National Weather Service Weather Forecast Office

Area Forecast Discussion

100
FXUS62 KJAX 211834
AFDJAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
234 PM EDT TUE MAY 21 2013

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
SCATTERED TO NUMEROUS SHOWERS AND STORMS ARE DEVELOPING ALONG THE
ATLANTIC SEABREEZE IN CONJUNCTION WITH WEAK TROUGHING/COOL POOLING
ALOFT ACROSS THE REGION. COVERAGE WILL CONTINUE TO INCREASE THIS
AFTN...PUSHING INLAND. WILL USE NUMEROUS POPS THROUGH EARLY THIS
EVENING FOR NE FL INLAND AREAS FROM 20-75 MILES FROM THE
ATLANTIC WHERE THE GREATEST SMALL SCALE BOUNDARY INTERACTION WILL
TAKE PLACE...WITH SCATTERED POPS FOR OTHER AREAS. ACTIVITY WILL
DIMINISH MID/LATE EVENING AS HEATING IS LOST. WITH AMPLE LOW LEVEL
MOISTURE AND SOME SUBSIDENCE OVERNIGHT...PATCHY/AREAS OF FOG WILL
DEVELOP. LOWS TNGT IN THE MID/UPPER 60S WILL PREVAIL.

FOR WEDNESDAY...UPPER LEVEL TROUGHING WILL APPROACH FROM THE
NORTHWEST...WITH A WEAK IMPULSE PROGGED TO CROSS THE LOCAL AREA.
THIS...ALONG WITH SEABREEZE AND SMALL SCALE BOUNDARY INTERACTIONS
WILL RESULT IN ANOTHER ROUND OF SCATTERED SHWRS/TSTMS WEDNESDAY
AFTN. WILL USE THE HIGHEST POPS INLAND AS GULF/ATLANTIC SEABREEZE
BOUNDARY COLLIDE...WITH LESSER COVERAGE COAST. HIGHS WILL RANGE
FROM THE LOWER 80S COAST...TO THE MID/UPPER 80S INLAND.

WED NIGHT THROUGH FRI...SURFACE WAVE AND UPPER SHORTWAVE TROUGH
WILL BE OVER THE AREA WED NIGHT BEFORE LIFTING NE ON THURS. WILL
KEEP POPS ALONG THE EAST COAST AND OVER THE WATERS THROUGH THE
NIGHT. WEAK OFFSHORE FLOW ON THU WITH THE SEA BREEZE GETTING A
LATE START. DRIER AIR WILL BEGIN TO ADVECT INTO SE GA AND DIURNAL
CONVECTION IS EXPECTED TO CONCENTRATE ACROSS NE FL BETWEEN HWY 301
AND THE EAST COAST. UPPER TROUGH WILL PIVOT OFF THE EASTERN
SEABOARD AND THU NIGHT/FRI PULLING A FRONTAL BOUNDARY THROUGH THE
REGION. DRIER AIRMASS WILL FILTER IN BEHIND THE FRONT...THUS WILL
GO WITH SLIGHT CHANCE POPS (20%) FOR ONLY NE FL. EXPECT NEAR NORMAL
TEMPERATURES FOR THIS PERIOD.

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
SURFACE HIGH PRESSURE WILL BUILD TO THE NORTH FRIDAY NIGHT INTO
SAT...THEN SHIFT TO THE NORTHEAST SUN/MON. DRIER AIR WILL PUSH
SOUTH WITH THE BUILDING HIGH...THEREFORE KEEPING THIS PERIOD DRY.
WITH A NORTH/NORTHEASTERLY FLOW THIS PERIOD...EXPECT TEMPERATURE
READINGS TO BE A LITTLE BELOW NORMAL.

.AVIATION...
SEA BREEZE BEGAN EARLY STORMS HAVE PASSED DUVAL TERMINALS. WILL
KEEP VCTS FOR POSSIBLE REDEVELOPMENT. HAVE TEMPO AT GNV FOR TSRA
FROM 19Z-21Z. FOG IS POSSIBLE TONIGHT AT TERMINALS WHERE HEAVY
RAINS OCCURRED. HAVE NOT INCLUDED IN TAFS ATTM.

&&

.MARINE...
SOUTHEAST WINDS EXPECTED THROUGH WED NIGHT WITH COMBINED SEAS 2-4
FT. WINDS SHIFT TO OFFSHORE THU/THU NIGHT AHEAD OF AN APPROACHING
FRONTAL SYSTEM...ALTHOUGH WEAK FLOW WILL ALLOW SEA BREEZE TO FORM
NEAR SHORE THU AFTERNOON. HIGH PRESSURE BUILDING NORTH OF THE AREA
FRI WILL PRODUCE A STRONGER NE FLOW THROUGH THE WEEKEND AND SCA
HEADLINES ARE EXPECTED FOR OFFSHORE LEGS WITH SPEEDS AROUND 20 KT
AND SEAS BUILDING TO 5-7 FT. EXPECT SCEC CONDITIONS NEAR SHORE.

RIP CURRENTS: MODERATE RISK THROUGH WEDNESDAY WITH ONSHORE FLOW AND
LONG PERIOD EASTERLY SWELL.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  64  89  66  91 /  30  40  40  30
SSI  69  81  70  85 /  20  30  20  30
JAX  66  85  67  89 /  20  30  30  30
SGJ  67  83  68  85 /  20  30  30  30
GNV  64  87  67  89 /  50  50  40  20
OCF  66  88  67  89 /  60  50  40  30

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&

$$

ALLEN/TRABERT