FNUS76 KSGX 241333
FWSSGX

SPOT FORECAST FOR SD COUNTY WILDLAND FIRE DRILL - APRIL 24 UPDATE...CNTY SD
NATIONAL WEATHER SERVICE SAN DIEGO CA
633 AM PDT SAT APR 24 2010

FORECAST IS BASED ON IGNITION TIME OF 0900 PDT ON APRIL 24.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...
HIGH PRESSURE RIDGE ALOFT BUILDING OFF THE WEST COAST TODAY WITH
A THERMAL LOW PRESSURE TROUGH AT THE SURFACE OVER SOUTHEAST CALIFORNIA.
THIS WEATHER PATTERN IS FAVORABLE FOR A STRONG INVERSION BETWEEN 2700
AND 3500 FEET. A THERMAL BELT WILL BE PRESENT ALONG THE MID AND UPPER
SLOPES THIS MORNING AND AGAIN TONIGHT. STABLE CONDITIONS WITH COOL
MOIST AIR WILL BE PRESENT IN THE VALLEY UNTIL THE INVERSION BREAKS
DURING THE LATE MORNING. WATCH OUT FOR GUSTY WEST WINDS OVERPOWERING
THE NORMAL UPSLOPE/UP VALLEY WINDS FROM MID AFTERNOON INTO THE EVENING
HOURS.

.TODAY...

SKY/WEATHER.........MOSTLY SUNNY. PATCHY FOG IN THE MORNING.
MAX TEMPERATURE.....72 VALLEYS TO 62 RIDGE TOPS.
MIN HUMIDITY........32 PERCENT VALLEYS AND 23 PERCENT MID AND UPPER SLOPES.
WIND................
 MID SLOPES.........EAST/UPSLOPE 3 TO 5 MPH IN THE MORNING BECOMING
                    WEST 10 MPH IN THE AFTERNOON WITH GUSTS 20 MPH.
 UPR SLP/RIDGETOP...EAST 5 MPH...BECOMING WEST 10 MPH IN THE AFTERNOON.
CWR.................0 PERCENT.
LAL.................1.
MIXING HEIGHT.......500 FT AGL...BECOMING 2500 FT AGL AFTER 1100 PDT.
MIXING WINDS........EAST 3 MPH BECOMING WEST 5 MPH IN THE AFTERNOON.

.OUTLOOK FOR THE REMAINDER OF THE DRILL...
HIGH PRESSURE RIDGE BREAKING DOWN TUESDAY. A TROUGH EXPECTED TO MOVE
ACROSS THE AREA TUESDAY NIGHT AND WEDNESDAY. HIGH PRESSURE REBUILDING
ON THURSDAY.

.TUESDAY APRIL 27...
SUNNY MORNING. INCREASING CLOUDS AND WINDY DURING THE AFTERNOON.
LOWS AROUND 45 IN THE VALLEY TO 55 RIDGES. MAX RH 90 PERCENT VALLEY
AND 20 PERCENT RIDGES. HIGH 76 VALLEY TO 68 RIDGES. MIN RH 20 TO 25
PERCENT. WINDS UPSLOPE 3 TO 8 MPH BECOMING WEST TO SOUTHWEST 15 TO 20
MPH WITH GUSTS 30 MPH IN THE AFTERNOON.

.WEDNESDAY APRIL 28...
MOSTLY CLOUDY AND COOLER WITH CHANCE OF RAIN. LOW 45 TO 50.
MAX RH 100 PERCENT. HIGH AROUND 55. MIN RH 60 PERCENT. WINDS
WEST 15 TO 20 MPH WITH GUSTS 30 TO 40 MPH RIDGES.

.THURSDAY APRIL 29...
MORNING CLOUDS THEN SUNNY. HIGH AROUND 66. MIN RH NEAR 25 PERCENT.
WINDS NORTHWEST 10 MPH WITH GUSTS 25 MPH RIDGES.

$$
FORECASTER...ROB BALFOUR
REQUESTED BY...MIKE MURPHY
TYPE OF REQUEST...PRESCRIBED
.TAG 20100424.SDCOU.02/SGX