in the
early morning hours. It hovered SW of San Diego by that evening. During
that time, Andrew was given the Category 3 Status. A Category 3 meant
rain and thunderstorms, with minor flooding, and minor wind damage.
Sunday Evening, that Category 3 showed it's self. Fast moving
Thunderstorms pounded the Orange County areas, giving Hail, and lots of
lightning.

Later that night, into Monday Morning, October 17th, Thunderstorms
developed in the Riverside, and Los Angeles counties. This was an
impressive line that lasted all night. Lightning was heard all night
long. Hail, and winds were detected, and minor flooding occurred.

During the day on Monday, Andrew gained strength over the coastal waters
SW of San Diego. It created a dynamic atmosphere primed for tornadoes in
the afternoon. One such thunderstorms developed over the Santa Ana
Mountains, and moved NW into Yorba Linda,and Brea dropping ping-pong
sized hail, and a tornado signature on radar. This cell is located
below. It trained all the way to Los Angeles where it died over the San
Gabriel Mountains. It dropped 2 inches of rain in some spots.

Andrew was then upgraded to a Category 4 Storm. Category 4 Storm with
Major Flooding, rain, and thunderstorms to come. Dynamics lacked for
numerous tstorms like the night before, but they were all there for
major flooding. Andrew showed that Monday Night. A model image from the
GFS analysis showed the proof. Southern California against the local
Northern Mountains had the best chance for flooding.

Category 4 Status happened on Monday Night, on time. Flooding rains near
the foothills, and southward happened, mainly Ontario east to San
Bernardino.

Andrew moved off on Tuesday, and out of the forecast area. Amy Tilley,
19, of Joshua Tree, and Barret Romaine, 18, of Twentynine Palms, were
killed when their vehicle slid out of control directly into the path of
a 2000 Dodge Durango. Andrew will be a Ontario Weather Service retired
name because of this. First Hurricane Andrew, now this retired, Winter
Storm Andrew, a Category 4 will be remembered.

GeoMan James