Flash Flood Warning 6, NWS Sacramento, CA

302 
WGUS76 KSTO 252343
FFSSTO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SACRAMENTO CA
443 PM PDT THU SEP 25 2014

CAC017-061-252350-
/O.CAN.KSTO.FF.W.0006.000000T0000Z-140926T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
EL DORADO CA-PLACER CA-
443 PM PDT THU SEP 25 2014

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR KING FIRE BURN 
AREA CENTRAL PLACER AND CENTRAL EL DORADO COUNTIES...

LIGHT SHOWERS ARE POSSIBLE OVER THE BURN AREA THIS EVENING...BUT 
ADDITIONAL RAINFALL IS EXPECTED TO BE LESS THAN ONE-QUARTER INCH.

LAT...LON 3894 12061 3903 12055 3908 12048 3910 12042
      3907 12041 3905 12042 3906 12038 3903 12040
      3892 12048 3884 12046 3877 12049 3879 12071
      3887 12069

$$

CS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
900 AM PDT Thu Sep 25 2014

.Synopsis...
Cooler and wet today as Pacific front moves through Interior
Northern California. Showers and isolated thunderstorms Friday,
lingering in the Sierra Nevada Saturday. Then dry and warmer early
next week with locally breezy wind.

&&

.Discussion...
Pacific front continuing to make slow progress across Interior
NorCal as surface boundary nearly parallels upper flow of vertically
stacked system. Baroclinic zone has tapped into atmospheric river
and resulted in some impressive rainfall amounts so far with record
precip already occurring at KRDD and KRBL. In general, upwards of 1
to 2.5 inches of rain has fell in portions of Shasta and Tehama
counties since last night. Urban flooding reported earlier in these
counties but precipitation is diminishing as front moves east.
Blended TPW still showing impressive PWS along the front, upwards of
1.5 inches. GFS IWV progs indicate that the baroclinic zone will
gradually become more disconnected from the moisture plume as it
continues to slowly progress east today.

Models push the front through eastern portions of the forecast area
this afternoon with cooler unstable air ushered in behind it. High
temperatures today expected upwards of 10 degrees or more below
normal with 70s for the Central Valley and 50s to 60s for the
mountains and foothills. Convective precip possible this afternoon
into evening with models showing best instability from around the
Central Sacramento Valley northward.

Associated upper low currently near 50N 134W with upper troughing
extending southward. Water vapor imagery showing several potent vort
maxes moving down backside of trough that will help elongate it and
split flow. Models all showing lower latitude closed upper low
developing west of the Bay area Friday morning and progress it
inland into Central Cal Friday night. Progs depict some instability
and moisture, mainly over the mountains, tomorrow to support a
continued threat of showers and thunderstorms. Light snow
accumulations possible over the highest peaks...above 8000
feet...Friday. Slight upward trend of high temps Friday under more
sunshine but continued well below normal.

Models continue to gradually progress the upper low east into the
Great Basin over the weekend with some differences in timing. Main
weather impact looks to be a lingering threat of wrap around showers
and thunderstorms over the eastern mountains Saturday into Sunday.
AMS begins to warms over the weekend with low 80s returning to much
of the Central Valley.

PCH

&&

.Extended Discussion (Monday through Thursday)

The upper low will finally eject to the east early next week, with
drier and warmer weather expected across the forecast area. The
way the pattern is shaping up, it's likely that we'll see periods
of northerly winds across Northern California through much of the
extended period. However, with some subtle differences in
position and strength of shortwave troughs as they pass through
the region, there is still considerable uncertainty on the
potential impact of these northerly winds.

Dang

&&

.Aviation...

Cold frontal system moving across the forecast area this morning.
Generally expect VFR/MVFR conditions across the Valley and IFR
conditions over the mountains in RA. Cold front should move south
and east of Sacramento TAF sites around 18z. Behind the front,
scattered SHRA and possibly isolated TS may develop this afternoon
and evening north of KMYV.

Winds across the Valley will remain around or below 10 kt today.
Over Sierra ridges...wind gusts up to 40 kt will be possible
through this afternoon.

Dang

&&

.STO Watches/Warnings/Advisories...
None.
&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SACRAMENTO CA
1044 AM PDT THU SEP 25 2014

...TIME...  ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
...DATE...  ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1010 AM     SNOW             LASSEN NATIONAL PARK    40.50N 121.53W
09/25/2014  M8.0 INCH        SHASTA             CA   PARK/FOREST SRVC

            8 INCHES OF SNOWFALL REPORTED AT 8500 FT AT
            LASSEN NATIONAL PARK. LASSEN LOOP ROAD
            CLOSED. ONLY RAIN AT VISITOR CENTER AT 6800
            FT. SNOW DURATION 8 HOURS.

&&

EK