Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA

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000
FXUS66 KMTR 221235
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
535 AM PDT TUE JUL 22 2014

.SYNOPSIS...A WEAK SYSTEM WILL BRING A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS TO A PORTION OF OUR AREA TODAY. BUILDING HIGH
PRESSURE TO OUR EAST WILL BRING A WARMING TREND THURSDAY AND
FRIDAY ESPECIALLY TO INLAND AREAS...AND WARM CONDITIONS WILL
CONTINUE INTO THE WEEKEND.

&&

.DISCUSSION...AS OF 3:00 AM PDT TUESDAY...KMUX RADAR AT THIS HOUR
SHOWS A FEW CELLS LOCATED ABOUT 50 MILES WEST OF BIG SUR HEADING
TO THE NE. THESE CELLS ARE ASSOCIATED WITH SUBTROPICAL MOISTURE
AND A WEAK AREA OF INSTABILITY THAT IS HEADING INTO OUR AREA.
RADAR SHOWS CELL TOPS TO 35K FT AND DBZ NUMBERS UP TO 55 -- NOT TOO
BAD FOR OUR AREA DURING OVERNIGHT HOURS. CURRENTLY NO LIGHTNING
STRIKES, HOWEVER WOULD NOT BR SURPRISED IF WE GET A FEW OUT OF IT.
AS THE DAY PROGRESSES, THE MOST UNSTABLE AIR WILL CONTINUE TO THE
NORTH AND EAST BRINGING A SLIGHT CHANCE OF SHOWERS OR
THUNDERSTORMS FOR SPOTS FROM SANTA CRUZ UP TO THE SONOMA COAST.
WORTH NOTING THAT THE LATEST NAM/GFS RUNS HAVE BACKED OFF A BIT
WITH THE DIFFERENT CONVECTIVE PARAMETERS SUCH AS CAPE AND MODIFIED
TOTAL TOTALS.

OUTSIDE OF THE POSSIBLE CONVECTION TODAY, LOOK FOR ANOTHER MILD DAY
ACROSS OUR AREA AS WATER TEMPS WILL REMAIN WELL ABOVE NORMAL ALONG
WITH HIGHER THAN NORMAL PW VALUES. HIGHS WILL BE IN THE MID 60S TO
UPPER 70S AT THE COAST WITH UPPER 70S TO LOWER 90S INLAND.

WARMER AND DRIER WEATHER WILL RETURN FOR THE SECOND HALF OF THE
WEEK AS A RIDGE OF HIGH PRESSURE OVER THE FOUR CORNERS REGION WILL
PUSH BACK INTO OUR CWA. 500 MB HEIGHTS AROUND 582 DM WILL JUMP TO
590 BY THURSDAY WHILE INCREASE 6C BACK TO THE 21-22C RANGE. THIS
WILL HELP TO BOOST TEMPS AROUND 10 DEGREES INLAND WITH ONLY 3-6
DEGREES OF WARMING AT THE COAST. HIGHS SHOULD FALL WELL SHORT OF
HEAT ADVISORY/WATCH/WARNING LEVELS. THE WARM WEATHER SHOULD
CONTINUE INTO NEXT WEEK.
&&

.AVIATION...AS OF 5:10 AM PDT TUESDAY...MID-LEVEL MOISTURE
COMBINED WITH A WEAK DISTURBANCE PASSING THROUGH THE REGION HAS
SPARKED A FEW ISOLATED THUNDERSTORM ACROSS THE COASTAL WATER.
THESE STORMS ARE CURRENTLY MOVING INLAND ACROSS THE BAY AREA. BAY
AREA...INCLUDING NORTH BAY AREA TERMINALS WILL EXPERIENCE MODERATE
SHOWERS...ERRATIC WINDS AS WELL AS POSSIBLE HALE AND LIGHTNING AS
THESE STORMS MOVE ACROSS THE DISTRICT. CONDITIONS ARE EXPECTED TO
IMPROVE BY THIS AFTERNOON. AN AIRPORT WEATHER WARNING HAS BEEN
ISSUED FOR KSFO FOR THUNDERSTORMS UNTIL 16Z THIS MORNING.

VICINITY OF KSFO...MODERATE DOWNPOURS...ERRATIC WINDS WITH
POSSIBLE HALE AND LIGHTNING EXPECTED WITH PASSING THUNDERSTORMS.
OTHERWISE MVFR CIGS EXPECTED THIS MORNING WITH AN EARLY CLEARING
AROUND 16Z. VFR CONDITIONS ANTICIPATED THIS AFTERNOON AND EVENING
WITH CIGS RETURNING AROUND 08Z TONIGHT.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...SCATTERED LOW CLOUDS THIS MORNING
OVER AREA TERMINALS WITH MID LEVEL CLOUDS STREAMING ALOFT. VFR IS
FORECAST AFTER 16Z THIS MORNING WITH CIGS RETURNING LATE THIS
EVENING AND TONIGHT OVER TERMINALS.

&&

.MARINE...AS OF 3:00 AM PDT TUESDAY...A WEAK DISTURBANCE MOVING
ACROSS THE DISTRICT TODAY WILL GENERATE SCATTERED SHOWERS AND A
SLIGHT CHANCE OF ISOLATED THUNDERSTORMS ACROSS THE COASTAL WATERS
THIS MORNING. A WEAK SURFACE PRESSURE GRADIENT ACROSS THE REGION
WILL MAINTAIN LIGHT WINDS AND GENTLE SEAS THROUGH FIRST HALF OF
THIS WEEK. BY MIDWEEK...NORTHWESTERLY WINDS WILL INCREASE AS A
THERMAL TROUGH DEVELOPS INLAND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...NONE.

&&

$$

PUBLIC FORECAST: BELL
AVIATION/MARINE: CW

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