FNUS76 KSGX 171656
FWSSGX

SPOT FORECAST FOR SD COUNTY WILDLAND FIRE DRILL - APRIL 29...CNTY SD
NATIONAL WEATHER SERVICE SAN DIEGO CA
938 AM PDT SAT APR 17 2010

FORECAST IS BASED ON IGNITION TIME OF 0700 PDT ON APRIL 29.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...FOR THURSDAY APRIL 29 2010
HIGH PRESSURE RIDGE ALOFT IS BREAKING DOWN AND MOVING EAST OF THE
AREA AS A STRONG UPPER LEVEL TROUGH APPROACHES FROM THE WEST. THIS
IS A CRITICAL FIRE WEATHER PATTERN THAT OFTEN RESULTS IN A WIND
SHIFT WITH GUSTY SOUTHWEST WINDS WHILE THE AIR MASS IS STILL VERY
WARM AND DRY. HOWEVER A RAPID RETURN OF MARINE AIR IS EXPECTED THIS
EVENING WITH THE MARINE LAYER DEEPENING ABOVE VIEJAS MOUNTAIN
TONIGHT.

TODAY...THURSDAY APRIL 29
SKY/WEATHER.........SUNNY MORNING. INCREASING CLOUDS DURING THE
                    AFTERNOON.
MAX TEMPERATURE.....72 VALLEYS TO 65 RIDGE TOPS.
MIN HUMIDITY........15 TO 20 PERCENT...OCCURRING LATE MORNING...
                    INCREASING TO 40 PERCENT DURING THE AFTERNOON.
WIND................
 MID SLOPES.........UPSLOPE 4 TO 8 MPH BECOMING SOUTHWEST BY NOON
                    THEN INCREASING TO SOUTHWEST 15 MPH WITH GUSTS
                    30 MPH AFTER 1400 PDT.
 UPR SLP/RIDGETOP...SOUTHWEST 15 MPH IN THE MORNING INCREASING TO
                    SOUTHWEST 25-30 MPH IN THE AFTERNOON.
CWR.................0 PERCENT.
LAL.................1.
MIXING HEIGHT.......WEAK INVERSION WITHIN 500 FT AGL TILL 0900 PDT
                    THEN MIXING TO 6500 FEET MSL.
MIXING WINDS........SOUTHWEST 17 MPH.


$$
FORECASTER...ROB BALFOUR
REQUESTED BY...MIKE MURPHY
TYPE OF REQUEST...PRESCRIBED
.TAG 20100429.SDCOU.01/SGX